The short version
Most termite problems in San Mateo are western subterranean termites, and the usual fix is a liquid soil treatment or bait stations. Drywood termites need fumigation or wood treatment instead. Start with an inspection; $75–$250 is typical.
- Look for mud tubes, shed wings and hollow-sounding wood.
- Swarms usually show up in spring.
- Drywood termites need wood treatment or fumigation instead.
- An inspection typically costs $75–$250.
- Insurance usually doesn’t cover termite damage.
Homeowners, landlords and anyone buying or selling a house in San Mateo, whether you've spotted something or just want to know what to watch for.
What to look for
Termites work quietly. A colony can feed inside a wall for years. Winters around San Mateo stay mild, with average lows near 43°F, so colonies keep feeding all year. Spongy floors or bubbling paint usually mean long-running damage. So it's worth an inspection, even for one or two signs.
- 1Live pale insects inside a broken mud tube.
- 2Mud in cracks of subfloor or joists.
- 3Termite tubes hanging down from ceilings or joists.
- 4Blistered or bubbling paint on wood surfaces.
- 5Crumbling baseboards behind furniture.
- 6Termite activity reported at a neighbor's home.
Why it’s worth acting soon
- Colonies grow and spread every year they go untreated.
- Damage hides behind drywall, flooring and trim.
- Homeowners insurance usually doesn’t cover termite damage.
- An active infestation can complicate a home sale.
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Termite activity through the year in San Mateo
Spring
swarm seasons. In San Mateo, swarms often follow the first warm days and the first fall rain.
Summer
with highs around 78°F in San Mateo, termites follow moisture, so watch AC drain lines, sprinkler zones and hose bibs.
Fall
with about 21 inches of rain a year in San Mateo, make sure gutters and downspouts carry water well away from the foundation.
Winter
a good time to book an inspection in San Mateo, before swarm season starts.
Treatment options and typical costs
Termite Inspection and WDI Report
$75–$250
The inspector checks the foundation, garage, attic and damp spots. Bring up anything you’ve noticed.
- Time
- 60–120 minutes
- Best for
- Every job, real estate closings, and yearly peace of mind
Bait Station System with Monitoring
$1,500–$3,500 install, plus $300–$500 per year
Ask how many stations they plan for your San Mateo home, how often they'll check them, and what the annual fee covers.
- Time
- 2–4 hours to install; checked quarterly
- Best for
- Colony elimination, wells and slabs, homes near water
Fumigation for Drywood Termites
$1,200–$4,000 (often $1–$4 per square foot)
Tenting is thorough but leaves no residual protection behind. New drywood swarmers can land on a San Mateo home the following season, so follow-up inspections still matter.
- Time
- 2–3 days including tenting and aeration
- Best for
- Widespread drywood termites throughout a structure
Liquid Soil Termiticide Barrier
$1,200–$3,500 (often $3–$16 per linear foot)
Where a slab or porch blocks the trench, the San Mateo applicator drills holes and injects underneath. The goal is a continuous treated zone with no gaps.
- Time
- Half a day to a full day
- Best for
- Active subterranean termites; fast knockdown around the foundation
Prices are typical published ranges. Ask what’s included before you compare quotes.
Cardboard boxes stacked on a garage slab are termite food sitting right on their doorstep. Keep storage on shelves.How treatment works on a typical San Mateo home.
With a basement, the crew treats soil along the outside. Inside, they may drill where the floor meets the walls. Bait stations are the other main option. They're spaced every 10 to 20 feet. Termites carry the bait back to the colony. The stations are checked on a schedule, often every few months.
Which termites live around San Mateo.
The termite you're most likely to meet in San Mateo is the western subterranean termite. It nests in soil and builds mud tubes to reach wood. It needs steady moisture. Drywood termites are common around San Mateo as well, flying straight into attic framing, eaves and furniture without any soil contact. Look for tiny piles of pellets that look like coarse sand.
Subterranean termites don't stop in winter; they just go deeper. A quiet season is a good time for a non-urgent inspection.When termites swarm here.
