Details
Property Test Method Result
Nominal Thickness (in)4 1/2, 3/4, 1, 1 1/2, 2, 2 1/2, 3, 4
Nominal Board Width 4
Nominal Board Length (ft) 4 16 in / 2 ft / 4 ft 8
Edge Profile4 Square or Shiplap
Property Type ASTM C578 IV Compressive Strength, Min.
(psi@ 10% deflection) ASTM D1621 25
Water Absorption, Max. (% by volume) ASTM C272 0.1
Density, Min. (lb/ft³) ASTM C303 1.6
Water Vapor Permeance, Max.² (perm) ASTM E 96 (Dessicant Method) 1.5
Service Temperature, Max (°F) 165
Thermal
Thermal Resistance, R-value1
(°F.ft².hr / Btu per in thick)
ASTM C518
(@75°F Mean Temperature) 5.0
Thermal Conductivity, k-value
(Btu.in / hr.ft².ºF) ASTM C518
(@75°F Mean Temperature) 0.2
Fire & Smoke
Flame Spread³
Smoke Developed³ ASTM E84 / UL723 15 (Class A)
140