Termite Control in San Juan Bautista, CA

Local Context

Adobe Does Not Feed Termites. The Wood Buried Inside It Does

San Juan Bautista holds California's most intact concentration of mission-era adobe, and adobe itself is not termite food. Clay, sand and straw sustain nothing. Every adobe here has wood in it, though: vigas and roof beams, door and window lintels, floor joists, and the frame of every balcony hanging off a second story. Those members are the target. Subterranean termites (Reticulitermes spp.) reach them from the ground, and the thick earthen walls that keep a building cool through a 90-degree afternoon also hold the steady moisture those colonies want.

The exposed wood is a separate problem with a separate species. Balcony joists, porch posts and the deep eave tails on the 19th-century buildings along Third Street sit out in the sun and the fog, and western drywood termites (Incisitermes minor) fly to that kind of weathered end grain. They live entirely inside the member, so a beam can be hollow for years before the first pellets of frass land on the porch board below it.

Most of the town is not adobe, and that matters. The streets spreading out from the historic core are ordinary 20th-century housing, much of it single story on a raised foundation with a stucco skirt and a sill plate close to grade. The town sits on a terrace at the foot of the Gabilan Range where winter runoff collects, so from November through March that soil stays wet and subterranean termites move up through pier blocks and any wood touching dirt. Same species as the historic core, different structure, different inspection.