posted 12 years ago
Hi Frances: In my (perhaps biased) view, cordwood masonry has a unique and wonderful combination of insulation and thermal mass. In terms of comfort and performance, what we observe is a house which keeps a steady temperature. It takes a long time to change the temperature of something so massive. We normally think of this as a heating advantage during our long North Country winters, but the house can also store "coolth," my made-up word for heat at a lower temperature, a handy characteristic which helps keep the house cool during our short North Country summers. I don't know what "thermal mass leverage" is, but the effect of the mass is substantial. If you are looking for facts and figures, the best I can do for you at the moment is to say that a cordwood masonry wall, including the double mortar joint and insulation, will weigh somewhere between 40 and 60 pounds per cubic foot, depending on the density of the wood, the percentage of mortar, the thickness of the mortar, etc. The value of thermal mass is hotly debated by intelligent people. All I can say is that it seems to work for us.