Radon Resistant New Construction in Colorado
Colorado and the entire Rocky Mountain area is a hotbed for radon. All new homes in the region should be built using radon resistant techniques.
Passive radon mitigation systems can potentially keep radon levels low without the need for an eclectically powered radon fan. The way these systems are designed is through several phases during the construction process.
How radon resistant systems are installed.
- The plan- in some situations the architect or builder will spec a radon mitigation system in the plans. In other cases a certified radon professional will make a RRNC plan.
- The Sub-Rough- After the foundations and footings are poured but before the concrete slab, the soil contacting components are installed. The codes, standards and recommendations vary from state-to-state and city-to-city. Most RRNC sub-rough will have a soil gas collection system of perforated pipes buried in a gas permeable layer of clean gravel. These pipes will attach to one or more radon suction pipe riser. After the gravel is moved in but before the slab is poured, a plastic vapor barrier may be installed.
- The Rough- After the slab has been poured, the building is in frames and before drywall is placed, the rough components are installed. A radon suction riser pipe is attached to the previously installed suction point riser(s.) This suction pipe (vent stack) is routed inside an interior wall or flue chase in as vertical of a path as possible. A space large enough to access and accommodate the future potential for radon fan is left in the attic. The pipe then continues through the roof to vent radon gas safely above the home.
- The Post Test- After the building has been finished and is ready for occupancy, a radon test should be completed to know if the passive nature of the system is enough to keep radon levels below the EPA action level or the clients personal satisfaction. If radon measurements are low, follow up with another test at least every two years.
- The Activation- If radon levels are elevated after testing, the passive/RRNC system can be activated using an electrically powered radon vent fan. This fan is installed in the attic space and creates twenty-four hour suction in the previously installed radon suction pipes. This creates negative pressure in the soil below the home which collects the radon gas and vents it safely above the building.
- The Post Activation Test- Test again to make sure activation reduced the radon levels. Retest for radon every two years whether the system is active or passive.
Hide the radon system, be more efficient.
Radon mitigation systems that are installed using RRNC techniques are more effective than retrofit systems. If the system is unable to reduce radon passively, the activation can usually be done using a lower power radon fan. The lower power fan will save on the cost of electricity and reduce the amount of conditioned air that is removed from the home.