View Full Version : What is that black stuff under my vinly basement floor tiles?

Apr 22, 2007, 09:26 PM
I've seen posts about black mastic adhesive, but I'm not sure if that's what I've found.
My basement carpet got wet during the nor'easter last weekend when my power went out, preventing my sump pump from working.
It wasn't the 1st time this carpet got a soaking (no measurable water, but it was pretty squishy;), so I decided to remove it and the padding. There were some dark spots on bottom side of the carpet, but mostly near the edges, and the padding was in surprisingly good shape (the carpet was probably close to 20 years old!). However, under the carpet I found 9"x9" thin vinyl tiles, so I started pulling them up too. I used a putty knife, and some of the tiles came up very easily, but others cracked, either because they were more brittle or because they were stuck better? There was some moisture under the tiles, but what really concerned me was the 'black stuff'. It isn't sticky, and isn't 'lumpy', and I could get small bits to come off by scraping. My wife was convinced that it was mold, but I thought it was some kind of adhesive.
So, to (finally) get to the question(s):
1. Could this be mastic adhesive?
2. If so, does it contains asbestos?
3. Could the tiles contain asbestos?

I'm attaching a jpeg image that shows the tile and the 'black stuff' (and the edge of the floor with newer concrete where the french drains were added). Hope this helps!
Thanks for any and all comments!

Apr 23, 2007, 07:20 AM
Your basement looks all too familiar. The black stuff in the pics does look like mastic. The mastic and the tiles could contain asbestos depending on the age. You probably do have some mold based on your description of what has happened. To test for mold make a small amount of 50/50 bleach and water. Put some of the solution on suspected spots. If the spot lightens in the next few minutes there probably was mold or mildew. You can buy a fairly inexpensive asbestos test kit at many hardware stores. If you test positive for asbestos you should come back for more advice. It won't be from me since I stay clear of asbestos.

Apr 23, 2007, 09:31 AM
Thanks for the quick reply.
I mopped all exposed floor (some still with tiles, since I stopped 1/2 through) with 10% bleach, and didn't notice any change at all, but I'll peel up a few more tiles and try the 50/50 test.
And, I'll check out the hardware store on the way home from work for an asbestos test kit - is it worth testing the adhesive AND the tiles?

Apr 23, 2007, 10:24 AM
Yes I would test both the adhesive mastic and the tiles for asbestos. New products are free of asbestos but old products did contain the stuff. You should test now before removing any more tile. It is relatively safe when the tiles are in place. If you start removal of the tile or the adhesive you make it friable or air born. Try this site for some good homeowner info What is Friable Asbestos? (http://www.wisegeek.com/what-is-friable-asbestos.htm)

Apr 23, 2007, 12:10 PM
Yes the black stuff looks like the cut back adhesive. The dangers of asbestos are grossly exaggerated. Best thing to do is rip it out, trash it, and keep your mouth shut. Somebody that takes money for the job is in big trouble if they don't follow the law. It doesn't apply to DIY. Asbestos is a big rip off, a scam by the lawyers and remediation contractors abetted by the EPA trying to justify its existence. They have never traced a single case of the cancer from it to anybody that didn't work in a factory that used it.

The newer asbestos free tile is all 12''. Most of the old 9'' stuff did have asbestos.

Same with leaded paint. The laws on both have no scientific backing, pure junk science and fear mongering. Now that the lawyers are rich and many companies are bankrupt, silicone breast implants are OK.

Apr 23, 2007, 07:45 PM
OK labman, I see you feel pretty strongly about this issue!
I tend to agree that a little exposure probably isn't worth panicking about (which is good because I got a little exposure yesterday).
I did buy an asbestos test kit, and collected a sample - it's worth the peace of mind to know.
In any case, how should I go about removing the cut back adhesive from the concrete floor without putting 'too much' into the air?

Apr 23, 2007, 08:20 PM
Yeah, it is a big rip off.

I have just put down seamless vinyl down over the old black stuff. I never had a prob;lem with it bleeding through. Adhesion isn't an issue with it. Carpet shouldn't be either. New tile could be a problem.

Apr 24, 2007, 07:06 PM
We're probably going to do carpet, but not until I take care of the water problem. I don't want to leave the mastic exposed any longer than I have to, so I figured removing it makes sense. Maybe it would be cheaper to pick up a remnant and just cover it over for now?
I guess I'll wait and see what the asbestos test results show before making any decisions, but I would like to know how to remove it if it comes to that.

Apr 27, 2007, 07:17 PM
I got results today that say the tile has 3% asbestos. It doesn't look like they tested the glue separately like I thought they would. But let's assume for the moment that there is asbestos in the mastic. Given that I removed most of the tile before knowing any better, I now want to end this as painlessly as possible.
From what I've read, the asbestos is 'safe' as long as it isn't disturbed, and the best solution is to leave it alone. I'd like to just cover the mastic, but won't be finishing the basement for some time, since I want to take care of the moisture problem first.

The black on the floor is pretty well stuck, but I was wondering if painting it with a decent floor paint would help seal the asbestos to the floor.

Another option seems to be getting some cheap self-stick tiles and just putting it right on top of the mastic - that should seal it tool.

Does anyone feel like commenting on whether they think either of these seems like a reasonable solution at this point?

Apr 30, 2007, 08:00 AM
Since you have only removed some of the tiles, eventually you will need to level them out for the new flooring. Therefore, I think you should put down new tiles or sheet vinyl. If you don't want to do that, the paint would help seal any asbestos fibers that were disturbed during tile removal.

Apr 30, 2007, 08:41 AM
Paint is only going to complicate things, and the old black stuff could bleed through it. Yeah, pick up a cheap carpet remnant and throw it down on it. If it hasn't bled through in a few months, it should be safe to put down good carpet. If it does, we can talk about removing it or sealing it then. Again, I wouldn't trust tiles to stick to it.

Jan 2, 2011, 02:57 AM
We removed old tile in my bedroom about a year ago. It did turn to a dust when tiles were broken. We did not wear any protective gear because we did not know that it was asbestos or that it was dangerous. What should we do now?

Nov 28, 2011, 12:38 PM
LOL... your insurance company would have paid for all of that. Due to your power going out and causing your pump to go out. The water that flooded your basement was Cat 3 water. Sewage, drain water, etc.. All negative water. (Unhealthy) Your insurance would have paid for the dry out, removal of the carpet, new carpet, removal of the asbestos tile and mastic. To have everything done professionally done would cost thousands, but you'd only have to pay for your deductible $500-1,000. Looks like I'm 4 yrs too late.. hahaha some people

Nov 28, 2011, 02:40 PM
Hi people and welcome to AskMeHelpDesk.com. You piggybacked on an a 4 year old dead thread so I gave you one of your own. In the future, before you post, look in the upper left hand corner for the date.
However we appreciate your input and hope you keep on posting. Regards, Tom