I have a sag in my cantilever wood floors that's about a quarter inch deep. I'm able to access the subfloor and joists from below, but I'm hoping there's a way to fix this sag without having to remove the hard floor and add shims. I've checked everything I can online, and it seems like all the joists are level, so the issue might be that they were installed with the crown side facing down. Any advice on how to address this?
1 Answer
It sounds like you’ve done some good assessment already! Using a long straight edge and checking with a laser level is definitely smart. Since you said the joists are level and that jacking up the sagging area raises the whole joist, you might want to consider jacking up just the area between the joists instead. That way, you could potentially add a sister joist or blocking to help support that sagging section. Just be cautious and ensure you're not causing any other issues with the overall structure.

I agree with HandymanHero. My buddy had a similar issue and jacking up just the area between the joists worked for him. He added blocking and it made a huge difference!