This glossary contains many useful terms and definitions that will help you understand much of the work we do at ROOFCORP.

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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 adsorbs as much bitumen as it can retain under the processing conditions, but remains porous and contains voids.

SBCCI: Southern Building Code Congress International, Inc.

SBS: see Styrene butadiene styrene.

Scarfed: shaped by grinding.

Screeding: the process of striking off excess concrete to bring the top surface of the concrete to the proper finish and elevation.

Screen wall: a nonstructural wall erected around units or curbs on a roof. Typically the framing consists of girts with a wood or metal covering attached to the frame.

Scrim: a woven, non woven 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.

Scuttle: a hatch that provides access to the roof from the interior of the building.

SDI: Steel Deck Institute.

Sealant: (1) a material that has the adhesive and cohesive properties to form a seal; (2) a mixture of polymers, fillers, and pigments used to fill and seal joints where moderate movements is expected; unlike caulking, it cures to a resilient solid.

Sealant backing: a compressible material placed in a joint before applying a sealant.

Sealer: a coating designed to prevent excessive absorption of finish coats into porous surfaces; a coating designed to prevent bleeding.

Sealing washer: a rubber or neoprene washer, sometimes metal-backed, typically placed on a fastener to prevent water from migrating into and through the fastener hole.

Seam: a joint formed by mating two separate sections of material. Seams can be made or sealed in a variety of ways, including adhesive bonding, hot air welding, solvent welding, using adhesive tape, sealant, etc.

Seam sample: in single-ply and sometimes modified bitumen membrane roofing, a sample from the membrane that extends through the side lap of adjacent rolls of membrane, taken for the purpose of assessing the quality of the seam.

Self-adhering membrane: a membrane that can adhere to a substrate and to itself at overlaps without the use of an additional adhesive. The undersurface of a self-adhering membrane is protected by a release paper or film, which prevents the membrane from bonding to itself during shipping and handling.

Self-drilling screw: a fastener that taps and drills its own hole during application. Self-sealing shingle: an asphalt shingle containing a factory-applied strip or spots of heat sensitive adhesive in-tended to adhere the overlying shingle once installed on the roof and warmed by the sun.

Self-tapping screw: a fastener that forms receiving threads when turned in a previously drilled hole.

Selvage: (1) an edge or edging that differs from the main part of a fabric, granule-surfaced roll roofing or cap sheet, or other material; (2) a specially defined edge of the material (lined for demarcation), which is designed for some special purpose, such as overlapping or seaming.

Separator layer: refer to Slip sheet.

Service temperature limits: the minimum or maximum temperature at which a coating, SPF or other material will perform satisfactorily.

Set: to convert into a fixed or hardened state by chemical or physical action.

Shading: slight differences in surfacing color, such as shingle granule coloring, that may occur as a result of manufacturing operations.

Shark fin: an upward-curled felt side lap or end lap.

Shear strength: the resistance to forces that cause or tend to cause two contiguous parts of a body to slide relative to each other in a direction parallel to their contrast.

Shed roof: a roof having only one sloping plane and no hips, ridges or valleys.

Shelf life: the maximum time a packaged material can be stored under specified conditions and still meet the performance requirements specified.

Shingle: (1) a small unit of prepared roofing designed for installation with similar units in overlapping rows or courses on inclines normally exceeding 3:12 slope (14°); (2) to cover with shingles; (3) to apply any sheet material in succeeding overlapping rows like shingles.

Shingling: (1) the application of shingles; (2) the procedure laying parallel felts so that one longitudinal edge of each felt overlaps and the other longitudinal edge underlaps an adjacent felt. Normally felts are shingled on a slope so that water flows over rather than against each lap.

Shrinkage: a decrease in one or more dimensions of an object or material.

Shrinkage crack: in waterproofing, a separation in a material, such as a concrete substrate, caused by the inability of the material to resist a reduction in size which occurs during its hardening or curing process or both.

SI: an abbreviation for the International System of Units (Le Systeme International d’Unites).

Side lap: the continuous longitudinal overlap of neighboring like materials.

Side lap fastener: a fastener used to connect adjacent panels together at the side lap.

Siding: the finish covering of an exterior wall of a frame building; the siding may be a cladding material such as wood, aluminum or vinyl (but not masonry).

Sieve: an apparatus with square apertures for separating sizes of material.

Sill: the bottom horizontal framing member of an opening, such as below a window or door.

Sill flashing: a flashing of the bottom horizontal framing member of an opening, such as below a window or door.

Single-lock standing seam: a standing seam that uses one overlapping interlock between two seam panels, in contrast with the double interlocking used in a double standing seam.

Single-ply membranes: roofing membranes that are field applied using just one layer of membrane material (either homogeneous or composite) rather than multiple layers.

Single-ply roofing: a roofing system in which the principal roof covering is a single layer flexible membrane often thermoset or thermoplastic membrane.

