3 set a long straightedge tool or a straight piece of 2 by 4 inch lumber.
Floor with low spot wood.
Use a mixture designed for wood subfloors.
Repair low spots in wood or concrete floors and clean them use an underlayment floor leveler or floor patch product to fix low spots in a wood or concrete subfloor.
Use builder s felt or shingles stapled to the floor to fill small low spots if you.
It s used to help insulate absorb sound and reduce wear on your floor.
Use a trowel to spread the material then allow it to dry before proceeding.
An underlayment is a thin layer of material sandwiched between two other materials.
If you are nailing the hardwood floor in place choose cementitious leveling compound that you can nail through.
Fill cracks or major voids with wood putty or a self leveling compound.