A roof is priced by the square — 100 square feet of roof surface — and the total is mostly decided before anyone picks a shingle color. Pitch, size, layers, decking and flashing set the number. The brand on the bundle is a smaller variable than most people expect.
Here is the uncomfortable part of roof pricing. The three items that swing a bid the hardest are the three that a low bidder quietly leaves out.
What actually drives the number
Squares, not square feet. A 2,000 square foot house is not a 2,000 square foot roof. Slope and overhangs add surface, so the same floor plan can come in at 22 squares or 30 depending on pitch. Measure the roof, not the house.
Pitch. Under about 7:12 a crew walks the roof normally. Past that they are setting roof jacks, staging bundles and working in harnesses, and production per hour drops. Above roughly 9:12 the labor line stops being proportional and starts being a different job.
Tear-off layers. One layer comes off fast. Two layers is double the labor, double the dumpster and often double the disposal fee, and the fee is by weight.
Decking condition. Nobody knows this until the old roof is off. Deteriorated sheathing around chimneys, valleys and any old leak gets replaced, and that has to be a stated per-sheet price in the contract.
Flashing. Sidewall, chimney, valley, pipe boots, step flashing. New flashing costs money. Reused flashing costs money later.
Complexity. Every valley, dormer, saddle, skylight and penetration is hand work. A simple gable and a cut-up hip roof of the same square footage are not the same bid.
The line items worth paying extra for
Some upgrades are marketing. These four are not.
Balanced ventilation. Intake at the soffit, exhaust at the ridge, sized to the attic. A shingle roof over a stagnant 150-degree attic loses years off its rated life from the underside. This is the single most-skipped item in the trade and it is why roof ventilation is a line on our scope sheets rather than an afterthought.
Ice-and-water membrane at eaves, valleys and penetrations. In any climate that freezes, this is the difference between a wet ceiling in February and nothing happening.
All new flashing. Not reused, not caulked. Step flashing woven into the courses at sidewalls, and a real chimney counterflashing rather than a bead of sealant.
A written workmanship warranty with a stated number of years. Manufacturer warranties cover the shingle, which almost never fails first. Installation is what fails first.
What is usually not worth it
A 50-year shingle on a house you will sell in eight. You are prepaying for service life you will hand to a stranger.
Premium designer shingles chosen from a two-inch sample. Look at a full board in daylight on your own wall, or better, at an installed roof three streets over. Color reads completely differently at scale.
Ridge vent added without opening the intake. A ridge vent with no soffit intake pulls its makeup air from inside the house through ceiling penetrations. That is worse than no vent. If the soffits are stuffed with insulation, fix that first or skip the ridge vent.
How to read three bids that look nothing alike
Build a one-page scope sheet and make every bidder fill in the same rows.
| Line item | What to require in writing |
|---|---|
| Squares and pitch | Their measurement, stated |
| Tear-off | Number of layers assumed |
| Decking | Per-sheet replacement price |
| Underlayment | Product, plus ice-and-water locations |
| Flashing | New at every location, itemized |
| Ventilation | Intake and exhaust, net free area |
| Pipe boots | New, not reused |
| Warranty | Workmanship years, in writing |
| Cleanup | Magnetic sweep, dumpster placement |
| Permit | Who pulls it, whose cost |
Line three bids up against those rows and the differences stop being mysterious. A total is only as comparable as the scope behind it, and the low one is usually low because something on the list is missing from it.
What Maine law puts behind the number
Price is not the only thing that changes at a state line. So does what the contractor is allowed to promise you about it.
There is no license. The Maine Attorney General states it plainly: general contractors, and trades such as roofing, are not licensed or regulated in this state. What you get instead is the Home Construction Contracts Act - above three thousand dollars the contract must be written, your deposit is capped at one third, and it must carry a warranty and a choice between arbitration and mediation. A 2025 licensing bill passed both chambers, then died on adjournment.
The deductible is the one line in the bid a roofer may not quietly promise away.
Maine leaves this alone entirely. Nothing prohibits a roofer from paying, waiving or absorbing your deductible. The rebate provisions in the insurance code are aimed at insurers and producers and at what they may offer you on premium, not at contractors selling repairs, and Maine has no equivalent of the bans its neighbors have passed. A scheme to make the carrier fund your share is still fraud, and still an unfair trade practice.
A bid that ignores any of that is telling you something about the rest of it.
The signals that a low bid is hiding something
A number well under the others is information, not a bargain. Look for these tells.
