flat subfloor -compound or roofing felt to level?
Hello I need to know if levelling compound can adhere to a very well scraped glue from old carpet. I had to take up foam and and old carpet. IT is very well scraped but the guy I had into look at it says he does not know of his levelling compound would adhere to what is left on the floor after the scraping job. Also can you use roofing felt to help shim up a subfloor to make sure it is very flat and level for hardwood floor. I am in the process of having a floor replaced that was wrongly installed. now i took up part of the subfloor to discover that the plywood is not flat not level. They made a mess and used lattice for shims. Terrible job...floor is not flat or level. HELP!