San Francisco's iconic painted ladies and flat-front Edwardians are made of old-growth lumber, and termites have been eating it for generations. Unlike inland or southern parts of the country, the city is better known for drywood and dampwood termites than for the classic mud-tube subterranean problem, although subterranean termites also occur here. If you suspect termites, call (844) 725-1661. PestMinistry is a referral service that connects you with independent licensed providers; we do not inspect or treat buildings ourselves.
Three kinds of termites to know
Drywood termites live inside sound, dry wood and need no contact with soil. They push tiny, six-sided fecal pellets out of kick-out holes, which collect as small piles like salt and pepper beneath window frames, attic rafters and trim. Dampwood termites prefer wet or decaying wood and flourish in the foggy, humid conditions of the city, especially around leaking roofs, clogged gutters, and wood touching soil. Western subterranean termites nest in the ground and travel through mud tubes, often in basements, garages and foundations. Which species you have determines how the problem is treated.
Why SF buildings are so exposed
- Wood siding, trim and decorative millwork on Victorians in Alamo Square, the Haight and Noe Valley.
- Stucco homes in the Sunset and Richmond districts, where moisture can hide behind the exterior.
- Foggy summers that keep roof edges, decks and window sills damp.
- Hillside lots where foundations are terraced and crawl spaces are cramped and poorly ventilated.
- Close-set buildings that share walls and allow termites to move between structures.
Signs to look for
Small piles of pellets, discarded wings near windows after a swarm, blistered or hollow-sounding wood, tiny kick-out holes, and mud tubes on foundation walls all deserve attention. Dampwood termites are often found with visible water damage or fungal rot, so leaks and termites commonly go together.
Treatment possibilities
California requires structural pest control work to be performed by licensed operators, and inspections typically produce a written report describing findings and recommendations. Depending on the species and extent, a provider may propose:
- Localized treatment of infested wood using drilled injections or foam, appropriate for limited drywood activity.
- Whole-structure fumigation, when drywood termites are widespread; this requires vacating the building for a period, bagging food and medications, and coordination with neighbors in shared buildings.
- Soil or bait treatments for subterranean termites.
- Moisture correction and wood replacement for dampwood termites, since removing the water source often solves the problem.
Ask the provider why they selected a particular approach, how access to the building is handled, and what preparation you need.
Lowering the risk
- Repair roof leaks, failed flashing and clogged gutters quickly.
- Keep wood trim sealed and painted, especially on weather-facing sides.
- Maintain gaps between soil, planters and siding.
- Do not store firewood or lumber against the building.
- Schedule periodic inspections for older buildings, particularly before selling or renovating.
Homeowners and buyers in San Francisco should keep copies of any inspection report and treatment record. A new provider can use that history to decide whether current activity is old or recent, and to avoid repeating work that was already done. If you live in a condo or a building with a homeowners association, ask management who is responsible for common-area wood, since termite work often involves shared framing.
Termite questions in San Francisco
Is fumigation always necessary?
No. Limited drywood activity can sometimes be handled with localized treatment. A provider can evaluate the extent.
Can I tell termite types from the pellets?
Drywood termites leave dry, hard pellets. Dampwood termite pellets are larger and often wetter.
Do termites swarm in San Francisco fog?
Swarm timing varies by species and local conditions, with drywood termites commonly swarming on warm days in late summer and fall.
Will insurance cover damage?
Policies often exclude termite damage. Check your policy and ask your provider about documentation.