Skinning: the formation of a dense film on the surface of a liquid coating or mastic.

Skirt flashing: a formed metal counterflashing secured under a mechanical unit or skylight to cover and protect the upper edge of a base flashing and its associated fasteners.

Skylight: an opening in a roof that is glazed with a transparent or translucent material; used to admit diffused light to the space below.

Slab on grade: a horizontal placement of concrete placed directly over a prepared earth substrate.

Slag: a hard aggregate that is left as a residue from blast furnaces, which may be used as a surfacing material on certain (typically bituminous) roof membrane systems.

Slate: a hard, brittle metamorphic rock consisting mainly of clay minerals, used extensively as dimensional stone for steep roofing and in granular form as surfacing on some other roofing materials.

Slating hook: a steep-slope roofing attachment device, shaped like a hook, that can be used for fastening roofing slate.

Slip sheet: sheet material, such as reinforced kraft paper, rosin-sized paper, polyester scrim or polyethylene sheeting, placed between two components of a roof assembly (such as between membrane and insulation or deck) to ensure that no adhesion occurs between them and to prevent possible damage from chemical incompatibility, wearing or abrasion of the membrane.

Slit sample: in SPF roofing, a small cut about 1 inch x1/2 inch x1/2 inch (25 mm x 13 mm x 13 mm), in a half-moon shape, used to measure coating film thickness.

Slope: the angle of incline, usually expressed as a ratio of rise to run, or as an angle. (See Roof Slope.)

SMACNA: Sheet Metal and Air Conditioning Contractors National Association.

Smooth surface texture: in SPF roofing, the condition of the foam in which the surface shows spray undulation and is ideal for receiving a protective coating.

Smooth-surfaced roof: a roof membrane without mineral granule or aggregate surfacing.

Snap-on cap: a separate cap that snaps on over the vertical legs of some single standing or batten seam metal roof systems.

Snow guard: a series of devices attached to the roof in a pattern that attempts to hold snow in place, thus preventing sudden snow or ice slides from the roof; any device intended to prevent snow from sliding off a roof.

Snow load: the live load due to the weight of snow on a roof; included in design calculations.

Soffit: the exposed undersurface of any exterior overhanging section of a roof eave.

Soffit vent: a premanufactured or custom built air inlet source located at the downslope eave or in the soffit of a roof assembly.

Softening point: the temperature at which bitumen becomes soft enough to flow, as determined by an arbitrary, closely defined method (ASTM Standard test method D 36 or D 3461).

Softening point drift: a change in the softening point of bitumen during storage or application. (see Fallback.)

Soil stack: a sanitation pipe that penetrates the roof; used to vent plumbing fixtures.

Solder: a lead/tin mixture that is melted and used to bond two pieces of some types of metals together.

Solid mopping: see Mopping.

Solids content: the percentage by weight of the nonvolatile matter in an adhesive.

Solvent: any liquid used to dissolve another material.

Solvent cleaners: used to clean some single-ply roofing membranes prior to splicing, typically including heptane, hexane, white gasoline, and unleaded gasoline.

Solvent welding: a process where a liquid solvent is used to chemically weld or join together two or more layers of certain membrane materials (usually thermoplastic).

Spalling: breaking off of plate-like pieces from a concrete, rock or masonry surface.

Special steep asphalt: asphalt complying with ASTM D 312, Type IV. (see Asphalt.)

Specification: a precise statement of a set of requirements to be satisfied by a material, product, system, or service.

SPF: spray polyurethane foam.

SPFA: Sprayed Polyurethane Foam Alliance (a business unit of the American Plastics Council).

SPF compound: a term used to describe the raw materials (isocyanate and resin) used to make polyurethane foam.

Splash block: a small masonry or polymeric block laid on the ground or lower roof below the opening of a down-spout used to help prevent soil erosion and aggregate scour in front of the downspout.

Splice: bonding or joining of overlapping materials. (see Seam.)

Splice plate: a metal plate placed underneath the joint between two pieces of metal.

Splice-tape: cured or uncured synthetic rubber tape used for splicing membrane materials.

Split: a membrane tear resulting from tensile stresses.

Split slab: a term used to describe two separate concrete slabs. The first is placed as a slab on grade or suspended slab, and covered with waterproofing and a drainage system. The second slab, also referred to as a topping slab, is then placed over the underlying slab and waterproofing.

Spot mopping: see Mopping.

Sprayed polyurethane foam (SPF): a foamed plastic material, formed by spraying two components, PMDI (A component) and a resin (B component) to form a rigid, fully adhered, water-resistant, and insulating membrane.

Spread coating: a manufacturing process in which membranes are formed using a liquid compound that is spread onto a supporting reinforcement base layer and then dried to its finished condition.

Sprinkle mopping: see Mopping. Spunlaced: a nonwoven fabric made by mechanically bonding a dry-laid staple fabric by water jet, which entangles the individual fibers.

