Issue link: https://hi.iaq.net/i/248503
www.epa.gov/iaq/moisture Term Definition PVC A generic term for single-ply plastic sheet membrane (polyvinyl chloride). Seams are fused by solvent or hot-air welding techniques. R-value The number of minutes (seconds) required for 1 Btu (joule) to penetrate one square foot (square meter) of a material for each degree of temperature difference between the two sides of the material. The resistance of a material to the passage of heat. The reciprocal of conduction (1/c). Scuppers An opening for draining water, as from a floor or the roof of a building. Section A drawing showing the kind, arrangement and proportions of the various parts of a structure. It shows how the structure would appear if cut through by a plane. Shingle-wise The overlapping of materials shingle style so that impinging water, such as rainwater, will run harmlessly down and out. Slope The ratio between the measures of the rise and the horizontal span. SMACNA Sheet Metal and Air Conditioning Contractors' National Association. Soffit The finish on the underside of the roof overhang. Spall A fragment, usually in the shape of a flake, detached from a larger mass by a blow, by the action of weather, by pressure or by expansion within the larger mass. Stem wall The vertical part of a concrete or masonry retaining wall. Sump crock A hole designed to collect water and other spilled fluids. Swale A vegetated, open-channel management practice designed to treat and attenuate runoff for specified water quality and volume. TAB Test, adjust and balance. Tensiometer An instrument used to measure the surface tension of liquids. Vapor barrier Material used to retard the movement of water vapor into walls and prevent condensation in them; applied separately over the warm side of exposed walls or as a part of batt or blanket insulation. WBDG Whole Building Design Guide. Weep Holes Small openings left in the outer wall of masonry construction as an outlet for water inside a building to move outside the wall and evaporate. H-3