Q: I am installing 3/8″ engineered over existing old hardwood. Two questions: What is the best product for levelling out the low/uneven areas of this old floor? Also, What is the best underlayment? I am leaning towards roofing tar paper.
Thanks in advance.
A: As long as the dips aren’t too severe you could use that same building paper to fill in those dips. You can’t really use any type of compound mixed with water or you will buckle the wood you are installing on top of. Yes you can use the roofing paper. But you don’t have a moisture issue and the engineered won’t slide into place easily if you use that. I assume this is glue down engineered.