UC ANR’s article on termites says subterranean termites are the most common termite in California. They live in underground nests, infest wood in contact with soil, and do-it-yourself treatments are not recommended and are often not effective. This guide explains what that supports for a Fremont home and what an inspection of the building checks.
Key takeaways
- UC ANR says subterranean termites are the most common termite in California.
- They live in underground nests and infest wood that is in contact with the soil.
- UC ANR advises against do-it-yourself treatments, which it says are often not effective.
- The inspection reads the wood contacts, the soil line and the foundation.
- The Fremont sources do not give an infestation rate, so this guide gives none.
- A licensed applicator carries out any treatment decided after the inspection.
What does UC ANR say about subterranean termites?
UC ANR’s article describes subterranean termites as the most common termite in California. It says they live in underground nests and that they infest wood in contact with soil, and it advises against do-it-yourself treatment.
That is a statewide statement and it is the basis of this guide. It describes the species and its habit. It does not give a count for any county or city, and it does not say how many houses in Fremont are affected. The guide does not add a figure that the article does not give.
The article is the reason the inspection looks at the soil and the wood together. A termite that lives underground reaches the wood through the soil, so the risk sits where the wood and the soil meet.
Why do the nests matter for a homeowner?
The nest is underground, so the colony is not visible from the house. The inspection looks for the routes the colony uses to reach the wood, which are the signs a homeowner can see.
A homeowner rarely sees the nest. What is seen is the result of the nest: a mud tube on a foundation, wood that is soft or hollow, pellets below a sill and swarmers near a window. Each sign points to a route, and the inspection follows the route to the wood.
Digging to find the nest is not part of the inspection. It can damage a service line and disturb the soil that the inspector needs to read. The report says where a deeper check would be needed and who should carry it out.
What is wood in soil contact, and why does it matter?
Wood in contact with soil is a direct route into the structure for subterranean termites. UC ANR says they infest wood in soil contact, so each piece of wood that rests on the ground is a contact to check and, where possible, to correct.
The contacts in a Fremont house are the steps, the porch posts, the fence attachments, the deck posts, the planter edges and any stack of firewood against the foundation. Each one is marked on the plan with its height above the soil.
A contact that is cleared of soil and lifted on a support removes the direct route. The inspection report recommends the correction, and the homeowner or a contractor carries it out. The correction is simple, and it does not depend on a product.
What does a do-it-yourself treatment miss?
UC ANR advises against do-it-yourself termite treatments, which it describes as often not effective. A product placed by a homeowner rarely reaches an underground colony or the route it uses to the wood.
A treatment that misses the route leaves the colony working. The homeowner who has treated the visible part of the house may believe the problem is solved, while the colony continues to feed on wood out of sight. That is the risk the article warns about.
A licensed applicator places a treatment against the inspection, and the placement follows the route the inspector recorded. The applicator’s licence and the presence of the Qualified Applicator Licence holder can be checked with the state.
What does the inspection check?
The inspection checks the grade and the drainage, the wood contacts, the foundation and the sill, the crawl space or slab edge, the moisture at the soil line and any sign of activity. Each finding is recorded by location.
The walk begins outside, at the grade and the drainage, because the way water moves decides how much moisture reaches the foundation. The wood contacts are marked and the foundation is read for cracks and for tubes on its face.
Inside, the sill and the first course of framing are read where they can be reached, and moisture readings are taken at suspect points. The report lists what could not be reached, so the homeowner knows the limits of the check.
What should a homeowner do now?
Keep wood off the soil, clear soil and mulch from the wood, keep the soil line clear, and book an inspection if a sign appears. Do not treat the house yourself without the inspection and a licensed applicator’s advice.
The first steps are the simplest: move firewood, lift a step onto a block, clear the soil from a planter edge and keep the downspout away from the foundation. Each one reduces a route that UC ANR describes.
A sign such as a mud tube, swarmers or soft wood calls for an inspection promptly. The inspection decides whether a treatment is needed, and the treatment is placed by a licensed applicator, as the article advises.
