DIY mold project- am I in over my head?

Hi everyone,
I had some water leaking in between the drywall and brick on my 1912 rowhouse on the back wall and suspected there was mold. The source of moisture was a bad window/door that I have since replaced. I got a professional mold company to take a look at the wall, and the guy told me that his company would be more expensive than necessary, and that I could probably do it myself or hire a handyman. I took his candid advice to heart and made a plan. After sealing the area with plastic sheeting, I started removing the drywall and plaster until I got down to the brick. Then, my plan was to clean the brick with concobrium and a brush, then paint it with zinsser mold killing primer, before installing extruded polystyrene insulation and hanging new mold resistant drywall. As I removed the drywall and plaster, I saw that most of the brick is covered in black, which gave me concern that I had encountered extensive black mold and was maybe in over my head. Mostly it's dry and I can peal it off, but in some places it smudges. Honestly, I don't even know if it is mold, and if it is, if it is too dangerous to proceed with treating it as planned. So, I'm just looking for some feedback from the group - should I call in the professionals, or is it safe for me to do as a DIY project? If it can be done DIY, any thoughts on my plan? I'm attaching a few photos for reference- most are its current state, but also attaching 1 from before I sealed off the area and removed the drywall.
Thanks so much in advance for the help!
Gabe

before putting up plastic sheeting and removing drywall.

 

Pretty sure the black stuff you are peeling off the brick with your thumb is asphalt.

The only mold i see was on the drywall.

 

I agree..... asphalt was originally used as a waterproofing product.

 

Thank you PJMax and XSleeper! That is a relief to hear. In that case, I think I'll peel/scrub it off and use extruded polystyrene insulation as my air/vapor barrier directly on the brick. Then mount furring strips through the insulation and into the brick using tapcon screws and hang drywall on the furring. Does that plan sound good to you? FYI- I live in Washington DC, so we have hot humid summers but also a few months of cold weather.

 

I think that before you go any further, you would be wise to brush or roll some sort of thick waterproof coating onto the brick to do the same thing that the asphalt was doing. Brick is not waterproof.

 

Something like this masonry sealer? https://www.homedepot.com/p/BEHR-PRE...8001/100179930

I could actually apply it both to the interior and exterior of the brick wall.

 

No. That is thin like water and needs to be reapplied. You want something thick, just like the asphalt that was on there before.

 

I'd apply a liberal coat of drylok - that should do the trick.