Basement. Floor Andy engel style
I am finishing my basement. I want to do the subfloor with foam boards and ply wood. I have two questions though:
What is the best way to level the floor as I do this? I was thinking sleepers between the foam and plywood.
Can I use only one sheet of plywood to reduce the ceiling height I am losing or will it flex too much.?
Thanks
Mark
Replies
How to level depends on how much it is off. Options include the Spray can foam, SLC, or shimns
I would not use sleepers as that adds to height of assembly ( a concern you have already), and because that method would concentrate foirce to a small area on a material that needs that load spread out over a wide surface.
The dual ply surface is necessary so the staggered seams and glue let you achieve a single surface
An alternative to dual ply, if one is using sleepers of any thickness, is to have the ply joints fall off the sleepers and then glue/screw splice pieces (of similar weight plywood) on the bottom side of the ply. Tedious, though, and since some joints are necessarily at right angles to the sleepers those must be handled with short splice pieces between the sleepers, or else notch the sleepers.
And, of course, you wouldn't have the extra stiffness that you'd get from a true double-thickness scheme.
The floor is pretty significanly out of level. My idea was to lay the foam boards on the slab then fur it 16 on center starting with no slepper then slowly making my way down with thicker and thicker ripped down sleepers. I am putting down carpet in this area so being 100% level is not required just close enough that it is not noticable to the naked eye.
The idea of using sray foam seems good but how would you keep it from expanding too much and pusing the boards higher then you want? Also where would you use the foam to level, between the slab and the board or the board and the ply?
thanks
Mark
Have you ruled out leveling compound? Comes in a bag similar to redi mix concrete.
Mix it in a 5 gal bucket(s), pour it out and let it self level. We use it for the exact application you describe. Dries very hard and feathers out nicely. We then apply whatever floor covering or subfloor over the now leveled slab.
Great for filling in abandoned floor drains, too.
My thought of the foam was for if this was an undulating flor surface - say up and down as much as 1/2" but level overall. I did not realize the nature of the problem.
"Pretty significantly out...." is still not a really accurate description compared to " drops 1/4" in every four fee"t or one foot or wahtever....but you have hinted by saying you would need tapered sleepers how bad this is.
Jim has a good one with the SLC.