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Second Tap Attic Sub-Slab Radon System

Radon Mitigation System Information

Second Tap Attic Sub-Slab Depressurization Systems are installed in homes or businesses with slab flooring and are necessary in situations where a single tap or collection point is not adequate to bring radon levels down to safe levels. This complexity can be caused by the amount of radon gas found in the location or due to the soil composition found below the establishment. A second tap attic installation involves running PVC pipe from the sub-slab radon collection points to a fan in the attic which draws the gas up and expels it from the building through the roof stack installed in the roof. This is a common practice for homes that need more power or collection points to help mitigate the radon from underneath the home or business.

Second Tap Attic Sub Slab System
Diagram of a second tap sub-slab attic system for radon mitigation.

The system works by creating a negative pressure under the home where the radon collection points have been established, leveraging two collection points instead of just one. The radon fan that is mounted in the attic must run continuously in order for the system to work correctly to mitigate the radon from the building. From the two radon collection points under the slab, the radon gas is collected and the system’s fan pulls the radon gas from under the home out of the radon collection chambers, through the PVC piping up through the attic where the gas exits the building out of the installed roof stack.