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Top 10 Questions about PVC Trim

1. Does PVC trim require a primer?

A primer is only needed if you want the paint manufacturer’s warranty. Excellent adhesion can be achieved by properly cleaning the board before applying a topcoat of paint to PVC trim. (Refer to painting guidelines in the Versatex contractor handbook for more information on painting PVC trim.)

A Note from the Publisher:


If you are sensitive about articles that seem to favor a particular manufacturer, then DON’T read this one!! It’s written by the President of Versatex! But after years of experience, I’ve found that some manufacturers know more about their products than anyone else; if a carpenter wants to learn the best way to install a product, sometimes the best source of information is the manufacturer. In the future, look for more carefully-screened articles from manufacturers.


2. What type of paint do you recommend for coating PVC trim?

Just about any 100% acrylic latex, or 100% acrylic latex with a urethane additive, can be used to achieve superior coating durability and flexibility. Lacquers are not recommended with PVC trim because lacquers are a more brittle coating, and will not flex with any movement in the PVC trim. Paints like Duration by Sherwin Williams, Manor Hall paints by PPG and Moorelife by Benjamin Moore adhere well to PVC trim.

Paint on PVC trim will last three to five times longer than paints on wood or wood composites due to the absence of moisture in the substrate. Sherwin Williams also offers a field-applied coating under their “Green Seal®” product designation. Kem Aqua® BP Enamel is a water-reduceable polyurethane, acrylic topcoat that offers fast dry times and no critical re-coat times. Due to its excellent adhesion properties, it is an ideal coating for Cellular PVC.

3. Can PVC trim be painted dark colors?

Only light-to-medium colored paints—with a light reflective value of 55 units or greater—should be applied to PVC trim. For example, using paint with an LRV below 55 units will void our product warranty. LRV is measured based on color and its ability to absorb heat. Thus, an LRV of zero (0) is black, and an LRV of one hundred (100) is white. Don’t assume the paint is a light color. We have had cases where contractors believed that the paint they used was a light beige, only to find out it had an LRV in the 20s or 30s. Consult the paint manufacturer for the LRV of your paint before applying it to cellular PVC trim.

4. How long does it take the paint to cure on PVC trim?

That depends on the weather conditions. Warm/dry weather, or warm/humid weather, will allow the paint to cure faster than cool weather. It can take up to 30 days for paint to fully cure on PVC trim, because PVC trim is impervious to moisture. For the paint to cure, the moisture must evaporate through the surface of the coating that has skimmed over from drying.

5. What is the best glue for joining two pieces of PVC trim? What is the best glue for bonding PVC trim to wood? How about metal?

We recommend PVC pipe glue with solvent for bonding the ends of PVC trim boards to themselves (Weld-On 705 by IPS, TrimTight by Trim Glue, Inc. or Christy’s Red Hot). Be sure the PVC pipe glue has sufficient working time to allow you to apply the glue and push the boards together before it cures.

If you are looking for more of a structural bond at shiplap or scarf joints, miter cuts (window surround), or for gluing sheets of PVC trim, we recommend PVC TrimWelder. For bonding to wood, we recommend Liquid Nails Sub-Floor Adhesive or Heavy Duty Construction Adhesive. For PVC trim to metal, PVC TrimWelder Adhesive works best.

There are three types of PVC TrimWelder Adhesives. Slow and Fast Cure for field joints and small glue-ups, and Laminating Grade for sheet glue-ups. Slow Cure should not be used at temperatures below 40°F. Remember to apply any adhesive to only one bonding surface, thus allowing the adhesive to penetrate into the cells on the other trim piece.

6. What is the best fastening system for PVC trim that also hides the fastener head?

The best overall system for securing PVC trim is the Cortex Concealed Fastening System. It combines the advantages of using screws (strong connection) with the PVC trim tapered plug that fits into the hole created by the screw, thus eliminating the need for fillers or sealants to fill the nail holes. When comparing the cost of this fastening system to nails, keep in mind that you won’t have to go back over the trim filling in the nail holes.

7. What are your recommendations for dealing with expansion and contraction?

Use 8d stainless steel annular shank nails, or screws that are designed for wood trim, and are long enough to penetrate the solid substrate a minimum of 1 1/2 in. Simpson Strong-Tie makes an 8d nail with a 7d head in a 12-gauge thickness, available loose or collated, allowing it to be gun-nailed. The nail is called the “Trifecta.” It is half annular (tip) and half ring-shanked, and made from 316 stainless.

Screws are better for limiting the thermal movement of the trim. Allow PVC trim to acclimate to outside temperatures before installing. Bond PVC trim joints to prevent separation. Be sure to allow adequate expansion and contraction space at the end of long runs. If possible, decrease the on-center spacing between fasteners to 12 in. or less, and bond boards to substrate when practical.

Where you have an expansion joint, leave a full 3/16-in. gap when installing on a day where temperatures range from 30°F to 40°F. Leave a gap just large enough to accept a bead of sealant, or no gap at all (adhesive bond), when installing on a day when temperatures range from 80°F to 100°F. Shiplap joints are superior to scarf cut joints, especially on long runs.

If practical, install long runs of trim when the outside temperature and the temperature of the PVC trim board is 55°F to 65°F, in order to minimize thermal movement in the trim.

8. What is the best way to secure PVC trim to masonry?

Trowel the masonry with a sealant or adhesive to provide a level surface to accept the PVC trimboard. Then secure the trim to the masonry with Tapcon masonry fasteners.

9. How do I seal the open cells if I cut the PVC trimboard? Also, how do I clean PVC trimboards?

Handle PVC trim as you would a piece of premium lumber. Be careful not to damage the visible surface of the board. To seal cut edges or clean a cut edge that has gotten dirty, sand them with 320 grit sand paper, and then wipe the edges with Acetone—this will help to re-seal the cells.

To remove dirt and grime from the visible surface or edges of PVC trimboard, use Soft Scrub with Bleach, one of a variety of Clorox products (Clorox Outdoors, etc.), Mr. Clean Magic Erasers® with a little water, or Corte Clean, a composite deck cleaner that has been found to clean cellular PVC trim. As with any new product, try the cleaner in an inconspicuous area before cleaning the trimboards on your project.

10. What are the recommended sealants I should use with PVC trim?

As with adhesives, look for products that contain some type of solvent. NPC Solar Seal #900 Sealant/Adhesive in Trimboard white #111 has been found to be one of the best sealants for sealing and bonding PVC trim to itself, as well as many other substrates. Other recommended sealants include Quad and EP-1000 Enhanced Polyurethane by OSI, and Geocel 2300, or other polyurethane sealants. Do not use silicone sealants, as they are not compatible with cellular PVC trim.


174 Responses to “Top 10 Questions about PVC Trim”

  1. David Stuack

    I have found that “Spray Nine” works great for cleaning PVC. Once in a while I will use paint thinner to get off small stubborn black marks.

    The big question I have concerns filling the nail/screw holes left after installation of the PVC trim boards. Because most people just want the PVC left it’s natural white ( and so avoid painting) it would be nice if someone made a white nail/screw hole filler that wouldn’t turn yellow. Any suggestions? Thanks.

    • John Pace

      Good afternoon David:

      The very best solution for filling nail holes is the Cortex screw and plug. FastenMaster sells the screws and plugs as a system with a bit that countersinks the screw to just the right depth to accept the tapered Versatex PVC plug. Visit the FastenMaster website to find a dealer in your area. There are other companies that offer a stainless steel screw with a painted white head. A couple examples of these are Headcote and Simpson Strong Tie. Also, check out Simpson Strong Ties, white painted Trifecta nail it comes in 316 stainless. If you click the following links, you’ll be able to download some info on the Headcote and Simpson stainless steel screws with painted white heads along with a flyer on a white painted Trifecta nail offered by Simpson Strong Tie.

      I hope I have answered your question and thank you for the info on cleaning Versatex trim.

      • Blake

        I would think if you dont have immediate access to the cortex you could use a small tapered plug cutter and use the screws (countersunk) you have on hand.

        • John Pace

          You are correct. Many contractors still make their own plugs but for those who would rather buy them there is Cortex.

          • Pete Ottens

            Hi John
            I live in Calgary Alberta. I have a 100 + yr old character home and I am looking for your pvc trim and moldings. I talked to your rep out here last fall, who put me in touch with a dealer, they were (for lack of a better word) useless!!! Getting Versatex products here is worse than pulling teeth! Ordering on line is a hard call due to quantities and expensive shipping, not to mention ordering enough with wastage or having too much, and a reorder or a return would be painful and expensive. I’ve done my homework and feel that Versatex is the best product out there. Do you have any input of what i can or need to do?! my wife wants the house done.
            thanks Pete

  2. Matt

    This is a very informative article. I wish I had this last year … wondering if my previous PVC project will hold up, as I didn’t use any glue. I used a plastic putty to fill my screw holes and then sanded flush, hoping that seals properly.

  3. Keith Preston

    I read with interest your admonition to not use silicone sealant on PVC trim. My PVC deck is sealed with GE Silicone I to the house stucco and I suspect the bond to the PVC will not be durable. It bonds better to the stucco. What sealant would you recommend for this type of joint? Polyurethane glue (Gorilla glue) bonds very well to PVC but it is (1) brittle and (2) (I suspect) degrades in UV.

    • Rick

      I have had very good success gluing PVC to just about anything using OSI’s SF450 construction adhesive. I always sand the surface to be glued with 120 grit paper to give the adhesive something to grab onto. I have not glued anything to stucco, but with the rough texture, I have no doubt SF450 would be effective. The downsides are: 1) the care needed to ensure the adhesive doesn’t squeeze out around the edges of the trim as it is a tan color that probably won’t match the stucco color and removing it from the texture of most stucco’s would be nearly impossible; and 2) the trim needs to be held in place while the adhesive cures (although this is the same for most adhesives). SF450 doesn’t fully cure for several days, but it’ll stay stuck well by the following day.

      • John Pace


        Just a word of caution. I would expect the same response from any cellular PVC trim producer. Don’t rely solely on an adhesive bond to hold cellular PVC in place. Cellular PVC should also be secured to the substrate with mechanical fasteners (nails or screws). No cellular PVC manufacturer will warrant their trim when secured with just an adhesive.

      • Sam Axton

        OSI’s SF450 does not list PVC on their list of substrates to adhere. Liquid Nails makes a construction adhesive called Siding & Trim Construction Adhesive (LN-501) that will adhere PVC trim components to common construction surfaces.

        • John Pace


          The Liquid Nails Subflloor Adhesive approved for use with cellular PVC is LN-902 or LNP-902 not SF-450. The other Liquid Nails Adhesive Adhesive approved for cellular PVC is Liquid Nails Heavy Duty Construction Adhesive LN-903 or LNP-903. Henkel tested our cellular PVC trim with these two products before giving us approval in writing.

          • Sam Axton

            Thanks John. My comment was meant as a word of caution for Rick (above) who said he uses SF-450 for adhering PVC.

  4. Cory H.

    A very good article, I just wish I had found it a few days earlier as I also didn’t think to glue my ends together. Also appreciate the disclaimer at the beginning of the article stating who it was written by. Wouldn’t it be great if every news article you read was this up front and honest about their agenda?

