I wanted a BIG entry door for my new shop—at least 4/0 x 8/0—so I wouldn’t have to fight carrying materials into the shop. Sure, I installed a 12-ft. wide custom roll-up right next to the entry door, but I open that ‘garage door’ rarely, especially in January, February, August, and September, and barring a big order of sheet goods, I open the roll-up door just to take finished projects out of the shop. But the main door I’d be opening every day, all day long, and I knew I would never find the door of my dreams on a shelf at a store. So I built the door and the jamb myself, as one big pre-hung unit.
Rather than working with solid 12/4 stock for stiles and rails, so that I’d end up with a 2 1/2-in. thick door, I chose to laminate the stiles and rails for the door from 5/4 pre-finished rough-sawn beetle-kill pine—the same material I used for the trim and siding on the shop and house. And I didn’t start by laminating the stiles and rails—the way all woodworkers have been taught. I didn’t have the machinery for that, let alone the lumber, let alone the patience or the know-how!
|Instead, I built two 5/4-in. thick doors—using pocket-hole joinery on the backside of the doors, and then I glued them both together with PL Premium Advanced. Don’t laugh. It worked.|
I started by laying out the door on a story pole, then I cut vg Douglas fir for the upper panels.
|I rabbeted the interior edge of all the stiles and rails and cut all the panels with a small Shaker Style raised panel bit…|
|and then I prefinished them with several coats of pre-cat varnish, which gave them a little shine and made them resemble glass panels.|
|Next, I ripped and glued up the four rough-sawn pine panels—two for each door.|
|I took that material from ship-lap siding and ripped off the rabbets and resized the boards so that they’d be approximately the same width in each panel, then I used a story pole to layout mortises for Dominos.|
|I used 5x30m tenons and cut the mortises one-step wider than necessary, so there was plenty of wiggle room when it came time for glue-up and assembly.|
|I didn’t want the panels to separate, and I had plenty of dominos on hand, so I reinforced the joints a lot more than necessary.|
|The panels were barely 3/4 in. thick, so I used a lot of clamps to keep them flat during the glue-up.|
Stile and rail joinery
With all the panels drying, I cut the stiles and rails and used 12x100m dominoes for all those butt joint connections. The Domino XL is a door-making machine—I can cut mortises and assemble the stiles and rails for a door in less than 30 minutes, something I never could have done before. The XL has three registration pins, so you can pick which ones you want to use, and two different width settings, which—along with different domino sizes, provides plenty of options for any door size.
|For some of the mortises—whenever there wasn’t an edge to hook an index pin on—I used the center mark on top of the XL to align the cutter with the mortise location. The center marks are easy to see through the plastic guide.|
|But whenever possible, I prefer to use the index pins. They’re extremely accurate and difficult to screw up. Plus, you can check that the pin is located correctly by looking down through the delta-port in the top of the XL.|
|I cut all of the mortises for the stile-and-rail frames tight; there was no wiggle room during installation. But careful layout and precise machining made the job very, very easy.|
|With a little convincing, the frames came together quickly, tight and clean.|
I used pocket screws to secure the muntin bars between the upper panels.
Once the glue dried, I rabbeted the inside of all the stiles and rails with a 3/8 x 3/8-in. rabbeting bit, so that the matching rabbet left on the sides of the panels—cut by the Shaker Style raised panel bit—would seat in the stiles and rails.
|Then I secured the top panels with only two pocket hole screws—one at the top, and one at the bottom.|
|Next I installed the lower pine panels, using a minimal number of pocket screws, too—just something to hold them in place until the two halves of the door were glued up.|
I didn’t glue the panels into the stile and rails. I checked the moisture content of the material carefully before cutting even one piece. The moisture content of the 5/4 stiles was close to 12%, but the panels were pretty dry—around 7%. Still, I worried about excessive shrinkage, especially on the inside of the door because I’m a real wuss—I get cold easily! I heat my shop with firewood and sometimes it’s really cooking in there, which probably drives the moisture content well below 7% , and I didn’t want those wide panels to shrink and crack.
Laminating two door halves into a single door isn’t a common door construction technique—you won’t find it in any millwork catalogue from the early 20th century, and you probably won’t even find it in a contemporary magazine article, probably because the only reason I think the technique works is because of modern adhesives. I’ve never seen PL Premium Advanced adhesive fail on a well-prepared joint. And I used a LOT Of adhesive to glue the two halves together!
To make sure the door stayed relatively flat, I clamped it right to my work bench. I had no expectations of a perfectly flat door—it’s always been my job to hang doors so they look flat when I’m done, which I knew would be even easier on this jamb because the door stops were not rabbeted into the jamb legs but applied after the door was hung.
The door frame
I’ve always enjoyed building solid door frames with notched hardwood sills—whether for single doors, for pairs, or for mulled units with sidelights. Whenever you use a solid sill in a door frame, the built-up jamb is almost indestructible—it won’t wiggle around much and is easy to install. The trick is not being confused by the details.
The width of the sill must be equal to the thickness of the wall (width of the jambs), plus the thickness of the exterior casing or brickmold, plus enough for a good reveal between the brickmold and the leading edge of the sill—so add a little extra, like 1 in.! You can always rip the front nose of the sill down later, if you think it’s too wide.
I’d start by cutting the sill too long, too…especially if I’m not sure how wide the casing or brickmold might be (trust me, it’s easier to cut the ears or horns off a little later than it is to add on to them later!). The only known dimension might be the width of the door, so start with that, then add for casing on both sides of the jamb. I added 12 in. for the casing, which I thought would be plenty. Of course, when it came time to cut the trim, we all decided the tapered butt end should be even wider, so I had to glue extension blocks on to the horns. But let’s forget that part. Just cut the rough sill long, then run it through a surface planer so that there’s a 5-degree slope right up to where the door will sit—leave that area, in this case 2 1/2 in., flat.
Next, layout and notch the sill.
The depth of the notches is exactly the width of the jamb legs. And the measurement, from shoulder to shoulder, is exactly the width of the jamb’s I.D., which in this case is also the exact length of the head jamb (because jamb legs are not rabbeted!). That makes all the arithmetic very easy, which is important for me—I make a lot of stupid mistakes. Cutting the notches is the easy part.
|If all the parts are cut properly, assembling the frame is easy—another reason I like solid-wood sill frames. Simply clamp the jamb legs right to the notches in the sill and drive screws through the legs into the sill.|
|Do the same thing at the head jamb.|
Be sure to read this article for tips on installing the pre-hung unit.