Found mold in my basement, need advice...

Durt Ferguson

The situation :
We moved into this house at the end of last summer. The other day my wife calls me down into the basement with a "Honey, you should come look art this", which is never good. Our main basement area is carpeted with a small bathroom in the corner. The bathroom is approximately 5'x6' and has linoleum tile flooring. In the middle of the bathroom floor there is a small spot, about 2" in diameter, of greenish/black mold growing. The floor is slightly damp. The walls are not damp, the carpet is not damp. Just the linoleum. I believe the dampness is due to the fact that we've had extended periods of unseasonably hot and humid days, and the ground is still pretty cold and the basement floor is a concrete slab, hence condensation.

What I've done so far :
I pulled up one of the tiles and the slab appears to be dry and mold free. I cleaned the entire bathroom floor with a mixture of bleach and water.

What I plan to do :
- Get some Moldex spray and a stiff brush and clean the floor again to hopefully kill the root of the mold.
- This week I will be purchasing a dehumidifier for the basement. I don't know if the previous owner had one. When we saw the house, he had the basement as an office.

Is there anything else I can/should do? This is the first sign we've seen of this. If there is any other mold, the dehumidifier should keep the levels low enough such that it goes dormant, correct?

ccarlisle

Yeah; get yourself a little hygrometer - a scale device that reads relative humidity. Cost about $10, usually comes with a thermometer...then put that down near the floor and let it equilibrate for a day or so - then tell us the readings.

If the reading is over 50% RH and the temperature down there is 60 degF, then you may have a mould problem. Anything less like 35% humidity and 70 degF, means you don't. Mould need something like 70-100% relative humidity and room temperatures to grow but needs those conditions together, not individually.

Do you have good, continuous air movement down there? A good fan is fine if it's not over 50% humidity.

But don't go overboard either; we are surrounded by molds and killing off a colony or three down there isn't going to solve the problem nor do you any harm unless you're seriously asthmatic.

Maintenance 6

A random mold colony in a basement is certainly not unusual. Clean it up and move on. If you have a true moisture problem, it will likely not be in the middle of a tile floor.

Durt Ferguson

I will get a hygrometer and report back in a few days. I pulled one of the baseboards in the bathroom (the lower 40" of the wall is an artificial plastic wainscotting, the larger room uses old-school wood paneling) and was able to see a little behind it and there didn't appear to be any mold. I am going to get that dehumidifier and stop worrying about it.