SGM-SF_2017with 12/20 Revisions

10 SGM-SF 11.1.1 Flue Gas Spillage from Combustion Appliances 11.2.3 Asbestos 11.2.4 Lead-Based Paint The chances for flue gas spillage increases with ASD systems that either draw robust volumes of air from a home or draw air from a small room that contain an atmospherically vented combustion appliance. Where suspected asbestos is observed and may be disturbed, postpone work until an accredited asbestos inspector is consulted. In buildings constructed before 1978 where lead-based paint may be present, work practices may require compliance with the EPA Lead Renovation, Repair and Painting (RRP) Rule. SGM-SF Discussion CG 6.3 ASD Pipe Sizing 6.3.1 The minimum inside diameter 6.3.2 larger air volume needs 6.3.3 smaller if needs are verified ASD Pipe Sizing directly correlates to conditions below slabs or membranes in terms of air volumes that are needed to induce negative pressure. 6.3.4 Equivalent cross-sectional area 6.3.6 Maintain whole-system capacity 6.3.5 Multiple suction points 6.3.7 Alternative duct materials 6.3.8 Maximum and Minimum velocities Multiple pipes joined in parallel must retain equivalent capacity for needs of air volume movement. Configurations must not result in reduced air movement capacity that is required for the whole system. CG 6.4 ASD Exhaust Discharge Exhaust configurations for SGM-SF have been harmonized with those in RMS-MF and RMS-LB 2018 CG 6.5 ASD Fan Installation Advisory— The fan location is a health and safety consideration. It must not be located where a pipe connection failure can result in discharged soil gas entering the building. SGM-SF Discussion CG SECTION 7.0 SEALING 7.1 Background and Accessibility 7.2 Sealant Materials 7.3 Accessible Slab Cracks 7.4 Other Openings in Slabs or Walls A continuous air barrier that resists air movement between soil and indoor air is the goal. However, there are practical limits on the extent of sealing that is reasonable or necessary. Sealing efforts must not impair a buildings water drainage and control systems. 7.5 Sumps 7.6 Membranes Over Exposed Soil Specifications are provided to help ensure both durable closure and reasonable access to sump pits and pumps. Appropriate material and installation specifications are provided for soil gas retarder membranes. 7.7 Sub-membrane depressurization Section 7.7 adds more stringent closure requirements for membranes. One challenging situation is when a portion of the crawl space is inaccessible for applying a membrane. In most cases, close all edges of the membrane that are accessible prior to where the crawl space extends into inaccessible areas. If a large expanse is inaccessible, it is still to enclose accessible portions of open soil for sub- membrane depressurization or choose a strategy to create access ports for complete soil closure.