The radon system is an active sub-slab depressurization system.

 

Drain-Tile Depressurization Systems

The inspector should inspect drainpipes that extend to daylight for missing devices, such as one-way flow valves, or water traps that prevent outdoor air from entering the sub-slab area.

 

Sub-Membrane Depressurization Systems

The inspector should inspect the vapor retarder used for sub-membrane depressurization systems (passive or active) for seams that are lapped less than 12 inches, and edges that are not sealed to the walls, posts, or other penetrations.

 

Hollow-Block Wall Depressurization Systems

The inspector should inspect hollow-block walls for cracks, openings, and open top-courses.

 

Crawlspace Depressurization Systems

The inspector should inspect the crawlspace for the presence of asbestos-like material and combustible fuel-served appliances located within the crawlspace or in spaces adjacent to the crawlspace.

 

Heat-Recovery Ventilation (HRV) Systems

The inspector should inspect the area around the HRV system for the presence of asbestos-like material.

 

Piping and Fittings

The inspector should inspect for:

• penetrations of pipes or ducts that penetrate a firewall or other fire resistance-rated wall or floor not protected in accordance with applicable building, mechanical, fire, or electrical codes;

• submersible pumps not used in systems that use sump pits as the suction point for active soil depressurization if sump pumps are needed;

• joints and connections that are not permanently sealed with adhesives;

• joints and connections that are not airtight;

• attic and external runs subject to sub-freezing that are not protected to prevent the risk of vent pipe freeze-up;

• piping that is not PVC, ABS, or downspout (outside);

• piping that is less than 4 inches in diameter;

• piping subjected to weather or physical damage that is not Schedule 40;

• pipe and fitting connections of different materials;

• piping that isn’t solid and rigid;

• reducers that are installed in the direction of air flow;

• radon vent pipes blocking access to any areas requiring maintenance or inspection;

• radon vent pipes not designed with removable or flexible couplings to facilitate removal of the sump pit cover for sump pump maintenance;

• radon vent pipes not installed in a configuration that ensures that any rain water or condensation within the pipes drains downward into the ground beneath the slab or soil-gas retarder membrane; and

• a missing one-way flow valve, water trap, or other control device installed in or on the discharge line to prevent outside air from entering the system while allowing water to flow out of the system when a radon mitigation system is designed to draw soil gas from a perimeter drain tile loop that discharges water through a drain line to daylight or to a soak-away.

 

OBSERVATION #2: