CC-1000_2018

Soil Gas Control Systems ANSI/AARST CC-1000 2018 in New Construction of Buildings 5 less than the combined nominal cross-sectional area for inner diameters of all joined exhaust pipes. Exception: Smaller primary trunk exhaust piping is permitted if supported by prorated calculations for the cross-sectional equivalencies of duct pipe sizes relative to actual size of each plenum or if supported by diagnostic evaluations in accordance with Section 7.4 . 4.7 Limiting plenum and vent system size Design considerations shall include conditions that can warrant restricting the size of certain plenums. Examples include for limiting unintended transport or distribution of toxic vapors or explosive gas, or to compartmentalize active soil gas control for specific occupied locations. 4.8 Ventilated garages not required Garages attached to a foundation system do not require soil gas vent systems if compliant with ANSI/ASHRAE 62.1, Sections 5.15 and 6.5 for ventilation and pressurization of enclosed spaces surrounding the garage. SECTION 5: PLENUM CONSTRUCTION 5.1 Close the bottom of the collection plenum(s) 5.1.1 Subgrade surface closure Existing or constructed materials that surround the bottom and sides of gas permeable layers and permeable components of foundation drain systems shall be earthen materials that contain more than 35% sand, rock fragment fines, clay and silt to restrict permeability or be covered at all locations that do not meet this requirement with a soil gas retarder that is not overlapped or sealed at the seams or edges. 5.1.2 Grade drainage Grading below gas permeable layers shall be sufficient to prevent collected water from obstructing portions of inlet piping , suction pits or inlet trunk networks within soil gas collection plenums . 5.2 Close the sides of the plenum(s) before installing gas permeable materials 5.2.1 Walls and footings Openings below grade in walls and footings that surround soil gas collection plenums shall be closed with appropriate cementious or damp proofing products to include all openings around utility penetrations for plumbing or electrical components and any other openings of similar or larger size. 5.2.2 Waterproofing All foundation walls and floors in contact with the soil shall be damp proofed or waterproofed. Waterproofing methods shall be consistent with Section 1805 of the International Building Code. 8 5.2.3 Gaps and seams on exterior wall surfaces All gaps and seams on the exterior surface of foundation wall assemblies shall be closed, sealed or damp proofed for prevention of soil gas entry to include where walls adjoin footings and attached garages, exterior parking lots, sidewalks, porches, steps and other adjoining constructed closures over soil. 5.2.4 Hollow masonry unit walls In a manner that forms a closed barrier between soil gas within the hollow masonry units and interior spaces, a course of hollow block masonry walls that is not vertically lower in elevation than the adjoining exterior grade shall be made of solid masonry units or shall be fully grouted. Closure is also required for all openings in the wall below this closed course of masonry units using methods that normally include: a) fully grouted or solid masonry units that surround openings in the wall such as for doors, windows and under masonry ledges such as is often provided for brick veneer; and b) fully grouted joints between blocks on both interior and exterior surfaces. 5.3 Foundation drain systems Requirements for soil gas vent systems shall apply to exterior foundation drain systems if an interior soil gas collection plenum is connected to an exterior foundation drain system. 5.3.1 The portions of exterior foundation drain systems that are constructed below grade with materials to enhance permeable paths for water drainage (e.g., gravel, perforated pipe or drainage mats) shall be constructed to include: a) Closure to restrict airflow between outside air and the drainage system's water receptors, in accordance with Section 5.3.2 ; b) Closure to restrict airflow between outside air and the drainage system's disposal components in accordance with Section 5.3.3 ; and c) Inclusion in design for soil gas vent systems in accordance with Sections 4.2 , 4.3 a nd 5.3.4 . 5.3.2 Water receptors (ground or surface water) Closure shall be provided for grade-level drains and open pipes above grade such as roof or window well drains that drain into the exterior foundation drain system. Closure shall be accomplished by surrounding piping and pipe ends with aggregate or soil, capping open pipes, or using one-way flow valves with access provided for future maintenance or equivalent materials or methods. 8 The International Building Code (IBC) 2015 (as published by the International Code Council).