Thanks for the replies so far. It's about a 1/2" variance in the worst spots. I'm trying to keep everything within 1/8th of an inch. The worst spots are actually around the edges rather than in between the joists. It's like the boards around the outside on one wall are all about 1/2" lower.
The subfloor is plywood. I've already had to screw some pieces down to fix squeaks, and one section wanted to sag in between the joists. So I cut that up and braced in between the joists to give it some support. It really tightened that up.
There's multiple issues going on in my unprofessional opinion. There is some slight sagging in the middle between joists on a few spots, but that's relatively minor. Less than 1/8". The joists are 24" on center which seems too far apart. This is why I've had to cut the floor up and brace the worst.
The next issue is that there are two spots where the joists seem to be slightly higher which is creating a crown in each. They are joists that have walls under them on the floor below. I'm not exactly sure what went on here during the framing.
The 3rd is the issue I mentioned above. Along one wall it seems like the edge sheets are slightly lower. It's like that joist is lower underneath. Its the biggest variance and is about 1/2" +/- lower.
Neither of the contractors I know are flooring guys, but they are both telling me I need to address anything over 1/8" or it's going to be hard to install and I'm going to see and feel it in the floor. So that's what I've been aiming for.
I have been letting the flooring sit in the house to get acclimated to the moisture level here.
were no building codes required or permits when the house was built? Post some pictures of it. Sounds like the floor may need to be sheeted first. Before tung and grove osb they used plywood then 3/8 partical over that to help the floor not sag between joists and where there was 2 pieces of plywood butting up.
