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Underlayment Calculator
Estimate underlayment rolls for any floor area.
Underlayment is ordered by square foot of finished floor plus 10% for trimming and overlap: measure each room's length × width and add the areas. A standard foam roll covers about 100 sq ft, cork about 200 sq ft, and roofing felt about 400 sq ft per roll. Enter your floor area to get square feet and roll counts.
How does the underlayment calculator work?
Underlayment is sold in rolls of 100–200 ft². Divide floor area by roll coverage and add ~5% for seams and overlaps.
What else do people ask about this calculator?
Do I need underlayment for LVP?
Most click-lock LVP over 6 mm has attached pad. Thinner planks and floors over concrete benefit from a moisture-barrier underlayment.
How is underlayment sold?
In rolls, typically 100 ft² for foam and up to 200 ft² for cork or felt.
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