- QUV - An apparatus used to simulate the effects of weathering of materials.
- R Value - The resistance of a material to heat transfer. Insulators have relatively high R values. Units are °K·m2/W (°F·ft2·hr/Btu).
- Relative Humidity - The ratio of absolute humidity to saturation humidity, expressed as a per cent.
- Resin - (1) Component B in SPF. This component contains a polyol
catalyst, blowing agent, fire retardant, and surfactants. It is mixed
with the A component to form polyurethane.
term applied to a wide variety of more or less transparent and fusible
products, which may be natural or synthetic. Higher molecular weight
synthetic resins are referred to as polymers.
(3) Any polymer that is a basic material for coatings and plastics.
- Rigid Insulation - Rigid board material that provides thermal
resistance. Foam plastic such as EPS, XPS, and polyisocyanurate are
- Retrofit - The modification of an existing building or facility to include new systems or components.
- Saddle - A relatively small raised substrate or structure constructed to
channel or direct surface water to drains or off the roof. A saddle may
be located between drains or in a valley, and is often constructed like
a small hip roof or like a pyramid with a diamond-shaped base. (See
CRICKET) SAG: Undesirable excessive flow or run in material after
application to a sloped or vertical surface.
- Scarf - To remove the surface or coating from polyurethane foam by
cutting, grinding, or other mechanical means. Synonymous with SCARIFY.
- SCV - Solid content by volume.
- Sealant - Any of a variety of compounds used to fill and seal joints or
openings in wood, metal, masonry and other construction materials. Some
common types of sealants are Neoprene®, polysulfide, acrylic latex,
butyl, polyurethane, foams and silicone.
- Sealant Foam - One or two component polyurethane foam applied as a bead
and used to control air leakage as part of an air barrier system within
the building envelope.
- Shelf Life - The period of time within which a material remains suitable for use. Synonymous with STORAGE LIFE.
- Solvent - A liquid that dissolves other substances
- SPI / SPFD - The Society of the Plastics Industry / Spray Polyurethane Foam Division.
- 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.
- Tear Strength - The maximum force required to tear a specimen, the force
acting substantially parallel to the major axis of the test specimen.
Values reported as a stress per unit of thickness.
- Tensile Strength - The tensile (pulling or stretching) force necessary
to rupture a material sample divided by the sample’s original cross
sectional area. Units are usually kPa or psi or lb/in2.
- Thermoset - A polymeric material whose physical properties are
relatively unaffected by modest changes in temperature; when heated,
thermosets will degrade rather than melt.
- Thinner - A liquid used to reduce the viscosity of coatings or mastics.
Thinners evaporate during the curing process. Thinners may be used as
solvents for clean up of equipment.
- Toxicity - The quality, property, or degree of being poisonous or toxic.
- Two-Part System - A coating or polyurethane foam formed by the mixing and the reaction of two different materials.