I am installing blocking between the sill and joist to attach a top
plate to for a new stud wall in my basement. In doing so, I noticed
that one of my joists is twisted somewhat. The house was built with
the engineered I-joists (or TGI joists, whatever they're really
called) and all but one are straight. The one I'm referring to is the
one nearest the foundation wall, and it appears to be straight along
the top, where it meets the floorboard for the floor above, and it's
also equi-distant from the foundation wall at both ends; however, in
the middle of the span the i-joist appears to bow about 1" away from
the foundation wall. The top of the joist where it is attached to the
floorboard above is NOT bowed, only the bottom half. And there is
nothing pushing out to make this wood bend (well, the blocking I'm
putting in kind of looks like it is bowing the joist, but really the
joist was like that before). So essentially it looks as if someone
had installed a straight joist, then put in a block pushing the lower
part of the joist away from the foundation wall mid-span, then removed
whatever was bowing the joist. My question is - should I install
blocking between that joist and the next one over to prevent it from
bowing more from any "Mystery forces", or should I actually attempt to
bend it back straight by installing blocking and then banging it into
the bowed spot to force it back, or should I just leave it alone?
When I do install the blocking for the top plate the joist will be
mechanically locked to the sill plate by several 12d and 16d nails, so
it shouldn't move any more after that, I'm just concerned that it is
compromised structurally. Any advice?
You might try to pull or push it straight with a clamp, use gentle pressure
and adjust it slowly if it resists, possibly over several days. Do NOT bang
it into place, you may crack or damage the lower member and totally destroy
the strength of the joist. These engineered joists while strong, can be
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