Fumigation Coverage Calculator
Calculate tenting coverage, fumigant volume (Vikane/sulfuryl fluoride), cylinder count, and cost for structural fumigation by building dimensions and target pest.
About this calculator
This calculator sizes a structural tent fumigation job around the fumigant-exposure math used for sulfuryl fluoride (Vikane): dosage is expressed in ounce-hours per cubic foot, meaning a given concentration held for a given number of hours delivers the total exposure the target pest needs to die. Base dosages differ by target — 24 oz-hr/ft³ for drywood termites, 32 for powderpost beetles, 36 for bedbugs — and a temperature correction adds roughly 2% more dosage for every degree the average temperature sits below 70°F, since fumigant gas penetrates less effectively in cold structures. Dividing the corrected dosage by your chosen exposure time yields the required concentration, which is then multiplied by tarped volume — the building's raw cubic footage inflated by 15% to account for the tent's overhang beyond the walls — to get total fumigant weight, reported in both pounds and standard 30-lb/120-lb cylinder counts. Tarp area is estimated separately from a simplified box shape (roof plus four walls) with a 20% allowance for overlap and draping.
Cost combines fumigant at an assumed $5.50/lb, tarp rental at $0.15/sq ft, and labor as a $1,500 base crew charge plus $200 per thousand cubic feet of building volume. Because these are simplified box-geometry and single-market-rate assumptions, treat the output as a planning estimate: irregular rooflines, multiple structures under one tent, and regional fumigant and labor pricing will all shift the real number. Always confirm exposure time and dosage against the fumigant label and local regulatory requirements before scheduling a job.
Inputs
Results
Building volume (ft³)
30,000
Fumigant required (lbs)
2,156.3
Total estimated cost ($)
$20,205.38
≈ 10 gaming PCs
How to Use This Calculator
- Enter the structure total cubic footage (length times width times height of all spaces).
- Select the target pest (drywood termite, powderpost beetle, or bedbugs) — the dosage rate is calculated automatically.
- Set the temperature at the time of fumigation as it affects gas penetration.
- Review the Fumigant required (lbs) output and the number of cylinders needed.
- Use the tarp area needed and total estimated cost outputs to plan and budget the fumigation.
How the result changes with Building length (ft)
| Building length (ft) | Building volume (ft³) | Fumigant required (lbs) | Total estimated cost ($) |
|---|---|---|---|
| 25 | 15,000 | 1,078.1 | $10,960.69 |
| 38 | 22,800 | 1,638.7 | $15,767.92 |
| 75 | 45,000 | 3,234.4 | $29,450.06 |
| 125 | 75,000 | 5,390.6 | $47,939.44 |
What each input means
- Building length (ft)
- Exterior length of the structure.
- Building width (ft)
- Exterior width of the structure.
- Building height (ft)
- Peak height from ground to roof ridge.
- Target pest (0=Drywood Termite, 1=Beetle, 2=Bedbug)
- 0 = Drywood termites, 1 = Powderpost beetles, 2 = Bedbugs. Different pests require different dosages.
- Exposure time (hours)
- Duration the structure remains under tarp. Typical: 16–24 hours for termites.
- Average temperature (°F)
- Ambient temperature during fumigation. Below 70°F requires higher dosages.
What each result means
- Building volume (ft³)
- Interior volume of the structure.
- Tarped volume (ft³)
- Effective volume under tarp including overhang (~15% more).
- Tarp area needed (ft²)
- Total tarpaulin surface area with overlap allowance.
- Adjusted dosage (oz-hr/ft³)
- Temperature-corrected fumigant dosage rate.
- Fumigant required (lbs)
- Total weight of fumigant (Vikane) needed.
- 30-lb cylinders needed
- Number of small (30 lb) Vikane cylinders.
- 120-lb cylinders needed
- Number of large (120 lb) Vikane cylinders.
- Fumigant cost ($)
- Cost of the fumigant chemical.
- Tarp rental cost ($)
- Tarpaulin rental and setup cost.
- Labor cost ($)
- Crew labor for setup, monitoring, and aeration.
- Total estimated cost ($)
- Combined fumigant, tarp, and labor cost.
- Cost per ft³ ($)
- Total cost per cubic foot of structure.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersBuilding length (ft) = 50, Building width (ft) = 30, Building height (ft) = 20, Target pest (0=Drywood Termite, 1=Beetle, 2=Bedbug) = 0 = 6 input(s) provided
- Calculate Building volumeBuilding volume = lengthFt * widthFt * heightFt30000 = 30000
- Calculate Fumigant requiredFumigant required = totalFumigantOz / 162156.3 = 2156.3
- Calculate Total estimated costTotal estimated cost = fumigantCost + tarpCost + laborCost20205.38 = $20,205.38
- Calculate Tarped volumeTarped volume = buildingVolumeCuFt * 1.1534500 = 34500
- Calculate Tarp area neededTarp area needed = (roofArea + wallArea) * 1.25640 = 5640
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does increasing exposure time reduce the total pounds of fumigant needed?
Dosage is expressed in ounce-hours per cubic foot — a fixed total exposure the target pest needs to receive, whether delivered as a high concentration for a short time or a lower concentration held longer. The calculator divides the corrected dosage by your chosen exposure hours to get the required concentration, so stretching exposure time from 16 to 32 hours halves the concentration (and therefore the total fumigant weight) needed to deliver the same cumulative ounce-hour dose.
Why does bedbug fumigation require more fumigant than drywood termite fumigation for the same building?
The calculator assigns a different base dosage per target pest before any temperature correction: 24 oz-hr/ft³ for drywood termites, 32 for powderpost beetles, and 36 for bedbugs. Since total fumigant weight scales directly with corrected dosage, selecting bedbugs as the target pest produces a 50% higher fumigant requirement than drywood termites for an identical building and exposure time.
How does cold weather change the fumigant requirement?
For every degree the average temperature sits below 70°F, the calculator adds 2% to the base dosage, since sulfuryl fluoride penetrates less effectively in cold structures. At 50°F, for example, that's a 40% dosage increase over the same job at 70°F or above, which flows straight through to higher total fumigant weight and cylinder counts — temperatures at or above 70°F apply no correction at all.
Why does the tarp area calculation add 20% beyond the building's actual roof and wall surface?
Tarp area starts from a simplified box shape — roof area plus the four wall faces — then adds a 20% allowance for overlap between tarp panels and the extra draping needed to seal the tarp against the ground. This is separate from the 15% overhang added to building volume for computing tarped volume, since surface area and enclosed volume scale differently as the tent extends past the building's footprint.
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