Walls and foundations



Legerfoil is an expanded polystyrene type-1 insulation covered with a reflective vapour barrier designed for interior foundation walls. Legerfoil offers the protection of a vapour barrier and has a superior thermal value due to its membrane, which reflects radiant energy.

When installed in accordance with our guidelines, Legerfoil conforms to the standards contained in the National Building Code (NBC) and the Regulation respecting energy conservation in new buildings. Legerfoil is available in two thicknesses, (2 in. and 3 in.).

For new constructions the NBC requires a minimum of R-17. Our Mesure métrique à venir (3 in.) Legerfoil, installed according to three types of wall assembly tested in an independent laboratory, exceeds this minimum (see page 2 of the technical sheet).

Our installation guide suggests using the (4 ft. × 8 ft. × 2 ft.) panel for a thermal value of R-11, and the (4 ft. × 8 ft. × 3 ft.) panel for a thermal value of R-18, with slats or a dividing wall installed to create a sealed air space.


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 4′ x 8′ x 2″ r-11* 4′ x 8′ x 3″ r-15,5* * Avec l’installation de lattes créant un espace d’air
Compressive strength (min.) at 10% distortion lb/po2 ou psi (kPa) ASTM: D-1621 10,2 (70)
Bending strength (min.) lb/po2 ou psi (kPa) ASTM: C-203 25 (170)lb/po2 ou psi(kPa)ASTM: C-203
Dimensional stability: % of linear change (max.) % % ASTM: D-2126 1,5
Coefficient of thermal expansion (max.) po/po/°F (mm/mm/°C) ASTM: D-696 3,5×10-5(6×10-5c-1)
Water absorption (max.) % % ASTM: D-2842 6
Effective temperature range: › continuous › intermittent °F °C 167 (75) 180 (82,2)
Flame spread rating ASTM: (CAN/ULC S102,2 M) FR ‹ 115
Smoke developed ASTM: (CAN/ULC S102,2 M) ‹ 430
Capillarity Nulle


  • 5901, chemin de service
    Transcanadienne N
    Pointe-Claire (Québec)
    Canada H9R 1B7
  • 514 694-2493
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  • 480 Tapscott Road, Unit 1B
    Scarborough (Ontario)
    Canada M1B 1W3
  • 416 335-0192
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