I have a vinyl floor (tested neg for asbestos) in a bathroom. I am remodeling, and plan to put down porcelain tiles over backerboard.

I am able to scrap off the vinyl layer, but there is a paper backing and mastic left. I bought some Sentinel 747 cleaner, and it looks to be promising. Once I get it down to the 3/4" plywood, will I be ok using Hardiebacker (1/4") over thinset without any additional steps? Or do I need a rinse step? Thanks.


I have not used this brand on my job but once I have removed all the mastic I would clean the floor with water then I allow the floor to dry overnight and start installing my backboard and tile. If I was gluing another floor I would do a rinse with a cleaner. Hope this helps and saves time and money.


The paper backing and mastic may contain asbestos as it was used in cut back glues back in the day. Using additional cleaners or rinse steps to remove this glue may cause additional issues down the road. Adhesive issues with the thinsets used and potential buckling of the wood subfloor due to excessive moisture or reaction to the cleaner.

A simpler solution would to just "bury" the existing flooring and then tile over it. There is a product Tyroc Subfloor that is only a 1/2" profile that floats over existing flooring and provides the backer underlayment for setting tile.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.