Swarm season is when termites show themselves. In San Mateo, western subterranean termites usually swarm in spring, and again in fall after the first good rain. Drywood termites around San Mateo tend to swarm in late summer and fall. A swarm outside means a colony is nearby. A swarm inside usually means it's in the house. Save a few in a bag, or snap a clear photo.
Where to look around your house.
Plenty of homes in San Mateo have basements, so check where the wood framing sits on top of the foundation wall. Look around window wells and unfinished walls. Outside, check porches, steps and decks that touch soil. Wood should stay several inches above the ground. The same advice applies across the area, from San Mateo out to San Francisco and Oakland.
A year of termites in San Mateo.
- Spring and fall: swarm seasons. In San Mateo, swarms often follow the first warm days and the first fall rain. - Summer: with highs around 78°F in San Mateo, termites follow moisture, so watch AC drain lines, sprinkler zones and hose bibs. - Fall: with about 21 inches of rain a year in San Mateo, make sure gutters and downspouts carry water well away from the foundation. - Winter: a good time to book an inspection in San Mateo, before swarm season starts.
What happens at an inspection.
Most inspections take an hour or two. The inspector walks the outside of the house first. They check the foundation, the soil line and nearby wood. Inside, they check the garage, baseboards, plumbing gaps and the attic. They'll check the basement walls and sill plate. A moisture meter and a probe help them find hidden activity. Afterward, ask them to show you what they found. Photos help.
Termites or ants?
- Wings: termite wings are all the same length. Ant wings aren’t. - Waist: termites are thick through the middle. Ants are pinched. - Antennae: termite antennae are straight. Ant antennae bend like an elbow. - Debris: termites leave mud. Carpenter ants leave sawdust. - Tunnels: termite galleries are packed with mud. Ant tunnels are clean and smooth.
Getting ready for treatment day.
Soil treatments and bait stations need little prep. Clear a path along the outside walls. Move stored boxes away from garage walls. Mark sprinkler heads and any buried lines. Keep pets and kids inside while the crew works outside. Ask how long to stay off treated soil. Any drill holes in a slab or patio get patched.
Mulch and termites.
Keep mulch thin and pull it back from the foundation. A dry strip along the house lets you spot mud tubes. Wood chips right against siding hold moisture termites like.
Questions to ask before you sign.
- Which termites did you find, and where? - What product or system will you use? - Is the whole foundation treated, or just one spot? - What does the warranty cover, and for how long? - What does the yearly renewal cost? - What do I need to do before and after treatment?
What affects the price
- Warranty type: retreatment only or damage repair.
- Extent of existing damage needing repair.
- Local labor rates and licensing requirements.
- Access to crawl spaces and attics.
- Species: subterranean, drywood, or Formosan.
- Cubic footage under the tent for fumigation.
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What's your biggest concern about termites?
When to call for help
Lenders often ask for one. It's also the cheapest termite service. Carpenter ants leave clean tunnels and sawdust. Termites leave mud. Call if you see mud tubes, pellets or an indoor swarm. Hollow-sounding wood is another clue. Buying or selling? Get a wood-destroying insect (WDI) report either way.
What you can do yourself
Some of the work is yours. Pull mulch back from the foundation. Fix leaks and clear gutters. Keep firewood away from the house. Treating an active colony is harder. The product has to reach the whole colony. It also needs even coverage around the entire foundation. Store-bought sprays usually kill only the termites you see.
Termites in San Mateo
San Mateo only sees about 21 inches of rain a year, so local termites gather wherever water collects, like sprinkler zones, hose bibs and AC drain lines. Termite activity in California is above average. Most houses will see termites at some point. With summer highs around 78°F, San Mateo's mediterranean climate decides when local termites are busiest. A typical home in San Mateo is worth around $1,450k, which puts a few hundred dollars for an inspection and prevention in perspective. San Mateo has a mediterranean climate, and termites activity here tends to pick up spring swarm season (March-May), warmer earlier in the south. In San Mateo, most of the housing is urban, so the usual entry points, moisture spots, and sheltered areas near the structure are what an inspection checks first. In San Mateo, take a minute to note where you have seen activity and when it appears, so the inspection is faster and the quote more accurate. A local provider who knows San Mateo and California can point out the specific conditions that matter most here before you commit to a plan.
