Flat Roof Replacement Cost in 2026 (EPDM, TPO, PVC, Modified Bitumen)

A flat roof replacement costs $4–$15 per square foot installed in 2026 — $6,000–$15,000 for a typical 1,000 sq ft residential roof. Why the membrane is only half the invoice, the coating shortcut that saves 50–70%, and when a reroof triggers code-required insulation upgrades.