Termite fumigation is a whole-structure treatment where your home is sealed under a tent and filled with gas to kill termites living inside the wood. It’s the most thorough method available for drywood termite infestations, typically costing between $2,000 and $5,000 for most homes, and requiring you to vacate for two to three days. Here’s what the process involves, what it costs, and how to prepare.
Why Fumigation Is Used
Fumigation exists primarily to deal with drywood termites, which live entirely inside the wood they eat rather than traveling back and forth to the soil like subterranean termites. Because drywood termites can establish colonies deep within walls, attics, and other areas you can’t easily access, localized spot treatments only work when you know exactly where every colony is. The problem is that termite inspections are limited to visible, accessible areas. Detecting hidden infestations may require removing walls, paneling, or stucco, which is rarely practical.
Fumigation solves this by treating the entire structure at once, reaching every colony whether it’s visible or not. Inspectors look for feeding damage, shed wings, fecal pellets, and small “kickout holes” in wood surfaces during their assessment. If evidence suggests multiple colonies or infestations in hard-to-reach locations, whole-structure fumigation is generally the recommendation.
Subterranean termites, by contrast, are usually handled with soil treatments, bait systems, or barrier methods rather than fumigation. Dampwood termites are less common and typically managed by fixing moisture problems like roof or deck leaks and replacing damaged wood.
How the Process Works
The fumigation process follows a strict sequence managed by a licensed fumigator. First, the exterior of your home is covered with large tarps, creating an airtight seal. The fumigant used in nearly all structural termite treatments is sulfuryl fluoride, a colorless, odorless gas. It’s non-flammable and non-corrosive, and it doesn’t leave odors or chemical residues on your belongings.
Once the tent is sealed, the gas is released into the structure. It penetrates wood, wall cavities, and other materials quickly, reaching termites wherever they’re hiding. The gas works by disrupting the insects’ ability to take in oxygen, killing adults and larvae. Eggs tend to be somewhat less susceptible, which is one reason the gas is held at concentration for an extended period, typically 16 to 30 hours depending on the size of the structure, the severity of the infestation, and temperature conditions.
After the exposure period, the fumigator opens the tent and aerates the structure using fans and inlet devices for a minimum of 12 hours. The gas dissipates rapidly during this ventilation phase. Before anyone can re-enter, the fumigator must test the air inside and certify that gas concentrations have dropped to 1 part per million or less. Only the licensed fumigator in charge can authorize re-entry.
What Fumigation Costs
Most homeowners pay around $3,000 for a complete fumigation treatment, with the typical range falling between $2,000 and $5,000. Costs can run as low as $1,500 for smaller homes or as high as $8,000 or more for larger properties. The two main pricing models are $5 to $20 per linear foot of your home’s exterior perimeter, or $1 to $4 per square foot of interior space.
To put that in perspective by home size:
- 1,000 sq ft: $1,000 to $4,000
- 1,500 sq ft: $1,500 to $6,000
- 2,000 sq ft: $2,000 to $8,000
- 2,500 sq ft: $2,500 to $10,000
- 3,000+ sq ft: $3,000 to $12,000+
Heat treatment is an alternative that runs about $10 per linear foot or $1 to $3 per square foot, though it has limitations in how deeply and uniformly it penetrates large structures compared to gas fumigation.
How to Prepare Your Home
Preparation is the most labor-intensive part of fumigation for homeowners. You’ll need to arrange somewhere else for your family and all pets to stay for several days. Fish tanks and aquariums also need to be removed or relocated, since the gas is toxic to all living things.
Food, Medicine, and Consumables
Anything you eat, drink, or put in your body needs to be protected. Food, pet food, tobacco products, and medications (including items in your refrigerator and freezer) can stay in the house only if they’re sealed in their original airtight manufacturer’s packaging, like unopened cans, glass jars, or metal containers. Everything else must be either removed from the house or double-bagged in special nylon fumigation bags your pest control company will provide. Dry goods in bags or cardboard boxes, even unopened ones like cereal, chips, and rice, need to be removed or double-bagged.
Plants and Outdoor Areas
Remove all plants from inside the house and from any outdoor areas that will be covered by the tent. The day before fumigation, water the soil around the perimeter of your house to a depth of about six inches. This moisture helps protect plants just outside the tent’s edge and creates a better seal at the base to prevent gas from escaping. Shrubbery around the house should be trimmed back to give the crew room to secure the tent against the foundation.
Gas Lines and Sealed Items
The gas company needs to shut off your gas line the day before fumigation. Mattresses with plastic covers, like baby mattresses, need to have those covers removed or opened because the waterproof material slows the rate at which the fumigant aerates out. The same goes for plastic covers on chairs, sofas, and other upholstered furniture.
What Happens After Fumigation
Once the fumigator certifies the home safe for re-entry, you can return and resume normal life. Sulfuryl fluoride doesn’t leave chemical residues on surfaces, so you won’t need to deep-clean your house or wash every dish. The gas dissipates completely during the aeration process.
One critical thing to understand: fumigation kills every termite in the structure at the time of treatment, but it provides zero residual protection. The moment the gas clears, your home is just as vulnerable to a new infestation as any other house. This is the biggest limitation of fumigation compared to soil barrier treatments or bait systems, which provide ongoing protection against subterranean termites. For drywood termites specifically, there’s no long-lasting preventive treatment equivalent. Some homeowners in high-risk areas end up needing repeat fumigation years later if new drywood termite colonies establish themselves.
To reduce the chances of re-infestation, sealing cracks and gaps in exterior wood, screening attic vents, and painting or sealing exposed wood surfaces can help make your home less inviting to swarming drywood termites looking for a place to start a new colony.