Canopy: any overhanging or projecting roof structure, typically over entrances or doors. Sometimes the extreme end is unsupported.

 

Cant: a beveling of foam at a right angle joint for strength and water run off.

 

Cant Strip: a beveled or triangular-shaped strip of wood, wood fiber, perlite, or other material designed to serve as a gradual transitional plane between the horizontal surface of a roof deck or rigid insulation and a vertical surface.

 

Cap Flashing: usually composed of metal, used to cover or shield the upper edges of the membrane base flashing, wall flashing, or primary flashing. (See Flashing and Coping.)

 

Cap Sheet: a granule-surface coated sheet used as the top ply of some built-up or modified bitumen roof membranes and/or flashing.

 

Capacitance Meter: a device used to locate moisture or wet materials within a roof system by measuring the ratio of the change to the potential difference between two conducting elements separated by a non-conductor.

 

Caulk: a material (usually a composition of vehicle and pigment) used for filling/sealing joints or junctures, where no elastomeric properties are required. (See Sealant.)

 

Caulking: (1) the physical process of sealing a joint or juncture; (2) sealing and making weather-tight the joints, seams, or voids between adjacent units by filling with a sealant.

 

C-Channel: a structural framing member.

 

Chalk Line: a line made on the roof by snapping a taut string or cord dusted with colored chalk. Used for alignment purposes.

 

Channel Flashing: (for steep-slope roof construction) a type of flashing used at roof-to-wall junctures and other roof-to-vertical plane intersections where an internal gutter is needed to handle runoff. Commonly used with profile tile.

 

Chlorinated Polyethylene (CPE): a thermoplastic material, used for single-ply roof membranes, composed of high molecular weight polyethylene which has been chlorinated—a process that yields a flexible rubber-like material.

 

Chlorosulfonated Polyethylene (CSPE or CSM): (probably best known by the DuPont trade name Hypalon TM) a synthetic, rubber-like thermoset material, based on high molecular weight polyethylene with suphonyl chloride, usually formulated to produce a self-vulcanizing membrane. Classified by ASTM StandardD 5019-89.

 

Cladding: a material used as the exterior wall enclosure of a building.

 

Cleat: a metal strip, plate or metal angle piece, either continuous or individual (“clip”), used to secure two or more components together.

 

Clerestory: an upward extension of enclosed space created by carrying a setback vertical, wall (typically glazed) up and through the roof slope. Two intersecting shed roofs on different planes.

 

Clip: an individual (discrete) cleat. (See Cleat.)

 

Closed-Cut Valley: a method of valley application in which shingles from one side of the valley extend across the valley while shingles from the other side are trimmed back approximately 2 inches (51mm) from the valley centerline.

Closure Strip: a metal or resilient strip, such as neoprene foam, used to close openings created by joining metal panels or sheets and flashings.

 

Coal Tar: a dark brown to black colored, semi-solid hydrocarbon obtained as residue from the partial evaporation or distillation of coal tars. Coal tar pitch is further refined to conform to the following roofing grade specifications:

 

Coal Tar Bitumen: a proprietary trade name for Type III coal tar used as the dampproofing or waterproofing agent in dead-level or low-slope built-up roof membranes.

Coal Tar Pitch: a coal tar used as the waterproofing agent in dead-level or low-slope built-up roof membranes.

Coal Tar Waterproofing Pitch: a coal tar used as the dampproofing or waterproofing agent in below-grade.

 

Coal Tar Felt: a felt that has been saturated with refined coal tar.

 

Coal Tar Roof Cement: a trowelable mixture of processed coal tar base, solvents, mineral fillers and/or fibers.

 

Coated Base Sheet: a felt that has previously been saturated (filled or impregnated) with asphalt and later coated with harder, more viscous asphalt, which greatly increases its impermeability to moisture.

 

Coated Fabric: fabrics that have been impregnated and/or coated with a plastic-like material in the form of a solution, dispersion hot-melt, or powder.

 

Coated Felt (Sheet): (1) an asphalt-saturated felt that has also been coated on both sides with harder, more viscous “coating” asphalt; (2) a glass fiber felt that has been simultaneously impregnated and coated with asphalt on both sides.

 

Coating: a layer of material spread over a surface for protection or decoration. Coatings for SPF are generally liquids, semi-liquids, or mastics; spray, roller, or brush applied; and cured to an elastomeric consistency.

