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Radon vent in slab on grade

user-6825743 | Posted in Energy Efficiency and Durability on

I’m considering a radon perimeter drain in a slab on grade in Coastal Maine (zone 6A) with the vertical pipe to ride in an exterior double stud wall (1 ft thick) for a small library addition.  I wonder if it is possible instead to seal out potential radon with our super-insulated sealed envelope and eliminate the radon drain and vent?  It seems to me that the pipe traveling from under the slab into our envelope would cause more problems.

It is not drawn in the attached detail, but if it were, the 4″drain would appear under the slab insulation just inside the heel and travel horizontally through the heel and the 2″ riser pipe would come up through the exterior wall cavity.

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  1. GBA Editor
    Martin Holladay | | #1

    First of all, can you tell us your name? (I'm Martin.)

    Q. " It seems to me that the pipe traveling from under the slab into our envelope would cause more problems."

    A. A radon riser pipe connecting your sub-slab crushed stone layer to a termination above your roof line won't penetrate your home's air barrier, assuming that everything is properly detailed.

    Note that even a carefully air-sealed Passivhaus can have radon problems. The riser pipe is good insurance, so I advise you to install it. For more information, see these two articles:

    "All About Radon"

    "Radon and a Passive House"

    1. user-6825743 | | #2

      Thanks, Martin. My name is Jeri.

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