Q: I removed carpeting in my concrete basement and wooden stairs leading into basement. When we pulled up the carpet there were 9×9 tiles that were stuck to the carpet. So we removed the remaining tiles, and now am left with black mastic on the concrete floors and wooden steps. I got a few quotes on removing the mastic ranging from $1200 – $2500, some didn’t include the stairs. Some suggested I just leave it and put new flooring over it. Some suggested I have a carpenter come and replace the stairs. I have a limited budget and don’t have the extra money for removal of mastic or stair replacement. So I would like to be able to cover the mastic. What type of flooring would you recommend for concrete floor and wooden stairs with black mastic on it. My floor appears to be dry, though my basement is humid. I would like something moisture resistant. Can you give me some options, and what type of underlayment and/or moisture barriers would be required for each option? I did have the black mastic tested for asbestos, and it came back with none. I have read about encapsulating the mastic. I have been researching this and there are such differences of opinions, I don’t know what to do.
Any help will be greatly appreciated.
Thanks so much
Janet
I forgot to add a couple of things to my questions below. I have heavy exercise equipment and a desk that can’t be removed from the basement, during installation, without having to disassemble them. I know certain floors require that nothing can go on it right away. I was hoping for flooring that will not only hold the weight, but that it can be put on the floor right away. Perhaps doing one section of the floor then moving the stuff over onto it and then doing the rest of the floor. Any suggestions and/or recommendations would be very helpful as well.
Thanks again.
Janet
I did some follow up with Janet to address to moisture issue she mentioned and to ensure I gave the best advice possible.
I have a humidity meter that I bought. It has been ranging from High 40′s to High 60′s percent humidity. I have purchased a humidifier that I have to empty every 24 -48 hrs. I have a/c and gas heat. To me it doesn’t seem humid, I never thought it was. But I had rain come in from my chimney trap door, that was coming onto the carpet (though I thought originally it was coming up from the drain, so I tore up my carpet to get to the drain (because it was covered with carpet), only to find out, that was not the source. Finally I happened to be downstairs during a heavy rain fall, and notice where the water was coming from. That problem has been corrected, and since then I bought the humidifier and meter, so it appears my basement is humid, even though it is dry (or at least appears to be). My floor has the black mastic on it, but it is always dry. I have try the plastic taped on floor test in a couple spots, and it was dry.
A: That level of humidity isn’t too bad. The goal line level of humidity in the air should be between 40 and 50% for a wood floor of any kind. As far as the mastic is concerned there are few options to look into. Aside from carpet you will want to choose a floor that can be floated. The problem with a floating floor is that you will not be able to easily match your stairs. The reason behind this is that for stairs your flooring will be glued directly to the stair and this should not be done with the mastic remaining.
Beside flooring over the top of the mastic you can remove it yourself using a scraper in order to keep within your budget. The mastic should be somewhat brittle which will make it relatively easy to scrape away, but don’t use a sander or grinder as this will wear the mastic down and actually make it a bit harder to remove. I know this may not be an answer you want to hear, but these are really the only feasible options you can look into considering the mastic. What I would heavily suggest is to acclimate any product you get for at least a week to make sure that the product’s moisture content is within 2% of the subfloor’s moisture content.
As far as your exercise equipment is concerned, you will want to install the entire floor before putting any equipment over it. The reason why I say this is because as a floating floor, having weight on part of the floor without it being fully installed will cause a it to raise on the unfinished end which can cause quite a few problems when trying to engage the locking mechanisms on the rest of the floor. Since this is a bit heavier, I would use cork underlayment because cork’s natural density will hold up better to the weight. Also, I would suggest placing a pad over the floor then putting your equipment over the pad to protect your floor. Also, since this is a basement, make sure you use a moisture barrier over the mastic just to be sure you’ll have no worries or moisture vapor seeping up through the mastic into the floor.
Flooring wise, I would look into a laminate or cork as these will be better suited for handling your exercise equipment and the desk.
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