Saddle: a small tapered/sloped roof area structure that helps to channel surface water to drains. Frequently located in a valley. A saddle is often constructed like a small hip roof or pyramid with a diamond-shaped base. See Cricket.
Sag: undesirable excessive flow in material after application to a surface.
Saturated felt: a felt that has been immersed in hot bitumen; the felt absorbs as much bitumen as it can retain under the processing conditions, but remains porous and contains voids.
SBS: see Styrene butadiene styrene.
Scarify: sandblasting or other techniques used to produce a rough surface.
Scrim: a woven, nonwoven or knitted fabric composed of continuous strands of material used for reinforcing or strengthening membranes.
Scupper: drainage device in the form of an outlet through a wall, parapet wall or raised roof edge lined with a soldered sheet metal sleeve.
Sealant: generic term for a multitude of materials used to seal joints or junctures against moisture or weather.
Sealer: coating designed to prevent bleed-out or bleed-through.
Seam: a line, ridge, or groove formed from fitting, joining or lapping two sections together.
Self-adhering membrane: a type of membrane whose bottom surface will stick or adhere to a substrate without the use of an additional adhesive material.
Selvage: the non-exposed area on rolled roofing. Area without granules. Designed for nail placement and sealant.
Selvage edge: that portion of a granule-surfaced membrane that is designed to be overlapped by the following membrane course; usually two, four, or nineteen inches in width.
Shark fin: a curried corner or lap in a membrane.
Singly-ply roofing: roofing systems where the principal component consists of a single-ply membrane.
Skylight: a transparent or translucent item that is designed to admit light and set over a curbed opening in the roof.
Slag: residue from blast furnaces that is sometimes used for the surfacing on aggregate-surfaced built-up roof systems.
Slope: the angle of incline of a roof expressed as a percent or as a ratio of rise to run. See Roof slope.
Smooth surface texture: in SPF roofing, a relatively smooth surfaced texture that is considered ideal for receiving the base coating.
Smooth surfaced roof: A roof with no surfacing or with a smooth surfacing such as emulsion and/or a reflective coat.
Softening point: the temperature at which bitumen will begin to flow.
Solvent: (1) a liquid capable of dissolving other substances such as bitumen. (2) A liquid that is part of a substance and is used to make that substance easier to work with. Once applied, the solvent evaporates and leaves the working characteristics of the substance. Examples are solvent-based adhesives and solvent-based mastics.
Specification: written requirements for a construction project; contains but is not limited to the following: the scope of work, methods of construction, and materials.
SPF: Sprayed Polyurethane Foam
Splash guard: a fabricated metal pan or masonry block that is placed below a leader pipe or downspout and is used to help protect the roof membrane on a lower roof level or to prevent soil erosion when placed on the ground.
Split: the separation of a material resulting from tensile forces.
Sprayed Polyurethane foam (SPF): a monolithic sprayed-on roofing material with a high R-value; formed when isocyanate (“A” component) and resin (“B” component) are mixed at a 1:1 ratio.
Spud: to remove the top surfacing of a roof by scraping it with special tools called spud bars or power spudders.
Spunbond: describes nonwoven fabrics made from continuously bonded fibers.
Square: (1) 100 square feet of roof area (9.29 m2) in the U.S.A. (2) 10 square meters (107.639 ft.2) of roof area using the metric system of weights and measures.
Standing seam: a type of metal roof system where the longitudinal seams on adjacent panels are turned up, over-lapped and folded in various ways in order to prevent moisture entry and interlock the panels.
Steep-slope roof: a roof with a slope exceeding 3 in 12 (25%). Deemed appropriate to receive water-shedding type roofing materials such as asphalt shingles, wood shakes and shingles, concrete or clay tile, etc.
Styrene butadiene styrene (SBS): the modifying agent used in SBS modified asphalt roofing material that gives the material a rubber like quality.
Substrate: the surface that the roof is installed upon.
Sump: a depression around roof drains and scuppers to help promote roof drainage.
Surface erosion: the effect on a surface after being worn away from abrasion or weathering.
Surfacing: the top layer or layers of a roof covering, specified or designed to protect the underlying roofing from direct exposure to the weather.