Glossary
Square (roofing)
A roofing industry unit equal to 100 square feet. A 20,000 sq ft roof is 200 squares — bids and material quantities are often stated this way.
Plain-English definition
A roofing industry unit equal to 100 square feet of roof area — or the material needed to cover it. A 20,000 sq ft roof is 200 squares. Contractors, estimators, and suppliers price and order in squares, so bids and proposals are often stated this way.
Why it matters to you
Verified: The unit is standard across the trade — manufacturers define it exactly this way (GAF — roofing glossary). Knowing it lets you convert any bid into a per-square-foot price in your head (divide the per-square price by 100), which is the fastest way to compare proposals that are formatted differently. Two cautions when comparing: confirm whether each bid’s square count is measured the same way (field-measured vs. estimated from drawings or aerial measurement), and remember that material squares ordered typically exceed roof-area squares because of overlaps, flashings, and waste — so “squares of material” and “squares of roof” on the same page are not the same number.
Technical detail
None needed beyond the definition — the unit itself carries no technical nuance. The useful diligence is in the measurement: on reroofing bids, ask whether the stated square count comes from a field measurement, construction drawings, or aerial takeoff, and whether it covers roof area only or includes wall flashing area at parapets and curbs.