Searching around the internet for solutions we eventually landed on this article from ask the builder that suggests using construction felt and asphalt roofing shingles to level an uneven plywood or osb floor for hardwood installation.
Level plywood subfloor for hardwood.
When nailing down a wood floor the subfloor should be flat to within 1 4 in 10 or 3 16 in 6.
After vacuuming or sweeping the subfloor to clean it add a plywood.
The solution for leveling a subfloor.
What good is a beautiful and expensive hardwood floor if it squeaks and creaks when you walk on it.
A solid hardwood floor is only as good as the installation.
And a quality installation relies on having a level subfloor.
Do this by multiplying the room s length by its width.
Level floors are critical for reducing gaps between the flooring material and substrate and preventing sagging and other structural complications.
Whether you re going on to install hardwood ceramic tile or laminate one of the most important steps of any flooring project is making sure the subfloor foundation is level.
The key to a beautiful long lasting hardwood or laminate floor is a well prepared subfloor.
Laminate planks snap together and float above a subfloor which means tiny subfloor imperfections are okay although again a level subfloor will help prevent damage.
Before you install your plywood subfloor first calculate the room s square footage to find out how much flooring you ll need to buy.
To level a subfloor for installing laminate follow the directions above to remove high and low spots.
If not your floor covering which is the solid hardwood laminate tile or other exposed flooring that goes on top of the subfloor will never be flat and level this problem can be fixed but it all depends on exactly what kind of uneven subfloor you have.
What s worse is if boards start to stick up buckle or warp.
But not to worry if your subfloor is less than perfect.
How to level a subfloor for a hardwood floor install.
Hardwood floor installers often use the term level when referring to subfloors when actually they are meaning the term flat.