Styrofoam™ Brand Cavitymate™ Plus

Commercial | Residential | Multifamily | Wall

Keep moisture out of cavity walls with high-strength XPS insulation

DuPont™ Styrofoam™ Brand Cavitymate™ Plus Extruded Polystyrene Insulation is a proven, high-strength XPS solution that’s conveniently sized to fit between wall ties.


Styrofoam™ Brand Cavitymate™ Plus

DuPont™ Styrofoam™ Cavitymate™ Plus Extruded Polystyrene Insulation is an XPS insulation board with higher compressive and flexural strength than our standard DuPont™ Styrofoam™ Brand Cavitymate™ Insulation. It features square edges on all four sides and a special 16” width that makes it easy to fit between brick ties in cavity wall applications. The Styrofoam™ Brand XPS product line gives you the proven thermal and moisture performance of the original XPS, plus the product options you need to design and build energy-efficient, resilient structures all the way to the top. It’s lightweight and easy to install, which makes the work go faster, and it’s readily available through our wide distributor network. When and where you need it, Styrofoam™ Brand is there.


Features & benefits

Lightweight and durable
  • Easy to handle, cut and install
  • Helps save time and money on site
  • Closed-cell structure
  • High moisture resistance
  • Keeps cavity temperature above dew point to prevent condensation
  • Long-term thermal performance
  • Convenient size
  • Easy to fit between brick ties
  • Meet all wet cavity needs

    Physical Properties

      Method Unit Value
    Thermal Resistance per inch (25 mm) @ 75°F (24°C) mean temp.<sup>1</sup> C518 ft2•h•°F/Btu. R-value, min. 5
    Compressive Strength<sup>2</sup> D1621 psi (kPa), min. 25 (172)
    Flexural Strength<sup></sup> C203 psi (kPa), min. 50 (345)
    Water Absorption<sup></sup> C272, D2842 % by volume, max. 0.3 <0.7
    Water Vapor Permeance<sup>3</sup> E96 perm (ng/Pa•s•m2 ), max. 1.5 (90)
    Coefficient of Linear Thermal Expansion<sup></sup> D696 in/in•°F (mm/m•°C) 3.5 x 10-5 (6.3 x 10-2)
    Maximum Use Temperature<sup></sup> - °F (°C) 165 (73.8)

    1Values are consistent with the criteria of ASTM C578 and the requirements of the FTC R-value rule (16 CFR Part 460). R means resistance to heat flow. The higher the R-value, the greater the insulating power. Ask your seller for the fact sheet on R-value.

    2Vertical compressive strength is measured at 10 percent deformation or at yield, whichever occurs first. Since Styrofoam™ Brand Extruded Polystyrene Foam Insulations are visco-elastic materials, adequate design safety factors should be used to prevent long-term creep and fatigue deformation. For static loads, 3:1 is suggested. For dynamic loads, 10:1 is suggested.

    3Based on 1” (25 mm) thickness.


    Available Sizes

    Width Length
    16 96
    16 96