RADON MITIGATION INSPECTION ELEMENTS
(1) Vent pipe size/type and labeling
* Vent pipe/fittings appear to be PVC, ABS (or equivalent; down spout OK outside).
* Vent pipe diameter is approximately 3-4".
* Vent pipe labeled as "radon reduction system"; on each level where pipe is visible.
(2) Vent pipe location and installation
* Vent pipe appears to extend at least 10-feet above the ground, and at the exhaust point to end above the eave/roof (6-24" is typical)
* Vent pipe appears to end at least 10-feet from any opening into conditioned space (e.g., window or door), or at least 2-feet above any such opening.
* Vent pipe appears to end at least 10-feet from any opening into conditioned space (e.g., window or door), in an adjacent or nearby building.
* Fire collar/damper appears to be present if vent pipe penetrates fire rated wall or ceiling.
A short rough-in vent pipe ending above the slab within the basement is capped. (This type of vent pipe is not an approved installation. As a safety precaution the vent pipe should be capped or sealed to prevent radon entry. These installations are incomplete and a consequence of non-conformance with recommended standards)
(3) Vent pipe system Integrity
* Pipe, fittings/connections appear to be air tight, properly joined/sealed.
* There are no visible openings or breaks in the pipe system.
* A pressure monitor is present and operating, and is accessible.
(4) Vertical vent pipe penetration(s) (to subsoil beneath the basement floor or slab)
* The sealing/caulking around the vent pipe in the basement floor is intact.
* A vertical or horizontal vent pipe penetration is present in a (full or partial) crawl space.
* The crawl space vapor barrier (soil-gas-retarder, e.g., polyethylene) appears to extend to the foundation walls, and the seams appear to be overlapped by at least 12"
(5) Electrical (for active systems only)
* Vent fan plugged cord connection appears to be no more than 6-feet long.
* Vent fan plugged cord connection is visible, and not concealed within a wall.
* If outside the building, the vent/mitigation fan is hard wired to a disconnect switch.
* Vent fan appears to be wired into a non-switched circuit. (That is, not wired through any other switches, e.g., lighting wall switch.)
* The circuit/breaker controlling (hard-wired) vent fan is labeled "Radon System".
(In active systems only; a non-electric instrument, e.g., U-Tube manometer, cylinder, or gauge; or an audible instrument.)
(6) Vent or Mitigation Fan(s) (for active systems only)
* If outside, the fan is not below ground (e.g., in a pit).
* Vent fan is mounted in a vertical (not horizontal) section of pipe.
* If inside, the fan is located in an unconditioned space, e.g., the attic.
(A fan located in the basement does not meet post-1991 EPA recommendations or standards.)
(7) Sump
* If the sump is sealed, a trapped drain (or equivalent) should be present and located in the sump cover.
(Independent of whether the vent pipe(s) passes through the floor/slab or is installed in the sump.)
A periodic inspection of an installed Radon mitigation system is necessary to ensure that the system is working properly. Unfortunately, mitigaton systems have been installed by unqualified people. The system that was installed may no longer be capable of removing Radon from the house. Also, the amount of Radon entering the house may have increased over time and the original system cannot effectively remove the higher concentration. The EPA recommends inspection of a mitigation installation and performing a Radon test every two years.
The following inspection list was derived from the ASHI (R) mitigation inspection. Virginia Inspection Service provides this service as part of a standard home inspection or as a stand-alone inspection in conjunction with a short-term radon test.