 

Cohesion: the degree of internal bonding of one substance to itself.

 

Cold Forming: the process of using press brakes, roll formers, etc., to shape metal into desired profiles at ambient room temperature.

 

Cold Process Built-Up Roof: a continuous, semi-flexible roof membrane, consisting of a ply or plies of felts, mats or other reinforcement fabrics that are laminated together with alternate layers of liquid-applied (usually asphalt-solvent based) roof cements or adhesives installed at ambient or a slightly elevated temperature.

 

Cold Rolled: the process of forming steel into sheets, panels, or shapes on a series of rollers at ambient room temperatures.

 

Collector Box: see Conductor Head.

 

Column: a primary structural member used in a vertical position in a building to transfer loads from horizontal structural members (e.g., main roof beams, trusses, or rafters) to the foundation/footing.

 

Combing Ridge: a term used to describe an installation of finishing slate at the ridge of a roof whereby the slates on one side project beyond to the apex of the ridge.

 

Composition Shingle: a unit of asphalt shingle roofing.

 

Compressive Strength: the ability of materials and components to resist deformation or other damage caused by the weight of compression of either live or dead loads.

 

Concealed-Nail Method: a method of asphalt roll roofing application in which all nails are driven into the underlying course of roofing and covered by an adhered, overlapping course.

 

Conductor Head: a transition component between a through-wall scupper and downspout to collect and direct run-off water.

 

Contact Cements: adhesives used to adhere or bond various roofing components. These adhesives adhere mated components immediately on contact of surfaces to which the adhesive has been applied.

 

Coping: the covering piece on top of a wall which is exposed to the weather, usually made of metal, masonry, or stone. It is preferably sloped to shed water back onto the roof.

 

Copper: a natural weathering metal used in metal roofing; typically used in 16 or 20 ounce per square foot thickness (4.87 or 6.10 kg/sq m).

 

Cornice: the decorative horizontal molding or projected roof overhang.

 

Counter Batten: vertical wood strips installed on sloped roofs over which horizontal battens are secured. The primary roof covering is attached or secured to these horizontal battens.

 

Counterflashing: formed metal sheeting secured on or into a wall, curb, pipe, rooftop unit, or other surface, to cover and protect the upper edge of the membrane base flashing or underlying metal flashing and associated fasteners from exposure to the weather.

 

Course: (1) the term used for each row of shingles of roofing material that forms the roofing, waterproofing, or flashing system; (2) one layer of a series of materials applied to a surface (e.g., a five-course wall flashing is composed of three applications of roof cement with one ply of felt or fabric sandwiched between each layer of roof cement.)

Cover Plate: a metal strip sometimes installed over the joint between formed metal pieces.

 

CPE: Chlorinated Polyethylene.

 

Creep: the permanent deformation of a roofing material or roof system caused by movement of the roof membrane, or compression of a roof insulation board at fastener positions, that results from continuous load or thermal stress or loading. Creep at roof temperature is sometimes called “cold flow.”

 

Cricket: an elevated roof substrate or structure, constructed to divert water around a chimney, curb, away from a wall, expansion joint, or other projection/penetration. (See Saddle.)

 

Cross Ventilation: the effect that is provided when air moves through a roof cavity between the vents.

 

CSM: ASTM designation for chlorosulfonated polyethylene. (See CSPE.)

 

CSPE: chlorosulfonated polyethylene.

 

Cupola: a relatively small roofed structure, generally set on the ridge or peak of a main roof area.

 

Curb: (1) a raised member used to support roof penetrations, such as skylights, mechanical equipment, hatches, etc. above the level of the roof surface; (2) a raised roof perimeter relatively low in height.

 

Cure: a process whereby a material is caused to form permanent molecular linkages by exposure to chemicals, heat, pressure, and/or weathering.

 

Cure Time: the time required to effect curing. The time required for a material to reach its desirable long-term physical characteristics.

 

Curing Agent: an additive in a coating or adhesive that results in increased chemical activity between the components with an increase or decrease in rate of cure.

 

Cutoff: a permanent detail designed to seal and prevent lateral water movement in an insulation system, and used to isolate sections of a roofing system. (Note: A cutoff is different from a tie-off, which may be a temporary or permanent seal.) (See Tie-Off.)

 

Cutout: the open portions of a strip shingle between the tabs.

 

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