Radiant Comfort Heat Panels and Insulation

Advantages of Radiant Comfort Heat Panels

The groove channels of Radiant Comfort provide a heating system template that allow for simple installation and maintain consistent tube spacing. Simply walk the tube into the channels, securing them in place.

Unlike competing products, no professional design or shop drawings are needed for installation. The panels can easily be shaped or cut by using a utility knife. In addition, only one panel design is needed, eliminating the hassle of using left turn, right turn and straightaway panels.

The panel edges on the new construction Radiant Comfort panels have interlocking edges to provide secure placement and to prevent concrete from seeping through the joints.

Radiant Comfort is molded out of energy efficient EPS, providing thermal performance that is stable over time, assuring the R-value meets design requirements over the life of the structure.


About Radiant Heat Panels and Insulation

Radiant heat panels (or EPS NOT XPS foam board) are installed to prevent heat loss from a radiant floor heating system (most commonly, PEX embedded in concrete slab or stapled underneath the plywood subfloor). Different insulation types help to minimize heat loss from convection (air circulation), conduction (direct contact) or radiation (energy waves) modes of heat transfer. In slabs, Radiant heat panels (insulation) protect mainly against conduction heat loss, resulting from direct contact of the slab with the underlying level (i.e. gravel & sand).


Radiant Heat Panels-Insulation R-value

R-value of insulation determines its’ effectiveness against heat loss and will vary (even for the same type of insulation) depending on the installation type, environment conditions and other factors.


Radiant Heat Panels - Concrete Insulation

Foam Board & Foam Base Blanket Insulation

Radiant Heat Panel insulation is of crucial importance to a radiant heated slab with PEX. Without a thermal break between the slab and the ground, heat will sink into the ground under the slab, resulting in longer warm-up time, higher energy costs and overall poor performance of the system. Combined with a vapor barrier this is an excellent option. The two most commonly used types of insulation for under-the-slab installations are foam board and foam based blankets. Rigid foam board is probably the most common and widely used insulation and has R-values which vary from 3.6 to 5.0 per 1 inch of thickness, depending on the raw material and production method. It is generally manufactured in 4ft x 8ft, or such as Radiant Comfort Panels, in 3ft x 4ft sheets with an R-Value of 12 and a panel thickness of 2-7/8”.


  • Widely available.
  • Many thickness options (1/2", 3/4", 1", 1-1/2", 2", etc.)
  • Moderately priced.
  • PEX can be stapled directly on top of foam (1-1/2” and thicker only). No stapling is needed for Radiant Comfort Panels. You simply walk the pex into the board. **Although depending on the temperature and the bends, a few staples may be required.
  • Blanket or multilayer concrete insulation is comprised of multiple layers of different materials, incorporating radiant heat insulation, conduction insulation and a vapor barrier, into a single product. R-values of blanket insulation vary greatly depending on the thickness, composition and order of materials used in its’ construction. Among the most common varieties of blanket insulation is bubble insulation. However, in 2005 the Federal Trade commission investigated the use of bubble foil-multilayer products and determined that the R-Value the foil based products were not accurate. This is a link to the findings: Federal Trade Commission Letter on Reflective Under-Slab Insulation


Installation of Radiant Heat Panels

The installation of a heated floor slab begins by verifying the sub grade has been properly leveled and compacted. Although the heating system installer is probably not responsible for this aspect of construction, failing to check for proper sub grade preparation could eventually compromise the embedded tubing circuits. It could also leave the installer having to defend why the floor heating system isn’t at least partly responsible for cracks in the slab or other defects. After the sub grade has been prepared, the soil vapor barrier and radiant heat panels (foam board insulation) should be installed. Some building specifications may not call for an under slab vapor barrier. However, its ability to resist moisture migration from the underlying soils can be indispensable, especially when wood products are used as the finish flooring. We always recommend a vapor barrier in all installations. Heat loss from the edge and underside of a heated slab on grade can be substantial, especially in areas with high water tables or where the slab rests on bedrock. Edge and under slab insulation are essential in reducing these losses. They are a necessary part of any quality floor heating system. Not taking steps to mitigate such heat loss is like leaving the windows open throughout the winter. There’s only one opportunity to install under slab insulation—before the slab is poured. Discovering high downward heat loss after the system is in operation is a situation that’s virtually impossible to correct. It makes little sense to attempt the installation of a high quality heating system while omitting crucial and relatively low cost details. Do it right the first time. The most commonly used material for slab edge and underside insulation is extruded polystyrene. It’s sold in 2 by 8 foot and 4 by 8 foot sheets in several thicknesses. It’s also available in several densities to handle different floor loading. Extruded polystyrene panels are highly resistant to moisture absorption, and have a well-established record in ground contact insulation applications.


Frequently Asked Questions

Q: Do I need to install additional layers under concrete insulation?

A: No. You only need to use the foam board product.

Q: Can blanket insulation be used together with (on top of or under) foamboard insulation?

A: Yes. However, you will not need to use any other insulation product.

Q: Do I need to tape insulation at seams?

A: Yes, foam board insulation must be taped at seams. You can use 3" or 4" wide poly or duct tape. Unless you use a product like the Radiant Comfort Panels. They do not require you to tape the seams like traditional foam board.


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