TAKEOFF METRIC

Sheet set A · Architectural

Roofing

Squares, pitch, underlayment, ridge and valley.

Issued

1 of 1
A-102

Roofing Calculator

Squares, shingle bundles, underlayment rolls, ridge cap and starter for up to four roof sections, from the plan footprint and the pitch, with every yield read off a named manufacturer sheet.

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Quick reference

Pitch factor by rise, and the sloped area it gives over 1,000 sq ft of footprint
Rise in 12 Pitch factor Sloped sq ft per 1,000 sq ft of plan Squares
3 1.0308 1,031 10.31
4 1.0541 1,054 10.54
6 1.118 1,118 11.18
8 1.2019 1,202 12.02
10 1.3017 1,302 13.02
12 1.4142 1,414 14.14

The factor is geometry, not a table anyone had to publish: the square root of the rise squared plus twelve squared, over twelve. Multiply the footprint you can measure on the ground by it and you have the surface the shingles have to cover. Every material figure on sheet A-102 is read off one named product sheet instead — GAF Timberline HDZ, GAF Seal-A-Ridge, GAF Pro-Start and GAF FeltBuster, 4 documents in all — and each one stays a field you overwrite with the figure printed on the wrapper you are buying. Waste has no default there, and neither do nails, flashing or price: nothing we opened publishes a quantity for them.