I have a very small downstairs toilet/shower room that has thermoplastic tiles in. And I know the possible dangers with these tiles. The room is very small, and the floor has about 12-15 tiles. Its literally about 3 feet wide and about 4 foot long. Some of the tiles are missing, and the ones that are left are pretty much intact. I have no intention of pulling them up myself at all. Ive never had them tested but the house was built in 75, so its a good chance theres a risk involved. So were wanting to put down cheap and cheerful vinyl floor tiles, as its only a small room, and the vinyl tiles in B&Q say not to lay them over thermoplastic tiles. Problem is the vinyl floor underlay costs more than its worth, so I had thought of using some XPS underlay and a damp proof layer. Wondering what others would do? Have them removed, or will they be safe to cover with XPS and then lay the vinyl tiles on top of the XPS?