Mildew in hallway

[Doug Edwards]

Just a theory but...you said this home is 1960 circa. Would I be wrong in assuming it is an off-grade house with a crawl space? I live in the South and find many times that older homes do not have adequate (hell, most don't have any) crawl space insulation or a vapor barrier. Moisture will migrate up through the subflooring (usually T & G planking) and into the living area. The thing that keyed me on this one is the fact you mentioned about it only appearing in the summer. Look at the soil under the house (if there is a crawl), check for crawl ventilation, and check the condition and material used for the crawl space. If I find a home that has moisture problems and I do not see stains and evidence when I look "up" then I immediately start to look "down". The other obvious choices have already been mentioned. i.e. the AC condensate pan, line and etc. Just like Inspector Clouseau, I hope you "Es solvide the case"

[jcundiff]

Wow- what a round -about here, there, and everywhere thread!

I do alot of mold remediation and training. I'm surprised that no one questioned if the surface you were refering to was a hospitable place for mold to grow. Its like "why does mold grow on tile grout when mold doesn't grow on tile grout??" The answer is, mold grows on the dead shin and soap residue that coats the tile grout. Same thing happens often on the ceilings just outside of impropperly vented bathrooms. The vapor from the shower carries some of the organic products used in bathing. When the vapor condensates on the relitively cooler surface just outside the bathroom, those organic products are left behind. Mold spores come along to do there job, the occupant give it a nice drink of water vapor every day, bingo. Install a fan, clean the ceiling with a mildewcide every so often whether it needs it or not.

[jcundiff]

[quote=dedwards]The thing that keyed me on this one is the fact you mentioned about it only appearing in the summer.


I think the seasonal issue may be because of the relatively dryer air in cooler months not supporting new mold growth as well as warmer, humid summer air. Also, Outdoor air contains a greater number and variety of molds in the warmer months.

[Steven Brewster]

Good info, Thanks.

Steven