Cost guide · 2026
How much does a flat roof replacement cost in 2026?
- Mod bit
- Built-up
- TPO
- PVC
- EPDM
- Typical replacement, 1,500 sq ft roof
- $12,000
- Per sq ft installed, mainstream systems
- $5–$14
- Per sq ft added for tapered insulation
- $2–$5
- Typical permit fee range
- $150–$600
Flat roof replacement cost by material and roof size
| System | Installed per sq ft | Typical per sq ft | 1,000 sq ft | 1,500 sq ft | 2,000 sq ft |
|---|---|---|---|---|---|
| Modified bitumen | $5.00–$10.00 | $7.00 | $5,000–$10,000 | $7,500–$15,000 | $10,000–$20,000 |
| Built-up (BUR) | $5.50–$11.00 | $8.00 | $5,500–$11,000 | $8,250–$16,500 | $11,000–$22,000 |
| EPDM | $5.50–$12.00 | $8.00 | $5,500–$12,000 | $8,250–$18,000 | $11,000–$24,000 |
| TPO | $6.00–$12.00 | $8.50 | $6,000–$12,000 | $9,000–$18,000 | $12,000–$24,000 |
| PVC | $7.00–$14.00 | $10.00 | $7,000–$14,000 | $10,500–$21,000 | $14,000–$28,000 |
Add-ons that change a flat roof replacement quote
| Item | Typical cost | When it applies |
|---|---|---|
| Each extra layer torn off | $1–$5 per sq ft | Roof has been recovered one or more times |
| Deck replacement | $2–$5 per sq ft (about $65–$160 per 4×8 sheet) | Rotted or delaminated plywood found after tear-off |
| Tapered insulation | $2–$5 per sq ft of treated area | Ponding water or drains set high |
| Insulation upgrade | $0.50–$3.00 per sq ft | Adding thickness for energy savings |
| Cricket or saddle | $700–$1,500 each | Water trapped behind curbs, chimneys or between drains |
| New scupper | $200–$500; $450–$900 with conductor head and downspout | Parapet wall with no outlet |
| New or relocated interior drain | $600–$2,500 per drain, plus plumbing | Large roofs with no outlet near low points |
| Permit | $150–$600 | Nearly every reroof |
What does a flat roof replacement include?
A full replacement means tearing off the existing roof down to the deck, repairing any damaged decking, installing insulation or a cover board where the system calls for it, and installing a new membrane with new flashing, edge metal and drain connections. The roofer pulls the permit, schedules inspections and hauls away debris.
Our national baseline is a 1,500 sq ft residential flat roof with one existing layer to remove: $7,500–$21,000, with a typical project near $12,000. That works out to $5–$14 per sq ft depending on the system.
How much does each flat roof system cost?
Modified bitumen ($5–$10 per sq ft) is a widely used residential flat roof and usually the least expensive true flat-roof system. A two-ply torch-down or self-adhered system with a granulated cap sheet is the standard.
Built-up roofing ($5.50–$11) is heavier and more labor-intensive. It shows up mostly on older homes and commercial buildings.
EPDM ($5.50–$12) and TPO ($6–$12) are single-ply membranes priced in the middle. Thickness matters: 60-mil sheets cost more than 45-mil and last longer.
PVC ($7–$14) is the premium single-ply option.
Not sure which you have? See flat roof types explained.
What drives the price up or down?
- Deck condition. Nobody knows how much plywood is rotted until the old roof is off. Ask for a unit price per sheet or per sq ft in the contract.
- Layers. Each extra layer that must come off adds $1–$5 per sq ft.
- Drainage. Fixing ponding with tapered insulation adds $2–$5 per sq ft of treated area, plus crickets, scuppers or drains as needed. Reroofing is the cheapest time to do it. See how to fix ponding water.
- Details. Every skylight, AC curb, vent and wall adds flashing labor.
- Access and size. Two-story buildings, tight lots and small roofs cost more per sq ft.
- Warranty level. A manufacturer system warranty requires an authorized installer and an inspection, which can add cost but gives you broader coverage.
