Residential shear walls with I-joist floor at basement foundation. 1

[ThorenO2]

Hello,

I’m evaluating a detail from a Simpson blog where the hold-down uses a threaded rod extension and coupler nut. Like every hold-down foundation detail I’ve examined the post/chord is setting directly on the sill. My question is can the SW posts set on the floor instead (sole plate, floor sheathing, I-joists, sill plate, squash blocks & rim board) by using this rod extension? It’s similar in concept to the rods used at upper floors, but I’ve never seen it at the foundation. Or, would I get much more capacity out of setting the SW posts directly on the sill plate and then frame the floor around the posts to avoid the discontinuity? This seems like a pain(i.e. notching sheathing) and not as straight forward as platform construction. To get the favorable condition of the SWs on the basement sill I’ve heard of people using top flange I-joist hangers so the floor is flush with the sill, but in my view, the hangers are a very bad detail compared with direct joist bearing. The article notes 18” is the max unbraced rod length, where with a 16” I-joist system I’ll look to to select hold-downs with 3/4” rods. Appreciate any insight and comments on this detail, thanks.

 

[phamENG]

I have never the shear wall end post on the sill while the raised floor wraps around. Every house with a raised wood floor I've ever done has had the wall sitting where the wall belongs (on top of the floor) with blocking underneath. There is no lost continuity in doing it that way.

 

[ThorenO2]

Thanks @phamEng, I thought it was a poorly conceived idea. The rod is only subject to tension and the squash blocks handle the compression, so I’ll get the full capacity of the connection (no discontinuity). The 5 degree swivel is favorable to get the anchor further away from the concrete edge (flush with the studs), not the direction they’re showing it.