Co-written by Gary Katz
Over the years, several articles on eave returns have appeared in the Journal of Light Construction and Fine Homebuilding, and extensive discussions have occurred on website forums, too. But something about the details in those articles and discussions always seemed missing or confused. In 2007, Get Your House Right (GYHR) was published, and finally carpenters and architects had a reference that filled in the missing details and explained basic rules and proportions for eave returns. Understanding and following the advice in that book isn’t always easy. In this article, we’ll examine and expand on those details, and we’ll illustrate one step-by-step construction approach for a poor man’s return, too.
We’ve been working on this article for over three years. Our first SketchUp illustrations—early attempts to follow the rules and proportions laid out in GYHR—date back to early 2010. Many other stories distracted us during the last three years, but we always returned to this one, drawn by the multiplicity of lessons learned through studying and constructing elegant eave returns; and we were also drawn by the challenge—designing and constructing proper eave returns is not a simple task.
Well-designed eave returns seem rare today—maybe because most of them are designed by architects and carpenters who don’t know any better. And we’ve all been guilty of that! But if you keep your eyes open, there are some good examples out there…
Before we get to that, let’s define the difference between two historical examples—the classical return and the poor man’s return.
A classical eave return is based on a pediment, like this example.
Though this a true pediment, it has the appearance of a classical eave return because the break in the horizontal entablature occurs above what would be a vertical column, and the crown molding splits at the fillet as it turns the corner. The cyma portion of the horizontal crown miters into the raking cyma, while the cove portion continues horizontality and miters around the return. This type of detail requires two separate crown profiles: one for the horizontal eave and one for the rake. While the horizontal eave crown is usually a standard profile, the required raking profile will be different for every roof pitch.
Also, notice how the projection of the soffit, measured from the nose of the cove molding to the back of the corona, are balanced perfectly—even the modillion blocks turn the corner around what would be the pilaster, so that the soffit size is exactly the same.
|Trying to replicate this transition using only one crown profile forces the eave crown out of position. On a roof with a steep pitch, the eave crown can become almost horizontal—and this on a home in Providence, RI built in the 19th century!|
Not all classical eave returns were built in the Georgian or Federal styles. Many Victorian homes include them, too, like this example from Santa Cruz, CA on an Italianate home.
The design compensates for the deep eave overhang by shortening the length of the eave return roof. Though the soffit isn’t ‘balanced’ equally on both sides—the soffit on the end of the return doesn’t match the depth of the soffit on the eave—the length of the corona fits well beneath the proportion of the gable.
Poor Man’s Returns
The added cost of custom molding profiles, as well as the extra labor required for the intricate cuts involved, brought about a less expensive detail called “the poor man’s return.” This type of detail wraps the horizontal eave crown around the return and lets the raking crown simply resolve into the return roof or “cap.”
Poor man’s eave returns come in a variety of stiles.
|One good example is on Jed Dixon‘s 1860′s New England Farmhouse. As Jed says: “The poor man’s return on my home really dates from around 1816, but out here in the rural country, carpenters were a little behind the times. I’m sure the carpenter who built this return had a dog-eared and finger-stained pattern book.”|
GYHR explains how important it is to use the same eave soffit depth on both the face and the end of the eave return (pg. 203), though the projection on the face can be up to 50% less than the eave. Reducing the projection to zero also reduces the classical appearance of the return.
|From the opposite side of the continent, we can see an example of a Victorian poor man’s return. The same technique is used to resolve the problem of the raking cornice, but it also incorporates a decorative bargeboard and brackets.|
The Bad & The Ugly
We all know that just because something was built a hundred years ago, doesn’t mean it’s a model of perfection. Carpenters are carpenters, after all—there are good ones and there are mediocre ones.
Creating an elegant transition between an eave detail and the details on the gable end of a building really isn’t anything new. Unfortunately, the mass production of homes in this country has introduced some design shortcuts. Although we see them often, they just don’t look or feel right.
The Pork Chop
A common detail that’s seen frequently today is to simply avoid the difficult rake-to-eave transition all together by creating a triangular box on the gable end.
