Quart

Thermal resistance.

The supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.

A groove or slot, often cut in a masonry wall or other vertical surface adjoining a roof, for inserting an inset flashing component such as a reglet.

Return Air Handler

(1) The sloped edge of a roof at or adjacent to the first or last rafter; (2) Edge of a roof at its intersection with a gable; (3) The inclined edge of a sloped roof over a wall.

Shingles on which tabs vary in size and exposure.

Roof Consultants Institute

Roof Coatings Manufacturers Association

Roof Deck Contractors Association

Steel reinforcing rods set in wet cement to add strength and flexibility to the finished concrete.

(1) The process of covering an existing roofing system with a new roofing system; (2) The addition of a new roof membrane or steep slope roof covering over a major portion of an existing roof assembly. This process does not involve removal of the existing roofing.. See REROOFING.

An inside corner of a surface, producing stress concentrations in the roofing or waterproofing membrane.

See LIGHT REFLECTANCE.

(1) A groove in a wall or other surface adjoining a roof surface for use in the attachment of counterflashing; (2) Horizontal groove in a wall or other vertical surface adjoining a roof surface for anchoring flashing; (3) A sheet metal receiver for the attachment of counterflashing. (A reglet may be inset into a raggle, embedded behind cladding or be surface-mounted.)

(1) A roofing or waterproofing membrane reinforced with felts, mats, fabrics or chopped fibers; (2) A roofing or waterproofing membrane that has been strengthened by the addition or incorporation of one or more reinforcing materials, including woven or non-woven glass fibers, polyester mats or scrims, nylon or polyethylene sheeting.

A material usually in fiber form (woven or nonwoven) used to strengthen and stiffen the dissimilar material it is embedded in.

(1) The ratio of the weight of moisture in a given volume of air vapor mixture to the saturated (maximum) weight of water vapor at the same temperature, expressed as a percentage. For example, if the weight of the moist air is 1 pound and if the air could hold 2 pounds of water vapor at the same temperature, the relative humidity (RH) is 50%; (2) Ratio (expressed as percentage) of the mass per unit volume (or partial pressure) of water vapor in an air-vapor mixture to the saturated mass per unit volume (or partial pressure) of the water vapor at the same temperature.

(1) A plastic or paper strip that is applied to the back of self-sealing shingles. This strip prevents the shingles from sticking together in the bundles, and need not be removed for application; (2) A plastic film or paper strip that is applied to the back of self-sealing shingles and other materials. The strip prevents the material from sticking together in the roll or bundle. With asphalt shingles, the strip need not be removed for application of the shingles.

Unit of vapor permeance resistance; reciprocal of perm.

The practice of removing an existing roof system down to the roof deck and replacing it with a new roofing system. See REROOFING.

(1) The process of recovering or replacing an existing roofing system or roof covering; (2) The practice of applying new roofing materials over existing roofing materials; (3) The process of re-covering or tearing-off and replacing an existing roof system; (4) Removing and replacing an existing roof system (as opposed to mere Recovering; also called Tear-off Replacement). See RECOVERING, ROOF RECOVER, REPLACEMENT and ROOF REPLACEMENT.

Basic raw material for manufacturing polymers, a synthetic polymer containing no deliberately added ingredients.

(1) The uppermost, horizontal external angle formed by the intersection of two sloping roof planes; (2) The highest point on a roof, represented by a horizontal line where two roof areas intersect, running the length of the area.

The last top course of roofing materials, such as tile, roll roofing, shingles, etc., that covers the ridge and overlaps the intersecting field roofing.

Shingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.

One of many products locates at the ridge that allows the escape of warm and/or moist air from the attic area or rafter cavity. Most ridge vents are either premanufactured metal or flexible shingle over.

(1) An upward, "tenting" displacement of a roof membrane, frequently occurring over insulation joints, deck joints and base sheet edges; (2) Membrane defect characterized by upward displacement of the membrane, usually over insulation board joints. See BUCKLE, CRACK, PICTURE FRAMING and WRINKLING.

Roofing Industry Educational Institute

Rubber Manufacturers Association

(1) An assembly of interacting roof components (including the roof deck) designed to weatherproof and, normally, to insulate a building's top surface; (2) An assembly of interacting roof components (includes the roof deck, vapor retarder [if present], insulation and roof covering).

A general term applied to rolls of roofing felt, ply sheet, etc., which are typically furnished in rolls

(1) Smooth-surfaced or mineral-surfaced coated, prepared felts supplied in rolls and designed for use without field-applied surfacing; (2) Asphalt roofing products manufactured in roll form.

A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder and roof covering.

(1) A trowelable mixture of cutback bitumen and mineral stabilizers, including asbestos or other inorganic fibers; (2) Trowelable, plastic mixture of bitumen and asbestos (or other inorganic) reinforcing fibers and a solvent (a stiffer more sag resistant material than plastic cement). See ASPHALT MASTIC, ASPHALT ROOF CEMENT, COAL-TAR ROOF CEMENT, FLASHING CEMENT, MASTIC and PLASTIC CEMENT.

(1) The exterior roof cover or skin of the roof assembly, consisting of membrane, panels, sheets, shingles, tiles, etc.; (2) The covering applied to the roof deck for weather resistance, fire classification or appearance.

See ROOF ASSEMBLY.

Raised frame used to mount mechanical units (such as air conditioning or exhaust fans), skylights, etc.

The flat or sloped surface not including its supporting members or vertical supports.

A structural roof deck that is capable of resisting shear that is produced by lateral forces, such as wind or seismic loads.

The trade name for the craftsman who applies roofing materials; subcontractor.

A metal bracket used to support toe-boards on steep-slope roofs. See FLASHING COLLAR.

A roof extension beyond the exterior wall of a building.

The process of installing an additional roof covering over a prepared existing roof covering without removing the existing roof covering.

Reconstruction or renewal of any part of an existing roof for the purpose of its maintenance.

The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.

Machine that crimps neighboring metal roof panels together or that welds laps of membrane sheets together using heat, solvent or dielectric energy.

The angle a roof surface makes with the horizontal, expressed as a ration of the units of vertical rise to the units of horizontal length (sometimes referred to as run). For English units of measurement, when dimensions are given in inches, slope may be expressed as a ratio of rise to run, such as 4:12 or as a percent.) See SLOPE.

(1) A system of interacting roof components (NOT including the roof deck) designed to weatherproof and, normally, to insulate a building's top surface; (2) A system interacting roof components, generally consisting of membrane or primary roof covering and insulation (not including the roof deck) designed to weatherproof and, sometimes, to improve the building's thermal resistance. See SYSTEM.

An enclosed structure on or above the roof of any part of a building.

The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from attics, cathedral ceilings or other enclosed spaces over which a roof assembly is installed.

A non-asphaltic paper used as a slip sheet in some roof systems.

A polymeric material which, at room temperature, is capable of recovering substantially in shape and size after removal of a force. May be natural or synthetic.

Horizontal dimension of a slope.