  5. adam

    So can water penetrate the open cells? I had to rip down some pvc brick mould for exterior window trim and I’m hoping I didn’t screw it up. I just siliconed all the edges…

  6. John Pace

    Cellular PVC is much like a honeycomb. If you examined it under a microscope it will look like an array of cells in a random geometric pattern. When you cut, rout, mould or mill cellular PVC, you break open a layer of these cells but you do not affect the integrity of the entire cell structure of the cellular PVC board or sheet. This is why cellular PVC is basically impervious to moisture and has a moisture content value of less than 0.5% when tested in accordance with ASTM test methods. So to answer your question no water will not penetrate cellular PVC because the cells are not openned throughout the thickness just the surface cells that you cut are open. As for the sealant you used, I would recommend you stay away from silicones in the future. Although some commerical silicone sealants will stick to cellular PVC when a primer is applied most over the counter silicones that you buy at your local lumber dealer will not. The best sealants for cellular PVC are polymer based sealants containing a solvent. To determine if a sealant contains a solvent check the inside lining on the tube if it is a thin metal/aluminum wrap and if the cap is also metal then the sealant contains solvent. Examples of good polymer based sealants with solvent include Solar Seal #900 by NPC Sealants and Quad by OSI. We like the Solar Seal #900 for a few reasons it is as much an adhesive as a sealant, it stays flexible for decades and it carries a warranty that I believe is either 15 or 20 years. Check with the manufacturer on the length of their warranty and availability in your area. You can find them on the Internet. Just Google NPC Sealants.

  7. Mark

    I have a job where I have to double up the thickness of the trim by using two 1x boards laid one over the other. To minimize thermal expansion, should I cement them together or will that exacerbate the problem? Thanks

  8. John Pace

    Laminating two boards together is a very common practice and has no affect on the potential thermal expansion and contraction of the board. I also wanted to let you know that Versatex produces a true 1 1/2″ board and sheet. F you want to eliminate the material, labor and time to laminate two pieces of 3/4″ you might want to consider this new product thickness.

  9. Tom

    I’ve read conflicting advice on cutting PVC trim and would appreciate anyone’s input. For circular saw blades some say to use a tooth count of about 40 (to avoid heat build up) while others say to use a 140 tooth blade (to ensure a clean cut). Insights on saw blades most appreciated as I’ve got about 500 feet to install next week. Thanks.

  10. John Pace

    The answer is simple. The fewer the teeth on the saw the better. We recommend a carbide tipped blade with 32 teeth. However, 40 teeth will be just fine. The more teeth the greater the frictional heat build-up in the cut causing you to melt and potentially burn the cellular PVC.

    Let me know if you have any other questions concerning the installation of cellular PVC trim.

  11. Tony Carey

    Hi I have a composite door about three years old, and the outside lamination is beginning to separate in three locations about two inches long each. Which adhesive would you recommend for repair the temperature range in Ireland is minus ten to 30 degrees centigrade. Any help would be greatly appreciated. The door is a Palladio door manufactured by Profile developments.

  12. Russell

    John, what is wrong with using a silicone sealer to bond a long yet thin trim board (with those fake wood grain paper finishes) to a sheetrock wall? Silicone should hold tight — and– some day be removeable, without tearing into the wall as a glue will, and it likely will come off the wall in one piece, to allow use of the trim board again someday (once the back side is cleaned up and flat again).

    • John Pace

      Silicone sealants or sealers are not compatible with cellular PVC and will not hold a board or sheet to a sheet rock wall. In fact I’m not sure what I’d use to hold cellular PVC trim to a sheet rock wall. No matter what you use as a base sealant, you still need to mechanically fasten cellular PVC to the frame of the wall.

    • John Pace

      Yes you can definitely use cellular PVC trim and sheet indooors. Just because most contractors use it outdoors doesn’t limit its application. I have seen cellular PVC used in foyers, hallways, mud rooms, bathrooms, laundry rooms, basements and garages. The only recommendation I have is check with your building code official to see if there is a maximum amount of cellular PVC you can use inside a home. Typically it is listed as square feet per room. I don’t think you’ll exceed the maximum allowable value but just to be safe I’d ask my code official.

      • Jerry

        I know you are selling this product but would it really kill your sales to just say that the outgassing is potentially s health hazard?

        • Gary Katz

          At first I deleted your comment because it was disrespectful. But I changed my mind.

          John Pace, the president and CEO of Versatex, a man I’ve known for many years, puts his heart and 150% of his effort into educating people about the material he manufactures. Trust me, if there was any dangerous off gassing–or anything else related to Versatex that endangered people–he wouldn’t be manufacturing it.

          I’m leaving your comment, so that others can see my response. As John said to me years ago: “In order for cellular PVC to off gas it must contain Phthalates. I can’t speak for the other producers or those overseas but Versatex contains no Phthalates.”

          In the future, please remember, unlike other areas of the internet and the political climate of this country, supports the arcane concept of respect.

          • John Pace


            Let me clear up any misconceptions you have concerning cellular PVC. Cellular PVC is created by introducing a foaming agent during the extrusion process. It’s the foaming agent that creates the cells. When the cells are cut via a router, saw, drill, CNC, moulder, etc. they give off carbon monoxide, nothing else. Per the MSDS, the foaming agent we use is not considered hazardous under 29CFR 1910-1200. It is not a controlled product under Canadian Regulations, it contains no hazardous ingredients, it does not contain any chemicals subject to CERCLA and SARA regulations, it contains no know toxic substances, and can be disposed of in an approved industrial landfill. We have conducted EPA air tests in our plant. The results shows no levels of any hazard. Thus no special air circulation or filtering system is need in the plant where we cut, rout, and mould cellular PVC. In addition, there is no need for any air permitting in our plant or the surrounding area. If you don’t believe me go on line and find a company that produces foaming agents for cellular PVC. Once you locate a company download their MSDS. I’ve been producing cellular PVC for over 13 years. Our company is one of the most environmentally conscious companies in our manufacturing space not only recycling over 99% of our processed waste but also buying back cellular PVC scraps from our OEM’s and recycling them back through our process. Whether you believe it or not, cellular PVC does not off gas for all of the reasons I’ve identified above. I hope I have made it crystal clear that “cellular PVC is not a health hazard and does not off gas, a phenomenon commonly found in plastics containing Phthalates.

  13. Jim Morrison

    I have a 1/8″ gap between 2 strips of pvc trimboard used as a drip cap above my windows. The carpenter & I used various caulking to seal it but they fell out. I have now used Ultima Caulking Sealant but when the hot sun beats down on it the caulking expands out of the crack. It stays intact but rises up about an 1/8″ out of the crack. When it cools off it goes back to its original shape but the process occurs again when it heats up again. Should I be concerned over this? Thanks

  14. John Pace

    Good morning Jim:

    First please call me John. Sir sounds too old for me.

    As I read your e-mail below, my first question is why are you getting so much movement between two boards used as a drip cap above a window? What are the lengths of the boards and what type or nail or screw was used to install the PVC trimboards? Do you happen to know what the temperature was when the boards were installed? That information will allow me to determine why the boards are moving?

    Now on to your questions. Ultima Caulking Sealant is a compatible product that will bond well to cellular PVC. The reason is because it has a solvent base that chemically breaks down the PVC and fuses to the trim. Other caulkings that are similar to or better than Ultima are NPC’s Solar Seal 900 and Quad by OSI.

    The sealant is moving up and down as the PVC trimboards expand and contract. There is no need to be concerned about this since you used a good caulking/sealant in the joint. The reasons the other caulks fell out is most likely because they were not solvent based. The way you can tell a the difference between a tube of sealant that has solvent in it and one that does not is by the tube and plug. If the tube and plug in the tube is plastic the caulking is not solvent based and will not bond to cellular PVC trim. If when you look at the bottom of the tube and see a metal foil lining the inside of the tube and a metal plug, you know the caulk/sealant is solvent based and will give the best bonding results with cellular PVC.

    In the future, to minimize movement between the two boards I would use a better nail (8d), or screw (Cortex screw and plug system). How I apply the caulk would depend on the time of year and the length of the run. In your instance, I can’t imagine the run was more than two boards (36′). If this was the case and with proper installation, I would have ship-lapped the ends of the boards and glued them together. I did a project this past summer on my home where the trim run was roughly 33’long. The install temperature was probably around 70F, the low reached -16F in Pittsburgh for a couple of weeks. The gap in my trim never got to be more than 1/32″ or less. Interestingly the gapping in my Miratec and wood trim was as much as 1/8″.

    Let me know if you have any further questions concerning cellular PVC trim.

  15. debbie

    What should I have used to fill in the screw holes in my pvc trim? The chalk my carpenter gave me turned yellowish even after I had it painted.

  16. John

    If installing cellular PVC trim with screws, I’d use Cortex screws and plugs it eliminates the need and use of nail hole fillers. If you plan on painting the trim, use any vinyl spackling. One type that is commonly used by contractors is Crack Shot by DAP. You’ll find it at any local lumber dealer location. Are you sure the yellowing is from the caulk? My concern is the contractor used galvanized screws and the galvanizing has peeled off exposing the steel screw which is now coroding. I’ve seen this happen before. If the issue is truly the caulking yellowing, it must be a very poor performing sealant. The best sealant for use with any cellular PVC trim is NPC’s Solar Seal 900. It is both an adhesive and sealant with excellent long term flexibility, weatherability and paintability. It also bonds exceptionally well to cellular PVC trim and comes in a wide array of colors.

  17. BrentF

    I scanned through the various Q & A of this thread, but didn’t see an answer to this:

    I have Versatex cellular PVC trim on the exterior of my cottage. Last winter one of the trim boards sustained a fairly deep gouge (3/16″ deep) from a falling tree branch. This trim board would be very difficult to replace. What can be used to repair this gouge?

    Thank you.

  18. John

    Good morning Brent:

    A small ding or dent can be removed with a heat gun. It will activate the residual foaming agent in the cells of the product and cause it to raise much like a cake repairing these small dimples or dings in our trim. In your case, a 3/8″ gouge is most likely too deep to raise up using a heat gun but you may want to try it first beofre filling the void. Any filler you use is going to require you to paint the boards since no filler is an exact match to our trimboard or anyones trimboard for that matter. Here are some possible fillers. TrimWelder by Extreme Adheisves, PVC TrimWelder Nail Stick, vinyl spacklings like DAP’s Crack Shoit and others and even Bondo. Although I’ve heard both good and bad results using Bondo as a filler with cellular PVC. You can find any of the above products on Google. Good luck and thanks for using Versatex PVC trim.

    • BrentF

      Thanks John for your fulsome answer.. The gouge is 3/16″ deep and not 3/8″, so my chance of success with the heat gun approach is better than otherwise. I will certainly try this approach. Sounds like the cellular PVC equivalent of using a steam iron to fix a gouge in wood.

      One question: Is the heat gun likely to cause discoloration?

  19. John Pace

    Not if you do it correctly. Just wave the heat gun or commercial hair dryer over the spot you are trying to raise. Don’t put it in direct contact with the Versatex trim. You should notice results in less than one minute. If not, then you’re going to have to use a putty and most likely paint the board.

  20. Steve Wailes

    I plan on using 1×8 PVC boards as a ledge, 2 sides of an old clawfoot tub, sloping slightly into the tub. I will need to cut the board into a curve to match the tub (likely using a jigsaw on slow speed). Edge will be rough sanded with a belt sander on slow & finished with 320 grit by hand, and the new finished edges resealed as you’ve mentioned 2012 article.

    1) What tpi (tooth per inch) jigsaw blade would your recommend for cutting the curve?
    2) Can a Router be used to:
    2a. provide a drip kerf on bottom edge of new curved edge, &
    2b. provide a rounded-over edge on the top side, say 3/8″ rad.?
    3) I will be bonding various pieces together with PVC pipe solvent/cleaner & cement, but want to seal the edges to an existing old lath & plaster wall. I’ve used a polyurethane sealant (ie Vulkem) to seal PVC Trim on exterior projects in the past, seems to be holding up well, & wondered if it would work here?

