I just joined but wanted to share my experience with mold behind wallpaper and where I'm at with the project.
We moved into our house a little over 2 years ago. The inspection report noted some mold in the bilco door stairwell in the basement. We had this professionally remediated, including the removal of all of the drywall along that back wall of the basement and the carpet. It cost $4K, and I wasn't that impressed with the work. They left he basement steps full of glue and staples, and I don't believe they used the proper containment methods after learning more about the industry standards...
Anyway, for probably about a year after that I complained that I could still smell some mold in the house, particularly in the living room. I'm not really sensitive to it allergy wise, but I don't like the smell at all and knew I smelled something. Nobody else was really smelling it though, so I ultimately let it go each time I brought it up. Well, that's until I realized the wallpaper peeling behind one of the reclining chairs against the outside wall.
I pulled back the wallpaper and was instantly hit with a rambunctious MVOC orgasm. And the visible mold was unsettling, to put it mildly. I pulled back some more paper in another area and found more mold. Pretty much every area along the outside wall had some mold behind the wallpaper. I pinned back the wallpaper and gave some thought about what to do and decided I was going to take the money I would normally pay to a remediator and do the job myself.
The first thing I wanted to confirm was whether the mold was on the other side of the drywall or if it was contained just behind the vinyl wallpaper which was also painted - which meant it did not let that wall breathe at all. So I used some Concrobium Mold Control from Home Depot on a section that looked pretty bad, effectively killing the mold in the general location and then cut a small hole with a hand powered jab saw. I was able to confirm the other side of the drywall did not have mold growing on it. This left open the possibility of saving the drywall, although many remediators will not suggest such a thing. The IICRC S520 (yes, I've read it) for the most part plays it safe and suggests removing anything that isn't a non-porous surface if it has visible mold growth. This approach is ultra conservative and most certainly leads to many remediation jobs being more extensive than necessary.
Here is a list of the things I purchased for the job:
Abatement Technologies Predator 750 air scrubber
10" diameter 24' long Heavy Duty Flex Ducting
Locking clamp for Flex Ducting
10" Powder Coated Inlet/Exhaust Collar for Flex Duct
Pullman-Holt 45 wet/dry HEPA vacuum
Set of 4 10' zip poles
1 gallon of Concrobium Mold Control Disinfectant - Professional
Concrobium Mold Stain whitening agent
North Safety 7700 series Respirator
North 75SCP100 Combination Gas and Vapor Cartridges
2XL Tyvek suit
DIF Wallpaper Remover
3.5 mil 10'x25' plastic sheeting
.7 mil 9'x15' plastic sheeting x 3
Disposable yet absorbent painters' throw - 4'x15'
Disposable Nitrile gloves
2 Garden Sprayers
1.88" thick Masking Tape
With these things I was able to set up containment in the room and tackle the job. I used the 10'x25' plastic sheeting to setup the wall for the containment with the zip poles. I then used the masking tape (3 days safe to pull without damage) to seal the edges around the ceiling, side walls, and floor. I then setup the floor to be covered with the .7 mil plastic. This plastic is very flimsy, but I utilized the plastic on the floor in this combo: 1 layer of plastic taped on top of the hot water heater elements and the basement, the absorbent painters' throw, and then another layer of plastic on top. This may be overkill, but I didn't want the wood floors to get wet.
I hooked up the air scrubber to exhaust air from within the containment (the side where I was going to be working) out the window. The result was a room under negative pressure. A good way to tell that you have a negative pressure is to look at the plastic and see which direction is being blown. When you are in the room that is experiencing negative pressure, the plastic will be sucked/blown toward you. This is because air is leaving the room faster than air is being replaced. This results in air from the other side of the barrier trying to rush in to the work space to displace that lost air. This is a safer way to do this kind of work because you wouldn't want air flow to be blowing into the other areas of the house should the containment fail for some reason. If the containment failed, the air from within the house would be blown into the work area and quickly exhausted outside. Note that changing pressures within a home can starve other appliances that require a draft to operate properly. If possible, it may be a good idea to turn these appliances off (boiler, wood burning stove, etc.) to avoid issues with carbon monoxide. It’s better to be safe than dead.
I then removed all of the wall paper and used the DIF in a garden sprayer to remove all of the mold soil and top layers of wallpaper glue. I used paper towels to wipe the walls clean, removing much of the mold in the process. I followed up with a nice soaking of the Concrobium Mold Control Disinfectant. I followed up yet again with the DIF, along with another soaking with the Concrobium Mold Control.
I did this all yesterday. Right now I have the room still setup with the containment in place and the air scrubber doing its job exhausting air outside. Today I plan on HEPA vacuuming the area to get all the flakes and nonsense that came off the walls. I then plan on using a putty knife and some DIF to remove the remaining and stubborn wallpaper glue – it must have been applied with Gorilla snot.
I will try to post some after pictures to help all see how far it has come. I do hope this may help some others who may fear going through so much to do the job yourself. If I can do it, anyone can.