Cape Dutch Gable Ends

[JungleJoe]

Hi all,

An interesting one here, at least I think it is. I'm working on a home that involves "Cape Dutch" architecture, one of the features being these gable end walls that stick up above the roof plane (see picture below). My thought is that those gable walls should be balloon framed and then a regular truss will be placed on the inside face of the wall. The concern is about transferring the shear from the roof diaphragm into the wall. My thought is to provide 2 bays of blocking every 4' or so and screw the end truss to the wall. See the detail below for a similar idea except with a ledger.

Do you think they'd balloon frame the walls to match the truss profile and then build the "fancy" part of the wall on top of that? Any feedback is appreciated. Thank you!

 

[phamENG]

Well that sure is different.

Let me guess - an architect is trying to incorporate a style based predominantly on masonry construction and use it in light frame wood? At least some things are universal...

Balloon framed end walls will be the best way to go. I'm sure you'll find plenty of contractors who assure you that they can cantilever some sort of wood wall off the roof to make the architectural features work...but they can't. At least not as easily as balloon framing them. The tricky part will be the curved bits that are just hanging out there.

Your shear transfer makes sense to me.

With those parapets, you may need something a bit more robust than a pair of screws at 16" on center in withdrawal to resist the suction and parapet wind pressures.

 

[SJBombero]

It is not uncommon for truss fabricators to provide an extra truss as a nailer that is fastened to the balloon-framed wall. If that dummy truss was designed as a collector, you could take advantage of both top and bottom chord connections to the wall for shear transfer.

 

[dhengr]

JungleJoe:
I would balloon frame the upper story, plus, maybe with 2x6’s instead of 2x4’s, from the second fl. framing to the ridge. You just will not be able to make such random canti. parapets work atop the roof plane, no matter how good the builder thinks he is. What is the exterior cladding going to be, and how does that detail in? Show a real full height elevation and sections through that gable wall so we can get some idea of the real proportions, and the intended framing at the various levels; 2nd fl. framing and gable wall at the eave elev., at a max. parapet canti. ht., at the ridge. Someone has to study this crap or it will end up being a cobbled mess. What does the Arch’s. wall cap detail look like, or do we have to figure that out for him too? That cap should maybe be made in pieces, in a sht. mtl. shop, of shingle lapped pieces, of soldered copper, which have a drip edge on each face of the wall; and are short enough to be properly fitted, adjusted, and tolerate some movement in all directions. The Arch. should draw what he wants, in shape, on grid paper, at a large scale, so the builder can use this to cut plywd. sheathing for both faces of the wall above the roof. This plywd. sheathing edge will define the gable shape, with due consideration for proper stud framing and blocking at the various transitions. You lay out the stud spacing, on a dimensioned elevation, to be sure you get what you want, and to show all the blocking you want. On the ext. the sheathing is staggered and tied into the rest of the sheathing, with joints blocked. On the roof side the sheathing should be tied into some sloped blocking at the roof plane. Now, you have a canti. plywd. box beam for the parapet. Pay particular attention to flashing and drainage, all around, don’t just leave that to the roofer.