Steep Return Caps
The eave return roof or “cap” on most contemporary examples are often much too steep. The cornice is supposed to be the architectural detail that is highlighted—not the roof. Ideally, the cap on the return should not be visible from the ground. It’s simply there to shed water.
While commenting on this common contemporary design practice, Steven Mouzon, the author of Traditional Construction Patterns, puts it very bluntly:
…It should come to no surprise then, that the overheated, ill informed attempt at traditional design on the front wall of a ‘McMansion’ would take an element that should be invisible and morph it into a design element (pg.190).
The proportions of an eave detail have a major impact on how the roof visually sits on the building. It’s important to not only get the eave sized correctly for the building, but also to make sure the individual parts of the cornice are sized properly.
The soffit depth on both sides of an eave return should normally be balanced. In most cases the corona projection on the return end should be equal to the projection of the eave. However, there are situations that may require shortening the projection on the return side, like the Italianate example we shared earlier. GYHR recommends not reducing the return projection by more than 50% (pg. 203).
|It’s not uncommon today to see eave returns that end abruptly…|
|…with no corona projection at all on the return side.|
Interpreting Get Your House Right
Architectural design can be very creative, but some details, especially those found on classically inspired homes, don’t lend themselves very well to creative interpretation. Carpenters can avoid some embarrassing designs if they rely more on classical examples than on their own imagination. Let’s work our way through the rules and proportions in GYHR and you’ll have a whole new appreciation for the effort that goes into a successfully designed poor man’s eave return.
Eave return design begins with the following simple proportion: The cornice height should be 1/15 to 1/18 the building height.
According to GYHR, the frieze is often included in that calculation on frame buildings to lighten proportions; on masonry buildings, the frieze is often omitted (pg. 201). Pay close attention to this detail because it’s the only area of ambiguity we found in GYHR, and it forms a critical part in the overall proportion.
If you include the frieze in the cornice design, as GYHR suggests, then the height of the entire entablature (frieze + cornice) will be 1/15th to 1/18th the height of the wall. If you don’t include the frieze in the cornice design, then the cornice itself becomes taller, and it projects farther. This critical judgment has a profound impact on the appearance of an eave return!
In our example we chose not to include the frieze in the cornice height because both the projection of the cornice and the height of the cornice allowed us to use standard size moldings. Plus, the end result was more pleasing, more common to what our eye expected. We used a 9-ft. building (a typical one-story), and a 1/18 ratio: 9 ft. = 108 in. 108 in. ÷ 18 = 6 in. (cornice).
Once the height is established, proportions for each individual detail—including the size of each molding and the projection—can be set.
Setting out the Box Eave
GYHR includes several different box eave designs along with their proportional divisions (pg. 201, figure 10.9). The example we chose for this article was the most ornate. It includes crown and a frieze, and the proportions are determined by breaking down the entablature into seven equal parts.
The cornice has four parts and the frieze has three parts. Because the cornice height we’re using is 6 in., each part equals 1 1/2 in. Since the crown is 2 parts, it should measure 3 in.; the corona is one part, so it measures 1 1/2 in.; the bedmold, at 1 part, should also measure 1 1/2 in.; and the frieze (3 parts) measures 4 1/2 in.
Of course adjustments often need to be made, especially because of stock molding sizes. In this article, we chose to use PVC trim for the whole eave return. PVC trim is a good choice for an ornamental detail that is completely exposed to the weather, and especially for pieces that will come in direct contact with the roof surface—wood trim must not be in contact with any roof surface. Nearly all of the moldings available fit perfectly with the proportions of our seven-part cornice, except the bedmold, which doesn’t quite measure up to 1/1 2 in. in height.
Eave Return Length
There are definite rules that apply to the eave return length, with the proportions determined by the length of the return frieze. According to GYHR, the frieze length should be equal to or up to 1 1/2 times the “overall height of the cornice”—which includes the entire entablature (pg. 203). That allows for some wiggle room, thankfully!
For this article, we stretched the length of the frieze to the maximum allowable dimension so that the raking frieze would resolve into the eave return roof before the hip return, which makes it much easier to cut the raking frieze!
