May 14, 2007
 
CULTURE ARTIST: Adobe: The Ultimate Earth-Friendly Building Material
 
By Chuck Hall
Special to Huntington News Network
 
Variations of adobe can be seen all over the world. In fact, most homes today are still made of some sort of earth. In its most basic form, adobe is simply mud mixed with straw, then dried to shape. Adobe is often shaped into bricks by forming it into a brick mold. It is then dried in the sun and used for building.
 
Once built, the walls are covered with a lime or earth-based plaster. It’s not advisable to use concrete or cement stucco. Adobe walls have to breathe. Plasters allow moisture to escape from the walls, where concrete and cement will not. If the walls cannot breathe, you run the risk of having the stucco crack and fall off.
 
Adobe has a lot of thermal mass. This means that it retains heat well when it’s warmer outside, and it radiates this heat when it’s cooler outside. Although it has excellent thermal properties, it is not a very efficient insulator, so if you live in an area where there are extremes of temperature, you might want to consider incorporating some sort of insulation in your design. One way is to put a layer of insulating material between two layers of adobe. Another is to trap pockets of air between two adobe walls. A third option is to drywall the interior, putting insulation behind the drywall. This is my least favorite option, because you lose the beautiful feel and texture of an earthen wall by covering it with sheet rock.
 
How extreme do temperatures have to be before you consider insulation? That depends on a lot of factors, such as amount of exposure to sunlight, thickness of your walls, prevailing winds, and available shade. I have a friend in Canada who manages to make it through Yukon winters in her un-insulated adobe cabin. She says she’s quite comfortable with only her wood-fired stove.
 
Adobe is the ultimate in earth-friendly building materials, since it is made primarily of earth. You can literally build your home from the ground up, using materials readily available on your property. There are a few drawbacks, however. Many building inspectors aren’t familiar with adobe, although it is covered by many building codes. You may have to have an architect or engineer’s assistance to get your building plans approved. It is also a very labor-intensive process. You have to dig the mud yourself, then form it in molds, then stack it yourself. It helps if you have a lot of family and friends. Building with adobe is a rewarding experience, though, if you have the time. There’s just something about digging in the dirt that touches the child in all of us.
 
If you’d like more information on building with adobe, check out Adobe Builder magazine’s Web site at: www.adobebuilder.com.