How much more does it cost in South Florida?
Plan on the upper half of these ranges in Miami-Dade, Broward and Palm Beach counties. Labor costs are high, and in the High-Velocity Hurricane Zone (Miami-Dade and Broward), products need HVHZ-valid approvals such as a Miami-Dade NOA, attachment requirements are stricter, and permit review takes longer. RoofingCalc’s Florida survey shows the gap on sloped roofs: Miami-Dade shingle replacement at about $8–$10 per sq ft versus $6–$8 in Jacksonville.
Florida reroofs can also trigger mandated upgrades. On site-built single-family homes in the wind-borne debris region insured or assessed at $300,000 or more, the code can require roof-to-wall connection improvements when the covering is replaced, capped at 15% of the reroof cost. Our Florida permits and rules guide explains this and the 25% rule.
What should you budget beyond the contract price?
Two items catch homeowners off guard. The first is decking. A contract that says “rotted wood extra” without a price leaves you exposed. With a unit price of $65–$160 per 4×8 sheet, ten bad sheets add $650–$1,600, so set aside a contingency. The second is drainage. If the roof ponds today, a new membrane over the same flat deck will pond tomorrow. Budget for tapered insulation or added outlets now, while the roof is open. Also confirm whether the quote includes the permit fee, dumpster and haul-off, and any required engineering for HVHZ or mitigation work.
How long will the new roof last?
Published lifespans vary by system: roughly 10–20 years for modified bitumen, 10–25 for TPO, 15–25 for EPDM, 15–30 for PVC and built-up roofs. Thicker membranes, good drainage and regular maintenance push results toward the high end, while heat, UV and ponding pull them down. Divide the price by the expected life when comparing systems. A cheaper roof that needs replacing sooner isn’t always the bargain.
Should you repair, coat or replace?
| Option | Typical cost | Makes sense when |
|---|---|---|
| Repair | $300–$2,000 for most single-area jobs | The roof is sound and the problem is local |
| Coating | $1.25–$4.50 per sq ft | Membrane is intact and dry, with only minor defects |
| Replacement | $5–$14 per sq ft | Insulation is wet, the deck is damaged, or the roof is at the end of its life |
A coating over wet insulation traps the water, so ask for a moisture check before you choose. See flat roof repair cost and flat roof coating cost.
How do you keep replacement quotes comparable?
Get at least two or three written estimates that name the same system, thickness, insulation, number of layers removed, deck unit price, flashing details and warranty. Make sure each roofer will pull the permit. Our hiring guide has a full checklist.
Frequently asked questions
How much does it cost to replace a 1,000 sq ft flat roof?
About $5,000–$14,000 depending on the system, with modified bitumen at $5,000–$10,000, TPO at $6,000–$12,000 and PVC at $7,000–$14,000. Expect the upper half of each range in South Florida and on roofs that need deck repair.
What is the cheapest flat roof replacement?
Rolled roofing at roughly $2–$5.50 per sq ft is the cheapest, but it is meant for slopes of at least 1:12 and has the shortest life. Among true flat-roof systems, modified bitumen and built-up roofs usually price lowest, at about $5–$11 per sq ft.
Can a new flat roof go over the old one?
Sometimes. Codes limit when an existing roof can be recovered instead of removed, for example when it is wet or already has multiple layers, and HVHZ rules in Miami-Dade and Broward are stricter. A recover saves tear-off cost but can hide wet insulation, so ask for a moisture check first.
Does insurance pay to replace a flat roof?
Only for covered damage, such as a storm, and subject to your deductible. Wear and age aren't covered. In Florida, the 25% rule and your law and ordinance coverage can decide whether a damaged section is replaced to current code. See our Florida permits and rules guide.
Do I need a permit to replace a flat roof, and what does it cost?
Yes, in virtually every jurisdiction, and your roofer should pull it. National cost guides put roofing permits at roughly $150–$600. Florida counties set their own fees; Charlotte County's residential roof permit, for example, was $94. Jobs over $5,000 in Florida also need a recorded Notice of Commencement.