specific application in the building code. Their ruling states "As the proposed insulation is not impermeable, it could allow water or moisture to enter the wall assembly, which could then cause damage or deterioration of the building elements." As of 2014-08-21, the domain airkretecanada.com appears to be abandoned. Polyisocyanurate Typically R-5.6 (RSI-0.99) or slightly better after stabilization – higher values (at least R-7, or RSI-1.23) in stabilized boards. Less flammable than polyurethane. Phenolic injection foam Such as Tripolymer R-5.1 per inch (ASTM-C-177). Known for its air sealing abilities. Tripolymer can be installed in wall cavities that have fiberglass and cellulose in them. Non-hazardous. Not restricted by depth of application. Fire resistant – flame spread 5, smoke spread 0 (ASTM-E-84) – will not smoke at all upon direct contact with flame and is a two-hour firewall at a , or normal stud wall, application per ASTM E-199. Great for sound deadening, STC 53 (ASTM E413-73); does not echo like other foams. Environmentally friendly. Non-expansive (good for existing homes where interior sheathing is in place). Fully sustainable: Consists of phenolic, a foaming agent, and air. Blown with air (no CFCs, HCFCs or other harmful blowing agents). Nontoxic, even during application. Does not shrink or settle. Zero VOC emission. Chemically inert (no known symptoms of exposure per MSDS). Insect resistant. Mold Proof. Insoluble in water. Disadvantages: Like all foams, it is more expensive than conventional fiber insulations when only comparing sq ft pricing. When you compare price to R value per sq ft the price is about the same. Polystyrene (expanded polystyrene (EPS) and extruded polystyrene (XPS)) Closed-cell polyurethane White or yellow. May use a variety of blowing agents. Resistant to water wicking and water vapor. Open-cell (low density) polyurethane White or yellow. Expands to fill and seal cavity, but expands slowly, preventing damage to the wall. Resistant to water wicking, but permeable to water vapor. Fire resistant. Some types of polyurethane insulation are pour-able. Here are two commercial open-cell, low-density polyurethane products: Icynene Icynene is a trademarked brand of isocyanate open-cell spray foam from Huntsman Building Solutions. The classic version has a thermal resistance (R value) of 3.7 per inch and other versions have even higher values. The formula also includes a flame retardant. Icynene uses water for its spray application and the chemical expansion is caused by the carbon dioxide generated between the water and isocyanate material. Icynene will expand up