As its name suggests, ROCKWOOL is made out of rock, the world’s most abundant material, and upcycled material. As a result it is fire and water resistant. Unlike cellulose, Rockwool does not reach a saturation point when wet. It dries out well and does not degrade with moisture although its insulative capacity is reduced temporarily while wet. It is also pest resistant. With an insulation value of R4 per inch, Rockwool is on part with other batt insulation products, but slightly higher performing given its durability over time.

In addition to subfloors, we use Rockwool products in wall and roof assemblies

Bottom line: ROCKWOOL is made from a natural and abundant material and upcycled content, easy to access and use, locally-made, and fire and water resistant. While not the “greenest” product on the market, it is still, relatively, greener than most and an outstanding means to improve a home’s energy performance and comfort.