Canadian Contractor

Understanding Thermal Mass: NUDURA ICF expert Gary Meine (VIDEO)



Ever notice how your driveway, after a hot summer day, keeps radiating heat well into the evening? That's thermal mass at work.

In this, our 6th video with NUDURA engineering technologist Gary Meine, we explore the concept of Thermal Mass.

Thermal Mass is the ability of a material to absorb and store heat energy. If you’ve ever noticed how your driveway remains warm well into the nighttime after a hot summer day, you have seen the principle of Thermal Mass at work. Whereas your front lawn cools off very quickly. Grass just doesn’t have as much Thermal Mass.

The principle of Thermal Mass works in your favour if you install Insulated Concrete Forms, such as those manufactured by NUDURA.


ICFs consist of a concrete core sandwiched between two layers of EPS foam.

While the inside of your client’s house is maintained at, say, 20 degrees Celsius, the exterior temperature can fluctuate in Canada wildly – from minus 20 to plus 30, depending on the season.

And this is why it’s the Thermal Mass of the concrete core of an ICF that makes this type of building product such an advantage.

As Gary explains in this video, the heat transfer that wants to occur across the ICF wall of the home is hindered by both the EPS and the concrete core. Much more so, in fact, that with a traditional cavity wall.

Gary cites one statistic that says it can take up to 13 days for the temperature to equalize between the exterior and interior surfaces of an ICF wall, once heating or cooling in the house has ceased. That’s how difficult it is for heat transfer to occur across ICFs.

For more information on ICFs, please visit



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2 Comments » for Understanding Thermal Mass: NUDURA ICF expert Gary Meine (VIDEO)
  1. Harold Orr says:

    Thermal mass is a benefit but it is most effective when there is no insulation between the mass and the space you want to keep at a constant temperature. In fact if all the insulation value were on the outside of the wall instead of being split between the inside and outside the thermal mass would be much more effective. The more insulation you have on the outside the more effective it becomes.

    • Gary Meine says:

      Correct Howard, to optimize the thermal mass of a wall the insulation can be moved away from the conditioned side. We do have a form which can create a wall like this, the One Series. The One Series form lineup allows for there to be insulation on 1 side of the wall and exposed concrete on the other. You can see images of this on our website. This does not discount that the traditional ICF is still a wall of Thermal Mass. The concrete is sandwiched between 2 layers of EPS foam, by doing this, traditional ICF’s get the benefit of a mass wall and at the same time allow for easy installation of electrical and interior finishes without the additional steps of furring or framing additional walls that a concrete would require. Building codes do recognize an ICF wall as a mass wall.

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