Square

A square in roofing is a unit of measurement equal to 100 square feet, commonly used for pricing roofing materials and labor.

What is a Square?

A square in roofing terminology is a unit of measurement equal to 100 square feet of roof area. This standardized measurement simplifies roofing estimates, material ordering, and pricing across the industry.

The term "square" makes it easier to work with large roof areas and standardizes pricing for roofing contractors.

Why Roofing Uses Squares

Industry Standardization

  • Simplifies large area calculations (30 squares vs. 3,000 square feet)
  • Standardizes pricing across contractors and suppliers
  • Makes material ordering more straightforward
  • Reduces calculation errors in estimates

Historical Practice

The roofing industry adopted squares decades ago as a convenient way to measure and price roofing work, and it remains the standard today.

Calculating Roof Squares

Basic Formula

Roof Area in Square Feet ÷ 100 = Number of Squares

Examples

  • Small house: 1,200 sq ft roof = 12 squares
  • Average house: 2,000 sq ft roof = 20 squares
  • Large house: 3,500 sq ft roof = 35 squares

Measuring Roof Area

  1. Simple gable roof: Length × width of ground footprint
  2. Complex roofs: Measure each section separately and add together
  3. Pitched roofs: Multiply ground area by pitch factor

Pitch Factor Calculations

Common Roof Pitches

  • 4/12 pitch: Multiply ground area × 1.054
  • 6/12 pitch: Multiply ground area × 1.118
  • 8/12 pitch: Multiply ground area × 1.202
  • 10/12 pitch: Multiply ground area × 1.302
  • 12/12 pitch: Multiply ground area × 1.414

Example with Pitch

House footprint: 40' × 60' = 2,400 sq ft Roof pitch: 6/12 Actual roof area: 2,400 × 1.118 = 2,683 sq ft = 26.8 squares

Material Coverage per Square

Shingles

  • 3-tab asphalt: 3 bundles per square
  • Architectural shingles: 3-4 bundles per square
  • Premium shingles: 4-5 bundles per square

Underlayment

  • 15# felt: 4 rolls covers ~4 squares
  • 30# felt: 2 rolls covers ~2 squares
  • Synthetic underlayment: Coverage varies by product

Other Materials

  • Roofing nails: 2-3 lbs per square
  • Ridge cap: ~33 linear feet per square along ridges
  • Starter strip: Coverage along eaves and rakes

Pricing by the Square

Labor Costs

  • Removal: $1-$5 per square
  • Installation: $2-$8 per square (varies by material complexity)
  • Tear-off and install: $3-$12 per square total

Material Costs

  • Basic 3-tab shingles: $50-$150 per square
  • Architectural shingles: $100-$300 per square
  • Premium materials: $200-$800+ per square

Total Project Costs

  • Budget roofing: $300-$500 per square installed
  • Mid-range roofing: $400-$700 per square installed
  • Premium roofing: $600-$1,200+ per square installed

Estimating Waste Factors

Standard Waste Allowances

  • Simple roofs: Add 5-10% for waste
  • Complex roofs: Add 10-15% for waste
  • Hip roofs: Add 15-20% for cuts and angles

Additional Considerations

  • Starter courses: Additional material needed
  • Ridge and hip coverage: Extra shingles for peaks
  • Future repairs: Consider ordering extra material

Common Roof Types and Square Calculations

Gable Roof

Simplest calculation: ground footprint × pitch factor

Hip Roof

More complex cutting, typically requires 15-20% additional material

Mansard Roof

Calculate each slope section separately and add together

Shed Roof

Single slope calculation: length × width × pitch factor

Professional Tips

Accurate Measurement

  • Use proper safety equipment when measuring roofs
  • Consider using drone technology or satellite measurements
  • Always verify measurements before ordering materials

Material Planning

  • Order all materials at once for color consistency
  • Keep extra shingles for future repairs
  • Coordinate delivery timing with installation schedule

Weather Considerations

  • Plan installation during favorable weather
  • Have tarps ready for unexpected weather
  • Consider seasonal pricing variations

Converting Between Units

Squares to Square Feet

Multiply squares by 100

  • 25 squares = 2,500 square feet

Square Feet to Squares

Divide square feet by 100

  • 3,200 square feet = 32 squares

Working with Partial Squares

Always round up to ensure adequate material

  • 23.7 squares = order 24 squares of material

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