    I would appreciate your response directly to me, but you’ve my permission if you wish to include in the questions attached to the article. Thanks in advance. steve

    • John Pace

      In response to your questions:

      1) The fewer teeth per inch the better the cut. When you run jig saw blades with an increased number of teeth per inch you create a lot of frictional heat which tends to melt the board and cause a very rough cut. It can also lead to the trimboard fusing together behind the cut. I can’t speak to the exact number of teeth per inch but I’d start with a 10 TPI blade and adjust up from there.

      2) Yes a router can be used to create the cuts mentioned in your e-mail below. The key to successful and smooth cuts is sharp router tools preferably carbide, the more flutes on the router bit the better the cut, securing the trim piece during routing to prevent surface chatter in the cut and good dust extraction to prevent heat build up at the router bit which can lead to a pulling and a yellowing of the core.

      3) Polyurethane sealants work well with all cellular PVC trims. The urethane chemistry is very compatible with PVC. Keep in mind urethane sealants are activated by moisture. If you like Vulkem stick with it. Other good sealants include Quad by OSI and Solar Seal #900 by NPC Sealant. However, both of them are solvent based and may not be practical for indoor applications like yours. Another one to consider is the new Quad Max by OSI with is not solvent based and works as well as if not better than polyurethanes.

  21. J

    Can versatex be bent to accommodate a circular patio? Thank you for your helpful information.

    • John Pace

      Yes Versatex can be bent to accommodate a circular patio. Can I assume you are bending it the easy way along its length? It is not only used to trim a curved paver or brick patio, it is also used as a concrete form for curved sidewalks and patios. Typically you can curve it along the length or what we call the easy way without heating the board. If you need to curve it across the width of the board, or the hard way, you’ll need to heat it to roughly 300F, hold it at that temperature for 20 minutes until the trimboard is as flexible as a cooked spaghetti noodle and then bend it around your form.

  22. paul

    what product should be used to fill small 18ga nail holes in pvc trim ?….the painter expects to use the same product he’s been using for years in wood..thanks paul

    • John Pace

      Are you planning to leave it as is or paint it? If you plan to paint it you can use any vinyl spackling or putty such as DAP Crack Shot. Wood fillers are not recommended. Also checkout Extreme Adhesives website. They have two products PVC Nail Eraser and TrimWelder nail stick that are very good nail hole fillers. You can buy these on line at their website or call them to find a local dealer in your area. The reason I asked the question about painting your trim is because I’ve never found a nail hole filler that is a perfect match to any cellular PVC Trimboard.

  23. Rick

    Great information thank you.
    I am preparing to trim a new shed with Veranda from HD. My plan calls for 1x4x8s for the corners. I have read articles telling me the best approach for creating the corners is to rip a 45 degree angle lengthwise on both trim boards and glue them together, using tape to hold together the two pieces until the cement hardens. Traditionally a woodworker, my experience tells me to rip one board 3/4 of an inch narrower than the other, and then glue and nail them together. (Hopefully that was clear).
    Can you suggest the best approach in your experience for putting together 2 boards to make a corner trim?

  24. John Pace

    I’ve made some corners before myself. Assuming you are using 1x boards, the easiest way is to rip a 3/4″ strip off one of the boards, use a solvent based PVC cement (like Weld-On 705) and pin nail them together to provide enough pressure for the glue to make contact with both boards assuring a good bond. If this were a historic house, you would be required to build a corner that way because that is how they did them in the 1800’s and early 1900’s. Some people don’t like the exposed edges of the boards when you butt them like this. One way to solve this problem is to hit those edges with some 220 or even better 320 grit sand paper. It will make the rough edges smooth like the surface of the boards. Other carpenters have tried making them by cutting a “V” grooving down the center of a board (they will first put a strip of tape down the length of the board at the center point. This tape is to hold the board together should you cut too deep), applying the same solvent based PVC glue in the center of the “V” groove and bending it at the apex. They will use a Velcro strap to hold the corner together while the glue dries. The type of corner you fabricate is left to the carpenter/contractor. Obviously, the second method is more time consuming and if not done correctly it could mean a poor looking corner that is not acceptable to your customer. However, for those who have mastered the second fabrication option the finished corner looks great. I hope I’ve answered your question. Good luck!

    Hopefully next time you’ll try Versatex instead of Veranda PVC trim.

    • Blake

      I too made my corners by grooving with a router. I set the router about 1/16 (ish) less than the thickness of the board. I used pvc cement and a few spots of that instant glue with the spray activator. It worked like a charm. I made a simple column the same way for three of the corners. The fourth corner i machined first by rabbeting one edge to about 3/16 – 1/4 from the edge. On that joint i used the instant stuff on the whole thing. Im too impatient to wait for curing. It was awesome. The fourth corner was then rounded over with a 1/8″ roundover bit. This made it look very similar to the other corners. Also the seam was off to one side where it isnt noticed like it would be if in the centre of the mitre. Corners were glued with pl premium to the substrate (more pvc) and cortex screwed sparingly. I also glued all but corners with the instant cement. You want to be sure not to get any on the faces of your work. Painters tape or some cover isnt a bad idea. If you research and make some test pieces you can save yourself and your customers some big issues.

  25. Rick

    Just caught your title :). It turns out you have an Elite Partner Level Dealer not so far from me. I’ll make the trip and look at the Versatex product. Thanks for the professionalism.

  26. Pat

    Regarding the filling of smaller nail holes say from a finish nail or trim screw , I use a white crayola crayon warmed to have it soft to push into the holes and then rubbing it clean with a towel or finger nail works just as well depending on the amount you apply. I use Tanza and typically the wood grain side which tends to have a slight gloss which lend well to the crayon. The matte side isn’t as concealed but it is a good solution to an issue. I used to use a white Minwax nail hole filler but it never matched so that didn’t last. Well hope this helps someone plagued with little black spots.

  27. Steve

    Continuing the cornerboard discussion, I plan to create corners with 5/4 PVC with 90 deg butt joints using plastic biscuits, pvc cement and clamping. My longest corner is 24′. Any concerns using biscuit joinery here?

  28. John Pace

    Your entire approach to the fabrication of your corners is spot on. If you’d like to use plastic biscuits, Versatex produces it own #20 biscuit. Good luck.

  29. Steve


    Moving down from the corner board I’m trying to decide between installing a starter skirt board or a water table molding on top of 5/4 trim. Versatex pictures show the skirtboard butting up to a cornerboard vertical edge. I have not found pics of Versatex or other manufacturers water table corner details. My understanding is historically a corner would drop on top of such a water table detail, but with the starter fin on the top of the Versatex water table, it doesn’t seem like it was intended to have the corner on top of the water table. Do you recommend butting the water table against the corner vertical edge?

    Another question. You seem enamored of Solar Seal 900. What about Lexel?

  30. Judi

    Hi John,
    I wish I had seen this information before I started my job. I have mahogany tongue and groove – stairs….I used the pvc trim board for the kick plates. I got some hard wood stain on the pvc boards. What can I use to clean it, as I would do not want to damage it. The stain is water clean up (not as easy as it sounds).

    Thanks so much for any assistance!

  31. John D. Pace


    Not knowing the amount of stain on the trim, I’d recommend three possible solutions. The first cleaner I’d try is soft scrub with bleach or any cleaner with bleach. If this doesn’t work try a solvent like acetone. You can find this at any hardware store or lumber dealer location. If all else fails, sand it off using a 100 grit sandpaper to start and stepping down to a 220 and then a 320 grit to remove the stain while also smoothing the sanded surface of the trimboard.

    Hope this helps


    John D. Pace, PE
    President & COO
    Wolfpac Technologies, Inc.
    400 Steel Street
    Aliquippa, PA 15001
    724-316-9523 (cell)
    724-857-1111 (office)

  32. Kathy

    John ~
    I used Veratex T&G boards for siding a gazebo and other misc. trimming. Love the result!
    Now, would like to use Versatex sheets to build an 8′ tall privacy fence. What is recommended product and placement for expansion/wind/bitter cold brittleness?/etc. On the Minnesota/Canada border with +95 summers, -40 winters, and far colder (strong) windchills. Any suggestions?

  33. Sandy

    We are installing trim around our windows with the brick mold that has the J-Channel attached. How do you correctly miter the joints of the corners?


    • Earl

      Hi Sandy,
      Have you seen a reply yet about your J-channel brick mold? I just ordered some to redo my exterior door frame and am anxious to find out not only how the miters turned out but how you liked the results. Are you using it with vinyl siding? Is the J-channel too deep for vinyl or did it look ok? Thanks.

    • John Pace


      This is a question better suited for Gary Katz or one of his fellow contractors.

  34. Steve

    Are there any suppliers of white painted nails that can be used with a nail gun? Building a house and carpenter wants additional $3,300 to do screws and plugs… I am not painting trim.

  35. John Pace


    Although you might find a nail with a painted head, the problem is keeping the paint on the head when the nail is shot from a gun or pounded into the trimboard. Once the paint comes off you now have to look for a nail hole filler and I can tell you no nail hole filler is an exact color match to any PVC trimboard. Another option if your not willing to use screws and plugs is just a white headed trim screw. It will be less expensive than the screw and plug but more than the nail. Simpson Strong Tie, Headcote by Starborn Industries, and possibly GRK all make a stainless steel trim screw with a white head. Based upon my experience in the field your carpenter was correct in choosing the screw and plug system. It is the best means of securing cellular PVC trim to the frame of a home, it gives you the best overall aesthetic appearance, and provides the greatest holding power. We have specific cases where this system survived hurricane Sandy without the trim pulling away from the home or becoming lose from the hurricanes negative wind pressure. Plus you never have to worry about the screw holes or the color of the plugs since they are made from the same material as your trimboards. Good luck with your project.

  36. Jason C

    We have indoor support columns with PVC wraps. After much abuse from the little ones in the house, the paint is chipping away on the endcaps. It appears as if, when they were installed, there is a thin layer of drywall or some filler covering the cap and pole under the paint which will need filled in before I repaint them. Is there a good material to use for this?


  37. John Pace


    There are several filler and bonding materials compatible with cellular PVC. If you are looking for a very durable material that is stronger than the PVC trim itself, I recommend you consider Extreme Adhesives, TrimWelder. It is a two part epoxy that cures to a hardness equivalent to an acrylic sheet. It has exceptional bond strength to cellular PVC and comes in white. If all you are looking for is a filler that will bond to cellular PVC but not have the hardness or durability of TrimWelder, you can use just about any vinyl spackling sold by your local lumber dealer. One spackling that we recommend is DAP’s Crack Shot.

    Good luck!

  38. Noah woodruff

    Mr. Pace,
    We have been asked to look at fixing some long runs of pvc fascia which split last winter. They actually sheered across the width, not at a joint, due to the cold. In the summer the jagged cracks all but close. However, as the temperature goes down the gaps increase. Up to 1/2″ at the worst. We have emailed azek and kleer for advice. They suggested adding screws and caulking the joints with a pvc joint caulk. We did both but with no real remedy. We have also tried kleer’s nail stick filler, also with no real success. Short of removing the entire fascia, is there a fix? We have thought about cutting out the cracked section, maybe 6″ on each side, and replacing that section with a shipped laped patch. Does that seem like it might work? Thanks for the help.

  39. Ron

    To protect the joints on the top our sub kitchen sink cabinet doors, we need to install a drip edge below the sink. Wood is not a good choice….I believe pvc board is the way to go. Sherman williams can match the cabinet manufacturer’s off white color. The board will have rounded edges and perhaps decorative routing. What do you recommend to ensure water will not raise the paint.


