I have a basement floor I want to tile with ceramic tile. It previously had linoleum tile which has been removed. Is it possible to tile over the old mastic or will that affect adhesion of the Thin-set. I am trying to avoid the cost of removing the old mastic which has been estimated at $1,200.00.

I do hope that was actually Linolium tile you pulled up and not the Asbestos tile commonly used at least into the 70's.

Smoothy: this doesn't answer the question asked. For the record. I am asking this question on the behalf of a potential customer AND myself. He has already removed the tile and it was ascertained to potentially have asbestos and he checked with proper authorities and disposed of it properly. But he was told that the mastic itself may have more asbestos than the tile and all forms of removal are costly and potentially harful and he has two young kids. According to him the EPA says containment is acceptable and that's why we're looking for ways to just cover over the old mastic. So the question remains. Can Thin-set or some similar product go right over the old mastic and still be reliable. This is a concrete floor, not wood and screwing down backer board or other products is just too difficult/time consuming and costly.

If the question had pertained to if its safe to wash stuff clean in the kitchen sink using Carbontetraflouride solvents you found in your grandparents basement... I would point out the very serious dangers just the same.

You presented no professional credentials in your original post that would indicate you were other than an average homeowner who was totally ignorant to the dangers. Or was certified to handle hazardous materials cleanup or removal.

I siad this because few people are even aware that houses that aren't that old have have that asbestos tile... or the risks. The mastic doesn't pose a health risk because its not friable, its bound to the adheasive components in it. The tile on the other hand is far from it. IF that was not pulled up in accordance to recognised procedures there will be airborn asbestos fibers. And checking it AFTER the fact doesn't mitigate the problem.

And if HE the potiential customer... had to contact the EPA after the fact, it shows proper procedures would not have been taken.

For my OWN health I wouldn't proceed until an independent test has proven there is no airborn fibers to be of concern. IF the test proved otherwise... I'd report it because it poses a risk to other individuals.

I am not personally Certified to handle Asbestos waste... but I have been trained to the risks, and to identify WHEN to call in professionals, and have been annually for a number of years now. And based on both your original post and your follow up... I see a lot of red flags waving.


And this is assuming (which I highly doubt) the tile was removed under and in accordance with EPA regulations... you can't simply use thinset because it can't bond to the concrete because of the layer of mastic. It would have been easier to encapsulate with the old tile in place.