Is a Concrete Floor a Good Insulator?

R-value

• Heat moves from concentrations of higher heat to lower heat. If it is colder on the bottom side of a floor, the heat will move from the upper side to the lower, making the upper side feel colder from the loss of heat. It's not really the cold seeping through as some people believe, it is the heat seeping out. The rate of heat loss in buildings is called the R-value. The higher the R-value, the slower the loss as the heat finds it more difficult to cross the barrier.

Water Porous

• Concrete floors have a tradition for being cold in the winter because of poor insulating qualities. This is partially because concrete also is porous to water. Moisture moves easily through concrete, and is a very good conductor of heat. If the concrete is built on bare soil without a good gravel foundation to drain away water and without a vapor barrier to prevent moisture from seeping through, the heat loss will be much greater.

Low R-value

• A typical 6-inch concrete slab has an R-value between 0.6 and 1.2, according to Concrete Producer Online. This is not very high but is little different from other natural materials such as stone or slate. A major advantage of concrete floors, though, is their ability to store heat and slowly release it. By building into the slab a radiant heat system that works from steam or electric, the floor can maintain a constant level of heat.

Radiant Heat

• Radiant heat woven throughout a concrete floor provides an allergy free, no-draft heating system that keeps an even temperature. The low-energy heating system cuts down on utility bills as it is more efficient than other methods. If your home already has a concrete slab, you can fit a new radiant heat system over it without too much disruption.