The fight against termites is still going strong, and new ways of foiling the pests in their attempts to infiltrate and infest our structures are continuously being developed by termite control experts all around the globe. An especially interesting form of termite protection among the newer techniques is the Basaltic Termite Barrier, also known as BTB. This termite treatment was developed not too long ago by Dr. Minoru Tamashiro, Emeritus Entomologist of the Department of Plant and Environmental Protection Sciences in the University of Hawaii.

Dr. Tamashiro’s creation is unusual among other termite prevention methods in that it does not create a chemical barrier against the pests but rather a physical one: a layer of compacted basaltic rock formed out of particles chosen with an eye to specific properties such as size and hardness. The resultant layer is what is known as the BTB, and it is a preventative measure against termites because the insects are incapable of penetrating it.

The BTB has to be created out of specific particles because only a particular set of granules with specific sizes, shapes, weight, and hardness can achieve the effect Dr. Tamashiro was going for. The granules need to be small enough to permit for close packing—i.e. packing such that no air gaps or possible passageways are left for the termites in between grains—yet also big enough such that termites cannot lift them from the layer. The weight consideration helps in this respect, as granules of a particular weight shall be too much for termites to handle. Finally, the hardness is important because it prevents termites from chewing up the granules in an effort to reduce them or create a passageway.

Tested under laboratory conditions, BTB performed wonderfully, with the non-BTB construction—a small model house made of wood and placed atop a layer of sand—was ruined by the termites artificially placed in the layer below the concrete sand surface. The construction with a BTB layer below it was clear of damage.

The true brilliance of BTB as a termite prevention treatment, of course, is that unlike chemical layers, it has the potential to stay in place for just about a lifetime. Chemical barriers wear out eventually and new termite treatments are required after that. If the barrier is physical, as in the BTB, there may not be a need for the constant reapplication. This is not a flimsy, still porous barrier of chemicals, after all: it is quite literally a wall.

At the moment, BTB is under licence by the University of Hawaii, and is already being sold for use in construction programmes as a termite prevention pretreatment. The company with whom the University has an agreement for the sale of BTB is Ameron HC&D.