  40. John Pace

    Ron, I’m assuming you plan to rout or mould the PVC trim piece to produce the rounded edge and decorative routing. If my assumption is correct, here is how I would prepare the PVC trim piece for painting. To minimize the size of the cells for painting, I would sand the trim piece after it has been routed with 320 grit sand paper. I would then blow off any residual dust on the routed piece and wipe it down with a wet rag. This should give you a very smooth finish after painting. Paint adhesion to PVC, when tested in accordance with ASTM test protocol, is excellent and equivalent to that of paint on a pine board. Paint on PVC lasts 5 times longer than paint on wood due to the absence of moisture in the PVC trim. Your issue will not be with the substrate but the paint. The paint manufacturer needs to specify a paint that will perform in a high moisture environment. If such a paint exists you should not have any paint adhesion issues. Good luck.

  41. Tony

    We sometimes make one piece CNC routed exterior shutters from Versatex. Can these shutters be painted dark colours since they are basically free-standing isolated units? Why is it suggested that Versatex not be painted dark colours?

  42. John Pace


    Millwork shops and fabricators across the US have made one piece shutters and painted them dark colors with much success. The key is to use heat reflective paints from companies like Aqua Sur Tech, Benjamin Moore (Vinyl Select) and Sherwin Williams (Vinyl Safe). Shutters made from multiple pieces have a tendency to open at the seams if painted certain dark colors like Black, Forest Green or Cocoa Brown. The reasons dark shutter perform even when painted a dark color are because they are free standing, as you mentioned, and also the fact they are not very long or tall. All cellular PVC trim producers do not recommend they be painted dark colors. It’s not just a Versatex thing. If they don’t say it in their installation guidelines check their warranty. The reasons we do not recommend Versatex be painted a dark paint color are these: 1) Cellular PVC trim, no matter the manufacturer, has a heat distortion temperature of 140 to 150F. This is the temperature where cellular PVC begins to lose some of its physical properties. If you use an embossed or textured finish on your PVC trim board the pattern may disappear when the board reaches the heat distortion temperature. 2) Coefficient of Thermal Linear Expansion. The amount of expansion or contraction of cellular PVC trim is directly proportional to the length of the board and the difference between the install temperature and the max and min temperatures the project will reach after installation. It is best to try to minimize the max. temperature. Painting the board a dark color makes it more susceptible to excessive expansion and potential buckling on the wall if it is a long run of trim (i.e. fascia, frieze, rake). In my opinion a long run is 3 or more boards. I hope I’ve answered your question. John

  43. Bille

    I am replacing some wood posts and bottom wood ledge on my second story balcony due to dry rot. The balcony has glass panels. Am also replacing the vertical and horizontal 3/4″ quarter round molding holding the glass. Would like to use PVC molding if at all possible due to the non-dry rot capability. Is it appropriate to use a air nail gun to fasten the PVC molding to the wood post? If so, is there a max gauge I should use? Am afraid the gluing the molding to the posts and ledge will not be sturdy enough to hold the glass securely and screws may be too big. Also, since the posts are white and I may have to paint the moldings to match, what paint should I use and what type of sealant should I use for the 90 degree seams in the corners? Thanks for any advise.

  44. John Pace

    Per your questions, yes it is appropriate to use an air nail gun to fasten the PVC moulding to the wood post. Use an 18 gage or 16 gage trim nail. Test the nail gun and nail on a scrap piece of quarter round first to make sure you have the right setting so that you don’t damage your moulding trim. As for paint use any latex acrylic paint or a latex paint with urethane. Sherwin Williams Duration, Benjamin Moore Regal are just two water based paints that I’m familiar with. There are many more that bond well to PVC trim. When it comes to sealants, there is only one I recommend, NPC Solar Seal 900. If you can’t find that brand use Quad by OSI or Geocel 2300 they are close but in my opinion not to the performance standards of Solar Seal 900. Good luck with your project.

  45. Marc Myerson

    A friend wants me to fix a pic molding to painted drywall in her bathroom as a crown molding. Can I use a double sided tape as she does not want to paint or see nail holes?

  46. Gary Hardina

    Hi John:

    We built a new home in 2009 extensively using Azek smooth trim boards throughout the exterior of the house. We also used the Azek molded trim around windows and sills. The main exterior siding is Hardie Board. We did paint all of the trim. All of the trim and window surrounds are now in pretty bad shape after 6 years with the caulking having cracked and separated on just about every joint. Our builder attempted to use various sealants and bonding products recommended by Azek to fill in the joints several times over but none have held through the winter months. Our house exterior is now a mess of failed joints. Our builder says that Azek has refused to provide any further assistance other to say that their installation procedures have changed since our house was built and that there is nothing wrong with the product. Other than replacing all of the exterior trim with another product, is there a something new on the market available that can be applied to the joints that will not crack and pull apart during cold weather months?

  47. John D. Pace

    Hi Gary:

    Although you didn’t use Versatex, I’m happy to help you with your problem. One aspect of our business that separates us from the competition is our analysis of complementary products to enhance the performance of our trim. We have tests numerous sealants with our cellular PVC trim and the one that in our opinion outperforms them all is Solar Seal #900 sealant/adhesive produced by NPC Sealant in a suburb of Chicago, Illinois. I recommend their color #111 which is a match to our trimboard but should also be a close match to your Azek trim. What I like about this sealant/adhesive is it’s solvent based which gives you better bond strength than a pure sealant but with the flexibility of your better sealants. I live in Pittsburgh and built an outdoor living area with Versatex Trim including the outdoor cabinetry. I used Solar Seal #900 for the joints between our brick home and the trim. Temperatures reached -18F last winter and the sealant performed as expected with no cracking or pulling apart at the seams. I recommend you call them to find a local supplier in your area. Their telephone number is 708-681-1424. You can also e-mail them at Good luck.

  48. Dylan

    Hi John,

    This article has a lot of good information that would have changed my approach to past PVC projects. But I still have a few questions, specifically about Versatex products:

    1) Do you have to shim Versawrap column wraps in order for them to be snug to the structural post enough to keep them true and square; or can they maintain proper shape with the 1/4″ gap that is designed to exist? (I understand that they must be shimmed if using treated lumber due to twisting, so I am asking about untreated lumber)

    2) When using construction adhesives to bond beaded ceiling to ceiling joist, is there any chance of oils bleeding through and staining the pvc?

    3) What are the recommended fasteners for Versatex’s 1/2″ regular and stealth beadboard planks?

    Thanks for your help.

  49. John PAce

    Sorry for not responding sooner. In response to your questions.
    1) Do you have to shim Versawrap column wraps in order for them to be snug to the structural post enough to keep them true and square; or can they maintain proper shape with the 1/4″ gap that is designed to exist? (I understand that they must be shimmed if using treated lumber due to twisting, so I am asking about untreated lumber). ½” Versatex wraps are self-supporting. However, they will give or push in if someone leans into them and there is no support, shim or otherwise, on the backside/inside. . You can reinforce the gap between the wrap and the structural post using a dense insulation or even low to medium expansion spray foam insulation. It works well with both treated and untreated posts. I’ve seen this technique used quite often in Florida. Another way wraps are installed is to firmly attach them to the structural post on the side most likely to receive occasional contact and let the other three sides float. If you need a more durable wrap consider a ¾” wrap.

    2) When using construction adhesives to bond beaded ceiling to ceiling joist, is there any chance of oils bleeding through and staining the pvc? In my 12 years in this industry, I have never seen an instance of any bleed through the PVC onto the face of the beaded ceiling. Adhesives like Liquid Nails Sub-Floor and Heavy Duty Construction Adhesive skin over in a relatively short period and do not bleed. See Liquid Nails Sub-Floor spec sheet for further information on the product.

    3) What are the recommended fasteners for Versatex’s 1/2″ regular and stealth beadboard planks? ¼” wide x 1” long crown staples. Nails and screws might fracture the leg of the Stealth beadboard.

  50. John

    I love the PVC board, but the stucco guys left a 1/2 gap between my recessed vinyl window frames and their stucco, so they used backer rod and NP1 caulk to fill it. The caulk failed after a few years and water leaks in. I recaulked, but the gap is just so large it looks like a long term problem. I carefully cut a piece of PVC board to trim around the windows and wanted to seal it really well to fill the area with the big crack that was previously caulked. I used a DAP caulk that said was OK with PVC board, but after a month it never cured, so I had to undo a whole days work and pull the boards off and clean up the old wet caulk as well as I could. I was thinking of trying again. Is there a caulk at the Lowes or HD that would bond well to both EIFS stucco and the vinyl window frame where I could have a smaller caulk seam around the window? Thanks for the advice.

    • Emanuel

      Hi John,
      I would use OSI Quad Max. I’ve had great results with it. Check with your local lumber yard.


      • John

        I found OSI Quad at Lowes…no “Max” in the name. It is solvent based. Can I used this to caulk between PVC board and vinyl window frame. I guess the solvent won’t bother either of those? Then on the other side I will caulk between EIFS and the PVC board if that is OK? Thanks much for the suggestion.

  51. Rich Kissane

    Hi John,
    I am building shutters in the Bahamas. I concerned about the warmer temps and the material sagging in temps of 100 degrees. Am I right to be worried?

  52. John D. Pace


    To answer your question there should be no concern provided:

    • You’re painting the shutters a light or pastel color.
    • You’re not spanning more than 2 or 3 feet without proper reinforcement
    • You’re using a thickness that will allow you to span the required distance without sagging.

    A temperature of 100 degrees F is not a concern. Most cellular PVC has a heat distortion temperature of 145F which means the product will not lose any of its physical properties until it reaches a temperature equal to or higher than 145F. One advantage you have in the Bahamas is the temperature differential (high and low) is not that great. Thus, you don’t have to be concerned about expansion and contraction.

    I hope I have answered your question. If you’d like some further help in designing your shutters you might want to contact Ted Hagemeyer of Finyl Sales in Ocala, Florida. His website is Be sure to tell him he was recommended by John Pace at Versatex. Ted’s company designs and builds shutters, pergolas, column wraps and other outdoor components from cellular PVC in the state of Florida.

    Good luck with your project.

    John Pace

  53. Brian Rodoalph

    I use PVC trim extensively in the new England region and love the products…I have a home in south Florida and would like to replace the wood trim with PVC and have not seen much of the product here. Also, few dealers to buy from as well. I am wondering if the extreme temps have adverse effects to PVC trim here in the south.?? Also I am designing a pergola and am considering using the INTEX products and again what are the effects here in the south for these products? Thank you for any input….

  54. John Pace

    Good morning Brian:

    In response to you question, PVC is gaining popularity in Florida, and the Carribean. New England was the first market to embrace cellular PVC trim and have done so in a big way. The southeast including Florida has been slower to convert. Cellular PVC actually performs better in the south than in the northeast because the high to low temperature swing is much less. Thus, it experiences less expansion and contraction. Cellular PVC trim has been used in the Villages in Ocala Florida since the early 2000’s and along the east and west coasts of Florida for at least the past 10 years. There are dealers stocking cellular PVC trim in Florida let me know if we can help you identify one. Also Intex is a great Millwork shop. However, there are also PVC Millwork shops throughout Florida fabricating all sorts of gingerbread items. So in summary, you can use cellular PVC trim in Florida without any concerns or issues. In fact it will expand and contract less than what you’ve experienced in the northeast.

  55. Steve

    I want to build some 48″ radius curved surfaces made of 1/2″ or 3/8″ cellular PVC sheets. I plan to build curved plywood forms to bend them on. Any advice regarding a heat gun purchase, etc etc?

