Concrete Block Walls

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Concrete-block walls are not themselves air barriers. Since soil isn't an air barrier either, the block wall can transmit soil gases to the home. If the cores of the blocks are open at the wall's top, (where the sill plate resides), the concrete block wall can be one large thermal bypass. The cores of concrete blocks should be filled with insulation. If not, air travels unimpeded throughout the wall's area, since the mortar doesn't seal spaces inside the block. Convection within the cores also speeds heat transfer through the wall.

If you know of anyone in the profession that has an infra-red camera (and you live in a climate where there is a minimum 20% temperature difference from the inside of the home to the outside), you will see a glowing red (or white, if not in color) band where the exposed block is located. It's truly amazing the heat loss that occurs.

We touched in a prior writing on insulation foam - so let's touch again. Inexpensive and easy to install. Contact a contractor that provides "safe" foam.

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