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.
- 1Sagging or spongy floors near exterior walls.
- 2Layered, honeycombed wood packed with soil.
- 3Buckling laminate or warped hardwood flooring.
- 4Termite tubes hanging down from ceilings or joists.
- 5Piles of identical shed wings on windowsills.
- 6Dry hexagonal pellets under window frames or eaves.
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.
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
Fumigation for Drywood Termites
$1,200–$4,000 (often $1–$4 per square foot)
Fumigation does not treat subterranean termites living in the soil. A San Mateo home with both species may need a soil barrier as well as the tent.
- Time
- 2–3 days including tenting and aeration
- Best for
- Widespread drywood termites throughout a structure
Localized Wood, Foam, and Borate Treatment
$250–$1,500
A local treatment is cheaper than fumigation but only covers what the San Mateo technician can find. Hidden drywood galleries elsewhere in the house are not touched.
- Time
- 1–3 hours
- Best for
- Small drywood spots, wall voids, and exposed framing
Bait Station System with Monitoring
$1,500–$3,500 install, plus $300–$500 per year
Instead of a chemical barrier, baiting in San Mateo removes the colony itself. Stations are checked on a schedule, commonly quarterly, and refilled.
- Time
- 2–4 hours to install; checked quarterly
- Best for
- Colony elimination, wells and slabs, homes near water
Prices are typical published ranges. Ask what’s included before you compare quotes.
Check under the kitchen sink for dampness and soft cabinet wood. Plumbing walls are a common path for termites coming up from a slab.Which termites live around San Mateo.
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. The termite you're most likely to meet in San Mateo is the western subterranean termite.
Local termites conditions in San Mateo.
Across San Mateo, the area is mostly urban, so termites pressure can differ from one block to the next depending on how tight the entry points are and how much food, water, or shelter is close by. An inspection in San Mateo usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing San Mateo's seasonal timing lets you schedule treatment before the busy stretch rather than after it, which usually means faster service and a more accurate quote. A provider who works San Mateo and California every day can point out the specific conditions that matter most here, and getting the scope, price, and follow-up terms in writing makes it easier to compare options. San Mateo sits in a mediterranean climate, and that sets the pace for termite activity here: spring swarm season (March-May), warmer earlier in the south.
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.
Across 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. Swarm season is when termites show themselves.
Where to look around your house.
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. Plenty of homes in San Mateo have basements, so check where the wood framing sits on top of the foundation wall.
A year of termites in San Mateo.
- Winter: a good time to book an inspection in San Mateo, before swarm season starts. - Spring and fall: swarm seasons. Across 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.
What happens at an inspection.
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. Most inspections take an hour or two.
Termites or ants?
- Tunnels: termite galleries are packed with mud. Ant tunnels are clean and smooth. - 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.
Getting ready for treatment day.
Clear a walking path along the exterior walls. Move boxes away from garage walls. Flag sprinkler heads and buried lines. Keep kids and pets inside while the San Mateo crew applies the product, and ask how long to stay off treated soil. In California, 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). Drill holes in slabs or patios get patched afterward. Prep is light for liquid treatments and bait stations.
Mulch and termites.
A dry gap along the house makes mud tubes easier to spot; in San Mateo that means extending downspouts and pulling mulch back from the slab. Wood chips touching the siding trap the moisture termites are after. Pull mulch back from the foundation and keep the layer thin.
Questions to ask before you sign.
- What do I need to do before and after treatment? - 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 affects the price
- Time of year and how booked up local companies are.
- Liquid barrier versus bait station system.
- Annual renewal and monitoring fees.
- Access to crawl spaces and attics.
- Wells, drains, or water features limiting chemical use.
- Number of bait stations required.
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What's your biggest concern about termites?
When to call for help
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. Lenders often ask for one. It's also the cheapest termite service. Carpenter ants leave clean tunnels and sawdust. Termites leave mud.
What you can do yourself
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. Some of the work is yours. Pull mulch back from the foundation. Fix leaks and clear gutters. Keep firewood away from the house.
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.
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
- Check the foundation for mud tubes every spring.
- Ventilate crawl spaces and control humidity.
- Set deck and porch posts on concrete, not soil.
- Keep the termite renewal contract current after treatment.
- Keep mulch at least a foot from the foundation.
- Install a vapor barrier over crawl space soil.
An inspection starts outside, with a flashlight along the foundation line where mud tubes show up first.Did you know?
Across San Mateo, some tropical termites grow fungus gardens inside the nest and eat the harvest.
Across San Mateo, termites are closer cousins to cockroaches than to ants, despite the old nickname white ants.
Questions people ask
What does a WDI report include?
It lists any termites or damage found. It also notes conditions that invite them, like wood touching soil. It only covers areas the inspector could reach.
How long do termite bait stations take to work?
Usually several weeks to a few months. Termites have to find the stations first. Then the bait spreads through the colony.
How long does termite treatment take?
A liquid barrier takes half a day to a day. Bait stations take a few hours to install. Fumigation takes two to three days.
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.
How much does termite treatment cost?
For a homeowner budgeting a termite job, the professional-reported average post-construction price in Pest Control Technology (PCT) magazine's 2025 termite market report (about 145 respondents, 2024 pricing) was $1,100. Treat it as a benchmark, not a promise, since house size and method drive the quote.
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