Saddle: a relatively small raised substrate or structure constructed to channel or direct surface water to drains or off the roof. A saddle may be located between drains or in a valley, and is often constructed like a small hip roof or like a pyramid with a diamond-shaped base. (See Cricket.)

 

Saturated Felt: a felt that has been partially saturated with low softening point bitumen.

 

SBS: see Styrene Butadiene Styrene.

 

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, nonwoven, or knitted fabric, composed of continuous strands of material used for reinforcing or strengthening membranes. Scrim may be incorporated into a membrane by the laminating or coating process.

 

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

 

Seal: (1) a generic term for a function that prevents or controls the passage of water; (2) to secure a roof or structure from the entry of moisture.

 

Sealing Washer: a rubber or neoprene washer, sometimes metal-backed, typically assembled 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 may be made or sealed in a variety of ways, including adhesive bonding, hot-air welding, solvent welding, using adhesive tape, sealant, etc.

 

Seam Strength: the force or stress required to separate or rupture a seam in the membrane material.

 

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 drills and taps its own hole during application.

 

Self-Sealing Shingle: an asphalt shingle containing factory-applied strip or spots of heat sensitive adhesive intended 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 into a previously drilled hole.

 

Self-Vulcanized Membrane: a membrane manufactured from compounds that are thermoplastic during manufacture and installation, but whose polymers eventually cross-link and cure during exposure.

 

Selvage Edge: an edge designed for certain sheet good materials, e.g., mineral-surfaced sheets. With mineral surfaced sheets, the surfacing is omitted over a portion of the longitudinal edge of the sheet (e.g., mineral surface cap sheet) in order to obtain better adhesion of the overlapping sheet.

 

 

Shear Strength: (in roofing) the stress required to disrupt a seam or bonded joint or attachment by forcing the substrate material to slide out from the overlying material or vice versa.

 

Shed Roof: a roof containing only one sloping plane. Has no hips, ridges, or valleys.

 

Sheet Metal Flashing: see Metal Flashing.

 

Shingle: (1) individual unit of prepared roofing material designed for installation with similar units in overlapping rows or courses on inclines normally exceeding 3:12 slope (25%); (2) to cover with shingles; (3) to apply any roofing material in succeeding overlapping rows or courses similar to shingles.

 

Shingling: (1) the application of shingles; (2) the procedure of applying shingles or laying parallel felts so that one longitudinal edge of each felt overlaps and the other longitudinal edge of the adjacent shingle or felts underlaps. Felts are normally shingled from a downslope portion of the roof to the upslope portion of the roof area so that runoff water flows over rather than against each felt lap. Felts are also applied in shingle fashion on relatively low slopes.

 

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 exterior wall finish material applied to a light frame wood structure.

 

Single Coverage: roofing material that provides one layer over the substrate to which it is applied.

 

Single-Lock Standing Seam: a standing seam that utilizes 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 of thermoset, thermoplastic, or polymer modified bituminous compounds.

 

Single-Ply System: generally, there are six types of single-ply roofing systems:

1) Fully-adhered

2) Loose-laid

3) Mechanically-fastened

4) Partially-adhered

5) Protected membrane roof

6) Self-adhering

 

Skylight: a roof accessory, set over an opening in the roof, designed to admit light. Normally transparent, and mounted on a raised framed curb.

 

Slag: a hard, air-cooled 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.

 

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.

 

SMACNA: Sheet Metal and Air Conditioning Contractors National Association

 

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.

 

Snow Load: a load imposed on buildings or other structures due to snowfall. (Categorized as live or environ-mental load.)

 

Soffit: the enclosed underside 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.

 

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 metals together.

 

Solid Mopping: see Mopping.

 

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).

 

Special Steep Asphalt: Type IV Asphalt. (See Asphalt.)

 

Specification: a statement of requirements for a given job or project. Usually describes products, materials, and processes to be used. A specification may also contain terms of the contract.

 

SPF: sprayed polyurethane foam.

 

Splash Block: a small masonry or polymeric block laid on the ground or lower roof below the opening of a downspout 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 rupture (generally linear) or tear in a material or membrane resulting from tensile forces.

 

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.

 

Sprinkle Mopping: see Mopping.

 

Square: 100 square feet of roof area.

 

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

 

Stainless Steel: an alloy of steel that contains a high percentage of chromium. Also may contain nickel or copper. Generally, has very good resistance to corrosion.

 

Standing Seam: a metal roof system that consists of an overlapping or interlocking seam that occurs at an upturned rib. The standing seam may be made by turning up the edges of two adjacent metal panels and overlapping them, 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, 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 application of the first course of roofing, 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.

 

Steep Asphalt: Type III Asphalt. (See Asphalt.)

 

Steep-Slope Roof: a roof of suitable slope to accept the application of water shedding roofing materials.

 

Steep-Slope Roofing: a category of roofing that includes water shedding types of roof coverings installed on slopes exceeding 3:12 or 25%.

 

Step Flashing: individual pieces of 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.

 

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

 

Storm Anchor: see Wind Clip.

 

Strip Mopping: see Mopping.

 

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

 

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 panel designed to be applied over open framing in which a structural deck is not required.

 

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 serves to promote drainage.

 

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

 

Synthetic Rubber: any of several elastic substances resembling natural rubber, prepared by the polymerization of butadiene, isoprene, and other unsaturated hydrocarbons. Synthetic rubber is widely used in the fabrication of single-ply roofing membranes.

 

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