What is your recommendation for wood floors to go over old black mastic adhesive covered cement in an apartment building? Thank you!

Your best will be an engineered floor that is pre-finished. Get the floor flat as possible, within a quarter inch in ten feet is recommended. A cementitious self leveling patch can stick to the asphalt based glue. You will need a plastic sheet and eighth inch thick foam under the floating floor. Floor mastic does not stick to that black stuff.

Thank you.

Multiple wood floor professionals, as well as the Bostik adhesive tech rep have agreed with you that the adhesive will not stick to the mastic. However, my building’s contractor is insisting that he wants to use adhesive directly on the mastic. No subfloor, no skim coating, no foam underlayer. Is there something that I can show them about why mastic over adhesive will not work?

The only thing that sticks to tar is more tar. This type of adhesive is not sold anymore because of clean air regulations.