Termite Damage: Signs, Scope, and Treatment Cost

Termites cause approximately $5 billion in US property damage every year — more than fires, floods, and tornadoes combined. Unlike those events, termite damage is slow and hidden. A colony can operate in a home for 5-15 years before structural damage becomes visible. Most homeowner insurance explicitly excludes termite damage, leaving the bill entirely to the homeowner. For buyers, a Wood-Destroying Organism (WDO) inspection is the single most important pre-purchase item in termite country.

This guide explains how to recognize termite activity, what treatment options cost, and how to read a WDO report.

This guide is organized the way the decision actually plays out in practice: what matters, what does not, and the reasoning behind each recommendation. Numbers and ranges reflect 2026 Connecticut, Massachusetts, and New York conditions and pricing.

Quick answer

Subterranean termites are the most common US species; drywood and Formosan termites are regional. Annual termite inspection costs $75-$200 and is essential in southern and coastal states. Active infestation treatment: liquid barrier $1,200-$3,500; bait station system $1,500-$4,500/year; fumigation (drywood termites) $2,500-$8,000. Structural damage repair can range from $500 for a single sill plate section to $50,000+ for extensive framing replacement. Termite bonds (ongoing service contracts) typically cost $200-$500/year and include retreatment if infestation recurs. Every home purchase in termite-active regions should include a WDO inspection, ideally with a licensed pest control operator.

Field context

Cost ranges published in a guide like this are benchmarks, not guarantees. Each range reflects a band within which most fair-market invoices actually land — low end for a clean, uncomplicated job in normal business hours, high end for predictable complications and peak-season pricing. The middle is where most real invoices sit. The ranges are built from trade-association wage data, aggregated regional cost-guide benchmarks, manufacturer and retailer equipment pricing, and current utility rebate schedules. Three important caveats follow from how the ranges are built.

First, the ranges are not negotiating targets. Contractors price to their local market, their own overhead and schedule, and the specific scope of the job in front of them. A contractor whose bid comes in near the middle of the published range is not overcharging; a contractor whose bid falls 15% below the low end is usually missing scope rather than offering a better deal. The useful pattern is three bids on identical written scope, not a single bid compared to the published range.

Second, the ranges shift materially with seasonality, location, and labor market conditions. Peak heating and cooling seasons push HVAC and plumbing invoices 10-20% higher than shoulder seasons. Coastal Connecticut, Boston metro, and New York City metro labor rates run 15-25% above national averages. The ranges here are calibrated to 2026 CT/MA/NY conditions; readers in markedly different markets should adjust expectations.

Third, cost is not the same as value. The lowest number that completes the job correctly, with licensed work by a contractor who stands behind it, is usually the cheapest outcome over a 10-year horizon even when it is not the cheapest invoice in the quote stack. Most homeowners who look back at a major project with regret report choosing on price alone.

Termite species in the US

Subterranean termites (most common)

Live in soil, travel through mud tubes to wood. Found in every US state except Alaska. Responsible for 80%+ of US termite damage.

Drywood termites

Live entirely in wood, no soil contact required. Southern coastal states — Florida to California. Produce distinctive "frass" (wood-colored pellets).

Dampwood termites

Require very wet wood. Pacific Northwest and parts of Florida. Most common in homes with active water problems.

Formosan termites

Aggressive subterranean species. Gulf Coast, Hawaii, California. Larger colonies, faster damage.

Treatment approach varies by species. A professional identification is the first step.

Signs of termite activity

Inside the house

• Mud tubes — pencil-diameter tunnels running up foundation walls or framing. Subterranean termite signature.
• Hollow-sounding wood when tapped with a screwdriver handle. Sound is distinct from solid wood.
• Wood damaged along the grain — termites follow the soft spring wood, leaving ridges of harder summer wood.
• Discarded wings near windows or light fixtures (spring swarming season).
• Frass (small pellets, sand-like) near wood surfaces — drywood termite signature.
• Bubbled or damaged paint on wood surfaces — termite damage pushing through.
• Clicking sounds in walls — soldier termites headbutting wood when disturbed.

Outside the house

• Mud tubes on foundation walls, pipes, or piers
• Damaged wood near ground contact — deck posts, fence posts, steps
• Swarming insects in spring (distinguish from ants — termites have straight bodies, equal wing lengths, straight antennae; ants have pinched waists, different wing sizes, elbowed antennae)
• Shelter tubes in crawlspaces

In the yard

• Wood piles, tree stumps, or mulch close to foundation (food source)
• Moist soil against foundation (travel route)
• Dead trees or stumps within 25 feet of the house

The WDO inspection

Wood-Destroying Organism (WDO) inspection covers termites, carpenter ants, wood-boring beetles, and fungal decay. Required by many lenders for southern-state home purchases; strongly recommended anywhere termites are active.

What the inspector does

• Visual inspection of accessible wood (crawlspace, basement, attic, exterior)
• Probe test of suspect areas with a screwdriver or moisture meter
• Documentation of any active infestation, historical damage, or conditions favorable to infestation
• Written report with findings by category

What the report categorizes

• Section I — Active infestation — live termites or other WDOs found
• Section II — Past infestation — evidence of prior activity, no current activity
• Section III — Structural damage — physical damage from WDOs
• Section IV — Conditions conducive — moisture, wood-to-ground contact, other factors that attract termites

Each section has separate remediation implications. A clean Section I doesn't mean no termites — it means none found during this inspection. Inspectors can only see accessible areas.

