Flat Roof Replacement Cost (2026)
What it costs to replace a flat or low-slope roof with a single-ply membrane (TPO or EPDM), by roof size. Planning ranges, not a quote.
How much does a flat roof replacement cost?
A low-slope membrane roof (TPO or EPDM) typically costs $3–$11 per sq ft installed, or $300–$1,100 per square. A 1,000 sq ft flat roof, common on additions, garages and row homes, lands around $3,000–$11,000. The wide range is mostly tear-off and insulation: re-covering a sound roof is at the low end; removing wet insulation and adding new tapered board is at the high end.
| Flat roof area | Squares | Installed cost (TPO/EPDM) |
|---|---|---|
| 200 sq ft | 2 | $600–$2,200 |
| 500 sq ft | 5 | $1,500–$5,500 |
| 1,000 sq ft | 10 | $3,000–$11,000 |
| 1,500 sq ft | 15 | $4,500–$16,500 |
| 2,000 sq ft | 20 | $6,000–$22,000 |
| 3,000 sq ft | 30 | $9,000–$33,000 |
A flat roof has almost no pitch multiplier, so roof area ≈ footprint plus the overhang or parapet. A 2,000 sq ft one-story house with a flat roof has about 2,190 sq ft of roof. Very small roofs often hit a contractor minimum instead of the per-foot price.
What changes a flat roof price
- Tear-off and wet insulation: an infrared or core-cut survey shows how much insulation is saturated. Wet board must go.
- Insulation and drainage: new tapered insulation to stop ponding adds cost but extends the roof's life; code may require a minimum R-value when you replace.
- Membrane choice: EPDM (rubber) is usually cheapest; TPO is white and reflective; PVC costs more and resists chemicals and grease.
- Edges and penetrations: parapets, curbs for HVAC units, drains and skylights all need flashing details.
Repair or replace a flat roof?
Seams and flashing on single-ply roofs can often be repaired for a few hundred dollars (see roof repair cost). Replacement makes sense when the membrane is brittle or shrinking, water sits in large areas for more than 48 hours after rain, or a survey finds widespread wet insulation. If part of the house is pitched, the roof replacement cost calculator covers that section.
Sources
- The Roofing Brief, 2026 Roofing Cost Report.
- RemodelCalculators, Roof Replacement Cost (2026).
- HomeGuide, How Much Does a Roof Replacement Cost? (2026).
- HomeMatchup, Roofing Cost Index 2026.
Accessed October 2026. Where sources disagreed, the range spans them. These are the same ranges used on the roof replacement cost calculator. Treat every figure as directional; local bids vary.
Frequently asked questions
How much does it cost to replace a flat roof?
About $3–$11 per sq ft installed for TPO or EPDM membrane (2026), so roughly $3,000–$11,000 for 1,000 sq ft.
Is TPO or EPDM cheaper?
EPDM is usually a little cheaper to install; TPO reflects heat and is often preferred in hot climates. Both fall inside the range above.
How long does a flat roof last?
A well-installed single-ply membrane commonly lasts about 20 to 30 years, depending on thickness, drainage and maintenance.
Is this a quote?
No. It is a planning range from national averages. Get at least three written quotes from commercial or low-slope specialists.
Last reviewed 2026-10-30. Results are estimates for planning; confirm quantities with your supplier and requirements with your local building code and the manufacturer's instructions.