Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: braced wall code

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I think we had this thread before. Yes, the 1994 UBC Conventional wood framing
provisions for braced frame does not have a connection requirement for
interior braced frame(shear wall) to roof framing. I agree that there should
be a direct connection and I would not sign the plans if there are no
connection details. 

If the whole building conforms with the UBC Conventional framing provisions,
then there are no calcs required, no engineer required and no signature
required. But sometimes the city wants an engineer's signature or if the city
allows partial compliance with the conventional provisions with calcs and
details only on nonconforming areas, then it is up to the engineer whether he
wants to acccept responsibility(partial or full???) or not.

I use judgement on a case to case basis. It's OK for a simple house with flat
drywall ceiling(no volume ceiling) with ceiling joist and the top of the
interior 'braced walls' are connected directly to the ceiling joists(w/ 2x4
with nails to top plate and to the side of the ceiling joist) or if the wall
is between ceiling joists(2x4 flat blocking at 24" oc perpendicular and
between ceiling joist, nail the flat blocking to the top plate and the ends of
the flat blocking to the ceiling joists). Somehow, even if it does not "calc
out", this typical framing connection will transfer some lateral loads to the
ceiling joist which are connected at the ends to the exterior wall top plate
and with the rafters connected to the top plate also, and with the drywall
horiz "diaphragm", and if the interior walls are spaced evenly aall over the
interior of the house, maybe it will work. Maybe overstressed but hopefully,
it wont fail or collapse. The Code allows it and if it is considered a
standard practice in the industry, I'll stick my neck out.

On more complicated structures or if you feel that there should absolutely be
a direct connection from wall to roof, then you can detail a simpler and
easier connection without extending the wall and sheathing all the way up. I
know framers do no like this. A compromise detail I've seen on some other
engineer's plan some time ago shows 2x4 diagonals from the top of the wall to
the roof rafter at maybe 4 to 6 feet oc, nailed at diagonal ends directly to
top plate and rafter or use use 2x4 nailers  or Simpson A35 or 2x4 blocking as
required between rafters. Again it does not calc out but it's better than

I think we should work hard to make sure this ommited connection provision is
included in the next Code(if it has not been included yet).

Ernie Natividad