A second option would be to adjust the size of the raking frieze to meet the peak of the return hip roof—just don’t let the frieze get smaller than the corona. In some situations it may be necessary to use a combination of extending the return length and reducing the size of the raking frieze.
We did make one design decision based entirely on ‘finish carpentry experience’: we used a 15-degree pitch for the slope of the eave return roof. This allowed us to take advantage of the scale and detents on the saw and easily reproduce the exact angle on various components during the build. According to GYHR, the maximum pitch for the return should be a 3:12 (14.04 degrees). Increasing the pitch by less than one degree has no noticeable impact. However, this is a ‘rule’ that carpenters should remember: do not match the slope of the return to the slope of the main roof: an 8:12 pitch on a return is much too steep.
Work from the Finish Back to the Rough
As Jed Dixon is fond of saying, you always have to start with the finish and work back to the rough framing. Which means you always have to start with a good drawing (and story poles help, too!). In this case, a drawing is essential, before the roof is framed, because the rafter tails (the length of the overhang and position of the plancher cut) define the final proportions of the cornice.
If the roof is framed properly, the foundation of the eave return is determined by one single backing block. We’ll call this the primary block. Cut that block precisely, and the entire job flows easily; cut that block wrong and you’ll be on a ladder with a reciprocating saw.
|To determine the size and shape of the primary block, I started with a full-scale drawing.|
|According to the drawing, the total run, from the tip of the crown to the peak of the hip, is 7 in. Using a construction calculator, a 7-in. run with a 15-degree pitch will have a total rise of 1 7/8 in.|
|I marked that dimension on my full-scale drawing.|
|Then I struck a line at the slope of the roof—the underside of the sheathing.|
|The green rectangle describes the exact size and shape of the primary backing block.|
|I cut the block to length and ripped it to width and at a 15-degree bevel.|
I laid out the 15-degree pitch using a calculator, not a protractor. If you want to control your future miter angles, do not use a protractor—they’re not accurate enough.
With a 4 1/8-in. run and a 15-degree pitch, the rise will be 1 1/8 in. I made that cut with a track saw.
|The next steps were simple. The soffit miters around the bottom of the eave return. Because the fascia (corona) includes a groove to accept the soffit, the soffit must be cut about 1/2 in. long.|
|I installed the fascia, mitering both outside corners. These were simple cuts made on-the-flat at a miter saw.|
|I did the layout for the crown molding carefully, both at the top and the bottom of the crown. It must plane out perfectly beneath the sheathing. I used the top layout line to position solid continuous backing.|
|I installed the crown molding. The poor man’s eave return makes installing the crown easy.|
We used a Construction Master Pro and BuildCalc for this article. Both are handy tools, but BuildCalc also provides a digital window where all the necessary measurements and calculations can be viewed simultaneously, and it calculates advanced hip roof functions, which makes cutting the eave return sheathing much easier. Let’s walk through those calculations now, before making any cuts.
First, enter the run and pitch of the eave return roof. Then hit the Hip/V button and BuildCalc provides a new window with advanced features that make this job much easier.
The sheathing must be cut for a regular hip on the left side, where the eave returns to the gable wall; it also must be cut for an irregular hip on the right side, where the 15-degree pitch eave return tucks under the 8/12-pitch main roof. BuildCalc displays the sheathing angles and hip backing angles required to cut the sheathing for the roof. We can save the step of converting those angles into miter saw settings for our small roof by using the purlin miter and bevel settings that are displayed.
For the regular hip side, press the Regular Button, and press the Miter Saw button. The miter and bevel settings for cutting the roof sheathing on the miter saw can be found by referring to the “Purlin” angles.
For the irregular hip, press the Irregular Button and the Miter Saw Button. You’ll also need to enter the pitch of the irregular or Minor Pitch. Remember, the eave return roof is the roof you’re really working on, so that’s the Major pitch. The miter angle for the sheathing on the right side is the Major Purlin Miter Angle: 21.22 degrees. The required bevel angle is a little more difficult to visualize since the return roof doesn’t miter into the main roof on this side—it tucks under and butts against it. The angular difference between these two roof planes is called the dihedral angle, and it is the bevel angle required for this joint.
