How thick must subfloor be?
We are doing an extensive remodel. During the demo, I recall seeing the guys removing a lot of plywood, which I assumed would be put back. The flooring contractor was just here, and they noted that our subfloor is only 1/2" on the first floor hall. It used to be tiled, so I wonder if when they broke up the tile, they removed that layer of subfloor. The living room subfloor is 1/2 higher than the hall.
In the upstairs, there is a large area of subfloor that is 1", but then there is a large area that is down 1/2" from that level, and you can tell that there used be more wood there.
Does code call for at least 3/4"? Right now we are at only 1/2" in the area of new construction in our front hall and entire master suite, the upstairs hall, and two upstairs bathrooms. The biggest problem is that we have brand new stairs, and I believe the calculations for the risers was done without the 1/2 inch. I don't want saddles between rooms if I don't have to have them, and more importantly, I don't want only 1/2" of subfloor, especially if code is 3/4".
Does anyone know what you have to have?