RMS-LB 2018 with 12/20 Revisions

ASD (revised 12/20) 16 ANSI/AARST RMS-LB 2018 (with 1220 revisions) Radon Mitigation Standards for Schools and Large Buildings 6.1.2.3 Labels Required ( sumps ) Sump lids shall be labeled in accordance with Section 8.4.6 a . 6.1.3 Sub-membrane suction points For sub-membrane depressurization (SMD), suction pipe ducting shall extend under the soil gas retarder membrane and shall be installed to prevent obstruction of air volume flow at the air inlet opening(s) of the suction pipe(s). The suction pipe inlet configuration shall be made open to soil air in a manner that allows PFE under the entire expanse of the membrane. Informative advisories —(1) To prevent membrane material from obstructing suction pipes, it is recommended to attach not less than 3 feet (1 m) of perforated pipe to suction pipe air intakes. (2) To prevent restricted PFE , such as where membrane material might adhere to moist soil, it is best to attach ≥ 10 feet (3 m) of perforated pipe. Geotextile matting can also achieve the intent of this recommendation. (3) For large membranes, longer lengths of perforated pipe or multiple suction points are recommended. 6.1.3.1 Seal the Suction Point (membranes) The opening around penetrations of a soil gas retarder shall be sealed in a permanent, airtight manner. Appropriate seal materials shall be applied for ASD duct piping and other utility pipe penetrations through the membrane such as gasket fittings, pipe clamps, roof flashing or an appropriate sealant. 6.1.3.2 Seal the Membrane(s) The soil gas retarder , including seams and edges, shall be sealed to resist air movement between soil and air above the membrane and installed in accordance with Sections 7.6 and 7.7 . 6.1.3.3 Labeling Required (membranes or crawl space access) Membranes or crawl space access locations shall be labeled in accordance with Section 8.4.6 b. 6.1.4 Non-habitable air spaces Note—These ASD systems depressurize an entire airspace that is not used or constructed for habitation. Examples include crawl spaces , utility tunnels, under raised flooring, behind partitioned walls and sometimes entire rooms. 6.1.4.1 Sealing (non-habitable air spaces) When depressurizing a non-habitable airspace, sealing of all surfaces of the non-habitable airspace that adjoin both indoor and outside air shall be performed in accordance with Section 7.9 Sealed Isolation Assemblies. 6.1.4.2 Prohibition 1 Depressurization of non-habitable airspaces , such as crawl space depressurization , shall not be installed unless conditions exist where an area cannot be safely accessed or has insufficient height to work in. 6.1.4.3 Prohibition 2 Depressurization of non-habitable airspaces shall not be used as a mitigation system when: a) atmospherically vented combustion appliances are installed within the airspace to be depressurized; Sub-membrane Pipe to Fan Membrane over soil Pipe to Fan Non-habitable air space