Treatment options

Liquid soil treatment (barrier)

Termiticide (typically imidacloprid or fipronil) is injected into the soil around the foundation perimeter, creating a chemical barrier that kills termites passing through.

Pros: proven effectiveness; one-time application (with periodic retreatment); works against active infestations.

Cons: requires drilling through concrete slabs and patios; chemical presence in soil near home; 5-10 year effective life.

Cost: $1,200-$3,500 for a typical home.

Bait station system

Stations installed at regular intervals around the foundation contain wood baited with termite-killing compounds. Termites consume and carry back to the colony, eliminating the colony.

Pros: no chemical soil injection; eliminates entire colonies; easier to install in complex properties.

Cons: ongoing service contract required; slower than liquid for active infestations.

Cost: $1,500-$4,500/year for installation and monitoring service.

Fumigation (drywood termites only)

Home is tented and fumigated with sulfuryl fluoride. Effective against drywood termites that cannot be reached by soil-based treatments.

Pros: eliminates drywood termites throughout the structure.

Cons: expensive; homeowner must vacate for 2-5 days; all food, plants, and pets must be removed or sealed.

Cost: $2,500-$8,000 depending on home size.

Localized spot treatment

For small, contained drywood or dampwood infestations, local injection of insecticide into affected wood.

Pros: less disruption than fumigation.

Cons: only works if all infestation is found and treated.

Cost: $300-$1,500.

Structural repair

After termites are eliminated, damaged wood must be assessed and replaced. Scope varies enormously:

• Single sill plate section: $500-$1,500
• Multiple framing members: $2,500-$8,000
• Extensive structural damage: $15,000-$50,000+

A structural engineer assessment often accompanies significant termite damage repair.

What treatments actually cost in 2026

National ranges.

The buyer playbook

For any home purchase in termite country (roughly the southern half of the US), include a WDO inspection in the contract contingency.

If the inspection shows:

• Section I active — seller typically treats before close and provides warranty
• Section II past — negotiate based on extent; treatment often still recommended
• Section III structural damage — engineering assessment and repair cost negotiation
• Section IV conducive conditions — correction responsibility negotiable (grading, wood-to-ground contact, moisture)

Termite clearances (Section I and III clear) are required by some lenders, including FHA and VA loans. Plan for potential treatment before close if you're using one of those loan programs.

When to call a professional

All termite treatment is professional-only. State pest control licensing is required for termiticide application.

Call a licensed pest control operator for:

• Any suspected termite activity
• Annual inspection in termite country
• WDO inspection for any real estate transaction
• Any new home construction (pre-treatment soil application)

Stela Home earns no referral fees from contractor connections.

Preventing the next infestation

• Annual inspection. $75-$200 for peace of mind in termite country.
• Eliminate wood-to-ground contact — wood siding, deck posts, fence posts at least 6 inches from soil.
• Keep mulch 12+ inches from foundation. Wood mulch near foundation is a direct invitation.
• Fix moisture problems. Termites need moisture; dry foundations are less attractive.
• Remove tree stumps and wood piles within 25 feet of the house.
• Store firewood off the ground and away from the house.
• Inspect deck ledgers and posts annually — both termite entry points and sources of damage.

Diligence and documentation

Diligence on cost management centers on three practices. First, written scope before any contractor conversations. A scope document listing every line item — equipment, labor, materials, permits, disposal, warranty terms — standardizes quotes and exposes where contractors are pricing differently. Second, three competitive bids on identical scope, not three contractor interviews followed by loose estimates. Third, license and insurance verification through the relevant state registry, plus two references on similar jobs completed in the preceding two years. These steps take a few hours and routinely save five to fifteen percent on the final invoice, independent of any negotiation.

Documentation at the back end matters as much as diligence at the front. A paid invoice with itemized scope, photographs of the completed work, and a record of any permits pulled belongs in the homeowner's records — not just for warranty claims but for the eventual resale, where a documented maintenance and improvement history routinely adds real value at closing. The homeowners who build this habit from day one of ownership tend to recover disproportionately more of their project costs when they sell; the homeowners who treat records casually tend to give money back at inspection.

Bottom line

The honest bottom line on cost: the right number is rarely the lowest quote. It is the lowest quote attached to complete scope, licensed work, and a contractor whose license, insurance, and references check out. Every one of those three items has quietly saved more money than bid negotiation in the long arc of home ownership.

Related Stela Home coverage

• Reading a WDO or Termite Inspection Report: Buyer's Checklist
• Siding Damage: Wood, Fiber Cement, and Vinyl Issues
• Active Mold Growth: Remediation Cost and When DIY Is Okay
• Cost to Replace All Windows in a House

How Stela Home helps

Three Stela Home tools work together on this kind of decision:

• Stela Report — pre-purchase property intelligence with disclosure, condition, and risk flags.
• Repair Calculator — modeled cost ranges by category and ZIP, calibrated with regional and complexity multipliers.
• Stela Guides — step-by-step repair walkthroughs reviewed by licensed professionals, with safety callouts and disclosure.

Sources and further reading

• US Environmental Protection Agency — termite prevention and control
• National Pest Management Association — termite resources
• US Department of Agriculture — termite distribution and species
• International Residential Code (IRC) Section R318 — termite protection
• HUD Handbook 4150.2 — WDO inspection requirements

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