Scarfed: Shaped by grinding.
Screeding: Bringing the surface of concrete to the final, desired look and finish by removing any excess or unwanted material.
Screen or Screen Wall: See Equipment Screen.
Scrim: Woven or nonwoven material used to reinforce membranes; it is usually laminated or coated to produce the membrane.
Scuttle: A unit that provides access to the roof from the interior of the building. See also Hatch.
SDI: Steel Deck Institute
Sealant: Generic term for a multitude of materials used to seal joints or junctures against moisture or weather.
Sealer: Coating designed to prevent bleedout 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.
Self-Drilling Screw: A screw with a small drill-bit like tip that will drill its own hole and eliminate the need to pre-drill a hole.
Self-Sealing Shingle: Asphalt shingles with adhesive strips that will soften and stick to the following course of shingles when heated by the sun; used to help against wind uplift.
Self-Tapping Screws: Fasteners that make screw thread receivers when screwed into a hole.
Self-Vulcanizing Membrane: Membrane that is initially thermoplastic in nature but that cures after installation.
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 curled corner or lap in a membrane.
Shed Roof: A roof with only one sloping plane. Also known as Half Gable.
Shelf Life: The length of time between the manufacture of a material and when the material is no longer suitable for use.
Shiner: Term used to describe an exposed nail; one that was not covered by the following course of roofing material.
Shingle: (1) A single piece of prepared roofing material, either asphalt or wood, for use in steep slope roof systems. (2) To install a wood or asphalt shingle roof system.
Shingle Fashion: Refers to the way courses of like materials are overlapped in order to have multiple layer coverage.
Shrinkage: The process of shrinking; depreciation in size.
Shrinkage Crack: A crack caused by material shrinkage. May be the result of thermal expansion/contraction, material failure, or cure.
SI: The international system of weights and measures (metric system). Système International [d'Unit[eacute]s]
Side Lap: The longitudinal overlap of neighboring materials.
Siding: Exterior wall finish materials applied to the outside of a structure.
Sill: The bottom framing member of a door or window opening.
Sill Flashing: Flashing material(s) used to waterproof the bottom framing member of a door or window opening.
Single Coverage: One layer of roofing material.
Single-Lock Standing Seam: A standing seam system with one overlapping interlock between two seam panels.
Single-Ply Membranes: Roofing membranes that are applied in one layer. Thermoplastic and thermoset membranes are usually Single-Ply Membranes. Single-Ply membranes come in five basic types: (1) Ballasted, (2) Fully-Adhered, (3) Mechanically-Fastened, (4) Partially-Adhered, and (5) Self-Adhered. Seams of Single-Ply Membranes can be heat welded, solvent welded, and adhered using seam tape or other adhesives.
Single-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.
Slate: A fine-grained metamorphic rock that splits into thin, smooth-surfaced layers used in steep slope roofing applications.
Slating Hook: A hook-shaped device used to secure roofing slate.
Slip Sheet: Sheeting material placed between roofing components to prevent those components from adhering to one another or to prevent material damage due to component incompatibility. Slip Sheets may be polyethylene, rosin-sized sheathing paper, or other material.
Slit Sample: A cut made in SPF roofing to measure coating thickness. The cut should be about 1.5" long by ¾" deep by ½" wide.
Slope: The angle of incline of a roof expressed as a percent or as a ratio of rise to run. See Roof Slope.
SMACNA: Sheet Metal and Air Conditioning Contractors National Association
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 coating.
Snow Guard: Devices secured to the roof to prevent snow and ice from sliding off of a roof.
Snow Load: A roof load resulting from snowfall. Snow load is a major structural consideration when roofs are designed in areas that receive heavy snow.
Soffit: The underside of a roof overhang.
Soffit Vent: An intake ventilation device located in the soffit. An exhaust vent should be installed on or near the ridge of the roof to work in conjunction with the soffit vent in order to properly ventilate the attic space. The ratio of intake vent area to exhaust vent area should be 1:1.
Softening Point: The temperature at which bitumen will begin to Flow.
Soil Pipe: A pipe that penetrates a roof and is used to vent a buildings plumbing.
Solder: Any of various fusible alloys, usually tin and lead, used to join metallic parts.
Solid Mopping: To continuously apply hot asphalt or coal tar leaving no areas without bitumen.
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.
Solvent Weld: To weld materials using a liquid solvent.
Spall: A chip, fragment, or flake from concrete or masonry.
Special Steep Asphalt: A roofing asphalt conforming to the requirements of ASTM Specification D 312, Type IV. This asphalt can be used on roofs with slopes up to 6 in 12 (50%).
