CALORIMETER: An apparatus for measuring quantities of heat developed by combustion.
CANADIAN URETHANE FOAM CONTRACTORS ASSOCIATION: Also known as CUFCA, this is a national contractor organization promoting education, research, and certification of SPF contractors and applicators throughout Canada.
CANT: A beveling of polyurethane foam at a right-angle joint for strength and water runoff.
CANT STRIP: A beveled strip used under flashings to modify the angle at the point where the roofing or waterproofing membrane meets any vertical element.
CAP FLASHING: Usually composed of metal, used to cover or shield the upper edges of the membrane base flashing, wall flashing, or primary flashing.
CAPACITANCE METER: A device used to detect 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 nonconductor.
CAPILLARY ACTION, CAPILLARITY: The movement of liquid in the interstices of insulation or other porous material as a result of surface tension.
CATALYST: An ingredient in a coating or polyurethane foam system that initiates a chemical reaction or increases the rate of a chemical reaction.
CATHEDRAL CEILING: A high, open, usually sloped or pointed ceiling. Unlike a standard ceiling, there is minimal airspace between the inside surface of the roof sheathing and the interior cladding or drywall.
CAULK: A flexible waterproofing material used to seal cracks, seams, or small breaks in a waterproofing or an air barrier system. Usually supplied in tubes and applied with a caulking gun. (See SEALANT.)
CAVITATION: The vaporization of a liquid under the suction force of a pump. Usually due to inadequate flow to a pump, the vaporization can create voids within the pump or the pump supply line. In polyurethane foam spray pumps, cavitation will result in off-ratio foam. (See also OFF-RATIO FOAM).
CAVITY WALL: An exterior wall, usually of masonry, consisting of an outer and inner wythe separated by a continuous air space.
ccSPF: Closed cell SPF. (See MEDIUM-DENSITY SPF.)
CELLULAR: Describes a composition of plastic or rubber with relative density decreased by the presence of cells dispersed throughout its mass. In closed cell materials, the cells are predominately separate from each other. In open cell materials, the cells are predominately interconnected.
CENTIPOISE (cps): A unit of measure of absolute viscosity. (Note: The viscosity of water is 1 cps at 20°C [68°F]. The lower the number, the less the viscosity.)
CFC: Chlorofluorocarbon. A physical blowing agent containing at least one carbon, one fluorine, and one chlorine atom in its structure (for example, CFC-11). CFC use was phased out in the United States as a spray foam blowing agent between 1993 and 1996.
CHALKING: The formation of a powdery substance due to weathering on a coated surface.
CHECKING: A defect in a coated surface characterized by the appearance of fine fissures in all directions. Designated as “surface checking” if superficial or “through checking” if extending deeply into the coating or to an adjoining surface.
CHEMICAL BOND: See BOND, CHEMICAL.
CHEMICAL RESISTANCE: The ability to withstand contact with specified chemicals without a significant change in properties.
CHLORINATED RUBBER: Resin formed by the reaction of rubber and chlorine to form a coating (i.e., primer or Hypalon) or single ply membrane.
CLOSED CELL SPF: See MEDIUM-DENSITY SPF.
COAL TAR: A dark brown to black hydrocarbon obtained from the destructive distillation of coal. Used in built-up roofs or in below-grade construction as a waterproofing agent. COAL TAR when mixed with mineral spirits will produce a yellow-green to amber color, but will not dissolve.
COALESCENCE: The formation of a film of resinous or polymeric material when water evaporates from an emulsion or latex system, permitting contact and fusion of adjacent latex particles. Also the action of the joining of particles into a film as the volatile evaporates.
COARSE ORANGE PEEL SURFACE TEXTURE: A surface showing a texture where nodules and valleys are approximately the same size and shape. This surface is acceptable for receiving a protective coating because of the roundness of the nodules and valleys. This surface requires at least 25% additional material to the theoretical amount. (See SPFA-145, “Surface Texture of Spray Polyurethane Foam.”)
COATING: A layer of material applied over a surface for protection or decoration. Coatings for polyurethane foam are liquids, semi-liquids, or mastics; are spray, roller, or brush applied; and are ELASTOMERIC. (See ELASTOMERIC.)
COBWEBBING: Production of fine filaments instead of the normal atomized particles when some coatings are sprayed.
COEFFICIENT OF THERMAL EXPANSION: A mathematical formulation used to predict the change in dimension (typically length) of a material as a function of temperature change.
COHESION: The degree of internal bonding of one substance to itself. (See ADHESION.)
COLD-APPLIED: Capable of being applied without heating as contrasted to hot-applied. Cold-applied products are furnished in a liquid state, whereas hot-applied products are furnished as solids that must be heated to liquefy them.
