Termite Treatment Cost Calculator

Priced by the foot around, not the floor area

Termite work is quoted on the linear feet of foundation — the distance around the outside of the house at ground level, including the garage, the porch and any addition. A 40 by 50 foot house is 180 feet, and most houses come to 150 to 220.

That is because the treatment is a barrier around the outside, so a long thin house costs more to protect than a square one of the same size. Floor area has almost nothing to do with it.

And what the foundation is:

A slab costs more because wherever concrete abuts the house — garage, porch, patio, driveway — the barrier has to be drilled through on twelve-inch centers, injected beneath and every hole patched.

The warranty is the product

The most important thing on this page. Two companies quoting $1,400 can be selling very different things, and the difference is in the paperwork rather than the chemical.

• A repair bond — sometimes called a damage warranty — means the company pays to repair new termite damage that appears while the contract is in force. This is the valuable one.
• A retreat-only warranty means they will treat again for free and that is all. If termites come back and eat a floor joist, the repair is yours.

Ask, in these words: "If termites return and cause damage, who pays for the repair?" Then read what the contract says, because the answer at the kitchen table and the answer in clause 7 are not always the same.

Three more questions about the paperwork:

• What is the annual renewal? Liquid barriers renew at $200 to $300 a year, bait programs at $300 to $500. A warranty that lapses is a warranty that is gone, and reinstating it usually means paying for a new treatment.
• Is it transferable if the house is sold? It is worth real money to a buyer.
• Is there a graph of the structure attached to it? A proper treatment record includes a diagram showing exactly what was treated and where. It is the document a future lender or buyer's inspector will ask for.

Liquid or bait

They cost nearly the same installed, which surprises people. The difference is what they do and what they cost over a decade.

Liquid is the faster, cheaper, more disruptive answer, and it is the usual choice for an active infestation — it stops termites reaching the house today.

Bait eliminates the colony rather than repelling it, needs no trenching or drilling, and suits a house where a continuous soil barrier is impractical: a well nearby, a cistern, extensive hardscape, a crawl space you cannot get round, or a household that would rather not have a hundred gallons of termiticide in the soil. Its weakness is time — it is a monitoring program, not an emergency measure.

Some companies will do both: bait for the long term and a liquid spot treatment where termites are entering now. On an active infestation with visible damage, that is a reasonable recommendation rather than an upsell.

Is it termites or flying ants?

A swarm indoors is the most common way people find out, and the two are routinely confused. In the swarmers:

Discarded wings on a windowsill are the classic termite sign — they shed them after swarming, which ants do not do in the same way.

The other signs:

• Mud tubes — pencil-width tunnels of soil up a foundation wall, in a crawl space or behind siding. This is the definitive sign of subterranean termites.
• Hollow-sounding wood, and trim or baseboard that gives under a screwdriver.
• Blistered or rippled paint on a door frame or baseboard, which looks like water damage.
• Frass — tiny hard pellets like coarse sand — which indicates drywood termites rather than subterranean ones, and a different treatment.

Do not break the mud tubes open before the inspection. It scatters the colony and removes the evidence the inspector needs to find where they are entering, which is the part that determines the treatment.

Drywood termites are a different job

This page prices subterranean termites, which is what the great majority of US infestations are and what a soil barrier or bait program addresses.

Drywood termites live inside the wood rather than in the soil, so a soil barrier does nothing. They are a coastal and southern problem, and the treatments are localized injection, borate, heat, or tent fumigation for a whole structure — which is priced by the cubic foot of the building rather than the foot around it, and typically runs $1,200 to $4,000 or more.

If the sign you have is frass rather than mud tubes, the figures on this page are not the ones you want.

Fix the conditions, or keep paying

A barrier stops termites reaching the house. It does not stop the house inviting them. Before or alongside treatment:

• Break any wood-to-soil contact. Deck posts, fence rails against siding, stair stringers in the dirt, and siding that runs below grade. This is the single biggest invitation there is.
• Pull mulch back 6 inches from the siding and keep it thin. Mulch against a wall is moisture and cellulose at the entry point.
• Fix leaking gutters, downspouts discharging at the foundation, and AC condensate lines, which are the usual reason the soil beside a house is permanently damp.
• Move the firewood away from the house and off the ground.
• Ventilate the crawl space and keep the ground covered.
• Keep 6 inches between the soil and the bottom of the siding, which also lets an inspector see the foundation at all.

That last point matters practically: a house whose foundation is buried behind mulch and shrubs cannot be inspected properly, and the first thing an inspector will tell you is that they could not see three sides of it.

Buying or selling a house

A termite inspection — a WDI report, on the NPMA-33 form — is standard in much of the country and is required by some lenders, particularly on VA loans in termite-active states. It runs $75 to $150 standalone, and most companies waive it against a treatment.

Two things worth knowing:

• An existing transferable warranty is an asset. If you are selling and you hold one, transfer it; if you are buying and the seller has one, get it transferred rather than letting it lapse.
• A clear report is not a guarantee. It says what was visible on the day. In a house with a finished basement and a slab porch, a lot is not visible.

What you are paying for

A liquid barrier around a 180 foot crawl space or block foundation, at $1,425:

Eighteen hours is two days for one person or a day for two, and most of it is physical: trenching six inches by six inches around the whole house, treating at the label rate, and backfilling with treated soil. The two fixed hours before that are the inspection, the structural graph the warranty depends on, and mixing well over a hundred gallons of finished solution.

Can you do it yourself?

Realistically, no, for a whole-house barrier. The label rate is four gallons of finished solution per ten linear feet per foot of trench depth, which on a normal house is over a hundred gallons mixed to an exact concentration, trenched and backfilled correctly, and injected under every abutting slab. Doing it imperfectly produces a barrier with gaps, and termites find gaps.

Retail bait stakes are not the professional systems; the leading bait products are restricted to certified operators. And none of it gives you a warranty, which — as above — is most of what you are buying.

What is genuinely worth doing yourself is everything in the conditions list, and inspecting the perimeter twice a year with a flashlight and a screwdriver.

Questions worth asking

• If termites return and cause damage, who pays for the repair?
• What is the annual renewal, and for how many years?
• Is the warranty transferable if I sell?
• Will I get a graph of the structure with the treatment record?
• Liquid or bait here, and why that one for this house?
• How much of the perimeter needs drilling rather than trenching?
• What did you find, and where are they getting in?
• Which conditions should I fix, and does the warranty depend on fixing them?
• Is this subterranean or drywood?
• What could you not inspect?