Wood Shear Wall Corner Details and Anchors

[gte447f]

Looking for consensus or opinions on common ways to frame exterior corners when both walls that intersect at the corner are shear walls. How many studs do you typically use to build up the corner (I know this could vary depending on the shear wall chord forces, but assume 2 minimum are required for a shear wall), how are the studs oriented, do you specify the fastening between studs, do you use 2 separate hold downs for the walls or use just one hold down for both walls?

I usually just specify the number of studs required for each shear wall chord separately and specify 2 separate hold downs. I have a situation where a contractor left out the hold down anchors, so I am rethinking things as I look for an efficient way to fix the problem.

 

[jayrod12]

I'm a single holddown kind of guy. If it's super crucial I'll specify the nailing between the last stud from the one wall to the built-up post from the other, typically though, the sheathing itself will get the panel edge nailing to the built-up stud if you detailed it correctly, and the top plates should overlap at the corners, so for all intents and purposes, the studs at the corner reside in both walls.

 

[msquared48]

One holddown, and whatever number of studs are required for that holddown. Single 4x or 6x ok too. Nailing development of two SW ply to column should not be a difficult issue to solve.

Mike McCann, PE, SE (WA)

 

[TehMightyEngineer]

One holddown as well for me. I've only once ever needed to use two holddowns and it was a very unusual situation.

I position studs to ensure that the nailing from each wall's sheathing can transfer into the holddown.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL)
American Concrete Industries

https://americanconcrete.com/

 

[gte447f]

Thanks for the responses. I think I might change my ways and specify a single hold down at corners in the future. While we are on the topic, do folks pay much attention to fastening of the multiple plies of 2x studs together for the shear wall chord/post, or do you reckon that the attachment of the hold downs engages all the plies and effectively distributes the loads through the plies to the hold downs? This question applies to a single shear wall as well, not just to a corner at two intersecting shear walls. In other words, assuming that multiple studs would be fastened together with typical nailing patterns (e.g. 10d @ 6" for 2-2x4), would this suffice or would you go over and above this requirement to distribute the shear wall chord forces to the multiple plies of studs?

 

[msquared48]

One problem I see a lot is contractors includung a discontinuous cripple stud in the stud pack.

Even if the number of full height studs is correct, the presence of the cripple imposes an extra bending length on the bolts for the hold down, effectively reducing the capacity.

The cripple needs to be cut out at the bottom for the holddown and an extra cripple installed once the holddown is placed.

Not so critical with straps if just connected to the full height studs.

Mike McCann, PE, SE (WA)

 

[abusementpark]

I've been doing two separate gangs of studs and separate holdowns. It can be a bit overkill at your normal corners, but critical at re-entrant (inside) corners. I've found that two separate gangs can also allow you get the holdowns further away from the corner of the slab and better anchor capacity.