I am planning to install (nail down - 2” L cleats) 3/4” x 2-1/4” solid oak over a new 3/4” subfloor over 2”x12” joists 16” o.c.. The structure is sound, but I have an issue I’m not sure how to address.

The structural engineer on the project specified simpson metal straps (four total over ~450sf.) that run the length of the room in both directions (parallel and perpendicular to the joists). The straps can’t be removed because of structural/earthquake requirements.

The straps + plus nails used to fasten them are 1” wide and about 1/8” higher than the subfloor, and I’m looking for a way to lay the flooring that will avoid touching the straps.

I can think of two options:

1) mill the bottoms of the solid oak so that it doesn’t touch the straps

2) use cork underlayment up to the edges of the straps, and let the planks simply “ride” over them

I think the second option above makes the most sense, but are there other options I should be considering?

Many thanks for your guidance!

Matt

Whichever way you lay the floor parallel to a wall it seems like you may have a row that will be parallel to one or more of the straps. You may be able to find a wider or narrow board to solve the problem of ending up trying to nail through a strap.
Another solution would be to lay the floor diagonally as bridging a narrow gap will not be a problem.

Thanks for your response. My plan for avoiding nailing through the straps is to glue and clamp two pieces together with tightbond iii. That stuff has amazing strength!

Any reason to avoid doing a nail down over cork? I know I’ll lose some of the acoustical properties, and that is fine...the joists have rockwool between them for sound reduction. The main concern I have is whether I will get squeaks.

Your fasteners need to penetrate the sub-floor by at least 3/4 inch to be effective under normal conditions. The cork is pretty dense so it will not cause squeaks.