New Type of Insulated Block Hits the Market

Concrete block manufacturer Genest Concrete has developed an insulated block combining concrete and expanded polystyrene, reports Green Building Advisor's Scott Gibson. The blocks are designed to be assembled with a thin layer of adhesive rather than conventional mortar.

Basically an inside-out version of an insulated concrete form (ICF), Comfort Block uses three pieces of EPS insulation, protected inside concrete cavities and reinforced with steel and grout. The blocks sell for about $10.50 each, the company says.

Blocks come in a variety of sizes — wall block, end units, and corner block, for example. Wall blocks, what Genest calls the CB Stretcher, are 8 inches high, 12 inches long and 16 inches wide and weigh 45 pounds each.

The company's website says that the blocks have a "thermal mass performance" of R-30 or more. Genest says that's based on the R-value of the EPS, about R-4 per inch, plus estimates and modeling on both a similar German-made block and an earlier version of the Comfort Block. There has been no third-party testing of whole-wall R-values, so it's not clear how thermal bridging through the concrete webs of the block would affect performance. Genest acknowledges that coming up with a precise R-value for an assembled Comfort Block wall has been a challenge.