The Charm of Cordwood Construction

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

2. Economy. Log-ends can be cut from less-than-perfect or salvaged wood—fire-killed standing wood, ends and pieces from the sawmill, logging slash, and curved branches and trunks unsuitable for lumber. Even old fence rails and driftwood have been used.

3. Energy advantage. Cordwood combines insulation with thermal mass better than any other aboveground building system I can call to mind. The secret is the unique insulated mortar matrix that is woven around all of the log-ends. The mortar does not conduct heat directly through the wall because of an insulated cavity built into the middle third of the wall's width. With a 16-inch-thick wall, for example, we use a 6-inch-wide insulated space between the inner and outer mortar joints. The insulation can be sawdust and lime (at a 12-to-1 ratio), which results in about R-3 of insulation value per inch of thickness. Other loose-fill insulation, such as perlite or vermiculite, also can be used. (Cellulose, which can trap moisture, is not recommended, and we no longer use fiberglass because of its high energy consumption during manufacture, as well as the danger of inhaling the glass fibers.)

Unlike lightweight, wood-frame walls, cordwood walls contain tremendous thermal mass in the mortar. The log-ends themselves also possess both insulative and thermal mass characteristics. Because of this, cordwood homes do not suffer from wild temperature fluctuations; they are easy to keep warm and stay comfortably cool in the summer.

4. Environmental harmony. Cordwood masonry makes use of natural, indigenous materials—and even "waste" destined for the landfill. To further mitigate the environmental impacts of construction, some cordwood builders concerned with concrete mortar's high embodied energy use a cob mortar (clay, sand and straw) instead. My most-recent cordwood construction book, Cordwood Building: The State of the Art, discusses this innovative technique.

5. Esthetics. This acceptable spelling allows me to complete the "5-E" advantages of cordwood. To me, esthetics is just as important as any other consideration, because, ultimately, we must feel good about the house we call home. Jaki and I never tire of the appearance of our walls, which com bine the warm colors of wood with the pleasing relief and texture of fine stone masonry. Cordwood offers an almost limitless outlet for creative expression. We like to incorporate special features into the walls, such as shelves and storage nooks. Colorful bottles embedded in the walls admit sunlight in all colors of the spectrum (see photo). Our sunroom addition features an Easter Island motif on one of the cordwood panels.

RSS | Comments | E-mail | Print