Can I apply this product over rust and paint scale? 

No, the deck or walkways must be clean of oils, rust and paint scale.  You don’t want rust to continue to attack the metal underneath, weakening substrate materials/surfaces. Our adhesive will seal the deck and help protect it. Your deck will have less abuse and our anti-skid surfaces will last longer because of that initial surface care.

 This is not covered under Warranty; failure to properly prepare and clean the deck will be the responsibility of the installer.