Flat Roof Replacement Cost in 2026
Single-ply membrane — TPO, EPDM and PVC — plus modified bitumen. Covers whole low-slope roofs and the flat sections over additions, porches and dormers.
Estimated range — not a quote
Flat Roof Replacement Cost — national estimate
Low end
$3,600
Typical
$12,000
High end
$35,000
What this covers: tear-off and replacement of a low-slope membrane roof including insulation board, membrane, flashings and edge metal.
Per roofing square (100 sq ft of roof surface)
$450–$1,400(typical $800)
The job figures above are this per-square range applied to a 8–25 square roof (15 squares for the typical case). Multiply your own square count by the per-square figure and you will get a closer estimate than any national average can give you.
Modelled estimate. These figures come from national industry-typical ranges, not from quoted jobs, and no one has looked at your roof. Use them to sanity-check a bid — never as a substitute for one.
What the low, typical and high jobs look like
A range is only useful if you know which end you are at. These are the three jobs the numbers above describe.
Low$3,600
a small flat section — an addition, a porch roof or a dormer deck — in EPDM or mechanically-attached TPO
Typical$12,000
a whole low-slope roof of roughly 15 squares in 60-mil TPO over new insulation, with existing drains reused
High$35,000
a large low-slope roof in PVC or fully-adhered TPO, with tapered insulation to correct ponding and new drains or scuppers
How this work is priced
Low-slope roofs fail for a different reason than sloped ones. A pitched roof sheds water and relies on overlapping layers; a flat roof holds water briefly and relies on a continuous, sealed membrane. That difference is why drainage is the dominant cost variable here and why "flat" is a misnomer — every low-slope roof is designed with some fall, and the ones that have lost it are the ones that leak.
Standing water is the thing to watch for. Water that has not drained within about 48 hours after rain is generally treated as ponding, and it shortens membrane life, strains seams and voids a good number of manufacturer warranties. Correcting it with tapered insulation is a real expense, but replacing a membrane over a deck that still ponds is money spent on a roof that will fail the same way again.
What is and is not in the price
Most of the distance between two quotes is scope, not margin. Read both columns before you decide one contractor is expensive.
Normally included in the price
- ●Tear-off of the existing membrane and wet insulation
- ●New polyiso insulation board where the assembly calls for it
- ●Single-ply membrane — TPO, EPDM or PVC — in the specified thickness
- ●Heat-welded or taped seams
- ●Flashing at walls, curbs and penetrations
- ●New edge metal or termination bar
- ●Reuse or reflash of existing drains
Normally billed separately
- ●Tapered insulation to correct ponding, which is priced separately and is not cheap
- ●New drains, scuppers or internal piping
- ●Structural deck repair — common on older low-slope roofs that have leaked for years
- ●Walkway pads for mechanical access
- ●HVAC curb work or unit disconnection
- ●Parapet masonry and coping repair
What pushes the price to the top of the range
Tapered insulation to fix drainage
A tapered package that builds slope where the structure has none commonly adds $150 to $450 per square. It is also the single change most likely to make the new roof last as long as its warranty says.
Fully adhered rather than mechanically attached
Adhered membrane performs better in wind uplift and looks flatter, and it costs more in both adhesive and labor. Wind-zone requirements sometimes make the choice for you.
PVC over TPO
PVC resists grease and chemical exposure, which matters where a kitchen exhaust discharges onto the roof. It costs more and is the right answer in a narrow set of cases.
Wet insulation under the old membrane
Saturated board has to come off and go in the dumpster. It is heavy, it is slow, and it is usually discovered rather than anticipated.
Penetrations, curbs and parapets
Every pipe, curb, skylight and parapet corner is hand-detailed. A busy roof with a dozen penetrations costs far more per square than a clean rectangle.
What keeps it at the bottom
A clean rectangle with sound drainage
A simple low-slope roof that already drains, with few penetrations, is quick work and prices near the bottom of the band.
EPDM where appearance does not matter
Black EPDM is the value option and has a long service record. It absorbs heat, which is a real drawback in a hot climate but irrelevant on a small shaded section.
Recovering instead of tearing off
Where the existing assembly is dry and code permits it, a recover board and new membrane over the old roof avoids tear-off and disposal. It is only appropriate when the insulation underneath is genuinely dry — a moisture scan settles it.
Component costs
The pieces a quote for this work is assembled from. Use them to interrogate a bid line by line — a contractor who can explain each of these is worth more than one who cannot.
| Line item | Range | Unit | Notes |
|---|---|---|---|
| EPDM, 60 mil, installed | $450–$850 | per square | Rubber membrane. Value option, long track record, absorbs heat. |
| TPO, 60 mil, mechanically attached | $500–$900 | per square | The mainstream single-ply choice. Reflective white surface. |
| TPO, fully adhered | $650–$1,100 | per square | Better wind performance, smoother finish, more labor and adhesive. |
| PVC, installed | $700–$1,400 | per square | Chemical and grease resistant. Specify where kitchen exhaust discharges. |
| Modified bitumen, 2-ply | $450–$900 | per square | Torch-applied or self-adhered. Common on small residential decks. |
| Polyiso insulation board | $100–$250 | per square | Priced by thickness and R-value. |
| Tapered insulation package | $150–$450 | per square | The drainage fix. Priced over the tapered area only. |
| Tear-off of existing low-slope roof | $100–$250 | per square | Higher where multiple layers or saturated insulation are found. |
| New roof drain or scupper | $400–$1,200 | each | Includes flashing the drain into the membrane. |
| Edge metal or termination bar | $8–$20 | per linear ft | Wind uplift performance starts at the edge. |
National baseline component ranges for low-slope work. Insulation and drainage decisions move this number more than the membrane brand does.
