Legerboard
Legerboard is a composite panel made up of type-2 expanded polystyrene insulation and a (7/16 in.) oriented strand board (OSB). The expanded polystyrene (EPS) insulation acts as a protection for the structural wall, whereas the OSB sheet reinforces the wall against diagonal distortion. The OSB sheet is available either with or without perforations in two sizes: (4 ft. × 9 ft. and 4 ft. × 8 ft.)
Legerboard R-4 panels are designed to break the thermal bridge between the structure and the exterior finish, in compliance with the National Building Code. Their solidity facilitates the installation of exterior finishings.
| PHYSICAL PROPERTIES | IMPERIAL | METRIC | TEST | LEGERBOARD |
| Thermal resistance: r-value at 75ºF (24ºc) for 1 in (25 mm) thickness | (hre.pi2 .°F) / BTU | (m2 °C W) / W | ASTM: C-518 C-177 | R4 1 5/16″ |
| Compressive strength (min.) at 10% distortion | lb/po2 ou psi | (kPa) | ASTM: D-1621 | 16 (110) |
| Water vapor permeability (max.) | – | (ng/Pa.s.m2) | ASTM: E-96 | 200 (seulement pour l’isolant) |
| Water absorption (max.) | % | % | ASTM: D-2842 | 4 |