Hardwood over poorly-installed asbestos sheet flooring

Question

In a guest apartment with three rooms the smallest room has two layers of sheet flooring in it. Below the two layers there's some sort of black felt paper. All those layers are glued onto each other and they are not tiles but one big sheet each.

The flooring jobs were done poorly, with the surface showing up to one third of an inch difference in height over maybe a yard distance and many small bubbles and spikes. The flooring was tested, the middle layer contains asbestos.

Now we'd like to put hardwood flooring in, avoiding removal of the existing floor since it contains asbestos. I have just the right amount of click type bamboo flooring (suitable for below grade) with 3mm thick underlayment and would like to use that.

My question is essentially what do I use best to make the existing floor level? Can I pour regular leveling compound over it? I'm afraid that it will be too thin and crumble over time. If I make it thicker, there will be a height distance to the other rooms. Is there some special leveling compound suitable for this situation (thin and over vinyl flooring)?

Answer 1

ArchonOSX's right of course that the best solution is to remove everything. But, if that's just not going to happen until hell freezes over for a 2nd time. Then, a few thoughts come to mind. If the Bamboo is underlayment approved, then even dime-thick padding will help.

First, get the floor as solid as possible...noticeably improved. Surface bubbles can be X-cut & glued back down...short screws into the lower layers, a heavy object or a floor to ceiling stick wedge for clamping would be needed. Cut, chisel or plane spikes to remove them.

As far as the big dips, hills & ramps go. I think you're right & I don't know of any "Floor Product" or "Concrete Resurfacing Product" that won't breakdown to dust. However, I do know of Bondo or Plastic Auto Body Filler & that won't dust, is easily manipulated & sanded, has decent open time, plenty strong & adhesive enough, is meant for large areas & is water resistant.

I think this line of thought is your only good option & you can start cheap & small to try it out & go get more if it's doing the job. These have the same benefits so you might choose them instead. I'd also say go with an Epoxy, but it gets expensive & is a lot worse goop to clean up & might slump or run too much. Finally, a soap & water clean-up would be Loctite Power Grab caulk adhesive since it dries good & hard & you'd be able to return unused tubes.

Answer 2

90% of any job is proper preparation.

Sounds to me like you have a really poor base to start with. You cannot simply cover it up and hope for a good outcome.

Although it will be a lot of work. I think you should take the time and expend the effort to strip this down to the sub-flooring or maybe even the floor joists and install the flooring properly.

If the asbestos is non-friable type floor tiles then removing it is not as bad as it sounds. As long as proper safety procedures are taken and you don't cut or grind it you should be successful.

Good luck!