    • John Pace


      Assuming you are bending the cellular PVC sheet along the length, 3/8″ and 1/2″ cellular PVC sheet will easily bend around a 48″ radius without the need for heat. The most important installation issue is bonding and fastening the PVC sheet to the plywood form. Again, assuming your application is for exterior use, thin sheets need to be bonded to the plywood frame and fastened 12″ on center in both directions. The concern here is bowing of the sheet between fasteners when exposed to the UV rays of the sun. The sun will heat this thin sheet and those areas not properly secured to the plywood frame will bow towards the sun. Remember 3/8″ and 1/2″ cellular PVC sheets were never designed for use as an exterior trim. These thin cellular PVC products are typically used by millwork shops and in the sign and graphics industry. If your interested in a non metal nail for this application Google Raptor Nails. This company makes nylon composite nails and have specific nail guns for installing their strip nails.

  56. Christine

    We are planning on trimming a bathtub with pvc trim. Our tub is a standard in a raised wood platform. The tub lip buts up against wood. We will be using a 2″ baseboard piece topped with a 3/8″ corner piece, it all seems to fit well. Questions ; what type of caulking should we use to seal to tub ? can we use an adhesive to attach to wood frame ?, I would rather not use nails and have to paint and fill. Should we miter and assemble on floor before installing ?. Thank you.

  57. John Pace


    Since this is an interior application, we would use modified silicone sealants such as Quad MAX or WeatherMaster. If this were an exterior application where we want maximum adhesion and sealant flexibility, we would choose a solvent based sealant. My first choice would be NPC Solar Seal 900. My second choice would be Quad for siding and roofing. Since this is an interior application, yes you can use an adhesive to attach the trim to a wood frame. However, how do you plan to apply enough pressure to the PVC trim to get an adequate bond? In this case you’ll need to use a sealant with solvent as part of its chemistry. We recommend Liquid Nails Sub Floor or Liquid Nails Heavy Duty Construction adhesive. I’m a believer in test fitting all trim before installing. However, that decision is up to you.

  58. Rob Alex

    I am looking at the feasibility of using 3/8″ thick pvc panels for a custom 3-D texture shower surround. Since the pvc can be routed like wood. Is this possible using a C.N.C. router, and sanded with 320 grit and using acetone to seal the open cells as with handheld routing?

  59. John Pace


    In reading about your project you’ve either been reading our installation guidelines or are very proficient on the installation of cellular PVC trim and sheet. First of all, I’m going to assume this is an interior application. Secondly, 3/8″ sheet is very flexible and should be fastened 12″ on center in both directions and glued to a solid wooden substrate using a preferred adhesive like Liquid Nails Sub-floor or Heavy Duty Construction Adhesive or PL Premium Urethane Adhesive. As to your question, yes 3/8″ sheet can be milled on a CNC router. Typical settings on a CNC machine when cutting cellular PVC are as follows: Tooling Speed – 15,000 to 20,000 RPM’s, Feed Rates – 20 to 30 FPM, Vacuum hold-downs to prevent vibration of the substrate, Bits – Vortex makes a 5600 series cutter with a single edge up cut spiral bit made for plastics, Chip load – 0.016” to 0.018”, and excellent dust collection. As for sealing the cuts by sanding and rubbing them with acetone, you do get more sealed cuts when following these steps and it is probably the best practice outside of painting. However, the cells are not 100% sealed and in time the cut areas may start to discolor. Good luck with your project. John

  60. Jim Connell


    I am planning on replacing some windows on the end of an A-frame house. The frames are built in place using 5/4″ trim boards which have rotted, and have fixed single-pane glass that I plan to replace with Thermopane units. I think I know how to build it all, but am concerned that the instructions for PVC trim caution against using it for structural applications, and I think what I’m planning is structural. (I can attach a drawing if my description isn’t clear enough…) Also, my plan was to install/seal the glass using silicone seal, but you recommend against using it with PVC trim. Any advice will be greatly appreciated. -jimc

  61. John Pace


    PVC is non load bearing. However, OEM’s and contractors have made doors, cabinetry, pergolas and other building elements with cellular PVC. Is the sash fixed in the frame or is it operable (single hung, double hung, casement)? You mentioned the fixed glass that you are replacing with Thermopane units. Thus the reason I’m confused on the type of window sash you are replacing. If the sash is fixed in the window what is the size of the sash? If the sash is operable I recommend another material or reinforcing the cellular PVC with aluminum. As for sealant, silicone does not bond well to cellular PVC. You could try modified silicones like Quad Max or even Weather Master. I’m not sure if they’ll bond to glass but they will bond to cellular PVC. If I still haven’t properly answered your question, send me a photo, drawing or something that gives me a better idea of what you are working with. Thank you.

    • Jim Connell

      This is a follow-up to my previous question. Your reply was very helpful in giving me a path forward. I’ve constructed frames out of PVC trim 5-1/2 x 15/16 and they came out quite well and while flexible they are quite stable. In answer to your earlier questions I’ve attached a picture showing the windows in question prior to the start of work. There are two identical units, and each unit has two upper fixed panes (now thermopane), and a double Andersen awning window below. When I get a picture of the completed project I will post that as well. Again, thanks for your help!


      • John Pace

        Jim, glad I could help. I look forward to seeing the finished product. Since you are using a 15/16″ board, I’m certain it’s not our product. Maybe next time you can give our 5/4″ board which is a true 1″ a try. Enjoy the rest of your day.

      • Jim Connell

        It’s not done yet but close enough to show. I’m still waiting on awning window units to go in the bottom. The insulated glass was sealed with Quad Max and came out great; thanks for the recommendation.

        If anyone is considering a similar non-trim application, I suggest giving PVC trim board a try.

  62. Allan

    I spent over 100 hours making a sign out of PVC board and it has garnered many compliments in the last 18 months. Unfortunately, it was vandalized this past week. The perp apparently thrust his whole weight against the sign breaking it in two (see photo). I need a glue with a long working time to get the pieces back together. I intend on pulling the joint together with pocket screws, but it will take two of us working quickly up to a half hour (estimated) to join the fractured pieces. I would very much appreciate a recommendation on glue.

  63. John Pace

    The guy did one heck of a job demolishing such a nice sign. Your question is an easy one. One of the best adhesives on the market that has a long cure time while also drying to a hard acrylic finish that has superior strength to the cellular PVC is TrimWelder by Extreme Adhesives. The adhesive is a two component solvent and silicone free structural methyl methacrylate or MMA. Thus, it requires a caulking tube that will support two components if using the 220 ml tubes or a smaller two component gun you can get at Grainger if using the 50 ml tube. It’s available in a slow, fast and laminating grade. I would read their technical data sheets on their website to determine which one is right for your application. I’m guessing the slow or laminating grades may be best. The company’s website is or Good luck with the repair.

  64. Jenice Delano

    I already put up this PVC product as casing, and i did not realize that you cannot paint it a dark color. I absolutely MUST paint it. Can anyone please give me advice as to what type of primer and what type of paint to use? I realize i lose the warranty, but i still must do it. Your advice of the best choice under these conditions would be much appreciated!!!

  65. John Pace

    Good evening Jenice. I prefer to see a photo or have more information before making a recommendation but
    I’ll do the best I can under the circumstances. My typical questions are maximum length of trim run, direction trim faces, temperature at which trim was installed, min and max exposure temperatures where the trim was installed, paint color, LRV if available, and fastener being used. Based upon what you’ve told me I’m assuming the trim is installed. Hopefully you used a strong fastener (min. 12 gage nail 8d with 7d head or 7d screw). If not I’d add a few more fasteners to the trim. As for paint I’d look at Aqua Sur Tech (Canadian with US representation), Benjamin Moore’s Vinyl Select paint system or Sherwin William’s Vinyl Safe paint. People who have used Ben Moore or Aqua Sur Tech have had the most success painting PVC trim a dark color. Finally, how the trim performs on the wall will depend on the temperature of the trim when it was installed, what direction the trim faces (N, S, E, W), and the length of the trim run. The lower the installation temperature the more chance the trim will buckle as it expands linearly. I hope you find this information of value. Good luck!

  66. Mark

    Hi John,
    Is it permissible to use Versatex sheets to fabricate outdoor cabinets for summer kitchens?

    • John Pace

      The short answer is yes. I designed an outdoor living area 32’ x 32’. The ceiling is ¾ x 6”x 12’ WP-4 cellular PVC T&G board. The columns are raised panels made of cellular PVC boards. The raised panels, custom mouldings and cabinetry were all fabricated by a local OEM. The soffit and fascia are also cellular PVC trim. All trim was secured with Cortex screws and plugs. OEM’s have embraced the use of cellular PVC for outdoor cabinets and kitchens.

      • John Pace

        What we have found is you can machine Cellular PVC just like plywood or solid wood. Pocket screws, dowels, and screwing thru sides all work well with Cellular PVC. However when preparing parts on a CNC router you have to use the proper bits. O-Flutes come in many sizes. These bits allow for quick chip removal, which is key to minimizing heat build up in the cellular PVC. Basically you can use Cellular PVC for anything you can do in wood.

  67. Bryan

    Hello. Im interested in using the pvc trim board at the corner of a home where the wood siding on each side stops. Will it work or look right?

    • John Pace

      Good evening Bryan. There are three ways to handle the corners on this project you can make your own corners from two boards, you can v-groove and fold a piece of Trimboard to create an outside corner, or you can buy a fabricated corner from a PVC trim and sheet manufacturer. The corners will look as natural as the wood you’re replacing.

  68. Bryan

    This is wood siding and trim. I wanted to know could i use the pvc trim boards to replace the wood, because of insects and wood peckers creating holes in the trim.

  69. John Pace

    Good evening Brian:

    Yes you can use cellular PVC trim to replace the wood trim on this home. It will not rot and will prevent insect and woodpecker damage. It can also be painted if necessary. If you plan to replace the wood trim with cellular PVC trim, and prefer not to paint it, please use screws and plugs. There is no nail hole filler or putty that is a good color match to cellular PVC trim. Good luck.

  70. Rory

    I used a white pvc window flashing trim material on the 1st phase of our home reno. 2 years later, it still looks good and flashing is uniformly white. I recently received a new batch of the same product to use on the next phase. Its the same manufacturer, same material. With the new batch, if left out of the box for as little as 24 hours, it turns from white to grey. I intend to approach the manufacturer for replacement, but problem is I see some that I already installed is greying. What is happening here (i am assuming some UV damage) and what is the best way to treat the pieces I have put on that are too difficult now to remove.

  71. John Pace

    Good afternoon Rory:

    I have never heard of SureSill window flashing. It appears to be more of a rigid PVC trim than a foamed PVC trim product but I can’t say for sure without more information. Why it has turned grey after only 24 hours of outdoor exposure is a mystery to me. Typical PVC building products that suffer UV damage will turn yellow (mild degradation), orange (serious degradation) or brown(total degradation). I have never seen any PVC building product, including vinyl siding and vinyl windows turn grey due to over-exposure to the sun. If I were you I would ask the manufacturer what happened. In their warranty the manufacturer states, “UV exposure of the SureSill Products in excess of that set forth in the SureSill Product specification is not covered”. If you have the specification ask them if the product in the photos you send me is covered under warranty and “specifically” what caused it to turn grey. Sorry I can’t provide you with further assistance.

