What is a roofing square?
A roofing square is a coverage unit equal to 100 square feet of roof surface.
Start with actual roof surface area
A sloped roof has more surface area than its horizontal footprint. Roof pitch, overhangs, dormers and separate roof sections should be accounted for before converting the area into roofing squares.
From roof squares to shingle bundles
Bundle coverage varies by manufacturer and product. A commonly encountered packaging arrangement is three bundles per roofing square, but the package coverage for the selected shingle should always control the final order.
Why roofing waste is necessary
- Shingles are cut at roof edges and penetrations.
- Valleys and hips can increase cutting losses.
- Complex roofs generally create more waste than simple gable roofs.
- A small reserve can also help with future repairs.
Example
If the measured roof surface is 2,000 square feet, that equals 20 roofing squares before waste. Adding 10 percent increases the material coverage target to 2,200 square feet, or 22 roofing squares.
Other roofing materials to consider
A shingle count does not include every component required for a roof installation. Underlayment, starter strips, ridge-cap material, flashing, fasteners and ventilation components may also be needed.
The number of shingles or bundles per square is not universal. Verify the coverage shown by the manufacturer for the exact product being installed.