Damp Basement Floor

[John P.]

A couple of years ago I painted my basement walls with Dry-Lock waterproofer and the floors with Dry-Lock floor paint. I have a workshop area, gym area, and storage in my basement. I thought my basement was dry, as I never got any water, and I run a dehumidifier. Actually my basement seems too dry; when most basements feel cool on hot days in the summer , mine feels hot and dry. However, in my workshop area I have large rubber mats, and I've noticed that a light coating of water collects under the mats. How can I prevent this water? My house does not have a high water table, and if it did wouldn't I be getting water from the area on the floor where the slab meets the walls? Also there are no cracks on the floor. Is this something I could even prevent ? The simple solution would be to get rid of the mats, but I like the non-slip surface. Thanks..

[Mark]

Hi John,

Thanks for your question, It's the end of a hot and humid August and we've had a lot questions just like this. In many cases it is a simple case of condensation. The best way to to control condensation is make sure that all windows and doors in the basement are closed and other potential air leaks sealed. Next keep running that dehumidifier. If possible have it drain automatically so you dont have to empty it or it won't shut off when full. This will also allow it to run at maximum efficency. The other possibility is that you have a case of vapor transmision. This is when water vapor comes up through the slab and is then trapped under a non breathable material, condensates and causes a puddle or damp spot. One way of testing this out is to tape a peice of plastic to the floor about 18" square and leave it for a few days. If there is moisture under it when pulled up it is vapor transmission. To test for condensation we have do it yourself test kits you set on the floor. Please call your local Basement Systems dealer for further questions.

Thanks
Mark Daconto VP
Basement Systems Inc.