Dampwood termite treatment for wet wood around Long Beach docks, decks and crawlspaces

Pacific dampwood termites cannot pull moisture from soil the way subterranean termites do, and they cannot survive in dry framing the way drywood termites can. They need wood with high moisture content, usually well above what a healthy stud in a heated house carries. That biology works in your favor. Once the leak stops and the wood dries, the colony struggles to survive in it.

This is why we rarely recommend tenting for dampwood activity. Fumigation would kill the termites in that board, but it would do nothing about the condition that drew them there. A targeted repair plus a localized treatment costs less and actually fixes the problem. When we see dampwood damage in a crawlspace, we also look closely at nearby wood for decay fungi, because the same moisture that feeds the termites feeds rot, and the rot often does more structural harm than the insects.

Homeowners often bring us a jar of insects or a photo of pellets, and the identification shapes the whole plan. Here is how the three termites in Long Beach usually differ in the field.

• Dampwood: largest insects, galleries in wet wood only, pellets larger and often clumped, no soil inside galleries, swarm in fall near dusk
• Drywood: smaller insects, colonies in dry attic and trim wood, tiny hard six-sided pellets falling from kick-out holes, swarm on warm sunny days in late summer
• Subterranean: smallest workers, mud tubes on foundations, damage along the grain packed with soil, swarm in spring after rain
• Mixed cases happen: a wet sill can hold dampwood termites while the attic above has a drywood colony, so we inspect the whole structure

The most common mistake is patching the surface. We regularly find painted body filler over a soft window sill or a new trim board nailed over a rotted one, with the termites still working underneath. Another is replacing a fence post with untreated lumber set straight into the same wet soil and sprinkler zone. A third is fixing the damage but leaving the irrigation head that sprays the siding every morning.

Planter boxes built against wood siding deserve their own mention. They hold wet soil against the wall for years and are one of the most reliable dampwood sites in older Long Beach homes. Pulling the planter away, adding a gap and letting the siding dry often does more good than any product we apply. When new wood goes in, use pressure-treated lumber where it meets soil or concrete, and keep untreated wood several inches above grade.

The harbor side of the city gives dampwood termites more wet wood than almost anywhere else in the region. In Naples, docks, gangway framing and the wood trim on homes facing the Rivo Alto Canal take on moisture from tidal splash and marine air. Along Alamitos Bay and near Colorado Lagoon, we find dampwood colonies in fence posts and deck footings set in damp, sandy soil.

Inland, the cause is usually plumbing. The raised-foundation Craftsman homes in Belmont Heights, Rose Park and California Heights have crawlspaces where an old cast iron drain or a slow supply leak can soak a sill plate for years before anyone crawls under the house. In Bixby Knolls and Los Cerritos, mature landscaping and sprinklers keep wood siding and porch skirts wet against the foundation. The marine layer slows drying across the whole city, so a leak that might dry out in an inland valley stays wet here, and that is exactly the condition this termite needs.