Spud: to remove the roofing aggregate and most of the bituminous top coating by scraping and chipping.

Square: a unit used in measuring roof area equivalent to 100 square feet (9.29 m2) of roof area.

Square-tab shingles: shingles with tabs that are all the same size and exposure.

Squeegee: (1) a blade of leather or rubber set on a handle and used for spreading, pushing or wiping liquid material on, across or off a surface; (2) to smooth, wipe or treat with a squegee.

Stainless steel: an alloy of steel that contains chromium and also may contain nickel or copper. Generally, has very good resistance to corrosion.

Standing seam: in metal roofing, a type of seam between adjacent sheets of material made by turning up the edges of two adjacent metal panels and then folding or interlocking them in a variety of ways.

Starter course: the first layer of roofing, applied along a line adjacent to the downslope perimeter of the roof area. With steep-slope watershedding roof coverings, the starter course is covered by the first course.

Starter sheets: (1) felt, ply sheet or membrane strips that are made or cut to widths narrower than the standard width of the roll and used to start the shingling pattern at an edge of the roof; (2) particular width sheets designed for perimeters in some mechanically attached and fully adhered single-ply systems.

Starter strip: roll roofing or shingle strips applied along the downslope eave line before the first course of roofing and intended to fill spaces between cutouts and joints of the first course.

Static load: any load, as on a structure, that does not change in magnitude or position with time.

Steel: a malleable alloy of iron and carbon produced by melting and refining pig iron and/or scrap steel; graded ac-cording to the carbon content (in a range from 0.02 to 1.7%); other elements, such as manganese and silicon, may be included to provide special properties.

Steel joist (open web steel joist): normally used as a horizontal supporting member between beams or other structural members, suitable for the support of some roof decks.

Steep asphalt: asphalt complying with ASTM D 312, Type III. (see Asphalt.)

Steep-slope roofs: a category of roofing that generally include water-shedding types of roof coverings installed on slopes exceeding 3:12 (14 degrees).

Step flashing: individual pieces of sheet metal material used to flash walls, around chimneys, dormers and such projections along the slope of a roof. Individual pieces are overlapped and stepped up the vertical surface.

Stick clip: in waterproofing, a non-penetrating fastener that is adhered to the waterproofing surface; typically used to retain insulation, drainage panels, prefabricated protection materials, etc., against the waterproofing to prevent sliding and displacement.

Stiffener rib: small intermediate bends in a metal pan used to strengthen the panel.

Storm anchor: see Wind clip.

Strapping (felts): a method of installing roofing rolls or sheet good materials parallel with the slope of the roof.

Straw nail: a long shanked nail. Sometimes used for fastening over tile at hips and ridges.

Stress: the internal resistance of a material to a force, measured as a force per unit area.

Striations: a parallel series of small grooves, channels, or impressions typically within a metal roof panel used to help reduce the potential for oil-canning.

Strip mopping: see Mopping.

Strip shingles: asphalt shingles that are manufactured in strips, approximately three times as long as they are wide.

Strippable films: (for metal) added protection of plastic films sometimes applied to coated or finished metals after the coil coating process. Applied after prime and top coats to resist damage to the finish prior to and during ship-ping, fabrication and installation.

Stripping or strip-flashing: membrane flashing strips used for sealing or flashing metal flashing flanges into the roof membrane.

Stripping in: application of membrane stripping ply or plies.

Structural panel: a metal roof panel designed to be applied over open framing rather than a continuous or closely spaced roof deck.

Styrene butadiene rubber: high molecular weight polymers having rubber-like properties, formed by the random copolymerization of styrene and butadiene monomers.

Styrene butadiene styrene copolymer (SBS): high molecular weight polymers that have both thermoset and thermoplastic properties, formed by the block copolymerization of styrene and butadiene monomers. These polymers are used as the modifying compound in SBS polymer modified asphalt roofing membranes to impart rubber-like qualities to the asphalt.

Substrate: the surface upon which the roofing or waterproofing membrane is applied (e.g., in roofing, the structural deck or insulation).

Sump: an intentional depression around a roof drain or scupper that promotes drainage.

Sump pan: a metal pan used to create a depression around a drain or scupper to enhance drainage.

Superimposed loads: loads that are added to existing loads. For example, a large stack of insulation boards placed on top of a structural steel deck.

Surface erosion: the wearing away of a surface due to abrasion, dissolution or weathering.

Surface texture: the resulting surface from the final pass of SPF. The following terms are used to describe the different SPF surface textures: smooth orange peel, coarse orange peel, verge of popcorn, popcorn, treebark, and oversprayed.

Surfacing: the top layer or layers of a roof covering, specified or designed to protect the underlying roofing from direct exposure to the weather.

Surfactant: contraction for “surface active agent;” a material that improves the emulsifying, dispersing, spreading, wetting or other surface-modifying properties of liquids.