What Affects Roof Replacement Cost?

1. Roof Size

Roofing is priced per "square" (100 sq ft of roof area). Larger roofs cost more, but economies of scale can reduce the per-square price slightly on very large projects.

2. Roof Pitch (Steepness)

Steeper roofs:

• Have more surface area than their footprint suggests
• Require more safety equipment
• Take longer to install
• Are more dangerous (higher labor rates)

3. Roof Complexity

Simple gable roofs are fastest and cheapest. Complex roofs with valleys, dormers, skylights, and multiple angles require:

• More labor hours
• More material waste
• More flashing and detail work

4. Material Choice

Material costs range from $350/square (basic asphalt) to $3,000+/square (slate). See our Material Cost Guide →

5. Tear-Off Requirements

Removing old roofing adds $100–$150 per square. Multiple layers cost more. Some jurisdictions require full tear-off by code.

6. Deck Repairs

If your roof deck (the plywood/OSB under the shingles) is damaged, it must be replaced before new roofing goes on. Deck repairs typically cost $2–$5 per sq ft.

7. Location & Labor Market

Labor rates vary significantly:

• High-cost markets (San Francisco, NYC, Boston): 20–40% above national average
• Average markets: National average
• Lower-cost markets (rural areas, Midwest, South): 10–20% below average