  72. Joe

    Hi John, Nice informative site. I plan to wrap some 8′ columns with 1x pvc. I was going to use 1×5 and 1×6 with a small bead on the outside corners of the 1×6’s. Obviously, I’m planning to use 90 degree joints(they will all be factory edges) and was going to use either the Solar Seal you recommend, Quad or even a tube of Kleer Structural Sealant which I happen to have, along with occasional 6d ss finish nails. My questions are: Does this all sound ok? and Should I also use biscuits? Thank

  73. John Pace

    Hi Joe: Your installation technique is very good. However, I’d use a solvent based PVC adhesive to bond the boards versus a sealant/adhesive. A solvent based adhesive will breakdown the PVC and create a strong chemical bond. Sealant/adhesives are thick, viscous and slow to cure. We’ve used Weld-On 705 PVC pipe adhesive for 13 years now to fabricate our one piece corners and have never had a claim or return on even one of them. When using an adhesive apply it to only one of the edges you plan to bond not both of them. You want a good board to board bond. An occasional 6d ss finish nail will add the needed pressure at the glue line producing a strong bonded joint. As for biscuits, there not necessary. However, if you plan to use them be sure to use a biscuit compatible with PVC. One last comment, if the post you are wrapping is a wet pressure treated allow ample room for any twisting of the post. Otherwise there is a good chance you will split open one or more of the joints. To avoid this take the necessary steps to make sure the post is semi dry before wrapping. In the future you might want to look into manufacturers that produce a one piece four sided column wrap in a 1x (3/4″) thickness. Good luck. If possible send me a couple of photos when you’re done with the project. Thanks. John

  74. Dale Gabrys

    Hi John, I am working with pvc for the first time. Before finding this site I wrapped an existing structure made of cedar with pvc. I used Loctite extreme to bond to both the painted cedar and other parts made of the pvc molding, on some trim I used special screws for pvc but not the mfg listed here.
    Will this be adequate? I also started to make a gate by routing the pvc, I did not realize that the cells would be exposed.
    How can I close the cells so the trim will not get dirty?
    I have attached a couple of pictures.
    Thanks for your assistance, I wish I would have found this site

    • Dale Gabrys

      Sorry I meant Locktite ultimate and the gate is going to be holding lattice.

  75. John Pace

    Good morning Dale:

    I’m going to assume your using Loctite Power Grab Ultimate. I’m not an adhesive expert but I believe both the Loctite product and Quad Max are Silane Modified Polymers. Assuming this is true they are MS Silicones that cure from the humidity in the air. These products are relatively new to the market so long term performance data is not available. When bonding to wood we recommend Liquid Nails Sub-Floor or Liquid Nails Heavy Duty Construction Adhesive because we have conducted independent ASTM testing of these products and others and find them to be superior when bonding cellular PVC to wood. They have also been in the market for years. The Liquid Nail products may not cure as fast but we discount that as a condition of use. What we do know is they have 2 to 3 times the shelf life than a plastic adhesive tube. If you read the tech data sheet on the Loctite product you’ll find the shelf life is 12 months from the date of manufacture not when you use it. So be sure to check this before buying. As for fasteners, if you have one you like great. If you’re looking for one that reduces the need for painting consider either Cortex by Fasten Master or Starborn’s Pro-Plug System for cellular PVC. Starborn offers a stainless steel screw. I’ve found many architects along the east coast prefer stainless over coated fasteners and write this into their specification. Finally, once you cut into cellular PVC you expose the core. The core is nothing more than an impervious honeycomb. However, it is susceptible to picking up dirt. We’ve found the best way to reduce the cell size is to first sand all cuts with sandpaper. I like to use a 220 grit first before stepping down to 320. You’ll find the surfaces to be extremely smooth after sanding. To minimize the cells even further take Acetone and a clean white rag and liberally apply it to the sanded surfaces. I hope you found the information helpful. Good luck with your project. Attached is an example of a large gate produced from cellular PVC. I plan to attached one or two more if the site allows me.

  76. John Pace

    Here’s another gate made of cellular PVC

  77. John Pace

    One more gate photo. This is an outdoor storage area. I believe it is for trash cans

  78. Dale Gabrys

    John thanks for the information I will send completed project pictures.

  79. Joe

    Hi John, Here are a couple of pics. It’s nothing too fancy but it came out pretty well. I couldn’t find Weld-on 705 locally so I used another pvc cement. I ordered some weld-on so I’ll have some for the next project. Thanks for your help.

  80. Joe

    Here’s one more pic. I couldn’t figure out how to send more than one at a time.

  81. John Pace

    Nice project. Glad to be of assistance.

  82. Becky Ochsner

    Hi John, I would like to create a shiplap look in my mudroom and bathroom using Versatex WP4, because of it’s abilities in higher humidity and will not absorb moisture like a wood wp4. I would love to continue the paneling around the entire walk in shower. Would it be possible to use WP4 for this level of water and humidity? I’m attaching my inspiration, where corian was used.


  83. John Pace

    Good evening Becky. Versatex can be used in areas with high moisture content and high humidity without an issue. In fact, you can place cellular PVC in water without fear of rotting or water absorption. The only concern I have and the one you need to consider is the surface durability of the Versatex WP-4. Most bathrooms are created from ceramic tile, stone, etc. very hard and durable materials. I’ve seen mud rooms, bathrooms and other high moisture environments use Versatex without issue. I just wanted to make you aware of my concern. Here’s a photo of a bathroom where Versatex was used

  84. Bill Chadbourne


    I am wondering if it’s possible to bend cellular PVC brick mould into a semicircle using a homemade wooden steam box (used for bending oak trim). I am not sure if the steam would be hot enough. Thanks in advance for your help.

  85. John Pace


    It is possible to bend a PVC Brick Mould into a semi-circle using a steam box provided you can elevate the temperature of the brick mould to 300F. I’m not talking the box temperature I’m talking the temperature of the product at the mid-point of the core. The use of an infra-red thermometer can help you determine the core temperature of your cellular PVC moulding. Bending is as much an art as it is a science. I’ve seen contractors go through two or three pieces of a trim or moulding before perfecting the process. So don’t get frustrated if it doesn’t look the way you want it to on the first try. Other equipment used to elevate the temperature of cellular PVC trim for thermo-forming includes a wall paper steamer with a piece of PVC pipe and two pipe caps and a pair of torpedo heaters and length of insulated duct pipe. If you prefer to have a professional thermo-form it, ask you local dealer if they have heat bend capabilities. Another option is OMC Arch trim. Google the name. They’re in Michigan. The company has a long history and success with hear bending cellular PVC trim and mouldings. They can ship your thermo-formed piece to anywhere in the US. Let me know if you have any other questions. Good luck with your project.

  86. John

    I removed vinyl siding and had to replace the “ears’ of the window sills. I used versatex for the replacement blocks. Since I have a bit of a gap between the two, I’m wondering if I can belt sand the versatex and wooden sill to make them a bit more even/smoother?

  87. Brent Geels

    I have PVC trim around vinyl windows and i need to caulk the 1/8″ joint between the trim and window. I see that you recommend a few solvent based caulk options. I am wondering if there are any caulk options that would not need to be painted and will not collect dust. I would like to take advantage of not needing to paint the windows or the trim, and use a caulk that will look good without painting.

  88. John Pace


    In my opinion the best sealant that bonds well to cellular PVC is NPC’s Solar Seal #900. Google NPC Sealant for their contact information. I don’t believe their sealant requires painting. They have outdoor exposure test racks at their manufacturing facility that have been there since the 1950’s if not earlier. There product is formulated to be UV resistant. I’m not a sealant expert but I believe most of them are formulated to perform well under UV rays from the sun. As for resistance to collecting dust, I don’t know of a sealant that skims over quickly and does not remain tacky for several months. Other good sealants for cellular PVC are Quad, and Geocel 2300. You might want to check the Quad Max or Weathermaster sealants to see if they are less tacky. They have other performance issues which is why I don’t push them as an option with cellular PVC. My responses are always focused on best practices/products not just good ones. Good luck. Sorry I couldn’t be of more help.

  89. John

    What is the tooth count of the saw blade using an electric mitre saw?

  90. Gail Nelson

    We have a 10′ x 30′ covered porch alongside our garage, with rafters spaced 24″ apart. The underside of the roof was painted, but we’ve been looking at the plywood decking and roofing nails for 23 years. I was able to purchase a large quantity of 1/2″ x 5-1/8″ x 96″ pvc beadboard planks on clearance to use for the ceiling. I know it would have been better to use thicker boards, but can we run the boards lengthwise to span the 24″ rafters to avoid having to cut the planks? Our carpenter thinks so, but I’m concerned about the expansion. Since the boards are only 8′ and the shortest width of the porch is 10′, we’d have to do a lot of cutting of the pvc planks and use firring strips if we ran the boards to span the 10′ width. Your advice about any precautions we should take to make this work will be greatly appreciated.
    By the way, I’m so impressed with the time John Pace has taken to respond to all of the above questions that I would definitely recommend the Versatex products to friends and family.

  91. John Pace

    Good morning Gail: 1/2″ PVC beadboard was never meant to span 24″ O.C. The product has too much flexibility. The concern is not expansion or contraction but the sagging of the beadboard between the joists or supports. Expansion and contraction is a function of length, the difference between the install temperature and the min. and max. temperatures the board will be exposed to, and the coefficient of thermal linear expansion. Thus, the boards only move along the length not the width. If you had 10′ beadboard planks and were to run them the short distance, you’d experience literally no movement. If you read the installation guidelines from any of the PVC trim manufacturers you’d see not one of them recommends spanning 1/2″ beadboard more than 12″. One way of possibly resolving this issue is to attach an underlayment to the joists before installing your beadboard planks. I’d also recommend you use an adhesive like Liquid Nails Subfloor or Liquid Nails Heavy Dusty Construction Adhesive to bond the board to the underlayment in addition to nailing them to the joists. If I were installing the ceiling planks, I’d hold them about 1/8″ back from the entire perimeter and use a bed moulding around the perimeter to dress up the project. I’d also use a “T” mould in the two beadboard plank joints rather than try to scarf cut or ship lap the edges. Much easier and looks much like the “T’s” in a suspended ceiling with the exception the panel is not routed to be flush with the face of the “T’s”. Some PVC trim manufacturers offer a pre cut “T” moulding .

  92. Gail Nelson

    You are the best, John! I’m very grateful for your quick reply and great advice. My husband is concerned about adding the weight of underlayment in addition to the planks on this roof section, which is supported by treated 4×4 posts placed 10′ apart. Do you think we could use firring strips running the 30′ length for nailers that are 12″ apart to reduce the weight and apply the Liquid Nails to the firring strips? By the way, I love the idea of the “T” molding to save the cuts–never would have thought of that one! I’ll send before and after pictures when the project is finished. Thanks again.

  93. John Pace

    Furring strips will definitely help. Not sure if they will totally eliminate sagging of the plank but it’s definitely worth trying.

  94. Donna J Cady

    Hi John and fellow contractors!

    I just want to say how glad I am that I stumbled across this web site! It has been unbelievably helpful in so many ways!!!

    Love the product and encourage all my homeowners to use it!

    Now, any suggestions as to what would look good on this house? It needs updating “badly” and it’s in a prominent area of Northville, Mi. I was thinking simple 1×8 except it also has sloped window sills (so I will have to cut the brick, I think) …

    Thanks in advance!

    I wish your had a web site cad program I could play with with the trim and exterior look!!

  95. John Pace

    Good morning Donna:

    We do have CAD as well as PDF drawings on our website. The easiest way to locate them is to scroll to the bottom of the home page and click on Drawing in the site map.

    As for home improvements, I’ll leave that to the experts. You have a very unique home with what appears to be brick, siding and even some board and batten on the porch. The partial bay window to the left is interesting. Now sure why the house was designed with a portion of the window missing. From purely a PVC trim perspective, you could 1) add a small gable end bracket, 2) upgrade the columns with a cellular PVC column wrap in either a smooth or raised panel look, along with accent wraps and moulding trim kits to dress up the top and bottom of the column wraps, 3) create a raised or recessed panel look on the bottom of the partial bay window using a cellular PVC sheet and some mouldings, and 4) add a PVC railing system between the porch columns. Without some major renovation work on the outside, I’m not sure what else can be done to the front of the home. Good luck with your project and thank you for your support of cellular PVC trim. John

  96. John Begg

    Hello! What do you recommend for a paintable caulking for the pvc ! I’m a painter and I see this stuff moves a lot ! Thank u ! In Charlton mass area!!

