Installing wood, over cement, that’s over wood?

Q: We have a wood floor covered in a cement slush which is about an inch thick. We want to go over the cement since it has asbestos glue on the cement. The two contractors we’ve spoken to are encouraging us to put down plywood and then solid hardwood on top of that.

We are also considering putting down a floating engineered floor with a sizable veneer. Which would you recommend?

Also, for an entrance way on the east coast, would wood be okay provided we wipe our feet on an inside mat?

A: I don’t even like the sound of this at all. All wood will absorb and release moisture. It will expand and contract. I don’t know how you could have a wood structure covered with cement and not expect stability problems. I would remove the entire mess down to the lowest sub structure and start over.

Follow-up Q: The house is a city house in Philadelphia that’s probably from the early/mid 1800s. It was once a restaurant and bar and they covered the wood floor with tile using glue with asbestos. A few months ago I ripped up the carpet, found the tile, and used a chisel to get the tile up. There is just a film of dry old glue on top of the cement slurry. I was told from a couple of floor guys who’ve been here that the glue with asbestos is not dangerous in solid form. It becomes dangerous if we were to use a power tool that would create air-borne, harmful dust. We’ve been told the best thing to do is not to disturb it and cover it with wood. (You see, my intention was to get down the original wood floor – no such luck). Do you agree?

A: I need to try to understand exactly what is going on here. Are you saying that there is a thin layer of cement sitting on or over a hardwood floor, and that tile was laid on this cement? You now have the tile up, and the thin layer of cement remains, covered in adhesive. How do you know there is a hardwood floor under the cement?

If there is, I have my doubts it could be salvaged now. And given the issue of asbestos, I think you would be wise to leave it undisturbed. I would screw down 1/2 plywood at least and install a floor on top of that. My choice would be 3/4 solid, unless you have a height issue that cannot be reconciled. There are some good engineered floors on the market with a very thick solid wood veneer. Mirage engineered is one of them. You could sand and finish such a floor about as many times as a solid 3/4, yet it is only half the overall thickness. I am not a huge fan of prefinished floors. If that is the type of engineered you had in mind, keep in mind that the day it has to be re sanded, the micro bevel will also have to be sanded off. I am ok with hardwood in an entry, provided the floor is well finished and you have a mat in place and wipe up any water over run right away. If the mat gets wet around the edges, eventually it will blacken your floor. I prefer ceramic in an entry way.