The concrete in my basement is, as most concrete is, very uneven. I was building up my subfloor to match an existing floor, so I got about 200 board feet of PT 4×4 and ripped 1/2" off using a table saw followed by a planer. Then they kinda sat for a month while I trecked across the trans-Canada railway. Anywho, the combined effect of the planing and the sitting was warpage. I put anchors in the concrete and tightened them down real good to flatten them, but some pieces are really far gone, where some of them snugged right up.
Here's a photo of how it is right now:
It has a lot of high corners because of the warpage, and I sanded a good bit down with my angle grinder and some 36 grit.
Every time I move the level though it seems like something else is too high or too low. It's been hours of back and forth and it's starting to seem impossible to make this flat. The floor isn't actually level, it's 2-3 degrees tilted outwards, but flat is what matters to me. I'm starting to think if I put the plywood down that things just might go well, although at some points the plywood seems like it would be resting on the edge of the 4×3's because of the warpage.
Is there a reasonable tolerance that I should abide by in making these flat? Is there a better way? Is it ok if not the whole sleeper is in contact with the floor board? (bonus points: my framing down there looks structurally sound enough, right?!)
(and because I know somebody will call me out on it, there's no plastic under there but the epoxy coat I have down there is one of the moisture barrier variety, and I also put PT on to just to be safe – I know already! I know!)
Best Answer
Perhaps you're thinking about this in the wrong order.
What if you applied the plywood to the almost level sleepers and then leveled a surface over the ply?
I think you''re going to have a very difficult time leveling sleepers as you have in that photo.
EDIT: Per your comment that you intend to install tile atop ditra.... you have a very forgiving tolerance with the subfloor, then! Glue and screw the ply into the sleepers. Then apply the Ditra. You can level out imperfections in the leveling with thinset below the tile depending on just how bad things are.