House Framing: "Let-in" braces

[Stephen Tashiro]

On the web, the traditional house frame has 1x4" diagonal "let-in" braces sweeping down the wall from the corners of the frame and recessed into the studs. I have often seen diagonal braces put on frames, but I think these were temporary bracing.

Are "let-in" braces routinely used nowadays ?

I'd think that any carpentry operation that involves notching out lumber is labor intensive. How are the notches cut when let-in braces are used?

[Joe Pelonio]

I have (back in the late 60's) done framing with braces, and used a radial arm saw to miter the ends of the 2x4 braces to fit against the studs. We toe-nailed them, did not notch them into the studs. They are still required but there are metal ones available such as Simpson RCWB but check local codes.

More recently, in earthquake country (I come from CA) it's important to place a triangle of 5/8" plywood on the lower corners at the foundation for additional strength

[Ken Garlock]

Hi Stephen.

With the advent of OSB and/or plywood, the let-in bracing is a thing of the past. Four by eight foot panels when copiously nailed to exterior wall studs will be stronger than let-in 1x4 or 2x4s.

[Ben Franz]

Let-in braces are old-school, to say the least. Modern design uses plywood or OSB solid panels to provide lateral bracing of stick framed walls. Simpson makes a metal strap with a short right angle leg designed to be "let-in" to a saw kerf that mimics the function of a 1x4 brace. I haven't seen a set of plans with this brace in 20 years or more and don't know if it's even available now. I don't think pieced in braces like Joe mentioned would do much since they couldn't resist a tension load IMO. Solid sheeting is much stronger and provides better support for the exterior finish.

[Jack Wilson]

Stephen I am on the opposite side of the country from Joe, I am in NY. Here we generally do not use the braces, but consider the plywood or OSB sheathing to be a structural member of the wall, however the wooden "Let In Braces" are not that labor intensive, and I have put more than a few in at times as it really does stiffen up the wall.

The Simpson steel braces only require 1 saw kerf and then you insert the steel track into the kerf and sheet over it. However if you wish to install the wood braces...

Build your wall, and while it is still down square it and make sure that at least your outside studs and plates are straight. Then lay your 1x or 2x brace on the wall where you want it, and tack it there. Next quickly run a pencil down both sides tracing its location and then remove it. Next set your circular saw depth to match that of the brace. Now cut thru next to your line on the inside, (where the brace goes), so two cuts. Lastly remove the cut out section with a hammer blow and set in your brace. I expect you will need to cut the angles to match the wall and plate but do that after its in place and secured with two nails per stud/plate. Now sheet the wall, cover it with house wrap and stand it up.

Let us know how it goes!

[Dave Ogren]

Stephen,

As you described is how I did it during the 1960's For the last 40 years we just use a sheet (4' x 8') of plywood on each face of the corner. You are right. This is a lot faster and I feel a lot stronger.

Dave

[Jim Becker]

I believe they are used where local code doesn't require plywood sheathing as the foam insulation doesn't add any rigidity to the structure, but I don't believe the let-in braces are needed when plywood or osb sheathing is used. I've even seen a variation when the corners get plywood but the rest of the structure gets insulation board of some sort. The better builders sheath with plywood (not OSB) over the whole structure.

But again local codes come into play on these things more often than not. We were plywood sheathed on our addition, but still had to do knee walls AND collar ties in the attic...and this under 2x12" rafters and a well supported, generously sized lam beam at the ridge. You could park a truck on the top of our addition and it would likely hold it....