Please help a service member find a solution to a huge basement moisture headache…   

We had some mold growth remediated on a foundation wall of an 1885 rowhouse in an unfinished storage area.  We think it had been there for a while, though we’ve only been in the house about a year.   “Didn’t look like mold” according to the inspector – said it was soot or something; see before picture.  (water under the bridge.)  Anyway, we got it tested so we could repoint and paint the room and it turned out to be a benign mold.  We had it professionally remediated in December.  They did a HEPA-vac/wire brush/HEPA-vac with a negative air containment and painted with the fungicide Aftershock. 

Around the same time as the remediation I had the outside regraded because I realized we had some water ponding at the foundation in one specific area (under a deck) and some mortar joints on the wall at the foundation were deteriorated (since repointed), plus there was a gutter failure last summer (since replaced), so I think that contributed to a huge intrusion of water into the wall (included picture also of water coming through the wall during a rainstorm).  It is a very thick, solid brick foundation wall, only about half below grade (you can see where the slate layer is at the grade).

So, one month after remediation the mold growth started to return… and has gotten progressively darker.  Tested and it’s acrimonium-type, which is toxic, so the area is sealed off.  But the wall still needs to dry out we’re told, so we have two dehumidifiers going 24/7 to suck the water out of the wall.  Moisture readings over time have improved, but only slightly.  So we’re in a Catch-22 – need to get the mold remediated (they’ll do it for free), but also need to have the brick wall dry out so it doesn’t come back. 

Have gotten three different opinions:

1.  “The wall needs to dry out to see if the regrading, repointing, and gutter fix has been successful.  Use the two dehumidifiers and maybe rent a desiccant dehumidifier to drop the humidity lower and suck it out faster.”  Cost – $1k to rent the desiccant for four weeks (and the mold sticks around for longer – it’s sealed off, but there are kids in the house so makes us nervous).

2.  “You need a full exterior excavation to seal the wall on the outside.  The water migrating through that wall over the years has created a path for vapors, and it will keep on coming – if you drop the humidity lower you’re just going to draw more moisture from the outside soil.”  Cost – $23k for about 45 linear feet, high in part because there are hardscapes, a small deck, and some brick stairs that need to come out. 

3.  “We can dig an interior trench for you and install a footing drain and a sump pump, then cover it and put a vapor barrier on the walls.  It’s not as ideal for old brick as concrete block, but it will allow the water a path to go, and the vapor barrier on the wall will ensure any microbial growth is contained inside.”  Cost – expect about $8-10k, though don’t have the estimate yet.  Concerned this might contribute to deterioration of the wall if the moisture just keeps on coming through…

At this point I realize I’m probably going to have to throw $$ at the problem – just want to throw it in the right direction and solve the problem for good.  Any opinions, recommendations, BTDT much appreciated…

 As an aside, one thing I’m nervous about is the original mold is still there, being fed by the water coming through the wall, and is now just underneath a “supposedly” fungicidal coating.  Maybe that coating needs to come off with Citristrip or something so the wall can breathe better?  I attached a close-up showing the coating chipping in places, I assume because the water is pushing on it from behind.

Thank you!