Fumigation in San Leandro, CA

Local Context

When Frass Turns Up in Four Rooms of a 1950s Ranch, Local Treatment Runs Out of Reach

Western drywood termites (Incisitermes minor) do not spread the way people picture. A swarm flight lands, a pair bores into one piece of wood, and that becomes a colony inside that member. Over six decades a house can collect a dozen of them independently: eave blocking, a window header, a garage top plate, attic framing. San Leandro filled in mostly between 1940 and 1965, which is exactly the run of exposure that produces that scattered pattern.

The warm side of the city produces the most of it. The foothill blocks, Bay-O-Vista, Halcyon-Foothill, Assumption Parish and upper Estudillo Estates, sit above the marine layer and hold their heat into the evening while the flats fog over. Drywood swarm flights come on exactly those evenings, from August into October. The wide overhangs and low-pitch roofs that came with the post-war tracts hand them a lot of weathered wood to land on: rafter tails, fascia, eave blocking, the exposed beam ends on hillside split-levels.

The decision is about reach, not drama. If the galleries sit in three accessible places, a local treatment gets them. If evidence turns up in separate rooms, or the inspection finds activity inside wall cavities and sealed framing, gas is the only thing that reaches every void at once. That is also what an Alameda County escrow needs when a WDO report comes back with Section 1 items scattered through the structure.