COLLECTOR BOX: See CONDUCTOR HEAD.
COLLOIDAL DISPERSION: A mixture wherein a finely divided material is uniformly distributed within a liquid. LATEX emulsion is a colloidal dispersion of resin in water. (See LATEX.)
COLOR STABILITY: The ability to retain the original color without significant change over time.
COMBUSTIBLE: Capable of burning.
COMPARATOR: See OPTICAL COMPARATOR.
COMPATIBLE MATERIALS: Two or more substances that can be mixed, blended, or attached without separating, reacting, or affecting the materials adversely.
COMPRESSIVE STRENGTH: The stress or force applied parallel to the direction of the polyurethane foam rise at 10% deformation or at yield point.
CONDENSATE: The liquid resulting from the condensation of a gas or vapor. (See also CONDENSATION.)
CONDENSATION: The action of a vapor converting into a liquid.
CONDITIONED CRAWLSPACE: See CRAWLSPACE, UNVENTED.
CONDITIONING: The exposure of a material to the influence of a prescribed atmosphere and/or temperature for a stipulated period of time or until a stipulated relation is reached between the material and atmosphere.
CONDUCTOR HEAD: A transition component between a through-wall scupper and downspout to collect and direct runoff water.
CONTINUOUS INSULATION (CI): Insulation that is continuous across all structural members without any thermal bridges other than fasteners and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope.
CONTROL JOINT: See AREA DIVIDER.
COOL ROOF: (1) A roof system that tends to reflect solar energy away from the roof surface and/or emit non-reflected solar energy away from the roof surface such that less solar energy is absorbed into the building, thus reducing cooling loads. Reflective cool roofs are generally white or other light color. Cool roofs may be rated by the Cool Roof Rating Council, EnergyStar, or other organizations. (2) Any roof system that exhibits energy load performance similar to a cool roof.
COPING: The covering at the top of a wall or parapet designed to shed water.
COPOLYMER: A polymer consisting of molecules containing large numbers of units of two or more chemically different types in irregular sequence.
CORE SAMPLE: The actual material of a cross-section of the roofing material, insulation, etc., showing the various layers.
COUNTERFLASHING: Formed metal or elastomeric sheeting secured on or into a wall, curb, pipe, roof-top unit, or other surface to cover and protect the upper edge of a base flashing and its associated fasteners.
COVERAGE: The unit quantity of material necessary to apply to achieve a desired thickness. Usually expressed in square meter per liter (square feet per gallon) or liters per square meter (gallons per hundred square feet).
CPI: Center for the Polyurethanes Industry, a division of the American Chemistry Council, whose members include producers or distributors of the chemicals and the equipment used to make polyurethane products.
CPVC: Chlorinated polyvinylchloride. A thermoplastic resin used to form sprinkler and high-temperature water piping and fittings.
CRAWLSPACE, VENTED: A low space beneath the floor of a building, giving workers access for the service of utilities, which is ventilated to the exterior of the building envelope. Insulation is typically installed in the crawlspace overhead (beneath the floor of the building).
CRAWLSPACE, UNVENTED: A low space beneath the floor of a building, giving workers access for the service of utilities, which is not ventilated to the exterior of the building envelope. Insulation is typically installed in the crawlspace walls. Also known as “conditioned crawlspace.”
CRAZING, CRAZE CRACKS: Fine, random cracks forming a network on the surface of a coating or film.
CREAM TIME: After mixing two SPF-forming components, cream time occurs when the mixture changes from a clear dark-colored liquid to an opaque light-colored liquid. The cream time represents the onset of the rise of the foam.
CREEP: (1) The permanent deformation of a material caused by slow movement over time resulting from thermal or load stresses. (2) Lateral movement of expanding foam.
CRICKET: A relatively small, elevated area designed to facilitate the flow of water around an obstruction on a roof, such as a chimney or skylight.
CROSS HATCH: An application method for liquid applied materials whereby successive layers or passes are applied at 90-degree angles to the previous application.
CROSSOVER: An undesirable mixing of ISOCYANATE and RESIN components as a result of unbalanced pressures at the spray gun. May result in an equipment blockage.
CUFCA: See CANADIAN URETHANE FOAM CONTRACTORS ASSOCIATION.
CURE: The completeness of the chemical reaction. At substantial completion, the foam should have near the maximum physical properties attainable for the particular formulation used. Cure is not directly related to levels of product emissions during or after SPF application.
CURE TIME: The time required for a foam to achieve the substantial completion of reaction.
CURING AGENT: An agent in a coating or adhesive that increases the rate of cure.