  97. John Pace

    Good evening John. Sorry for not responding sooner. The best sealants for use with cellular PVC are either ones with solvent as a component of the sealant or ones that have a polyurethane base. In our opinion, NPC Solar Seal 900, Quad by OSI or Geocel 2300 are all excellent solvent based paintable sealants. Since they contain solvent they must be fully cured before painting. Typically 24 hours before painting. The next best are polyurethane sealants. Polyurethane is very compatible with PVC and bonds well to PVC trim. Acrylic paints with polyurethane are also excellent coatings that provide super adhesion when compared to just straight acrylic paints. Finally, if you want a good paintable sealant use Quad Max or Weather Master . They are both paintable within one hour of application. The only shortfall with these is you won’t get the same excellent bond to the PVC trim you get with either a sealant containing solvent or one formulated from polyurethane. I hope you find this information of help. Enjoy the rest of your weekend.

  98. Tony

    We sometimes rout into the surface of Versatex with our cnc machine to create raised panel, or shaker style exterior shutters. As a result, the open cells and the milling marks tend to telegraph through the paint. Is there something that we can perhaps trowel over the surface and then sand smooth before paint, or between paint and primer?

  99. John Pace

    Good morning Tony:
    In my travels, there are three products I’ve seen used to fill in the surface of milled or moulded cellular PVC. The first, which I think is the best because it can be sprayed on, is 2 coats of Valspar Bonding primer. I’ve also heard of OEM’s using a one part, liquid, self leveling epoxy. Other options which are dependent on the amount of surface area you’re trying to seal are exterior vinyl spacklings like Dap Crackshot or Dynamic Dyna Patch Pro or automotive Bondo body filler. One other fabrication tip. We have a small Weinig moulder. To minimize the dust building up on the tooling and on the operators clothes, we keep spray cans of Static Guard at the work center. We have also placed an air line into the cabinet of the Weinig with multiple flex nozzles positioned at the tooling to move the dust away from the tooling and into the dust collection system.

    Hope you find this information of help with your Versatex fabrication projects. If I can be of any further help or if you’d like to see a photo of the air nozzle setup or a recent entry door sealed with epoxy before painting let me know.


  100. John Broderick


    I am planning to use PVC to replace a rotted window sill and window trim.
    I would like not to paint the PVC when finished.
    I intend to fasten the trim to the house with Cortex screws.
    I am not sure if I need to actually fasten the PVC sill itself – I may just wedge it in and let the wedges and trim hold it in place.

    The window is a standard size of about 36 inch by 30 inch so thermal expansion is probably not an issue. Do I still need to leave gaps where the PVC meets? Whether I intentionally leave a gap or not it probably won’t be watertight so I presume I will need to use a caulk/sealant to keep water out.

    My question is about the adhesive/caulk/sealant I need to use and where to apply it.
    I would like to use a single product, if possible.

    First can I get by with a sealant, rather than adhesive?
    Is caulk and sealant the same thing?
    Is there a sealant that works for PVC-PVC and PVC-wood?

    I want a watertight seal to protect the wood window and OSB to which the trim attaches. Here are the areas that may require caulk/sealant/adhesive:
    1. Where top horizontal PVC trim meets the side vertical PVC trim pieces.
    2. Where the vertical PVC trim meets the PVC sill.
    3. Where the inner edge of the PVC trim meets the wooden window frame
    4. Where the outer edge of the PVC trim meets the wood siding.

    The amount of cut edges here is very small – do I need to treat these differently to the PVC surfaces that are not cut?


  101. John Pace

    Good afternoon John:

    In response to your email.
    1) Although you may get away with wedging the PVC sill between the trim jambs, I would prefer you use a couple of screws mechanically fastening the sill to the house.
    2) I would not leave a gap between the trim and the sill moulding. One of the primary factors in the movement of cellular PVC trim is its length. Your dealing with pieces approximately 3′ long. The other is temperature differential between when you install it and the max and min temperatures it will be exposed to on the wall of the home. Assuming a temperature differential of 50F with a install temperature of 60F, the sill and trim pieces will want to move about 1/32″ in each of the joints.
    3) There are numerous sealants, adhesives and combination products that work well with cellular PVC trim and wood. One product that acts as both a sealant and an adhesive while providing unmatched flexibility is NPC Solar Seal 900. The product bonds well to PVC and wood, and performs exceptionally well in the field. This only issues are availability in your market and workability. You may find it difficult to work with if you’re use to applying latex and silicone sealants. The second would be Quad Sealant by OSI. You’ll find this at just about any local lumber dealer. It’s also solvent based which is ideal for bonding to cellular PVC. It has very good field performance characteristics but like NPC, you may find it a little more difficult to work with than non solvent sealants. Finally, consider polyurethanes like Duo-Sil by Siroflex or PL S40 sealant by Loctite.
    4) No need to treat the cut edges any differently than the smooth sealed surfaces. If you want to reseal the cut edges consider sanding them with 220 grit sandpaper stepping down to 320 grit. If they are still not as smooth as you’d like, wipe the cut edges with acetone.

    Hope you find this of help. Have a nice weekend.


    • John Broderick

      Hi John,
      Thanks for your detailed reply.
      I went ahead and got most of the job done this weekend.
      I have two more questions.

      1. Is it vital to put caulk/sealant/adhesive between the sill and sill nose?
      I went back at looked at a PVC sill I put in a few years ago and the caulk in this seam got very dirty/mildewed (its unpainted). To get it clean I had to scrape away all the visible caulk, although I assume its still watertight from the caulk that is hidden below the surface. I don’t know how dirty it will get again.
      Is there a particular type of caulk that I should use if I don’t intend painting? Is this an advantage of painting, that its easier to keep clean?

      2. How does one cleanup the excess caulk (OSI Quad max, in particular) from all sides of the PVC?
      I used rubbing alcohol and this eventually worked on the face of the trim boards. However the edges are giving me more trouble.
      For the particular brand of trim board I used it looks like the edges are not as smooth/finished as the faces, even though its marketed as S4S. What can I do to get the caulk off these edges and make it look as good as the face? Perhaps I should just apply white paint over it (kinda defeats part of the purpose of white PVC trim)?
      For the next window I’ll need to find a truer S4S trim board.


  102. Linda

    Hi, John –
    My husband and I have a two story stucco house in southern Florida and want to have the windows picture framed with PVC trim before the house gets painted. The windows are inset and we can’t put any trim on the returns because we need the width for our hurricane shutters, which we put up every fall. A local “expert” said we absolutely should not put PVC trim on the stucco as we’ll ultimately get water incursion somewhere behind the pieces and then we’ll get water and mold in the stucco and concrete wall. Also he said we’ll have to re-caulk the trim every two years. After thinking about it later I realized we have five PVC flower boxes screwed into the walls under some windows and we’ve had no problem with water or mold behind them for years. So, now I need to know from you: Should we be concerned about this? If not, what stipulations should we give the carpenter about how he should install the PVC on our stucco walls? Thanks so much for this site and the benefit of your vast knowledge on the subject.

    • John Pace

      Good morning Linda:

      Sorry for not responding sooner. I wanted to check with contractors in the Florida market to be sure my response was accurate and to make sure I wasn’t missing anything. We have projects throughout Florida where shutters, trim, mouldings and other cellular PVC elements have been attached to stucco without mould growth issues. As for sealing the trim to the wall, I recommend NPC Solar Seal 900. It’s the best sealant I’ve found for just about any substrate. I am certain you will not be caulking the window trim every two years if you use this sealant. Contact the manufacturer at 708-681-1040 or e-mail them at NPC Solar Seal® #900 has an expected life of approximately 20 years. As for installation guidelines I’ve been told PVC trimboards need to be secured with Tapcon fasteners in a exterior stucco wall application. I have a call into one more Florida builder to confirm this and will get back to you today with his recommendation. Again, sorry for the delayed response.

  103. John Pace

    Per your questions:

    1) I think it’s vital to seal any joints around a window to prevent moisture infiltration but I’m not a window expert.
    2) I don’t know of any sealant that skims over fast enough to prevent the pickup of dust and dirt. Yes, the advantage of painting is it limits the amount of airborne dust and dirt picked up by the sealant and also seals any cut edges which are prone to pick up airborne contaminants. This is why I mentioned sanding any cut or rough edges to reduce dirt pickup and wiping them down with acetone.
    3) Clean any tools and uncured sealant residue immediately with acetone or toluene. Note this is for “uncured” sealant. I recommend a stronger solvent than paint thinner. Keep in mind solvents will take away some of the gloss or sheen from the face of the boards. Cured sealant must be cut away with a sharp-edged tool or sanded off. If the sealant on the face is cured you have a problem. You’ll have to take it off without abrading the thin dense surface. Once you expose the core of the trim I believe painting is your only option for achieving a nice trimboard finish.
    4) I agree you should have selected a board with better sealed edges. Although many builders and remodelers feel all PVC trimboards are the same that’s not the case. There are not only differences in the finished product such as dimensional tolerances, quality of the finished surface, and core consistency, but also differences in chemical composition that affect the physical characteristics and field performance of the product.

  104. Rich

    Does pvc have compressive ability? If I put a chunk under a porch post to keep the post end grain from contacting the cement, would it withstand the weight of a porch as well as lumber would?

  105. John Pace


    Cellular PVC does have compressive strength. Two things to keep in mind. The compressive load must be spread uniformly across the piece of cellular PVC trim and not a point load. Secondly, the compressive strength varies by product thickness. For example the ultimate compressive strength of 1/4″ Versatex cellular PVC trim when tested under ASTM D695 is 6500 psi. If you use a factor of safety of 2 the allowable load would be 3250 psi. If you used 3/4″ thick Versatex cellular PVC, the ultimate compressive strength is 2000 psi. Finally, if you decided too use 1 1/2″ thick Versatex cellular PVC, the ultimate compressive strength is 600 psi. I can’t speak for competitive product values which is why I gave you those for Versatex. Hope you find this of help.

  106. Tor Torkelsen

    I have no question, they have been answered on the Q&A’s. Thank you for sharing your extensive knowledge of Versatex products. I am a builder and my supplier only sells your product and I have used for many years. The product is excellent and your tips have educated me to improve my performance skills with your product. Thank you again!

    Tor – Builder on Eastern Long Island, NY

  107. John Pace

    Good morning Tor:

    Thank you for the kind words and for your support of our product. As I told Mr. Katz, I enjoy responding to all the questions I receive. I know at times I’m a bit tardy on my answers and I apologize for not responding in a more timely fashion. My goal is to help, as best I can, in educating builders like yourself as well as contractors, remodelers, architects and even homeowners on what cellular PVC is and best installation/fabrication practices. There have been times where a question has stumped me or I’m not 100% sure my response is the right answer. For those times, I rely on a network of people like yourself to help with the response. Again thank you Tor and have a Merry Christmas with family and friends.


  108. Michele Rubin

    I saw this trim at the local HW store while I was looking for some wood and thought it might work for my purpose. I want to use it as a canvas for art. It is lightweight, very smooth, and straight! I would need to cut and seal the edge and, while I read the above comments I did not see anything that told me whether I could seal the cut edge to look as good as the manufactured edges. For a canvas, I need all 4 edges to look the same. Is this achievable? thanks!

