Mold in the basement - advice needed

Old 06-11-16, 02:10 PM
Thread Starter
Join Date: Jun 2016
Location: USA
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
Mold in the basement - advice needed

I'm sure my question gets asked a lot so please bear with me.

My friend has a home in an area with plenty of lakes (although hers is not on a lake) and therefore plenty of groundwater. Her basement has had a previous mold issue on an exterior wall. During that time, she had professionals come in to redo all the drywall, vapor barrier, insulation and framing of that wall. Basically tear down the wall to the concrete block and then put it back together. The pros used some kind of sealing paint on the concrete block wall before putting it all back together. She has the details of the sealant.

Everything seemed ok for a few years. She recently noticed new mold against the floor trim in an adjacent room that shares the same exterior concrete block wall. So I helped her cut away the bottom 18" of the drywall while being careful to not cut the vapor barrier. Not surprisingly, there was mold on the back of the drywall and vapor barrier but it was limited to the very bottom of the wall, near the trim where she saw the mold. The concrete wall appeared to be wet across the now exposed area but it dried out almost as soon as we exposed it. We've let the wall dry out and cleaned out the vapor barrier with bleach. We've been watching the wall for the appearance of more water during some heavy rainfalls and not seen any. Basically the concrete appears dry. I recently purchased a Ryobi moisture meter and it reports 21-26% moisture on the concrete wall which the meter reports as being in an acceptable range.

So my question is this: should we redo the entire wall as before or simply apply sealant to the exposed concrete before replacing the drywall and insulation on the part that was cut way?

Old 06-11-16, 02:19 PM
Join Date: Jan 2011
Location: USA
Posts: 4,463
Received 128 Upvotes on 113 Posts
Moisture issues need to be addressed on the outside wall not the inside.
Proper grading, gutters with long enough down spouts, no mulch or flower beds forming ponds.
Areas sealed where pipes or wiring was run through the wall.
May even need to dig out and water proof the outside wall then add a french drain.
Old 06-11-16, 02:23 PM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,135
Received 1,267 Upvotes on 1,207 Posts
Welcome to the forums.

I would recommend a drainage system to a sump pit with a pump.

Painting sealants on inside walls doesn't make sense to me - you're trying to stop the water after it already got through the wall.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: