Question 1

What is a roofing square?

Accepted Answer

A roofing square is a unit of measurement equal to 100 square feet of roof area. Roofing materials are sold and priced by the square. One square of standard 3-tab shingles requires 3 bundles.

Question 2

How does roof pitch affect material needs?

Accepted Answer

A steeper pitch means more actual surface area than the flat footprint. A 6/12 pitch adds about 12% more area compared to flat, while a 12/12 (45-degree) pitch adds about 41%. The calculator applies the correct pitch multiplier automatically.

Question 3

How many bundles of shingles do I need per square?

Accepted Answer

Standard 3-tab shingles require 3 bundles per square. Architectural (dimensional) shingles may require 3-5 bundles per square depending on the brand and style. Check the manufacturer specifications.

Question 4

What waste factor should I use for roofing?

Accepted Answer

Use 10% for simple gable roofs, 15% for hip roofs, and up to 20% for complex roofs with many valleys, dormers, or irregular shapes. The waste accounts for cuts at edges, ridges, and valleys.

Roofing Calculator

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