How Much Does a Flat Roof Cost? [2026 Data]

Flat roof installation costs $3–$15 per sq ft. EPDM rubber runs $4–$8 per sq ft; TPO $4–$10; modified bitumen $4–$8. Built-up roofing (BUR) costs $4–$8.

Commercial roofs often use TPO or EPDM. Residential flat sections (porches, additions) vary by size and access.

Proper drainage is critical. Ponding water shortens life. Get an assessment for existing flat roofs.