I would like to hear thoughts on flattening a sub floor. More specifically, the best way to flatten it. I have read a lot of threads about using asphalt shingles and builder’s felt to shim up the low spots.
Doesn’t the builders felt smell like tar? Can I use quik level cement based product to flatten a 3/4″ CDX plywood sub floor? I want to use the best method and I’m hoping someone here has some insight on what the best method is and why. Thanks much!!
Replies
Sounds like it's a plywood subfloor, rather than concrete slab. What's going on top of it? How bad are the dips and bumps?
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Yep, its a 3/4" plywood subfloor. I'm installing 3/4" Brazillian Walnut hardwood over the top of it. There doesn't seem to be too many dips or bumps -I still have to map out the floor, but there were some pieces of subfloor that sat a bit lower (maybe 1/8 inch) than the rest, and the floor will be installed through two rooms. In the middle of those rooms, it seems to peak and slope down a bit each way toward the opposing walls. Thanks for your reply!
I use one or more layers of rosin paper if the dips are minimal,this is the red rosin paper that goes over the subfloor. If the area is badly dipped then the structural problem that caused it must be addressed.
mike
I've used a number of materials to flatten out a subfloor- roof shingles, cedar undercourse, dash patch...
but the one I seem to use the most is 30# tar paper. It builds thickness pretty quickly, feathers out to flat quite well because of the width, is cheap, easy to work with, and stable under the finish floor.
Thanks all for your replies. Can you smell the emission from the tar paper after the floor has been installed? That stuff seems to have a strong smell to it.
I've never had a complaint. I think the smell disappates pretty quickly.
I never rely on my own nose for detecting odors. About the only thing its good for is holding up my glasses. <G>
Haha - Ok thanks very much!
I have never had a problem with the odor. Here's a reason not to use cementitious floor leveler: eventually the plywood subfloor is going to flex just a teensy bit, and the floor fill is brittle so it will start to crack and crumble. pretty soon it sounds like your walking on rocksalt."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
For small areas I have used a Bondo type filler.