Cap sheet: a sheet, often granule-surfaced, used as the top ply of some built-up or modified bitumen roof membranes and/or flashings.
Caulk: a composition of vehicle and pigment used at ambient temperatures for filling/sealing joints or junctures that remains elastic for an extended period of time after application.
Caulking: (1) the physical process of sealing a joint or juncture; (2) sealing and making weather-tight the joints, seams or voids between adjacent surfaces by filling with a sealant.
Cementitious waterproofing: heavy cement-based compounds and various additives that are mixed and packaged for use in a dry form; the packaged mixture is then mixed with water and liquid bonding agents to a workable concrete-like consistency.
Centipoise: a unit a measure of absolute, viscosity. (The viscosity of water is one centipoise. The lower the number, the less viscous the material.)
Chalk: a powdery residue on the surface of a material.
Coarse orange peel surface texture: a surface showing a texture where nodules and valleys are approximately the same size and shape. This surface is generally acceptable for installing a protective coating.
Coating: a layer of material that is spray, roller, or brush applied over a surface for protection or sometimes decoration.
Cold process built-up roof: a roof consisting of multiple plies of roof felts laminated together with adhesives that usually come right out of a can or barrel and require no heating.
Compounded thermoplastics: a category of roofing membranes made by blending thermoplastic resins with plasticizers, various modifiers, stabilizers, flame retardants, UV absorbers, fungicides, and other proprietary substances, alloyed with proprietary organic polymers. Some of the membranes listed in this generic category are CPA, EIP, NBP, and TPA.
Coping: the piece of material used to cover the top of a wall and protect it from the elements. It can be constructed from metal, masonry, or stone.
Cornice: a horizontal projecting part that crowns the wall of a building.
Counterflashing: formed metal sheeting secured to walls, curbs, or other surfaces, for use in protecting the top edge of base flashings from exposure to weather.
Course: (1) the term used for each row of roofing material that forms the roofing or flashing system; (2) one of multiple layers materials applied to a surface. For example, a three-course flashing consists of a layer of mesh or other reinforcing material sandwiched between two layers roofing cement.
Coverage: the surface area covered by a material.
Crack: a separation or fracture occurring in a material. See Split.
Creep: movement of roof membrane causing the roof system to be deformed.
Cricket: a roof component used to divert water away from curbs, platforms, chimneys, wall, or other roof penetrations and projections. See Saddle.
CSI: Construction Specifications Institute
Curb: (1) a raised member used to support skylights, HVAC units, exhaust fans, hatches or other pieces of mechanical equipment above the level of the roof surface, should be a minimum of eight inches (8") in height; (2) a raised roof perimeter that is relatively low in height.
Cure: a process by which a material forms permanent molecular linkages by exposure to chemicals, hear, pressure, and/or weathering.
Cure time: the time necessary to effect curing.
Cutback: bitumen thinned by solvents that is used in cold-process roofing adhesives, roof cements, and roof coatings.