Term Description
Smooth-surfaced roof

A membrane roof system that includes a weathering surface 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 because of the weight of snow on a roof (expressed in lb/ft2) included in design calculations.


The exposed undersurface of any exterior overhanging section of a roof eave.

Soffit vent

A manufactured 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 using test methods defined in ASTM D36 (ring-and-ball) or D3461 (Mettler cup-and-ball).

Soil stack

A sanitation pipe that penetrates the roof; used to vent plumbing fixtures.


A lead and tin mixture that is melted and used to bond two pieces of some types of metals together.

Solids content

The percentage by weight of the nonvolatile matter in an adhesive.


A measure of the extent to which a material can be dissolved in a given solvent under specified conditions.


Any liquid used to dissolve another material.

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).


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


The distance between supports or beams, girders or trusses.


In hot-dip coatings, the crystalline structure that develops on a metallic-coated surface when the molten coating metal solidifies, especially on steel sheet and articles coated after fabrication.

Special steep asphalt

See "asphalt, special steep."


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


See "spray polyurethane foam (SPF)."

SPF compound

A term used to describe the raw materials (isocyanate and resin) used to make spray polyurethane foam (SPF).


Sprayed Polyurethane Foam Alliance; a trade association of spray polyurethane foam applicators, manufacturers and distributors of polyurethane foam, equipment and protective coatings and providers of inspections, surface preparations and other services. It is an educational and technical resource and voice of the spray polyurethane industry.


Bonding or joining of overlapping materials. See "seam."

Splice plate

A metal plate placed underneath the joint between two pieces of metal.


Cured or uncured synthetic rubber tape used for splicing membrane materials.


A membrane tear resulting from tensile stresses.