Estimate shingles, underlayment, and roofing materials needed for your roof project.
Shingle Coverage: 3-tab shingles typically cover 33.3 sq ft per bundle (3 bundles = 1 "square" = 100 sq ft). Architectural shingles may cover 25-33 sq ft per bundle.
Waste Allowance: Add 10-15% for simple gable roofs, 15-20% for hip roofs or complex designs with many valleys and dormers.
Underlayment: Standard 15 lb felt covers ~400 sq ft per roll. Synthetic underlayment covers ~1000 sq ft per roll. You'll need one or the other, not both.
Safety First: Roofing is dangerous work. Consider hiring professionals for steep roofs (pitch > 8:12) or if you're uncomfortable with heights.
A 1000 sq ft roof (flat) = 10 squares. With a typical 5:12 pitch, multiply by 1.3 = 13 squares. Add 10% waste = 14.3 → 15 squares (45 bundles).
Multiply the footprint area (length × width) by the pitch factor. Common pitches: 4:12 = 1.3, 5:12 = 1.41, 6:12 = 1.54, 8:12 = 1.85, 12:12 = 2.61.
3-tab shingles are flat, single-layer, last 15-20 years, cover 33.3 sq ft/bundle. Architectural (dimensional) shingles are thicker, last 25-30 years, look more premium, cover 25-33 sq ft/bundle.
Add 10-15% for simple gable roofs, 15-20% for hip roofs or complex designs with valleys, dormers, and chimneys.
Most cities require permits for roof replacement (not repairs). Permit costs $200-500. Check local building codes. HOA may have rules about shingle color/style.