I-L

Spray Coating and Foam Glossary I-L

January 18, 2010

ICAA - Insulation Contractors Association of America.
Impact Resistance - Ability to withstand mechanical or physical blows without the loss of protective properties. The impact resistance of the roofing assembly is a function of all its components not just the membrane itself.
Insulation - Thermal: Any material which significantly slows down or retards the flow or transfer of heat. Building insulation types are classified according to form (e.g loose-fill, batt, flexible, rigid, reflective, and foamed-in-place) or material (mineral fiber, organic fiber, foam plastic). All types are rated according to their ability to resist heat flow (R-Value or RSI).
Electrical: A non-conductive wire covering, often rubber, thermoplastic, or asbestos. The thickness of insulation varies with wire size and type of material, application or other code limitations.
Isocyanate - A highly reactive organic chemical containing one or more isocyanate (-N=C=O) groups. A basic component in polyurethane foam chemical systems and some polyurethane coating systems.

Joints - An interface between elements. Joints may be needed to allow for movement of different parts of a building or assembly, or may be required to make construction sequences practical. In all cases, the functional requirements of the enclosure must be maintained the same as for the body of an enclosure element, although aesthetic requirements may be relaxed. A joint may pass through the entire enclosure assembly, in which case it is a building movement or assembly joint, often commonly (and imprecisely) referred to as an expansion joint. Control joints are surface cuts or intentional geometric features which control the location of shrinkage cracks. Construction joints are formed between successive building elements parts during construction work.

K-Factor - Thermal conductivity for a unit thickness of material. Expressed as W/m·°K (Btu·in/hr·ft²·°F). R-value is equal to the thickness of the material divided by the k-factor (R = x/k where x = thickness).
KNIT LINE OR LIFT LINE - Interchangeable terms describing the adhesion plane
where one pass is sprayed over another.
Krebs Units (K.U.) - A measurement of viscosity for materials that have the property of changing resistance to flow when under shear. Such materials are called thixotropic. Measuring is done with a Krebs/Stormer viscometer.

Latex - A colloidal dispersion of a polymer or elastomer in water that coalesces into a film upon evaporation of the water.
LIFT - The sprayed polyurethane foam that results from a pass.
Low Temperature Flexibility - The ability of a membrane or other material to remain flexible (resist cracking when flexed), after it has been cooled to a low temperature.
Low-Density SPF Insulation - SPF having a nominal density of less than one pound per cubic foot and used primarily as an insulation and air seal. Relative to medium-density SPF, typically Low-Density SPF Insulation is characterized by having a lower closed-cell content, higher water vapor permeance, and higher yields. Most Low-Density Insulations use water as a reactive blowing agent and are considered non-structural.
LOW TEMPERATURE FLEXIBILITY - The ability of a membrane or other material to remain flexible (resist cracking when
flexed), after it has been cooled to a low temperature.