CCAH-2020

Reducing Radon in New Construction of ANSI/AARST CCAH 2020 1 & 2 Family Dwellings and Townhouses 6 SECTION 402 SUB-MEMBRANE SOIL GAS COLLECTION PLENUMS 402.1 Crawl spaces without concrete floors. For each suction point in crawl spaces without concrete floors, a soil gas collector shall be installed in accordance with Sections 402.1.1 through 402.1.4 and Section 404.1. 402.1.1 Soil gas collector. Not less than one soil gas collector for each suction point shall be installed in accordance with Section 402.1.1.1, 402.1.1.2,402.1.1.3 or 402.1.1.4. 402.1.1.1 Pipe soil gas collector. The soil gas collector shall consist of a perforated pipe of 4 inch [10 cm] nominal diameter minimum. The pipe shall be not less than 10 feet [3 m] in length. Such piping shall be placed in a trench backfilled with clean aggregate meeting the criteria of Section 403.1.1.1 such that the pipe is completely surrounded by not less than 4 inches [10 cm] of aggregate. 402.1.1.2 Geotextile soil gas collector. The soil gas collector shall consist of a strip of geotextile drain matting not less than 10 feet [3 m] in length and having a cross sectional area of not less than 12 square inches [77 sq. cm]. The strip of matting shall be placed on top of the soil or in a trench. 402.1.1.3 Gravel soil gas collector. The soil gas collector shall consist of a uniform layer of clean aggregate not less than 4 inches [10 cm] in depth placed over the soil. The aggregate shall have a void ratio of not less than 35 percent or shall be in accordance with Size Number 4, 5, 56, or 6 as classified by ASTM C33. 402.1.1.4 Foundation form/drain/vent soil gas collector. The soil gas collector shall consist of a loop of interconnected lineals used to cast the foundation footing and left in place to provide ground water control and provide a separate channel above the ground water channel for soil gas ventilation. Said soil gas ventilation channel shall have a cross sectional area no less than 12 square inches [77 sq. cm]. 402.1.2 Suction points. One suction point shall be provided for each soil gas collector . Suction points shall be installed in accordance with Section 402.1.2.1, 402.1.2.2 or 402.1.2.3 as applicable for the type of plenum installed. 402.1.2.1 Suction point for pipe soil gas collector. The suction point for a pipe soil gas collector shall consist of a pipe fitting or other device having not less than three openings with two openings oriented so as to create multiple horizontal intake openings. Perforated pipe shall be inserted into both of the horizontal openings of the pipe fitting or device. One opening of the fitting or device shall be oriented in a vertical “up” position. Alternatively, the sub- membrane area and the other foundation types shall be interconnected by a pipe loop soil gas collector that is constructed in accordance with Section 403.1.1.3 and served by one or more suction points . 402.1.2.2 Suction point for geotextile soil gas collector. The suction point for a geotextile soil gas collector shall consist of a pipe fitting or other device having not less than three openings with two openings oriented so as to create multiple horizontal intake openings. The horizontal openings shall be connected to the matting in a manner to facilitate airflow from the collector. One opening of the fitting or device shall be oriented in a vertical “up” position.