Vapour Barrier Area Calculator

Add overlap at seams and edges.

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Formula

Sheet = area × (1 + overlap%)

Example calculation

1,000 ft² + 10% → 1,100 ft²; 1,000 ft² rolls → 2 rolls.

Practical HVAC use

Basement and wall assemblies.

Common mistakes

Placing poly where the assembly design calls for a vapour-open approach — follow local code.

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Educational tool. Results are estimates from the stated formulas; always confirm with manufacturer data and the code adopted in your jurisdiction. All calculators