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(Active Soil Depressurization) Exterior Installation  

The photo's and diagram illustrate how these systems look when they are installed and what you do not see once they are installed.  Installation procedures are as follows:   Example: a 1,500 square foot slab on grade home. A 4.5 inch hole is cored through the stemwall or monolithic footer from the outside just below the slab level. Low trauma equipment is used to "tunnel" under the home. Creating a long suction point through the middle of the structure. 2 or 3 inch PVC pipe is installed in the tunnel and sealed at the stemwall using expandable foam and concrete to create an air tight sea

The pipe is then connected to the intake side of a radon exhaust fan, which has been mounted on the exterior wall of the home. Since EPA protocol requires the exhaust to vent above the roof line, 3 inch PVC or decorative downspout is installed to extend vertically up the side of the building and around the overhang to terminate above the roof line. This system works on the same principal as any ASD system, to create a slight negative pressure below the slab and draw radon to the suction tunnel and vent it outside before it can enter the home. This system is installed when certain features such as a two story home where closets do not line up on top of each other making it impossible to get pipe into the attic or a home with no or little attic space.

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ASD Interior / ASD Exterior / Crawl Space / Commercial Mitigation Appliciations
Mechanical Ventilation / High Rise And Large Condominiums
Pre Construction / Home