Local research
Termites in San Mateo, CA: what the public record shows
Before you compare quotes, it helps to know which termites actually live in California, when they are busiest around San Mateo, and what the state figures look like. Everything below links to the agency or university page it came from.
Termite control products for drywood termites
Drywood and subterranean termite work in California is effectively professional-only; the state licenses it by branch.
UC Statewide IPM ProgramTermite species recorded in California
- Formosan subterranean termite (Coptotermes formosanus) — FDACS lists it in Florida, Alabama, Georgia, Louisiana, Mississippi, South Carolina, North Carolina, Tennessee, Virginia, Texas, Arizona, California and Hawaii. Colonies contain…
- Western drywood termite (Incisitermes minor) — UC IPM: 'California's second most important termite pest', 'commonly found along the Pacific coastal region extending into the Central Valley and deserts of Southern California'…
- Desert subterranean termite (Heterotermes aureus) — UA Extension calls it an 'important structural pest' of the desert Southwest. UC IPM: 'flies in the late afternoon or early evening in July, August, and September'.
- Western subterranean termite (Reticulitermes hesperus) — Oregon State: causes damage to structures in the Pacific Northwest and 'may swarm any time of year'. Utah State describes swarmers 3/8 inch long and workers 1/4–3/8 inch, pale c…
When termites are busiest around San Mateo
Reticulitermes swarm in the afternoon in spring or fall on clear days after a soaking rain; drywood swarmers fly in daytime during summer and fall; Heterotermes aureus flies late afternoon/early evening in July–September (UC IPM).
UC IPM: Reticulitermes 'can be encountered in nearly all regions of the state'; the western drywood termite is 'California's second most important termite pest', found along the Pacific coast, Central Valley and Southern California deserts. FDACS lists California among states with Formosan termites. Branch 3 covers 'the control of wood-destroying pests or organisms by the use of insecticides or structural repairs and corrections'; Branch 1 covers fumigation.
Rules that apply in California
Sources: Drywood Termites (Pest Notes); University of Georgia Extension; University of Missouri Extension; Formosan Termite Program; Not All Termites Are Terrible (Home and School IPM Newsletter); Termites | Solve Pest Problems. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep termites away
- Keep mulch at least a foot from the foundation.
- Keep the termite renewal contract current after treatment.
- Paint or seal exposed exterior wood.
- Install a vapor barrier over crawl space soil.
- Keep gutters clean so water does not pool.
- Extend downspouts so water drains away from walls.
An inspection starts outside, with a flashlight along the foundation line where mud tubes show up first.Did you know?
In San Mateo, termites are closer cousins to cockroaches than to ants, despite the old nickname white ants.
Some African termite mounds stand more than 25 feet tall.
Questions people ask
Can termites damage a house on a concrete slab?
Yes. They come up through expansion joints, plumbing gaps and small cracks. Inspectors check those spots first.
Will termites come back after treatment?
They can. Treatments wear down and new colonies move in. That's what yearly inspections and renewal plans are for.
What is the difference between subterranean and drywood termites?
Subterranean termites live in soil and build mud tubes. Drywood termites live inside the wood and leave tiny pellets. Both turn up around San Mateo.
Is termite treatment safe for kids and pets?
Used according to the label, yes. Soil treatments stay in the ground. Bait stations are locked and buried. Ask for the label and follow any re-entry times.
Are mud tubes always a sign of active termites?
Not always. Old tubes can stay on a wall for years. Break off a piece and check back in a week. If it's rebuilt, they're active.
Are termite baits or liquid treatments more common?
In San Mateo, termites are best caught early through inspection, because the damage is hidden inside wood until it is far along. In San Mateo, a professional inspection looks for mud tubes, damaged wood, and swarming activity, and treatment targets the soil and the colony rather than just the visible wood.
Are termites common in California?
Around San Mateo, the usual culprit is the western subterranean termite.
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Sources (11)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Termite Exterminator · Updated September 11, 2026 · How we write these guides