absolute humidity
The actual concentration of water vapor in air. May be expressed in units of kPa, grains of moisture per pound of dry air, pounds of moisture per pound of dry air, or as a partial pressure as inches of mercury (in. Hg).
The degree of attachment or bonding of one substance to another. The degree of attachment or bonding between applications of the same substance. (For comparison, see also: cohesion)
air barrier
A material that is applied in conjunction with a building component (such as a wall, ceiling or sill plate) to prevent the movement of air through that component.
air barrier association of america (ABAA)
ABAA is an organization that promotes the use of air barriers; offers technical specifications to designers; and offers on-site inspections. It develops standards of proficiency in the industry through the ABAA On-Site Quality Assurance Program. ABAA offers training to installers, estimators, managers and administrators on the contractor side, as well as AIA accredited courses for design professionals. Some types of SPF are recognized as an air-barrier materials via product testing and certified contractors.
ambient temperature
The surrounding air temperature
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.
building code
A set of rules that establish the minimum acceptable levels of safety for constructed structures. Building codes also provide minimum standards for the energy consumption of structures. In the United States, model codes are developed and published by the International Code Council (ICC, see also) and the National Fire Protection Association (NFPA, see also). Model codes acquire legal standing when adopted by state or local authorities.
building envelope
The exterior shell of the building that provides structural integrity and control of heat, air and moisture.
building science
Involves the application of basic science knowledge and analysis procedures to the design of buildings. There is a special knowledge and experience required, and such expertise is also beneficial in determining how to correct problems in existing buildings and to explain what went wrong to cause the problem.
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
closed-cell spf
See MEDIUM-DENSITY SPF. Compression Load Deflection (CLD) CLD is also a measure of firmness and is expressed in pounds per square inch (psi), at a given percentage deflection. The sample size is 2.25”diameter x 1” thick. The entire sample is compressed under the 4 in2 indenter platen in this test. The procedure is the same as IFD. Record 25%R & 65%R values. It is common practice on foam specifications is to specify only the 25%R-value. Both IFD & CFD can be tested at 10%R or any other deflection point based on customer / supplier agreement.
Density is weight per unit volume, weight/volume, and is expressed as lbs/ft3 (pcf).Density is usually measured in grams/cm3 and multiplied by 62.4 to convert to lbs/ft3 (pcf).Density can be obtained from any sample size. Density is not related to pore size, i.e., coarse pore and fine pore foams can have equal densities. Density is not a measure of firmness, stiffness, or load bearing capacity. That is defined by Indentation Force Deflection (IFD) or Compression Force Deflection (CFD).
density measuring set
ComTen specific package with graduated cylinder, miniscale and calculator for measuring density on site.
depht gauge
ComTen gauge measuring the thinkness for sprayed foam.
dew point
The temperature at which a vapor begins to condense.
ComTen instrument measuring humidity and dew point.
Indentation Force Deflection
IFD (previously ILD) is one test method to determine load bearing capacity (firmness or stiffness), and is expressed in pounds force per 50 in.2 at a given percent deflection of the foam. For example: P215-50, FHA grade carpet cushion foam has a target IFD of 50 lbs/50 in2 at a deflection depth of 25% of the original thickness of the sample after a rest period of one minute, 25%R. To obtain the 25%R value, a 50 in.2 circular indenter platen is driven into a 15” x 15” x 4” foam sample, stopping when it reaches a deflection of 1”, 25% of the 4-inch thickness. The testing device records the force in pounds required to hold this foam indented after one minute. The higher the force reading, the higher the load bearing capacity of the foam. This result can be reported in metric and the sample size can be varied.
infra-red thermography
Photography in the infra-red wave length wherein the temperature differences of objects and surfaces can be readily distinguished. Infra-red thermography is frequently used to (1) identify sources of heat loss or gain which effect building energy efficiency; (2) identify sections of building assemblies containing moisture; and (3) identify electrical or mechanical components which are overheating
low-density spf (Open-cell SPF, ocSPF)
A type of spray polyurethane foam expanded with reactive blowing agents to yield a semi-rigid cellular structure and a density between 8 and 22 kg.m3 (0.4 and 1.4 lb/ft3).
medium-density spf (Closed-cell SPF, ccSPF)
A type of spray polyurethane foam expanded with non- reactive blowing agents to yield a rigid cellular structure. It is characterized by a predominance of closed-cells and a density between 1.5 and 2.5 lb. per cubic foot.
A layer of material which acts to prevent the passage of a substance. Membranes may restrict the passage of air, liquid water or water vapor. Some membranes allow the passage of some substances while excluding others.
open-cell spf
See low-density spf insulation
Pounds per cubic foot or lb/ft3. A measure of density.
peel strength
The average force (or force per unit width) required to peel a membrane or other material from the substrate to which it has been bonded.psi
Pounds per square inch (lb/in2).
pull tester
ComTen specific Equipment performing pull tests and adhesion testers.
The resistance of a material to heat transfer. Insulators have relatively high R values. Units are K•m2/W (°F•ft2•hr/Btu).
Roof Consultants Institute.
roofing foam
SPF used in exterior roofing applications. Roofing foam nominal core density is typically 40 – 56 kg/m3 (2.5 -3.5 lb/ft3) and compressive strength is typically 280 kPa (40 lb/in2) minimum. Building codes do not limit the smoke development index (per ASTM E 84) for roofing foams; therefore, roofing foams should not be used for interior applications.
Acronym for Spray Polyurethane Foam.
Spray Polyurethane Foam Alliance.
spray polyurethane foam (SPF)
A foamed plastic material formed by the reaction of an isocyanate and a polyol and employing a blowing agent to develop a cellular structure. SPF may be a two-component reactive system mixed at a spray gun or a single-component system that cures by exposure to moisture. SPF can be formulated to have physical properties (such as density, compressive strength, closed cell content, and R-value) appropriate for the application requirements. Common uses of SPF include insulation, air barrier and roofing membrane.
An applied force which tends to deform a body. May be tensile stress (pulling or stretching force), compressive stress (pushing or compacting force) or shear stress (opposite but offset parallel forces tending to produce a sliding motion).
Thickness is the measurement of the distance between the top and bottom surfaces of a sheet of foam and is expressed in mils or inches. For example, 1/8 of an inch equals 0.125 inch or 125 mils; therefore, one inch is equal to 1,000 mils. Foam thicknesses are measured or gauged by thickness gauge. It is necessary to have as little force placed on the foam surface by the gauge as possible.
water resistant barrier (WRB)
Materials or combination of materials which are primarily designed to be used to keep liquid water from entering the building enclosure. Water resistive barriers are combined with flashing and other materials to ensure that there is a shingled assembly to direct liquid water which passes on the cladding system to be directed to the exterior. Also known as weather resistive barrier.
wet film gauge
A gauge for measuring the thickness of wet coating as applied to a flat smooth surface.