  109. John Pace

    Good evening Michele:

    First, cellular PVC is excellent for accepting inks, and house paints so I’m sure it will work fine in your application. However, keep in mind different cellular PVC’s have different gloss levels on their sheet surfaces some higher than others. This may affect the adhesion of the paint to the sheet. Be sure to check this before purchasing any cellular PVC sheet. Now to your question, there are two ways to seal the edges of the sheet for your application. The first way is to sand the edges with a 3200 grit sand paper and then wipe the edges down with a solvent (toluene) with will microscopically melt the cells further sealing them. However, you’ll never seal the edges 100% using this technique. The second method is to band the edges much like you would when edge banding a piece of veneered wood (counter top or table top). You can buy edge banding any width, any color and in a PVC substrate. There are several videos on You Tube showing you how to edge band with or without a machine. Good luck with your project. I’d enjoy seeing a sample of your artistry on PVC sheet when finished.


  110. John Pace


    Typo errors. 320 grit sand paper not 3200. which will not with will. My apologies.


  111. Ralph Shewell

    Hi’ I nail gunned PVC to the painted wood surface of the window frames of a 100 year old house, I did not glue them to the surface, only nailed them. I suspect I need to caulk where the PVC meets the wood so that moisture does not get trapped behind the PVC. What is the best caulk to use for this?

  112. John Pace


    Some of the better sealants between wood and cellular PVC are polyurethane sealants like PL Premium Polyurethane sealant, Quad by OSI, Geo Sil 2300 and my personal favorite since it acts as both a sealant and adhesive, is made in the USA and offers a 25 year warranty is NPC’s Solar Seal 900. Do not use acrylics or silicones.


  113. Brian Bremenstul

    John, I apologize if you’ve already answered this question, but can the PVC be painted with white, oil-based enamel? I am installing new window sills and attaching with screws or nails but prefer to paint in oil; same as windows. Thank you for the information.

  114. John Pace

    Good evening Brian:
    No need to apologize, I enjoy hearing from builders, contractors and remodelers. PVC can be painted with a white oil based enamel. However, you need to understand enamel paints are not as flexible as water base paints and won’t stretch to the same degree as the PVC trim expands and contracts during seasonal temperature changes. Since you are painting window sills, I’m going to assume they are no more than 4′ long. Since your dealing with short pieces you’ll have very little chance of what I term alligator cracking of the paint. So to summarize, yes you can paint cellular PVC with an oil based enamel but it has its limitations. The shorter the trim piece your painting the less likely it is to show signs of paint cracking due to expansion and contraction of the PVC trim. Hope I’ve answered your question. If I can be of any further help concerning PVC trim application or installation issues please feel free to send them to me on

  115. Joanne Jacobson

    We have PVC edging along our white kitchen cabinets (around 25 years old) that has yellowed. Can this be cleaned? painted? If so, how? Thanks!

  116. John Pace

    Good morning Joanne:

    Without seeing your edging, my guess is the product is either a rigid or flexible PVC not cellular PVC. The reason I say this is because I don’t believe cellular PVC for trim applications was available 25 years ago. The questions you’re asking are tough to answer not knowing the true composition of the edge. Here is what I would do if it were my house. I would find an inconspicuous section of the edging you can use for testing products. I would first test different cleaning products. Since PVC is comprised of 50% chlorine, I would start with any product containing bleach like soft scrub with bleach, Clorox clean-up or straight Clorox. If these don’t work, I would step-up to denatured alcohol, then a mild solvent and finally a strong solvent like Acetone. I believe one of them will clean the edging. If you want to paint the edging be sure to remove the sheen from it before applying paint. This can be accomplished with denatured alcohol. If the edging is PVC you can use an oil base or water base paint provided the edging is cleaned removing all dirt and grease before applying the paint. Since this is an indoor application and to achieve a good bond between the paint and the edging, I would recommend an oil base paint. Good luck with your project. I hope you found this response helpful.

  117. Tripp

    I need to replace three wooden 6″X6″X8′ posts under a porch roof. I am considering building these posts out of 4 1×6 made out of cellular pvc. Will that be structurally sound enough to support the weight ?

  118. Steve

    Hello – Just curious why acrylic latex paint is recommended but not acrylic latex caulk for basic trim joint filling?
    Also any recommendations on staining cpvc? Want to use for a summer kitchen. I did a test with a solvent spray stain, then used a clear topcoat a water based General Finishes product recommended for outdoor use. Test is doing well but not sure about LRV concerns?

  119. Dwv3

    Hi John

    I plan on using 3/4″×51/2× 29″ for under a porch. Substrate is 2×6 pressure treated on top and bottom. They don’t need to be too secure just looking to finish up under the porch. What is the best way for corners as I don’t plan on 45ing them.

    • Dwv3

      Sorry do I need glue for edges? Expansion gap? How many screws per board (vertically)

  120. Robert Cabrera

    Can I use PVC board instead of regular pressure treated to insulate my bay out window from the patio pavers? Unfortunately I just bought this house a year ago, and contractor who made that patio flushed the pavers and soil to the wood. Got all rotten but I replaced it an put a shower PVC liner under neath then the pvc board on top to avoid moist an humidity doing more damage. I caulked every Corner. Will this idea prevent more damage ?

  121. Deb

    I want to use an exterior cellular PVC breadboard 4×8 sheet product as a shower surround. I plan on using some type of flashing on the interior corners of the walls prior to putting the PVC sheet on just in case the caulk would ever become compromised. Is there a special type of calk I should use? The stall is 42 x 42. Do you think I will need to secure it to the walls with anything other than an adhesive? I am hoping to have as few areas for potential leaks as possible. We have well water that had a lot of rust in it before it was treated however it is now very soft and clear. Is there any reason that this may not be a good idea?

  122. Rebacca

    Hi there
    I have replaced garage door trim and seal with a PVC trim/seal product. I used stainless screws to affix the new trim, seating on wood and what appears to be a flat bed along the uneven (stucco) edge, looks like silicone caulk. It fits nicely and appears secure. I will need to patch a few areas where stucco came off with the old trim. My question is, what kind of caulk should I use to seal the trim to the structure? It will need to bond to the PVC trim, the underlying cured silicone (which extends out onto the stucco), and the stucco. I live in Las Vegas and this is a south-facing wall so it gets very hot in summer. I would like to paint over the trim and caulk with exterior latex. I noticed when starting to prep that the latex paint around the door did not adhere well to the silicone caulk used previously to seat the old trim. Thank you very much.

  123. Stan wiese

    I plan on using pvc beadboard as wainscoating and as a shower liner. I have seen it done on in a few places on the internet. My question is in the shower at this time I have unpainted ” green rock hung untapped and unpainted as of yet. The rock rests on a 1.5 inch wide strip of pvc lath strip that will be covered by the beaded panels and attached and sealed to it. The only joints in the Sheetrock are in the vertical corners and around the ceiling. What is recommended to seal the corners and the raw surface of the rock? What adhesive should be used to bond the pvc to the walls? Lastly what is the preferred method and product to seal any seams? My plan is to install the white panel and trim with out nails so I don’t have to paint it . Any room needed for expansion and contraction? Thanks in advance for your help.

  124. Tom

    It has been a warm & cold winter here in northern VT.
    A co-worker sent me this photo asking if this was a fire hazard. Obviously the siding contractor placed the pvc trim board very close to the heater vent and the sharp edge has distorted and discolored from the heat. I advised him to get it moved asap.
    My question is what are the recommended setbacks of this material from heat sources?
    Thanks for your thoughts…

  125. Bryan

    if you choose to paint Azek, how often will you need to re-paint?

  126. Anthony Johnson

    Can you use spray foam to seal around AZEK which is connected to brick?

  127. Lawrence Spoolstra

    I plan on building window trim frames with mitered corners glued with pvc cement and fastened with kreg screws,then fastening the completed assembly to a treated wood substrate with sub floor adhesive and screws only at the corners… will this work or will I need additional screws? thanks

  128. Bill Zinnikas


    Like the Comment/Discussion in #58, I need to bend a Versatex 1/2″ PVC Sheet that has been ripped to 27″ to cover the existing plywood at the inside top of the arched entryway of my home. (See attached photos.)

    I am having all of the existing exterior wood trim on my home replaced with Versatex Trimboard and want the material on the front entry arch to match (e.g., color, weathering, etc.) the new trim board. I chose Versatex because it appears to be manufactured with the free-form cooling process as opposed to the celuka-cooling process, because it doesn’t require painting, and because it should be woodpecker proof. Those little varmints have just DESTROYED the existing wood trim!

    However, unlike #58, the radius of the arch of my entryway is only 37″ (74″ across the arch). My question is how best to form a 1/2″ Versatex sheet of that width to conform to the inside of the arch. I have received a number of “opinions” from carpenters, dealers, and architects as to how best to do this. They range from “just let it sit in the sun,” to “just hit it with a heat gun,” to “use infrared propane space heaters,” to “use thinner (1/4″ or 3/8″) material.” I am looking for more definitive advice since these large sheets are expensive and will cover the focal point (entryway) of our home.

    The reason I didn’t go with the thinner material is because it is apparently too thin to effectively use the Cortex Concealed Fastening System with the PVC trim-tapered plugs (which is being used almost everywhere else on the house) and because I was told by the carpenters that S.S. finishing nails would easily pull out as/if the sheet flexes during seasonal variations in temperature.

    The installer has balked at purchasing the HeatCon Heat Forming Blanket Kit, and I’m not sure such a setup would even work on a cellular PVC sheet.

    Any advice that you could provide would be greatly appreciated.

  129. Jason

    Hello! I am attempting to wrap a 4×4 treated post on my porch using pvc trim boards. I will have to rip the boards to fit and was wondering if I need to leave a gap along the length of the seam where the boards meet at the corners. My current plan is to simply use butt joints as opposed to trying to miter 45 degree angles. I was concerned that the angles might not come out right due to variance in the 4×4 post. Am I doing the right thing here? I have not worked much with pvc before and am anxious to do it right.

    • Gary Katz

      As carpenters we always oversize column wraps, so that we don’t have to fight with the rough post. But I would definitely suggest mitering the corners and using biscuits or Dominos to reinforce the miters. Whether you’re using PVC or wood or anything, butt joints don’t look that great. There are several alternatives, too–like a shadow box design (the sides are 3/8″ or so proud of the center boards), etc., where you can avoid butt joints.

  130. Bill Zinnikas

    I posted entry #133 in the middle of June and am still waiting for informed guidance on bending a 1/2″ Versatex PVC sheet to conform to the arch over the entryway to my house. Could someone please provide same at your earliest convenience.
    Thank you in advance,
    Bill Zinnikas

    • Wm. Todd Murdock

      Hi Bill,

      I’m sorry that you haven’t gotten a response to your initial question. I know Mr. Pace has been a very busy guy (Versatex was recently acquired by Azek ) and may not have seen your post.

      The quickest way to get answers to your product questions would be to contact Versatex directly; either through their website or by telephone. I’ve attached a link to their Technical Bulletin on Thermoforming below. Page 3 briefly mentions some tips, other methods, and a telephone number and email address for technical questions.

      Good luck with you project!


      Wm. Todd Murdock
      Art Director

    • Gary Katz

      I think Todd is right! We were lucky to have John Pace write an article for TiC, let alone answer SO MANY questions himself! You don’t often see that kind of passion from the president of a manufacturing company.

      Bending PVC is a piece of cake, but you have to heat it up. We use heat blankets from Heatcon ( The blankets are expensive but that’s the best way to bring the temperature up to a consistent 270-280 degrees. We’ve used the same blankets to bend decking. Works like a charm.

  131. Barb

    Please help. We used the wrong sealant and now it has turned yellow. We don’t plan to paint. Can you recommend a product to get the sealant off.

  132. Jeffrey

    I want to use cellular pvc as a storage box and seat in a small fibreglass boat Can I attach it to the boat using fibre glass. What resins will work Vinyl Ester Epoxy? and can I just sand the parts I want to glass?