R303.2.1 Insulation Installation
Insulation materials shall comply with the requirements of their respective ASTM standard specification and shall be installed in accordance with their respective ASTM installation practice in Table R303.2.1 in such a manner as to achieve rated R-value of insulation. Open-blown or poured loose-fill insulation shall not be used in attic roof spaces when the slope of the ceiling is more than 3 in 12. When eave vents are installed, baffling of the vent openings shall be provided to deflect the incoming air above the surface of the insulation.
INSULATION INSTALLATION STANDARDS
|INSULATION MATERIAL||STANDARD SPECIFICATION||INSTALLATION PRACTICE|
|Mineral Fiber Batt/Blanket||ASTM C665||ASTM C1320|
|Mineral Fiber Loose Fill||ASTM C764||ASTM C1015|
|Cellulose Loose Fill||ASTM C739||ASTM C1015|
|Polystyrene Foam||ASTM C578||—|
|Polyisocyanurate Foam||ASTM C1289||—|
|Reflective||ASTM C1224||ASTM C727|
|Radiant Barrier||ASTM C1313||ASTM C1158|
|Spray-applied Rigid Cellular Polyurethane Foam||ASTM C1029||—|
|Interior Radiation Control Coating Systems||—||ASTM C1321|
Insulation that has been compressed to 85 percent or less of the manufacturer's rated thickness for the product shall use the R-values given in Table 303.2.1.1. These values are to be used except where data developed by an independent testing laboratory are provided.
Insulation shall be installed in a permanent manner in substantial contact with the inside surface in accordance with manufacturer's recommendations for the framing system used. Flexible batt insulation installed in floor cavities shall be supported in a permanent manner by supports no greater than 24 inches (610 mm) on center (o.c.).
Exception: Insulation materials that rely on airspaces adjacent to reflective surfaces for their rated performance.