Vapor barriers & mold
ElEs
| Posted in Green Products and Materials on
I live in a rural area (95415) without attic , only some walls with R13 insulation.
I am considering NSF certified elastomeric paint to cover shingles for the purpose of collecting rainwater for potable uses. It serves to cover toxic shingles, acts as a cool roof as well as a vapor barrier.
I am also planning on 2-3 coats of latex paint for the interior walls and ceilings of the kitchen and bathroom. This should also act as a vapor barrier.
I’m wondering if any building science folks might comment on the potential for mold potential between 2 vapor barriers.
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Replies
Laura,
Adding paint as you describe (a roof coating to cover your asphalt shingles, and interior latex paint on your walls and ceiling) will not cause any vapor problems, moisture problems, or mold problems.
That said, without knowing more about your house -- what type of insulation you have in your roof assembly, how thick it is, and whether or not your roof assembly has a ventilation channel -- it's hard to know whether you have a pre-existing condition that might cause problems.
THANK YOU IMMENSELY. I may be able to catch rain this winter (after gutters, roof paint, water tank, etc.) Appreciatively, Laura
Laura said; "I am considering NSF certified elastomeric paint to cover shingles for the purpose of collecting rainwater for potable uses"
Do you plan on drinking this water?
I concur with Martin on the needed details. If your interior humidity surpasses 60% rh for long periods of time then you may risk mold forming in your home. You can control humidity via ventilation or dehumidification if this is your experience. Paint without moisture will not cause mold.