Interlocking Expanded Polystyrene Panels

Air infiltration is the main cause of heat loss through unfinished basement walls and costs homeowners millions of dollars every year. Cobourg, Ontario, Canada-based ARXX Corp. offers the reFIT system of polystyrene panels, which was showcased in the February issue, page 62, as a cost-effective solution to add comfortable energy-efficient living space to a home and reduce energy waste. Because it is based on insulating-concrete-form technology, reFIT installation requires little time, labor or material to create an energy-efficient basement.

  • The system includes lightweight, vertically interlocking insulation panels with embedded fastening strips for drywall or gypsum board attachment; multiple attachment points for wall clips; wall clips with connecting shim inserts that straighten finished walls; and 45- and 90-degree angle panel connectors for secure corner connections.
  • The interlocking panels are 2 1/2-inch-wide expanded polystyrene insulation, 16-inches high and 48-inches long, with an interlock on the top and bottom for a seamless, locking vertical connection.
  • The interlocking panels have an R-value of 13.9; don’t require a vapor barrier; and are resistant to mold, mildew and rot.
  • The wall clips have three hole locations for attachment to the wall and a locking connection for the optional adjustable reFIT shim inserts.
  • The wall shims are used to straighten the finished reFIT wall when working with basement walls that are not vertically straight or plumb.
  • The wall shims lock on the shim connector on the wall clip and are available in 1/4- and 1/8-inch sizes, both with an expandable interlock.
  • The corner panel connectors are made from durable extruded vinyl and measure 47-inches high.

For more information about the reFIT from ARXX Corp., type 69 in E-Inquiry Form or visit

Comparative Companies:

Owens Corning’s Basement Finishing System lets moisture pass through the wall to reduce the chances for mold growth. The system allows the removal of wall panels for easy access to foundation and wiring, as well as has built-in acoustic and thermal properties. Type 41 in E-Inquiry Form

BARRICADE Basement Wall Panels combine the insulating quality of closed-cell insulation Styrofoam with the stability of oriented strand board. The panels do not require studs, allowing drywall to be nailed directly to them. For a complete system, BARRICADE offers a matching insulated subfloor system. Type 42 in E-Inquiry Form