tile over Congoleum?

My kitchen floor is 20 yr old Congoleum. it is level and solid--that is, the tiles are very securely stuck down. The floor is also level. Can I tile right over it or do I really have to remove the tiles and their adhesive? TIA.

It can be done with either mastic or epoxy adhesive. For mastic prime the entire floor first with a thin coat and let cure 24 hours. Afterward lay in the normal fashion. Epoxy adhesive is expensive, messy, and difficult to work with if you haven't used it before. In the end I can think of many reasons not to do it this way, but the choice is yours.

I have the same situation - linoleum over concrete - was going to install cementboard underlayment - isn't this okay to do rather than removing the old linoleum?

If you're going to install the cement board "by the book", you will need to prime the existing flooring, attach the cement board with thinset and concrete nails (or screws) every six inches.

That's a lot of trouble. Are you certain that the existing flooring is not just bonded at the perimeter? If it is, getting it up may be quick and easy. Test to see how it's bonded by taking a plumber's plunger and "sucking" it up 2-3 feet from an edge. If the flooring lifts up with the plunger, it's only glued at the edges and you should take it all up.

If it is glued down all over, and you want to use cement board, consider how your slab will handle the nails or screws. I've seen slabs that literally crumble when concrete nails are driven in. If that happens, you have a real mess on your hands.

If I were going to be responsible for your installation, I would remove about a 3 inch square of the existing flooring from 5 or 6 places randomly selected around the area. I would drive a concrete nail into each of those areas and see how the slab handles the stress.

I had an installation just last week where the slab started to disintegrate! It's certainly better knowing that information BEFORE the boards are anchored with thinset.

Dan

Dan - the local home depot guy said all I had to do was use "liquid nails" to attach the cement board - nothing about using cement nails. I want to do this right - this project started because of a previous owner's improper (or lack of proper maintenance)of the existing shower stall...

If I remove the tiles (it appears easy, they are very brittle and come off easy enough, I am just worried about abestos) can I cover the black adhesive (isn't that what has the abestos in it?) with tar paper/poly or something and then set the tiles?

I really appreciate you responding - I keep asking and reading....and, it's so hard to get a straight answer. Thanks - in any event, I am very grateful for oyur response - I was going to lay the cement board tomorrow!