Expert: Stephen Hayes - 11/6/2007

Question
I just bought a building and moved my business into a below grade basement office space. After extensive renovation, i put down carpet tile on to the concrete floor. I am now getting "black ooz" coming up between the seams of the tile. It is not in all area of the space but seems to be the worse in high traffic areas. The total amount of carpet tile laid out is 4000 sq feet. I am at a loss of what to do? Please advise

Answer
What type of floor covering was on the concrete floor before you installed the carpet tiles?  It sounds like there was an installation of either asphalt tiles, vinyl asbestos tiles, or vinyl composition tiles that had been installed with an old black colored cut back adhesive that was either visible to you when you installed the carpet tiles, or, if not visible, had been absorbed by the concrete.  If this is the case, then a normal chemical reaction occurred between the adhesive used to install your carpet tiles and this old black cut back adhesive.  This reaction results in the old adhesive becoming gooey, which negatively affected the adhesive used to install the carpet tiles (if the tiles had adhesive already on the back of them such as a peel and stick tile, the same reaction occurred), which has caused the entire installation to fail.  The only remedy would be to take up the existing carpet tiles, put down a flat, new underlayment over the concrete, such as a proper lauan or plywood, properly anchor that underlayment to the concrete, and install new carpet tiles, new carpet & pad, etc., on to that new underlayment.  Another solution would be to have a moisture test taken of the concrete, and, if no moisture problem exists, seal that concrete with a very thick coat of white milk latex after scraping up ALL residues from the old and new adhesives, install the new underlayment, and then install your new floor covering, however, it is most important for us to know what had been on the concrete prior to the installation of your carpet tiles.  Please let us know.

Thank you,

Stephen Hayes
MBD Floor Covering Inspection Service
<steve@mbdinspectfloors.com>
973-334-9747