Size your own roof before you read a quote
Every number in this guide is priced against roof area, and roof area is not house area. Put your footprint dimensions and your pitch into the squares calculator and you will know how many squares you are buying — which turns a vague estimate into arithmetic you can check against a bid.
Flat Roof Replacement Cost by city
The same model, adjusted by each metro’s cost index and written with the climate and building context that applies locally. Only the metros we have modelled appear here — there is no page for a city we have not.
North Carolina
North Carolina roofing contractorsIllinois
Illinois roofing contractorsGeorgia
Georgia roofing contractorsCommon questions
How long does a flat roof last?
Broadly 15 to 30 years, and the spread within that band is driven more by drainage and installation quality than by which membrane was chosen. A well-drained EPDM roof outlives a ponding PVC roof comfortably.
TPO or EPDM?
TPO is white and reflective, which helps cooling load in a hot climate, and its seams are heat-welded, which many contractors consider more reliable than taped seams. EPDM is black, absorbs heat, and has the longer field record. In a hot southern climate TPO is usually the better default; on a small shaded section, EPDM is often the sensible economy.
Can I coat the roof instead of replacing it?
A silicone or acrylic coating over a sound membrane can extend service life for a fraction of a replacement, commonly $150 to $400 per square. It is a maintenance measure, not a replacement, and it is the wrong choice over wet insulation or a membrane that has already failed at the seams — you would be sealing the water in.
Why does my flat roof pond after every rain?
Either the deck has deflected over time, the drains are blocked or badly placed, or the original build simply lacked slope. Diagnosing which one you have decides whether the fix is cleaning the drains, adding a drain, or building slope with tapered insulation.
How we build these cost ranges
The short version: these are industry-typical ranges, not a quote.
These are modelled ranges, not quotes
Every figure on this page is an estimate produced by a model, not a price anyone has been charged. We do not collect invoices, we do not receive bid data from contractors, and we do not have a feed of completed jobs. If you need a number you can rely on, the only source of one is a written quote from a contractor who has been on your roof.
Where the national ranges come from
The national baseline for each work type is an industry-typical installed-price band: the range that published cost guides, manufacturer installation literature and ordinary contractor pricing conventions broadly agree on for 2026. Each band is expressed low / typical / high, and where the work is genuinely sold by the square we show the per-square price and the roof size assumptions separately, so the whole-job figure can be re-derived rather than taken on trust.
Where the city adjustment comes from
Each metro carries a single cost index, with 1.00 meaning the national baseline. The index is our own editorial estimate of where local labor, overhead and permitting sit relative to the national middle, based on the well-established general pattern that construction costs run higher in large, high-wage, densely-built metros and lower in smaller ones. It is not a measured price feed, it is not a licensed location-factor dataset, and it is not derived from local quotes. The city figure is simply the national band multiplied by that index.
What we deliberately do not do
We do not publish invented local statistics. There is no "average roof size in your city" on this site, because we have not measured one. Local context here is limited to climate, geography and building-practice factors that are true of the region and that you can verify independently. We would rather be generic and correct than specific and made up.
Why the numbers are rounded
Modelled figures are rounded before display — to the nearest $500 above $10,000, the nearest $100 above $1,000, and more finely below that. A modelled estimate printed to the exact dollar is claiming a resolution it does not have. The rounding is the honest representation of how coarse these estimates really are.
What the model cannot see
It cannot see your pitch, your decking, how many layers are up there, how a truck reaches your house, what your local supplier quoted this month, or how booked the good crews are after the last storm. Those factors routinely move a real quote further than the entire spread between our low and high figures. Treat these ranges as a way to tell a plausible quote from an implausible one — nothing more than that.
A note on this particular topic
The job-size band here is narrower and smaller than for pitched roofs because most residential low-slope work is a section of a house rather than the whole thing. If your entire roof is low-slope, price it toward the upper end of the size assumption.
Cost model version 2026.08. Baselines and the regional index are reviewed periodically; the date shown on each page is the date that page's figures were last reviewed. Contractor listings on this site are compiled from public records — confirm any contractor’s licence and insurance with your state licensing board before work begins.
Other cost guides
Roof Replacement Cost
$5,625–$27,000
Full tear-off and re-roof in architectural asphalt shingle — the job most homeowners mean when they say "new roof". Priced per square, with the size assumptions shown.
Roof Repair Cost
$250–$3,500
Localized fixes — leaks, flashing, boots, valleys, a section of shingles. Priced per visit rather than per square, because that is how the trade actually sells it.
Metal Roof Cost
$8,250–$56,000
Exposed-fastener panel through steel and aluminium standing seam. The widest price band in residential roofing, because "metal roof" covers products that differ by a factor of four.
Storm Damage Roof Repair Cost
$450–$12,000
Wind, hail and impact damage — from a tarp on the night of the storm to a full insurance-scoped replacement. The one topic where the price you pay and the price of the work are usually different numbers.
Roof Tear-Off Cost
$1,500–$9,000
Stripping and hauling away the existing roof — the line item that is usually bundled into a replacement quote and is worth pulling out and looking at on its own.
Roof Decking Replacement Cost
$500–$14,000
Replacing sheathing under the shingles — the change order that surprises more homeowners than any other, because it cannot be quoted until the old roof is off.
Roof Inspection Cost
$0–$1,200
From the free look that comes with an estimate through to an infrared moisture scan or an engineer's report. Priced per visit, and often free — which is itself worth understanding.
- ●Longer-form background on this work: The complete flat roof guide.
- ●All eight cost topics and every city guide: the roofing costs hub.
The only real number is a written quote
Get three, scoped alike — same material line, same underlayment, same flashing treatment, same per-sheet decking rate. Search roofing companies by city or state and contact them directly, free and with no middleman.