Crawl Space Encapsulation Calculator
Calculate liner area, dehumidifier size and cost for crawl space encapsulation.
About Crawl Space Encapsulation Calculator
Liner covers both the floor and the walls up to the sill, and seams need generous overlap to stay sealed. A dehumidifier is required because an encapsulated crawl space no longer vents moisture to the outside. Encapsulating without dehumidification traps moisture rather than removing it, which makes conditions worse than leaving the space vented.
Formula
Crawl Space Encapsulation
Liner area = (floor area + perimeter × wall height) × (1 + overlap allowance)
- overlap
- Seams must overlap and be taped, typically adding 15 to 25 per cent
- encapsulation
- Sealing the crawl space from ground moisture and outside air
Worked example
With the default values below, Crawl Space Encapsulation Calculator returns Liner Area Required of 120.72. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Crawl space floor areaminimum 0 m2
- 70 m2
- Perimeterminimum 0 m
- 34 m
- Wall heightminimum 0.1 m
- 0.9 m
- Liner overlap and wasteaccepts 0–60 %
- 20 %
- Installed cost per square metreminimum 0
- 55
Results
- Liner Area Required
- 120.72 m2
- Floor Liner Area
- 84.00 m2
- Wall Liner Area
- 36.72 m2
- Dehumidifier Capacity
- 9.8 L/day
- Total Estimated Cost
- $3,850.00
Step by step
- 1Values used
- 2Crawl Space Encapsulation
- 3Liner Area Required= 120.72 m2
- 4Floor Liner Area= 84.00 m2
- 5Wall Liner Area= 36.72 m2
- 6Dehumidifier Capacity= 9.8 L/day
- 7Total Estimated Cost= 3,850.00
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Crawl Space Encapsulation calculated?
Liner area = (floor area + perimeter × wall height) × (1 + overlap allowance) Liner covers both the floor and the walls up to the sill, and seams need generous overlap to stay sealed. A dehumidifier is required because an encapsulated crawl space no longer vents moisture to the outside.
Why does Crawl Space Encapsulation matter?
Encapsulating without dehumidification traps moisture rather than removing it, which makes conditions worse than leaving the space vented.
What values do I need to enter?
This calculator takes 5 inputs: Crawl space floor area, Perimeter, Wall height, Liner overlap and waste, Installed cost per square metre. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.