I am considering doing a sub-slab mitigation system in my house/garage...as you may know this is simply a low level active or passive suction through pvc pipe from below slab to roof. Drilling into the slab will result in penetration of the vapor barrier, which worries me a bit for possible moisture issues...is my concern justified or would this small penetration not be an issue to worry about? Also, would it be possible to use spray foam or something to re-seal best I can? Thanks so much for any insight.
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Vapor barrier penetration question...
- Thread starter jlane
- Start date
Radix2
Well-known member
No issue, vapor barriers are effective based on % of coverage. Say it was 1000sq ft, cut a 1x1 hole, vapor barrier is now 99.9% effective.
An air barrier needs to watch small holes where pressure can drive wind and water, but vapor barriers are based on overall permeability.
An air barrier needs to watch small holes where pressure can drive wind and water, but vapor barriers are based on overall permeability.
LegacyIndustrial
ALLIANCE MEMBER
Seal the penetration as best you can. Water will seek the path of least resistance.
We had a Radon mitigation system in our previous house. This was 4" PVC tube through the basement slab into the underlying gravel. This tube was vented up and out of the house. It had a constantly running fan that pulled a small vacuum from under slab. Never any moisture buildup and likely a drying effect for the under slab space. FWIW.