The Radon Resistant Construction Act

  • 32 ILAC 422.160 contains the requirements of The Radon Resistant Construction Act.
  • This Section contains the requirements for new construction in Illinois in accordance with the Radon Resistant Construction Act [420 ILCS 52].
  • The following required construction methods are intended to resist radon entry and prepare the building for post-construction radon mitigation, if necessary.
  • Required in all ILLINOIS Counties, Municipalities. 
  • All components of the radon vent pipe system must be installed to provide positive drainage to the ground beneath the slab or soil gas retarder.
  • Radon vent pipes must be accessible for fan installation through an attic or other area outside and above the habitable space. The radon vent pipe need not be accessible in an attic space when an approved roof-top electrical supply is provided for future use.
  • 32 ILAC 422.160 MS in New Residential Construction

  • Option I – Suction pit with “T” Pipe
    • A minimum 3-inch diameter Schedule 40 PVC must be embedded vertically into the sub-slab aggregate or other permeable material before the slab is cased.
    • A “T” fitting or equivalent method must be used to ensure that the pipe opening remains within the sub-slab permeable material.
    • Alternatively, the 3-inch pipe must be inserted directly into an interior perimeter drain tile loop. 
    • The vent pipe must be extended up through the building floors, terminate at least 12 inches above the highest roof in a location; at least 2 feet above any window or other opening into the conditioned spaces of the building and 10 feet from any window or other opening in adjoining or adjacent buildings.
  • Option II  – Cored Suction Point
    • A penetration into the sub-slab permeable material may be cored through sub-slab after the slab is cased. 
    • A minimum 3-inch diameter Schedule 40 PVD embedded vertically into the sub-slab aggregate or other permeable material
    • Must extend up through the building floors
    • Must terminate at least 12 inches  above the penetration in the highest roof
    • Must terminate in a location at least 2 feet above any window or other opening into the conditioned spaces of the building
    • Must terminate at least 10 feet from any window or other opening in adjoining or adjacent buildings