Why does a sill or a joist get attacked from below?
The sill and the joists sit close to the soil in a crawl space or a raised foundation, and the termites reach them through the foundation or along a pier. The inspection reads those members first, because they carry the weight of the house.
A sill that rests on a concrete wall with no barrier between can be reached from the soil through a crack or a joint. The inspector probes the sill along its length and records any section that is soft or hollow.
A joist that rests on a pier or a wall close to the soil can have the same problem. The report records the position of each joist that was reached and any damage found, with a note of the moisture reading.
What about slabs and the garage connection?
A house on a slab has no crawl space, so the risk sits at the slab edge, the garage connection and any wood trim that touches the ground. The inspection covers those points, and the report states the foundation type first.
The slab edge is checked for cracks and for soil banked against it. Trim and fascia boards that sit low against the stucco or siding are read for contact with the ground. The joint where the house slab meets the garage slab is checked for gaps.
A slab house still has wood on the ground at its steps, its porch and its fence, and those contacts are recorded in the same way as in a crawl-space house.
How should a homeowner read a termite report?
Read the report by location. A line that says the sill was sound at the points probed is useful, because it can be checked later. A line that says the house is clean is not a finding, and it should be questioned.
The list of what was not reached is as important as the list of findings. A section behind a finished wall or under a fixed cabinet is a gap in the check, and the homeowner can decide whether to open it.
The recommendations are ordered by urgency. A contact that needs clearing before the rainy season comes before a cosmetic repair, and the report says which is which.
Moisture, drainage and the soil line
Moisture at the foundation is one of the conditions that keeps the soil damp where termites can move. Keeping the soil line dry and the drainage away from the wall is a step a homeowner can take alone.
A downspout that discharges at the foundation keeps the soil damp against the wall. Extending the downspout several feet, or fitting a drain line that carries the water to the street, removes that moisture. The inspector records each downspout and its discharge point.
A grade that slopes toward the house holds water against the foundation. A regrade that takes the soil away from the wall is a permanent change, and it is recommended in the report where the slope is the cause. A planting bed against the wall holds moisture too, and its edge is kept below the siding.
What a seasonal check looks like
A seasonal check repeats the walk of the foundation, the wood contacts and the soil line. It takes less time than the first visit and it confirms the work of the season before.
The check begins at the soil line on each side of the house, where the first sign of activity or moisture is most likely to show. The homeowner looks for mud on the foundation, soft wood at the base of a post and a change in the colour of the soil.
The check then moves to the inside, with a look at the crawl space or the garage edge. A damp smell, new staining on the sill or a new crack in the slab edge is a reason to book an inspection before the next season.
Frequently asked questions
Are termites a common problem in California?
UC ANR calls subterranean termites the most common termite in the state. That is a statewide statement, and an inspection tells you what is present in a particular building.
Can I treat termites myself?
UC ANR advises against do-it-yourself treatment, which it describes as often not effective. A licensed applicator is the right step after an inspection finds activity.
Is a mud tube a sign of an active colony?
It can be, but an old tube that leads nowhere may be inactive. The inspector follows the tube and reports whether the activity looks current.
Do I need the inspection before buying a house?
A buyer may want one. This site does not set that requirement, and the buyer or lender should state the scope they need when the inspection is booked.
Is a crawl space with dirt floor a risk?
A dirt floor in contact with the wood adds to the contact risk, and a damp one adds to the moisture. The inspector records the floor and the moisture, and the report recommends the drainage or the covering that the building needs.
Should the homeowner keep a record of the checks?
Yes. A dated record of each check, with a photo of the soil line and the contacts, is the most useful document to bring to an inspection or to a buyer.
Sources
- UC Agriculture and Natural Resources, article on termites in California (ucanr.edu)
- UC Integrated Pest Management Program (ipm.ucanr.edu)
This guide is general information for Alameda County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.