micgall

Hello,

I have been working on my basement (unfinished) when I have free time. I have been installing drywall over the last year and was preparing to paint. I noticed surface mold along the floor line (on the dryall - standard; non mold resistant drywall).

I am wondering if it simply caused by the fact that my floor (non finished) is causing the issue and that this situation will be remedied by floor covering. Or (option 2) do I need suspect the worst?

CallMeVilla

Your floor covering will not help. The problem is excess moisture originating through the floor or the wall. Basic drywallis a bad choice in basements because of moisture. ALWAYS use mold resistant board in basements which might have moisture problems. Did you install a vapor barrier in the wall?Also, did you leave a gap along the floor line so the drywall does not sit on the floor?

I fear you will have to remove some of the existing drywall (near worst mold area) to check for the source of the moisture.

Get rid of the wetness or you will have big mold issues forever.

nealtw

Did you check for dampness before you started. Did you keep the wood structure away from the concrete and did you put something waterproof under the bottom plate.
Doing a basement a little at a time can cause problems all by it self. If you have done everything right, warm moist air can get behind your wall and cool off where the moisture can condence and cause wet insulation, drywall and mold.

micgall

[QUOTE=CallMeVilla;74630]Your floor covering will not help. The problem is excess moisture originating through the floor or the wall. Basic drywallis a bad choice in basements because of moisture. ALWAYS use mold resistant board in basements which might have moisture problems. Did you install a vapor barrier in the wall?Also, did you leave a gap along the floor line so the drywall does not sit on the floor?

Let me preface by saying the house is 5 years old and has dimpled high-density polyethylene (HDPE) membrane and I have had zero moisture through the walls. The house is a ranch style with an 8`basement with about 1' over grade.

Here`s what I have; 2" x 3" framing (pressure treated directly on floor). A 1" gap between framing and foudation wall with R12. Over this a 6mm vapour barrier, then the drywall.

I have removed two sheets and found little or no moisture (maybe some mold, but mostly looks like dust marks from my fingers). I do see humidity inside vapour barrier on the insulation side. This accumulation has dropped to the pressure treated framing base an seems to have caused mold issues on the inside (front) side of the drywall.

I have washed the walls where the mold was spotted, purchased a dehumidifier and am waiting 3-4 days to see if the mold returns.

nealtw

Concrete is not waterproof and moisture will draw from cold to warm. Treated lumber may be a good idea but it in it self will not stop moisture from wicking. You should have sill gasget under it to prevent wicking. A 2x3 wall 1" from the wall leaves your insulation touching the concrete. The 1" space is there to allow air movement behind insulation and should be treated as a cold zone.
Your problem could still be caused by the vapour barrier or lack of. I can see you had it there but you have not got the outlet box in the plastic box for vapour barrier and the the poly should have been sealed to the floor with aquostical sealer(black goop in a caulking tube)
You have seen in new house constuction a space between sheets of plywood when the house is being built. That allows any moisture in the wall to dryout. Out here that space is required in every bay even if we have to drill holes under window and such.
That isn't always watched carefully in an unfinished basement but should be looked at.
Not related but there should be staple holding that wire above the box.