- A-Side (A-Component): One component of a two component system. For polyurethane foam and coatings the isocyanate component.
- Absorption: Process whereby a porous material extracts one or more substances from an atmosphere, a mixture of gases, or a mixture of liquids.
- Acrylic Coating: A coating system based on an acrylic resin. Generally, a "water based" coating system that cures by coalescence and air-drying.
- Acrylics: Resins resulting from the polymerization of derivatives of acrylic acids, including esters of acrylic acid, methacrylic acid, acrylonitrile, and their copolymers. They can be carried in a water or solvent solution and they are film-forming materials.
- Adhesion: The degree of attachment or bonding of one substance to another. The degree of attachment or bonding between applications of the same substance.
- Adhesive: A substance or compound used for bonding surfaces together, usually applied in the form of a liquid or paste. An adhesive and sealant or base coat may be the same material.
- Aliphatic (Polyurethane): An organic polymer containing straight or branched chain arrangements of carbon atoms. As compared to aromatic urethanes, coatings based on aliphatic urethanes usually have better gloss, color retention, and weathering.
- Aromatic (Polyurethane): An organic polymer usually containing one or more benzene ring structures. Coatings are usually tougher and at a lower cost than aliphatics. As compared to aliphatic, coatings based on aromatic polyurethane's usually have tougher physical properties and cost less.
- Aromatic Solvents: Hydrocarbon solvents comprised of organic compounds, which contain an unsaturated ring of carbon atoms, including benzene, xylene, toluene and their derivatives.
- B-Side (B-Component): One component of a two component system. For polyurethane foam and coatings the resin component.
- Back Wrapping: The carrying of EIFS mesh reinforcement and base coat around the ends of the insulation boards and terminating between the insulation and substrate. Typically used at system interfaces and terminations to firmly attach the base coat to the substrate and protect the edges of the insulation board at these locations.
- Base Coat: The first coat of a multi-coat system. This should be applied the same day as the spray polyurethane foam.
- Bead: A line of sealant or adhesive. In glazing, an applied sealant in a joint such as caulking bead, heel bead, glazing bead, etc. Also a molding or stop used to hold glass or panels in position.
- Bleeding: (1) The diffusion of coloring matter through a coating from its substrate (such as bleeding of asphalt mastic through coating). (2) The absorption of oil or vehicle from a compound into an adjacent porous surface.
- Blister: An uplifting of coating or polyurethane foam caused by an enclosed pocket of gas or liquid entrapped between coating passes, foam and coating, foam and substrate, or within the foam itself. Caused by the delamination of one or two components in an insulation or roofing system.
- Bond (Chemical): Adhesion between surfaces, usually of similar materials, resulting from a chemical reaction or cross linking of polymer chains.
- Bond (Mechanical): Adhesion between surfaces resulting from interfacial forces or a physical interlocking.
- Butyl Coating: An elastomeric coating system derived from polymerized isobutylene. Butyl coatings are characterized by low water vapor permeability.
- Catalyst: An ingredient in a coating or polyurethane foam system that initiates a chemical reaction or increases the rate of chemical reaction.
- 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 of the pump supply line. In polyurethane foam spray pumps, cavitation will result in off-ratio foam.
- Caulking: Another term for sealant.
- CFM: abbreviation for Cubic Feet per Minute. A unit of volumetric flow rate, ofter used as a metric of ventillation, airflow, or air leakage.
- Coating: A layer of material applied over a surface for protection or decoration. Coatings for polyurethane foam are liquids, semi-liquids, or mastics; spray, roller or brush applied; and are elastomeric.
- Cream Time: The time, measured in seconds at a given temperature, when the polyurethane foam components will begin to expand after being mixed.
- Cure: To develop the ultimate properties of a wet state material by a chemical process. Different than drying, which is not a chemical process, although drying is often a necessary part of a chemical process.
- Cure Time: The time required to effect curing. The time required for a material to reach its desired, long-term characteristics.
- Curing Agent: An agent in a coating or adhesive that increases the rate of cure.
- Delamination: The separation of layers within a material or materials. May result in a blister formation.
- Deliquescence: The process that occurs when the vapor pressure of the saturated aqueous solution of a substance is less than the vapor pressure of water in the ambient air. When water vapor is collected by the pure solid compound, a mixture of the solid and liquid, or an aqueous solution of the compounds forms until the substance is dissolved and is in equilibrium with its environment, at this time the vapor pressure of water over the aqueous solution with equal the partial pressure of water in the atmosphere in contract with it. Deliquescence is the revers of efflorescence.
- Dessicant: A drying agent.
- Dew Point: The temperature at which the relative humidity of a sample of air with constant water vapor reaches 100%. The air is saturated with water when it reaches the dew point and condensation will occur on a surface.
- Diisocyanate: An organic chemical compound having two reactive isocyanate (-N=C=O) groups; used in the production of polyurethane foams and coatings.
- Drying Time: The time required for the material to become tack free and will no longer be adversely affected by weather phenomena such as dew, rain or freezing.
- Durability: The capability of a building, assembly, component, product or building to maintain serviceability over a specified time.