Q: I’ve been considering building a log home but wonder about using chemically treated wood, which protects the home from termites and other pests. How can I have a healthy log home and avoid termites? —Patricia Roshaven, via e-mail
A: Wood is both an excellent and problematic building material. Because it’s biodegradable, insects, fungi, and bacteria eat it. Wood preservatives, which are designed to kill these organisms, raise environmental and human health concerns. Balancing concerns about termites, carpenter ants, bees, wood borers, and the effects of moisture with concerns aout the toxicity of preservative treatments is a longstanding challenge. It’s best to do some research and make choices based on your situation, needs, and personal preferences.
That said, here are some things to consider. Log cabins, like all wood structures, are susceptible to insect infestation and deterioration related to moisture. One way to eliminate or reduce the use of treated wood is to substitute other materials where wood is most vulnerable to these problems, especially at the base of the building. Another way is to design the structure with proper overhangs, gutters, flashing, and detailing to keep wood dry, thereby minimizing rot.
Building codes require that any wood in contact with concrete foundations or the ground be pressure treated or made of naturally decay-resistant species. Wood used elsewhere may not need to be treated with toxic chemicals if it’s protected from weather and moisture. Some log cabin builders routinely treat all logs, so if you aren’t building yourself, ask about chemicals being used.
Other eco-friendly options include barrier methods (termite shields, stainless steel mesh, sand barriers, diatomaceous earth), the use of naturally decay- and insect-resistant wood, and less-toxic preservatives. Effectiveness and acceptability depend on conditions, specific designs, building codes, and other requirements particular to your situation.
David Eisenberg, co-founder and director of the Development Center for Appropriate Technology in Tucson, Arizona, is best known for his national work to make building codes more environmentally responsible and as a co-author of the best-selling book The Straw Bale House (Chelsea Green, 1994).