Radon Mitigation
Protect your family from invisible radon gas. Our encapsulation systems can be upgraded with sub-membrane depressurization for maximum safety.
Radon is a naturally occurring radioactive gas that forms from the decay of uranium present in soil and rock. It moves upward through the ground and, in homes without adequate mitigation, accumulates in enclosed below-grade spaces including crawlspaces and basements. From there it migrates into the living space above. Health Canada identifies radon as the second leading cause of lung cancer in the country after cigarette smoking. It is invisible, odourless, and the only way to know your home's radon level is to test.
Radon levels vary significantly by geography and soil type. While BC is not uniformly a high-radon province, localized geological conditions — particularly in areas underlain by certain glacial soils or rock types — can produce elevated readings. The only definitive answer for your specific home is a radon test using a long-term alpha track detector (90 days minimum for a statistically meaningful result, particularly across the heating season when windows are closed and the house is under negative pressure relative to outside). Health Canada's action level is 200 becquerels per cubic metre; many practitioners recommend mitigation at levels above 100 Bq/m3.
The standard mitigation technique for crawlspace homes is sub-membrane depressurization (SMD). A suction pit is created beneath the vapor barrier (or the existing ground surface), and a small inline fan draws air from beneath the membrane and exhausts it through a pipe routed to the exterior above the roofline. This creates a slight negative pressure zone under the membrane relative to the crawlspace and living space above, which reverses the pressure gradient that drives radon upward. The system runs continuously on a low-wattage fan and is very reliable.
Radon mitigation and crawlspace encapsulation work well together. A sealed vapor barrier serves as the membrane in the SMD system, so homes that are being encapsulated can have the radon piping installed as part of the same project for minimal additional cost. For homes that already have encapsulation in place, a penetration through the existing membrane, a properly sealed connection collar, and the fan and exterior piping are all that is required.
Ongoing testing after mitigation is good practice. A follow-up test 30 to 90 days after system activation confirms the fan is creating adequate depressurization and that radon levels in the living space have dropped to an acceptable range. After that, periodic testing every two to five years is reasonable to confirm the system continues to perform as intended.