[aka_rawhide]

Hi. We are installing new 9.5 " LVL floor girders to replace damaged 2x10" (9.25") girders. These sit on steel lally columns. One girder sits under a load bearing wall. The space from lally to bottom plate of wall is 9.75". The 9.25" 2x10 with 1/2" plywood subfloor totals 9.75". The new LVL being 9.5" would push the 1/2" plywood along with the wall on top, up 1/4". Don't want that, so one option was to cut the lally columns down 1/4". Another option was to put a 1/4" notch in the LVL where it sits on lally. And another, the way we went (now doubting in retrospect) was to cut out the 1/2" plywood under the bottom plate, just the strip bearing the load, and replace it with a 1/4" ply strip. This levels the wall properly. however, it concerns me because it breaks up the 1/2" plywood that spanned under the wall plate. We can attach blocking on both sides of the girder to attach the new ends of the old, but now disjoint, 1/2" ply, but the lateral support offered by the single piece is lost at this wall. Any one have concerns with the approach we are taking ?

 

[Mingledtrash]

If its engineered for 2x10 and you are replacing with LvL being as the lvl is much much stronger the easiest way to go is to just rip the entire lvls down to 9.25 in.

 

[carpdad]

If your subfloor is just 1/2", there would be a flex when you walk over the joint. As you suggest, I'd put blocking under the cut. It does not have to fit exact, I'd cut the blocks 2" shorter than the bay for easy fit and nail to the girder.

 

[aka_rawhide]

Thanks guys. I will reinforce under the cut with with blocking fastened to the lvls.