Hello all, I posted a message earlier this week regarding covering a concrete slab with a dimpled membrane and then laminate floor. i appreciate the responses to my earlier questions and concerns. I have a new question and hoping someone can shed some light. The concrete floor is currently covered in chipping epoxy paint, under which is possible asbestos black mastic. The area is 230 sq feet, and a small area (probably 3'x4') tends to get moist and the concrete looks dark. I am assuming the moisture is creeping up from the ground. The worst its ever been is some droplets, never a puddle. I keep the humidity at 55% via a dehumidifier. As a temporary measure (two years ago) we laid a poly sheeting(not sure of mil) and on top of that RAM board (very heavy paper) until we could lay a floor. This spring I looked under the paper and saw that beneath the poly there was some condensation (not puddling) in the moist area. It is not within our budget at this time to address the moist slab. Here's my question/concern: Is it necessary to pull up the poly sheeting before we lay the dimpled membrane (Platon) and the laminate floor? Is it better for the poly to be removed or is that an unnecessary step? I initially planned to pull up the poly and wash the floor down. Once dried we would put down the dimpled membrane. If we leave the poly would the condensation be trapped there perpetually or can it migrate back under the slab? And if the condensation remained would it grow mold despite lack of oxygen under poly? I know once the dimpled membrane is put down there will be a thermal break, I'm not sure if that will help with the moisture coming up. Thanks to anyone who took the time to read this and give advice!!

So, if I understand correctly, you have HW, sticky stuff, carpet; and these are the options after taking off the carpet: 1. Put new carpet down 2. Scrape whatever it is off and refinish the old HW floor 3. Remove old HW floor and site install new HW What would be the impact and the cost for each option if it were asbestos/if it were not? For instance, 1. if you knew it were asbestos, would you put a carpet on top of it? Or would you want to remove the asbestos? 2. How much work would it be to remove the stuff, sand, refinish the old HW, even if it were not asbestos? If it were asbestos? 3. If it were asbestos, could the old HW floor be easily removed without disturbing the asbestos? If yes, I'd probably do that. Basically, if you don't mind living with asbestos but are worried about liability if it were asbestos and don't plan to remedy it, the way to go would be to just put new carpet on top and never remove it --- unless option 3 would work. I personally would do a test and then figure out what to do. In terms of logistics, the guys in our house did the whole 500 sqft in two days. I was amazed how little dust and smell there was. Here is a link that might be useful: asbestos test kit with lab fee

The risk is for exposure to friable asbestos, which would be in the form of airborne particles. Do not use brushes or scrapers that would release particles into the air. We had tile and mastic removed by a licensed abatement company and they used a liquid solution to break up the mastic, and then sucked up the solution with a water vacuum. However, they also wore protective suits and masks the entire time, and had postive ventilation for the area. This youtube video will give you a better idea of the process. https://www.youtube.com/watch?v=9bFgNyfjiKk Since your tile and most of the mastic is already gone, I would do some research to find a non-petroleum based Vinyl Adhesive Tile (VAT) mastic remover (in liquid form) and use it to clean the floor. The product I have seen mentioned in a few articles is called Bean-e-Doo mastic remover, but I'm sure there are other brands. You do not want to use anything with a petroleum base because it will be absorbed by the concrete. It may retain petroleum odor, and may prevent some adhesives from bonding properly with the concrete if you try to lay down new tile. Bruce

I’m renovating a 1/2 bath in my 1970 home. Previous owner redid bathroom 10ths ago. During that renovation, the contractor left in the original vanity (and the tiles underneath, but cut way and removed the remaining tile and laid new tile. I had the original tile and the mastic tested for asbestos. The tile came back negative but the mastic came back 3%. My question is, since the original contractor removed the original tiles and adhesive and laid down thinset directly to the subfloor, am I at risk if I just remove the newer tiles and thinset, but leave the rectangle of original tiling (that was under the vanity) and adhesive alone.