The Roofing Term You Must Know - "Square of Shingles" Defined
For homeowners planning a roofing project, learning the lingo used by roofers is essential. One term that repeatedly comes up is "square," a unit of measurement that simplifies material calculations for the roof area.
But what exactly does a "square" represent when it comes to shingles and roofing supplies? We will demystify this common industry term so you can understand bids and determine material needs.
Defining a "Square" in the Roofing Industry
When roofers refer to a "square," they are talking about 100 square feet of roof area. This conversion to a simplified unit, rather than using total roof square footage, allows for easier computation when ordering shingles, tiles, and other coverings.
The concept dates back decades when roofers realized calculating materials based on the total roof area resulted in unwieldy fractions. By breaking things down into 100 square foot sections--called squares--the math and material estimates became more straightforward.
Why 100 Square Feet?
Using 100 square feet as the standard roofing industry square offers a nice round number that simplifies the math compared to actual square footage. It breaks a roof down into manageable sections for calculations and materials ordering.
Rather than working with a total measurement like 1,500 square feet for an entire roof, roofers can instead estimate things based on 15 squares. This allows bid prices and material quantities to be listed in easy-to-understand units.
Converting Between Squares and Total Area
Wondering how many squares are on your roof? By measuring the total roof area and dividing by 100, you can translate square footage into units of squares:
- 1500 sq ft roof / 100 sq ft per square = 15 squares
- 2000 sq ft roof / 100 sq ft per square = 20 squares
The same logic applies in reverse--simply multiply squares by 100 to determine what the total roof area would be in square feet.
Using Squares to Order Roofing Materials
The main purpose of breaking things down into roofing squares is to make material quantity estimation and purchasing simpler. By using squares as the pricing and order unit, roofers can quickly dial in the right amount of supplies.
Bundles, Packs, and Coverage
For popular asphalt shingle roofing, squares give an approximate sense for how many bundles to buy. Each architectural shingle bundle covers around 33 linear feet. With 100 square feet working out to about 33 linear feet, one square is approximately three bundles:
- 1 square = ~3 bundles
- 15 squares = ~45 bundles
As you scale up your order, it becomes easier to calculate bundle needs from total squares rather than handling all the linear feet math.
Waste and Safety Factor
When estimating materials, most roofers add a 10-15% safety margin to account for potential damage, unusable pieces, and odd size gaps. More complex roofs require more cutting and custom fitting, wasting more material as a result.
Factors Impacting Square Pricing
While the square simplifies the measurement process, it does not imply materials are equal cost across the board. Many variables affect pricing per roofing square:
- Type of shingles/material
- Level of durability and longevity
- Roof slope, layout, accessibility
- Regional labor and material costs
- Economy of scale discounts
As you evaluate contractor bids and quotes, be sure to compare how price per square differs across material types like asphalt, metal, tile, slate, etc.
In addition to ordering covering materials by the square, ensure your roof system allows for proper ventilation. Airflow under the roof surface helps regulate temperature and prevent moisture issues like mold growth and rotting.
Talk to your contractor about installing soffit vents, ridge vents, and other ventilation fixtures while the roof is under construction. Proper airflow should be accounted for in every new roofing project, regardless of size or squares needed.