HVAC penetrations through plywood shearwall bottom plate

[skimboard20]

Hi all,

I'm working on a project where a contractor needs to drill holes in a few plywood shearwall bottom plates in order to run HVAC ducts. The bottom plate is 2x6, and the required penetration is about 5", so we can assume the bottom plate is essentially gone for about 12" of shearwall length (less than one stud bay). The bottom plate is nailed to joist blocking, with anther shearwall stacked directly below.

How big of an issue is this? My initial thought is that we are losing the bottom plate nailing along the length of the penetration. But I can figure out a way to get a few more nails into the bottom plate either side of the penetration. Are there any other considerations I need to address?

Thanks for the help!

 

[KootK]

In principle, I think that you're okay here. We typically assume that the wall shear delivery is uniform-ish by the time that it gets to the bottom plate. To the extent that is the case, the bottom plate is not technically a collector and, therefore, does not need to be axially contiguous.

That said, I'm sure that the real shear distribution at the bottom of the wall is, in reality, not perfectly uniform. As such, it would be nice if there were an axially contiguous plate at the bottom of the wall. It would also be nice if I had a Porsche rather than a rusty 2012 GMC Terrain. One must pick their battles, in life and engineering. This bottom plate thing would not be mine.