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The Pennsylvania Code website reflects the Pennsylvania Code changes effective through 54 Pa.B. 2336 (April 27, 2024).

25 Pa. Code § 240.308. Radon mitigation standards for detached and attached residential buildings three stories or less in height.

§ 240.308. Radon mitigation standards for detached and attached residential buildings three stories or less in height.

 (a)  The certified individual shall conduct a thorough visual inspection of the building prior to initiating any radon mitigation work.

 (b)  Terminal discharge. To prevent re-entrainment of radon, discharges of depressurization systems, whether fan-powered or passive, must meet all of the following requirements:

   (1)  The termination point shall be above the immediate edge of the roof for vent pipes attached to the side of the building.

   (2)  The termination point must be vertical, upward, outside the structure and discharging to the atmosphere. A 45-degree elbow is permitted. Rain caps may not be used.

   (3)  The termination point must be 10 feet or more above the ground level nearest to the point of discharge.

   (4)  The termination point must be 10 feet or more from an operable window unit, door or other opening into conditioned spaces unless it is 2 feet above the top of the openings. The 10-foot distance may be measured directly between the opening and the exhaust point or with a flexible tape following the shortest path possible around intervening solid objects. A chimney is not considered an opening into conditioned spaces.

   (5)  The termination point must be at least 5 feet horizontally from a vertical wall that extends above the roof or higher than the vertical wall.

   (6)  The termination point must be 10 feet or more from an opening into an adjacent structure and be:

     (i)   At least 12 inches above the surface of the roof for vent pipes that penetrate the roof.

     (ii)   At least 10 feet from any openings of conditioned spaces in the structure.

 (c)  Fan location. A radon fan used in active soil depressurization or a block wall depressurization system may not be installed:

   (1)  Below grade, in a window well or egress window well, or in the conditioned space of a building.

   (2)  In a basement, crawl space or other interior location directly beneath the heated or cooled spaces of a building.

 (d)  Sealing.

   (1)  When accessible, the following are required to be adequately sealed with urethane caulk or equivalent material using methods and materials that are permanent and durable when installing a mitigation system:

     (i)   Perimeter channel drains.

     (ii)   Cracks that exist where the slab meets the foundation wall (floor wall joint).

     (iii)   Expansion or control joints.

     (iv)   Openings around utility penetrations of the foundation walls.

     (v)   Sump pits that allow entry of soil gas or that allow conditioned air to be drawn into a sub-slab depressurization system.

   (2)  When the opening or channel is greater than 1/2 inch in width, a foam backer rod or other equivalent filler material shall be inserted into the channel before application of the sealant. Materials inserted into the channel must leave adequate space below the filler material to allow subsurface drainage from the channel into the subslab material.

   (3)  If the mitigator and homeowner determine that the perimeter channel drain cannot be sealed for water control reasons, then the mitigator may leave those areas unsealed and shall provide the following written statements to the homeowner:

     (i)   This technique may contribute to increased heating and cooling costs.

     (ii)   This technique may reduce the effectiveness of the radon mitigation system.

     (iii)   This technique may increase the potential for backdrafting natural draft combustion appliances.

 (e)  Labeling.

   (1)  If the mitigation system is accessible and visible, a system description label shall be prominently and permanently affixed to the mitigation system piping. If the mitigation system is concealed or not accessible, then the label shall be placed in another prominent location. The label must be legible from a distance of at least 3 feet and include all of the following information:

     (i)   ‘‘Radon Reduction System.’’

     (ii)   The name and certification number of the mitigation certified individual or firm.

     (iii)   The contact telephone number of the mitigation certified individual or firm.

     (iv)   The date of installation.

     (v)   ‘‘Building should be tested for radon at least every two years.’’

   (2)  Each exposed and visible interior radon mitigation system vent pipe section shall be identified with at least one label on each floor level. The label must read ‘‘Radon Reduction System.’’

 (f)  Required client information. Upon completion of the mitigation project, the mitigator shall attach an information package to the mitigation system in a secure and permanent manner, visible location and labeled ‘‘Radon Mitigation Information.’’ The information package must include all of the following:

   (1)  A copy of contracts and warranties for the mitigation system.

   (2)  A description of the installed mitigation system and its basic operating principles.

   (3)  A description of the proper operating procedures of installed mechanical or electrical systems, including the manufacturer’s operation and maintenance instructions, drain-filling instructions and warning device interpretations.

   (4)  A list of appropriate actions for the client to take if the system failure warning device indicates system degradation or failure.

   (5)  A recommendation to retest at least every 2 years.

   (6)  A recommendation to have an electrical inspection performed on the applicable components of the installed system.

 (g)  Compliance. A person conducting radon mitigation activities shall conduct the mitigation in accordance with Department-approved mitigation standards and shall comply with applicable statutes, regulations, ordinances and building codes. The following protocols, ‘‘Protocols for Radon and Radon Decay Product Measurements in Homes,’’ ‘‘Indoor Radon and Radon Decay Product Measurement Device Protocols’’ and ‘‘Pennsylvania Radon Mitigation Standards’’ are available upon request from the following source:

 Department of Environmental Protection Bureau of Radiation Protection Rachel Carson State Office Building, 13th Floor 400 Market Street Post Office Box 8469 Harrisburg, Pennsylvania 17105-8469


   The provisions of this §  240.308 amended under sections 301 and 302 of the Radiation Protection Act (35 P.S. § §  7110.301 and 7110.302); section 1920-A of The Administrative Code of 1929 (71 P.S. §  510-20); and the Radon Certification Act (63 P.S. § §  2001—2014).


   The provisions of this §  240.308 amended May 16, 2008, effective May 17, 2008, 38 Pa.B. 2243; amended October 26, 2018, effective January 24, 2019, 48 Pa.B. 6791. Immediately preceding text appears at serial page (388457).

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