SGM-SF_2017with 12/20 Revisions

ASD (revised 12/20) 15 ANSI/AARST SGM-SF 2017 (with 1220 revisions) Soil Gas Mitigation Standards for Existing Homes e) where local codes allow temporary removal and airtight replacement of ASD pipe sections to provide access to areas requiring maintenance or inspection of equipment as described in Section 6.2.9. 6.2.7 Secure duct piping 6.2.7.1 Duct piping shall be fastened securely to the structure of the building with hangers, strapping or other supports that will adequately and durably secure the duct material. To durably withstand natural forces such as wind, ice and degradation over time, requirements include: a) Mechanical hardware or fasteners shall be durable for the purpose and weather-rated when employed outdoors; b) The anchoring method and fastening materials shall be suitable to secure the anchors in a durable manner to whatever building surface is chosen for securing the duct piping; c) Existing plumbing pipes, ducts or mechanical equipment shall not be used to support or secure duct piping; and d) Fastening systems that rely only on extending a nail or screw through the duct piping and into a wall or other supporting surface shall not be used to secure duct piping. 6.2.7.2 Supports for ASD plastic piping shall be installed no less than every 10 feet (3 m) on vertical piping and 4 feet (1.2 m) on horizontal piping. Alternate ASD duct materials identified in Section 6.2.5 , such as iron, steel or copper, shall be secured in a manner that meets codes 5 and manufacturer recommendations. Informative advisory —Configurations that prevent both lateral and vertical movement of duct piping are far less vulnerable to failed joint connections, dislodged rubber couplings and water leaks. Where exposed, such as in basements and attics, pipe lengths that can move laterally or vertically are commonly witnessed to cause failed or leaking joint connections. This is known to occur merely as a result of occupants or workers jarring or bumping into pipes, or by natural forces such as wind. 6.2.8 Unnecessary noise Duct piping, fans and support configurations shall be installed in a manner that minimizes transfer of vibration to the structural framing of the building. Suction pipe openings, such as under membranes and in non-habitable airspaces, shall be configured to minimize unnecessary objectionable air-rushing noise if the noise can be heard inside occupiable spaces. Note— Section 6.3.8 Air Velocities provides guidance on air-rushing noise at the point of exhaust . Common methods to reduce other objectionable air-rushing noise, such as under a membrane, include: a) reducing the size of air inlet pipe openings (if air volume flow of the duct pipe is greater than needed to establish a vacuum); b) extending perforated pipe under a membrane or into a non-habitable airspace to allow the same air volume to enter more slowly through dozens of slits or holes; and c) altering whole system airflow (when pipe or fan are transporting significantly more air than needed to establish a vacuum in all airspaces being depressurized). 6.2.9 Provide access clearance Duct pipe routing shall not: a) block egress from entrances and exits to the building, including those designated for fire and safety; c) compromise effectiveness of fire suppression systems; or 5 As point of reference for securing alternative piping, see, as applicable, the International Mechanical Code (IMC), the International Plumbing Code (IPC) or the International Residential Code (IRC) that are published by the International Code Council.