Mold Kill Primers & Dormant Mold

  1. MOLD KILLING PRIMERS: What is IAC2 and EPA thoughts about the primers being sold to DIY people called “MOLD KILLING PRIMERS”. It seems like it goes against all of our EPA training unless, the mold happens to be less than 10 sq-ft but even then we would recommend cremoving contaminated porous material. The attached Zinnser instructions discusses EPA but sounds like it can just be rolled right on to mold although it mentions if mildew needs removed, use EPA approved remover. It also doesnt address what is behind the walls which brings me to my second question.

Are you okay with homeowners and home flippers just killing mold with these type products.

  1. DORMANT MOLD behind walls: Another question, I a did a Roof Inspection Only where the roofing material had been laying off for quite some time warping the sheathing. The ceiling was warped and water stains on wall and in attic there was thick mold. The area under the exposed warped sheathing was vaulted with no visible internal sheathing access.

A very large well known respected Mold Re-mediator in Kansas City area gave price to re-mediate the one small section of mold but said that when they reroof, it didnt matter if there was mold on the drywall or studs inside that corner that it rained on the whole time because the mold would be dormant.

I advised my Client against this so she ended up walking from the deal (which Realtor likely didnt appreciate). I told her all mold is an allergen and although it lays dormant, it is in the wall and with humidity or another leak the roots will start allowing growth again. I also told her that the microscopic pores could spread if disturbed, so I would recommend that area be looked at further and all porous materials be replaced and all wood scrubbed/sealed per the mold protocols we are trained in.

Thoughts please

Steve Anzelc CPI PE
Dove Inspections
Best of Houzz Service Category

You are basically right in what you are saying. Dormant mold will start to grow after moisture or humidity is reintroduced. Mold needs to be removed from wood before sealing. Any porous items should be removed at least two feet from any visible mold. The most used standard on mold remediation is the ANSI/IICRC S520, 3rd Edition, which does a decent job explaining this.

AS James said dampness = mould .
You need to control the moisture to control the mould .

Over 50% and it will grow We try to keep, our home under 40% Right now temp is
72 F and moisture is 28% out side is 28f