Mold/Mildew in ceiling

Three years ago I moved into a house that had minor drywall damage in the ceiling. The previous owner said the origin of the leak had been fixed. (This seemed to be true since the stain never got bigger or seemed wet to the touch.) Recently, the ceiling has started to develop black spots. Is this mold/mildew? The original stains are still not expanding or feeling wet (just the spots). Could I have initiated this by touching or using regular paint to try and touch up the ceiling? I have tried using KILZ, but I don't know if this is doing any good. Can I kill this mold? Do I have to cut it out....How can I tell if the ceiling is still getting wet )if not by touch)?

 

MarkK:

Try applying bleach straight out of the jug to those black spots and see if that clean them up. If it does, and they were mold or mildew, clean the walls with a reasonably strong solution of TSP and repaint with Bathroom paint.

The difference between ordinary latex paint, Kitchen & Bath paint and Bathroom paint is primarily in the amound of mildewcides added to the gallon. Bathroom paint has the most, about twice what K&B paint does. I use Zinsser's Permawhite Bathroom paint tinted an off white I like. In practice, it remains mildew free for well over the 5 years it's guaranteed to remain mildew free.

 

MarkK:

RINSE the TSP off the walls well. I didn't rinse well after cleaning a bathroom with TSP and the paint peeled off the wall.

It's easier to rinse the TSP off than it is to fix a bathroom where the paint is peeling off the walls.

 

How big is the area? Bleach only kills mold on hard, non-porous surfaces like tile, porcelain, etc, but only if it's left on the surface (wet) for 5-10 minutes. Bleach does not kill mold on porous surfaces like drywall and wood

White vinegar actually works well - it kills 82% of mold spores. Or, you could use an EPA registered fungicide. I like MoldStat Plus (amazon.com or homedepot.com). Moldstat cleans and kills mold. TSP will work, it just seems really ... harsh?

BEFORE CLEANING - spray the moldy area with water to help keep mold spores from becoming airborne. ALSO, WEAR GLOVES AND A MASK. Clean with - soap and water; then apply white vinegar (straight from the bottle) to kill the mold. Or, just use MoldStat Plus. Rinse surface and allow to competely air dry.

I'd prime it with KILZ (it also helps cover mold stains) and then paint the entire ceiling wit some kind of paint that contains an antimicrobial additive. OR repaint and then spray area with an antimicrobial surface protectant (it can be used on faucet handles, cabinet doors, high chairs, etc. to inhibit the growth of mold and other microorganisms

 

There is a product called MILGO (- Microban Milgo Plus (formerly QGC)) which is a disinfectant/fungicide/mildewcide that was originally developed for cleanup after fires, flooding, and other events that introduce a lot of water into areas that weren't designed for saturation. It works on both porous and non-porous surfaces and substrates and continues to work for an extended period, unlike bleach, and doesn't have an odor, unlike vinegar. In fact, one of its uses is odor removal. Another is eradicating MRSA on surfaces in hospitals. We used to use it to kill mold and mildew on and in logs and wood siding prior to refinishing.

MILGO is sold as a concentrate for about $45/gal and appears to be available only in commercial quantities these days, i.e., 4-gallon case lots, but you might be able to purchase a small amount from a local water damage restoration company. The formula has probably changed, but we used to mix it at 1 fl.oz. Milgo to 2 gallons water.

Zap the problem area with Milgo, let it dry, and then prime with Kilz. That should be the end of your mildew problem.

 

And once you try all that and find out the mold spores are still there behind the paper and the stain still comes back go in the attic and remove the insulation that by now is all molded up and replace it, and cut out that section of drywall and replace with new.

 

And once you do all that and the mold keeps coming back because the mold spores are in behind the paper go in the attic and remove and replace the molded up insulation and cut out that section of drywall and replace it.

 

Welcome to the forums Jeff8, hopefully the OP has long since solved their mold/mildew issue as it's been over 10 yrs.