We are planning on re-carpeting our basement floor which is cement. We have removed the old carpeting and padding as well as the tile that was underneath (before realizing we were working with asbestos-based products!!). The tile was very easy to remove with just a scraper. What we have now is the black mastic that was used to adhere the tile to the concrete floor. We would prefer to paint or seal over the black mastic rather than going through the process of removing it before the new carpet is installed. Our basement will be used partially as a play area the kids and considering the mastic most likely contains asbestos, I want to do what is safest, yet least expensive. Is it absolutely necessary to remove the mastic or is it okay to leave it and paint or seal over it? Any product suggestions would also be greatly appreciated!