I removed floor tiles (3% asbestos) from my basement floor. I do NOT want to go through the hassle of removing the black mastic that remains behind (10% asbestos). The mastic is virtually flat on the cement surface. It just looks like black paint. I will be having the carpetlayers come in next week to lay down the new padding and carpet. I am not overly concerned about leaving down the mastic and going right over it. But it would give me a bit more peace of mind if I could apply some type of sealant right on top of the mastic covered floor, just to ensure that the mastic stays down. I know that many cement basement waterproofing and dustproofing sealants talk about how you must get everything up off the floor so that the product can properly bond to the cement floor. If I were to apply such product right over the mastic anyway, would I gain even an ounce more of protection, or would it simply fail outright and do me no more good than if I just didn't apply it at all? Thank you, folks!!