Structural Under-Slab Insulation/Ventilation Panel

Foam-Control® Radon Guard® is a patent-pending, structural under-slab insulation and ventilation panel system that provides for radon gas removal, insulation, and a capillary break. Radon Guard is a sub-slab depressurization insulation panel that provides radon gas movement between the ground and the soil-gas-retarder to a vent pipe.

What is radon and how does radon get into your building?

Radon is a gaseous radioactive element. It is an extremely toxic, colorless gas derived from the radioactive decay of radium. It comes from the natural decay of uranium that is found in nearly all soils. It typically moves up through the ground to the air above and into your building through cracks and other holes in the foundation. Your building traps radon inside where it can build up. Any building may have a radon problem. Radon Guard together with a soil-gas-retarder will ensure your new building is safe and free from harmful levels of radiation.

How does Radon Guard work?

The interconnected channels on the underside of the Radon Guard panel depressurize the sub-slab space to direct radon gases to the vent pipe.

Radon Guard® Advantages

• Provides for the extraction of radon gas from the sub-slab area to mitigate its entry into the building.
• Code compliant one-to-one replacement for gravel.
• Meets code requirements for radon mitigation.
• Structural under-slab insulation.
• Provides capillary break.
• Superior moisture resistance.
• No long-term R-value loss or thermal drift.
• No CFC, HCFC, HFC, or formaldehyde.

Radon Guard® Strength/R-Value

Load Capacity¹, psi


75º F3

40º F4

150 260 10 12
250 390 11 12
1 Based on compressive strength @ 1% deformation. Each structure designed with Radon Guard must be reviewed by a qualified design professional.
2 R-value units are °F·ft2·h/Btu.
3 Recommended for design in WARM climates.
4 Recommended for design in COLD climates.

Proven to meet, or exceed, building codes.

Proven to meet, or exceed, building codes. Radon Guard is manufactured under an industry leading quality control program monitored by UL and further recognized in UL Evaluation Report UL ER11812-06. Evaluation Report UL ER11812-06 confirms that Radon Guard is a code compliant replacement for a 4 inch thick layer of clean granular fill material as required by code. Radon Guard meets ASTM C578, “Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation” and ICC-ES AC461, “Acceptance Criteria for An Alternate Gas Permeable Layer of a Subslab Depressurization System for Radon Gas Control”