Framing Rake Walls
Rookie framing question:
I’m a little confused with code (2015) whether I need to:
A. balloon frame the rake wall so that there is no hinge point, or
B. have a horizontal top plate and then fill in space between top plate and rafter with short studs?
It appears that I can use either approach, but option B requires installation of a product like Simpson coil straps. Is this correct?
A few details:
~16’x16′ lean-to roof, single story, extending from existing house,
~8’6″ wall height at short end
1/12 pitch roof
sloped ceiling on interior to underside of rafters
Zone 6a, not high wind
It’s such a short section above where the top plate would be so I was just planning to do the “fill-in” studs.
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Replies
Either way can work. I usually balloon-frame tall walls because I don't like dealing with hinge points; you just need to add fire blocking so no bays are more than 10' high. In your situation the hinge probably wouldn't be a problem either. I don't know of a reason why Simpson straps would be required for your situation. If it were a high-wind area they might be needed for uplift resistance.
Thanks Michael, much appreciated. I'll likely just go with the non balloon option since it's such a short rise. I'll be sure to bridge the transition well with sheathing.
I just didn't want to have to re-frame this area because I missed something code-wise.
If you have any doors on the rake walls, do balloon framing. It will make a stiffer wall because the king studs will be full height, and you'll notice a clear difference when the door shuts.
You're doing a low-slope roof (less than 5 degrees) and a fairly short wall height, so it's pretty easy to just balloon frame it and move on to the next task. That next task won't be cutting short infill blocking above the top plate, and removing and reinstalling half of it when it splits during nailing.
R602.3 in the IRC (2015) does not allow for "stacked" framing:" Studs shall be continuous from support at the sole plate to a support at the top plate to resist loads perpendicular to the wall". The only framing members allowed to not be full height are jacks, trimmers, and cripples at openings. This is low-hanging fruit for inspectors to find, just my 2 cents.
I try to frame rake walls in place whenever possible as opposed to building them flat and standing them up. A three dot laser to plumb up and measure the "long" edge of the studs makes quick work of it after the bottom plate is laid out, and after the first three or four you can use the variance to cut the rest.
Good luck with your project.
Mike
Mike.
Our code here in BC has a similar provision:
9.23.10.4. Continuity of Studs
1) Wall studs shall be continuous for the full storey height except at openings and shall not be spliced except by fingerjoining with a structural adhesive. (See Note A-9.23.10.4.(1).)
Thanks everyone, great feedback.
Mike J: Agreed, that's the code section that I was concerned with.
Chrisd: Great point with the door, I hadn't really considered that.
I'll have to reconsider and likely chat with my code guy. I know having stud continuity would be the preferred method.