2243
8880.002
Environmental Building News
Article
1994
March-April
6, 7
Y
The sand barriers described for preventing termite entry to buildings, can be LWA instead. In addition, the aggregate drainage layer and the “clean gravel fill” can be LWA.The principal is quite simple. Subterranean termites live in moist underground colonies and travel upwards into buildings to feed on wood. (Unlike carpenter ants, termites actually feed on wood; they don’t just tunnel through it.) Termites are very effective at digging through most kinds of soil, and they build shelter tubes around obstacles and locations where they would be exposed to the outside air–which would dry out and kill them. But it turns out that they are unable to dig through sand of a certain grain size. Large-grained sand in the 1.6 to 2.5 mm particle size range (mesh sizes 12 to 8) works well. Grains this size are too large for termites to move, and the interstitial cavities are too small for them to squeeze through.