The following checklist is a quick reference guide for field use. If additional state non-compliance, structural or health-safety issues are detected, note such issues and report immediately your regulating entity. It is good practice for radon professionals to periodically (at least annually) review mitigation standards and update your personalized field checklist. Inspect for marked or unmarked passive systems to document in report. Builders sometimes install passive or skeletal systems during construction. These systems may ormay not be effective and may or may not be clearly marked as a radon system. Observe all the vent chases for a possible mitigation system.
Radon Vent Pipe Installation
- The main run of vent pipe, from primary suction point to exhaust is a minimum 3-inch in diameter (exteriorly 3-inch by 4-inch metal downspout may be used).
- Ideally, vent pipe and fittings are Schedule 40 PVC, should be air tight and properly joined / sealed.
- Schedule 20 PVC may be used but is not a best practice.
- Vent pipes are supported every 6 feet on horizontal runs, every 8 feet on vertical runs that do not penetrate floors, ceilings or roofs and supported at the floor.
- Vent pipes are installed in a configuration that ensures that any rainwater or condensation drains downward into the ground beneath the slab or soil gas retarder membrane.
Vent Stack Discharge Point
- The vent stack discharge point is above the highest eave of the roof and as close to the roof ridge line as possible to prevent re-entrainment of radon or direct exposure of individuals outside the building to high levels of radon.
- The vent stack discharge point is 10 feet or more above the ground level.
- The vent stack discharge point is 10 feet or more from any window, door or other opening into conditioned spaces of the structure that is less than 2 feet below the exhaust point.
- The vent stack discharge point is 10 feet or more from any opening into an adjacent building.
- Vent stacks that penetrate the roof must discharge point at least 12″ above the surface of the roof.
- Vent stack pipes attached to the sides of buildings must also discharge at least 12″ above the roof.
Soil Gas Retarder Requirements
- A soil gas retarder membrane should be installed in crawlspace areas without a concrete floor.
- The soil gas retarder membrane should be a minimum of 6-mil (3 mil cross-laminated) polyethylene.
- Seams are overlapped at least 12 inches and sealed using compatible glues.
- The soil gas retarder is secured to the wall using furring strips or appropriate caulks.
Sump Pit Requirements
- If the sump pit is used as a primary or secondary suction point it should include rubber couplings.
- The sump pit is covered durable plastic or clear polycarbonate material, sealed and incorporates a clear view-port to permit observations of conditions in the sump pit.
Radon Vent Fan Installation (for active systems only)
- The radon vent fan should be installed in the attic, in garages that are not beneath conditioned spaces or on the exterior of the building.
- The radon vent fan is installed in a vertical run of the vent pipe.
- The radon vent fan is mounted to the vent pipe with removable or flexible connections.
Inspect for marked or unmarked passive systems to document in report
- Observe all the vent chases for a possible mitigation system.
- Builders sometimes install passive pipes during construction. These systems may or may not be effective and may or may not be clearly marked as a radon system.
Monitors and Labeling
- Vent pipes are labeled “Radon Reduction System” on each level where pipe is visible.
- An exterior vent fan and vent pipe installation should be clearly labeled “Radon Reduction System” in a weatherproof manner.
- The circuit breaker controlling the circuit on which the radon vent fan operates is labeled “Radon Reduction System.”
- A manometer is installed and clearly marked indicating the initial system differential pressure readings.
As a best practice, a system description label should be installed next to the manometer. This label or ‘Tag’ is a requirement in some states such as Illinois and Ohio. The Tag information must include:
- Installers Name
- Installers Phone Number
- Installers License/Certification Number
- Date of Installation