To find the miter saw setting that corresponds to that angle we need to subtract 90°:
143.48° – 90° = 53.48°
This bevel setting is beyond the capacity of most miter saws. A few passes with a block plane or some work with a sander could tune this joint, but we cut it as steep as the saw would allow and left it. After all, this joint will be nine feet in the air and hidden by the drip edge!
With the sheathing angles for both sides, it’s pretty easy to cut and even preassemble the eave return roof.
|With the 1/2-in. PVC ripped and beveled, I started by cutting the irregular side at a 21 1/2-degree miter and the maximum bevel my saw could cut. Not much of that joint is visible, so a perfect fit isn’t necessary.|
I checked the fit, figuring I could scribe or adjust the miter angle if necessary. But it wasn’t necessary. The miter angle was perfect. A real first for me. In the past, I’ve hunted and pecked for that angle, which is why I always start with a long piece of material.
|With the irregular side tight, I marked the length at the long point of the regular hip.|
Years of cutting crown molding have taught me to always cut the self-return cap first—which is really what the hip return is—otherwise, the piece might be too short to hold safely in the saw.
|The short return piece is simply cut so that the miter daylights out to zero.|
Then I swung the saw and cut to my measurement mark—the long point of the miter at the short point of the bevel:
|The long point of the miter because I marked the board at the crown molding, not the wall; the short point of the bevel because I marked the board on the bottom of the sheathing.|
I preassembled the PVC sheathing using 2P-10 glue, the same way I preassemble everything for a presentation/demonstration. If I were working in the field, I’d use PVC cement or Bond-and-Fill.
|After the glue set, I scraped off the excess.|
The sheathing fit perfectly the first time. As Mike Sloggatt likes to say, “Always trust the math—it’s never wrong unless you enter the wrong numbers.”
Cutting the Raking Cornice
Cutting rake angle miters might confuse you, but keep your eye on the prize—don’t be distracted by something that seems hard and isn’t.
All of the rake angle moldings are exactly that: moldings that are attached at the angle of an 8/12 raked roof, which has a 33.69 pitch. That means they must be cut with a 33.69-degree miter angle at the eave return roof. You can’t cut that angle on a miter saw. The saw won’t swing far enough to create such a sharp angle between the blade and the fence.
So you have to use an acute angle jig.
|With a 45-degree jig as the new fence, every degree you swing the saw toward the jig is like subtracting one degree from 45 degrees.|
|So swing the saw to 11.31 and you’ll be cutting a 33.69 angle.|
|And don’t forget to tilt the bevel to 15 degrees for the slope of the eave roof!|
Cutting rake molding is just like cutting baseboard that goes up and down stairs—the molding must lie flat in the saw; the base of the saw is the wall, the fence is the roof. So all the molding must lie flat against the base of the saw except the soffit—that’s the roof!
|You have to stand the soffit up flat against the fence (if your saw can cut that tall).|
|You can also lay that material flat on the saw and cut it at a 25.78-degree angle—that’s the “Minor Sheathing Angle.”|
All of the remaining pieces (corona, frieze, bedmold, and crown) should lay flat against the base of the saw.
|First I installed backing for the raking cornice. The dimension of the soffit backing is identical to the depth and projection of the eave cornice.|
|Next, I tacked on the soffit board…|
|then the frieze…|
|then the corona…|
|then the crown…|
|…and finally the bedmold.|
Those of you paying close attention will have noticed that this article doesn’t include flashing! Obviously, even though the eave is made entirely from PVC, flashing would still be required from the sidewall to the eave roof. But with so many creative carpenter/readers around, I’m sure we’ll get plenty of comments about how to flash an eave roof properly.
One last word, both about eave returns and about the purpose of THISisCarpentry: This type of return doesn’t go with every architectural style. Know the style you’re working with, as Stephen Mouzon writes in Traditional Construction Patterns:
Buildings that speak an existing architectural language should take great care to follow the prescribed eave proportions of that language. In other words, be fluent in whatever language you choose (pg. 200).