Since termite pest activity in the United States causes billions of dollars in damage to structural wood each year, it seems reasonable to make lumber resistant to termite attacks. For the past several years, many studies have aimed to determine which timber species naturally repel termites. Many tropical timbers have been found to effectively repel termites, as tropical timbers produce relatively large amounts of defensive chemicals due to their location in regions where termites are abundant year round pests. North American timber species are generally less effective at naturally repelling termites since the winter season provides trees in most areas of the continent with an annual respite from termite pests. However, research has shown that many North American timber species are far more effective at repelling termite pests than timbers currently used for construction. Unfortunately, there does not exist one single timber species that can repel all common termite pests in the US, and converting alternative timber sources into lumber is considered largely impractical. Today, most commercially available lumber is treated to resist fungal growths and wood-destroying insect damage, but this does not mean that all of the structural wood within modern homes has been treated to resist termite attacks.
Today’s building codes demand that all lumber that makes contact with soil must be pressure-treated. Ideally, this rule would prevent subterranean termites from directly accessing a home’s wood from the soil where the insects dwell. Despite this well-intentioned rule, subterranean termites can bypass pressure-treated lumber by building mud tubes that allow the pests to travel in between untreated structural wood sources and the soil. Pest control professionals used to spray the surface of a home’s structural wood with borate solution to prevent termite attacks. Today, this method is no longer in favor, as researchers showed that borate solutions do not protect wood below the surface from termite attacks. Borate-treated structural wood is particularly vulnerable to Formosan subterranean termite attacks. Nearly all modern homes contain pressure-treated lumber, especially around the foundation, but even the newest homes may contain untreated lumber.
Do you worry about termites attacking your home?