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.
SPF Compounds: Refers to the Isocyanate and resin components used to make polyurethane foam.
SPI: The Society of the Plastics Industry
SPI/SPFD: The Society of the Plastics Industry/Sprayed Polyurethane Foam Division
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.
Splice: To join by overlapping along ends.
Splice Plate: A metal plate placed beneath the joint between two pieces of metal.
Splice Tape: A self-adhering (usually double-sided) tape used for splicing membrane materials.
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.
SPRI: Single Ply Roofing Institute
Sprinkle Mopping: To scatter hot bitumen over a surface.
Spud: To remove the top surfacing of a roof by scraping it with special tools called spud bars or power spudders.
Spud Bar: A long-handle tool with a stiff flat blade on one end (usually 4" or 6" wide) that is used to scrape and remove the top surfacing of a roof down to the membrane.
Spunbond: Describes nonwoven fabrics made from continuously bonded fibers.
Spunlaced: Describes nonwoven fabrics that have the fibers intertwined by water-jet method.
Square: (1) 100 square feet of roof area (9.29 m2) in the USA. (2) 10 square meters (107.639 ft.2) of roof area using the metric system of weights and measures.
Stack Effect: The occurrence where air escapes through opening in the upper part of a building and is replaced with outside air which enters through an opening lower down. In roofing, the Stack Effect helps create proper air flow for attic or roofspace ventilation. The Stack Effect will be affected by atmospheric conditions such as temperature and wind.
Stainless Steel: A highly corrosion resistant steel alloy containing either chromium, nickel, or copper.
Stair Step: The diagonal method of laying shingles.
Standing Seam: A type of metal roof system where the longitudinal seams on adjacent panels are turned up, overlapped and folded in various ways in order to prevent moisture entry and interlock the panels.
Starter Course: The primary course of roofing materials. The Starter course is installed along the downslope perimeter edge and usually covered by the first course of roofing.
Starter Plies: Felt or ply sheets that are cut into widths that are proportionate to the reciprocal of the number of plies being installed. For instance, with a three-ply built-up roof, the first starter ply would be one-third of the roll width, the second two-thirds of the roll width installed over it, and then a full ply over those.
Starter Strip: Strips of shingles (usually 3-Tab shingles with the tabs cut off) or roll roofing material that is laid along the eave line of the roof prior to the application of the first course of shingles. The starter strip is used to fill in the gaps created by shingle cutouts and joints.
Static Load: Roof loads that do not move such as HVAC units.
Steep Asphalt: A roofing asphalt conforming to the requirements of ASTM Specification D 312, Type III. This asphalt can be used on roofs with slopes up to 3 in 12 (25%).
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.
Steep-Slope Roofing Materials: Roofing materials that depend on their water-shedding capabilities to keep moisture from entering a building. These materials are generally installed on roofs with slopes that equal or exceed 3" in 12" (25%).
Steeple: A tall tower forming the superstructure of a building, such as a church or temple, and usually surmounted by a spire.
Step Flashing: Pieces of metal or other material that are used to flash roof projections such as chimneys, walls, curbs, etc. The pieces are installed between each course of roofing and generally have a vertical flange equal in length to that of the horizontal flange.
Strapping: Installing roofing felts so that they run parallel with the slope. Not a recommended installation method for slopes that are 1:12 or less.
Strawberry: See Tar Boil.
Straw Nail: Long-shanked nails used to fasten tile along hips and ridges.
Strip Flashing: Pieces of membrane material that are used to flash metal flashing flanges such as gravel stop. Also referred to as Stripping.
Strip Mopping: Hot bitumen applied in parallel bands.
Strip Shingles: Asphalt shingles that are manufactured in strips.
Styrene: A colorless oily liquid, C6H5CH:CH2, the monomer for polystyrene.
Styrene Butadiene Styrene (SBS): The modifying agent used in SBS modified asphalt roofing materials 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.
Surface Texture: The final appearance and quality of an SPF surface. SPF surface textures will be one of the following: Orange Peel Surface Texture, Coarse Orange Peel Surface Texture, Smooth Surface Texture, Verge of Popcorn Surface Texture, Popcorn Surface Texture, and Tree-Bark Surfaced Texture.
Surfacing: The top-most layer of the roof system designed to protect the system from damage.
Surfactant: Short for "surface active agent." A soluble compound that reduces the surface tension of liquids, or reduces interfacial tension between two liquids or a liquid and a solid having cationic (positive charge), anionic (negative charge), or non-ionic (no charge) nature. The ingredient in SPF that controls the cell size.
SWRI: Sealant, Waterproofing and Restoration Institute