No decking line. Reused flashing, or the word "caulk" doing structural work. No permit. A large deposit demanded before material delivery. No proof of workers' compensation coverage, which is the one that leaves you personally exposed if somebody falls. And a start date tomorrow in a market where everyone else is three weeks out.
When you should not replace at all
We turn down replacement work regularly. A roof with fifteen good years on it and one bad valley needs a valley, not a re-roof. A single failed pipe boot is a sixty-dollar part and an hour of labor, and it produces exactly the same ceiling stain as a dying roof.
A roof inspection that ends in "not yet, call us in four years" is a completely normal outcome. We would rather deliver that than sell a roof early.
The one exception worth naming: if the covering is close enough to the end that a re-roof is coming inside a couple of seasons anyway, and you are about to spend real money on repairs first, buy the roof now. Look back at the bid sheet and notice how much of it is mobilization rather than shingles — crew day rate, dumpster, staging, permit. None of that gets cheaper for being ordered twice in eighteen months, and it is the half of the bid people forget they are paying for at all.
Bottom line
Get three bids on one written scope. Insist on a per-sheet decking price, new flashing everywhere and balanced ventilation. Ignore shingle brand marketing and spend the upgrade money on the assembly underneath. Then pick the contractor whose scope sheet came back most complete, which is usually not the cheapest one and is almost never the most expensive one either.
Portland ME Roof Pros prices roof replacement, asphalt shingle roofs and roof inspections across Portland and southern Maine, itemized so you can compare it against anyone else's. Call (866) 413-9856 and we will measure the actual roof, including telling you if it can wait.
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Related services in Portland
Portland ME Roof Pros money pages — go straight to the service you need.
- Roof Replacement →
A replacement here is two jobs printed on one estimate. There is the field, meaning tear-off, deck work, underlayment and covering, and there is the roof edge, where the drip edge lands on painted rake, fascia and soffit boards.
- Roof Inspections →
An inspection here answers three questions, and the third one is the reason people call us rather than a general home inspector. How much life is left, what will it cost when it goes, and does the work you are contemplating cross into the painted trim.
- Asphalt Shingle Roofs →
Asphalt covers most roofs in Portland and it should. It is the cheapest square foot on the market, it handles this climate, and on a house whose real problem is the trim at the edge, spending the covering budget on something exotic is money in the wrong place.
- Roof Leak Repair →
Most leaks we get called to in Portland announce themselves outside before they ever reach a ceiling. Paint blisters and peels on the underside of a soffit, or a rake board darkens and holds a fingernail.
- Storm Damage Restoration →
Storms that damage roofs in this city arrive as nor'easters: a long fetch of wind and rain over many hours rather than a violent twenty minutes. The damage pattern follows.
Frequently asked questions
How is roof replacement priced?
By the square, which is 100 square feet of roof surface, not floor area. A 2,000 square foot house with a moderate pitch usually has somewhere around 22 to 30 squares of roof once you account for slope and overhangs. That is why two houses with identical floor plans and different roof pitches get meaningfully different bids, and why anyone quoting a price over the phone from your address alone is guessing.
Why do roof replacement quotes vary so much?
Usually because they are not the same scope. The three items that move a bid most are tear-off layers, decking replacement and flashing. A low bid frequently means one layer of tear-off assumed, no decking allowance and reused flashing. Put every bid on the same scope sheet before you compare the totals, because otherwise you are comparing two different jobs.
Does a steeper roof cost more to replace?
Yes, for two reasons. There is more surface area than the footprint suggests, and above roughly 7:12 the crew needs staging, roof jacks and fall protection that slow the work down considerably. Anything past about 9:12 is walk-with-equipment territory and the labor rate reflects it. Very low slope is its own premium because the material changes entirely.
How much should I budget for decking replacement?
Ask for it as a stated per-sheet price rather than a lump allowance, because nobody knows the decking condition until the old roof is off. Some roofs need zero sheets and some need twenty. A bid with no decking line item is not a cheaper bid, it is a bid with a change order waiting inside it.
Is a roof replacement covered by insurance?
Insurance covers sudden damage from a covered peril such as hail, wind or a fallen limb. It does not cover a roof that reached the end of its service life, and most policies now settle older roofs at actual cash value rather than replacement cost, which means depreciation comes out of the check. Age of roof and cause of failure are the two things an adjuster is deciding.
How long does a roof replacement take?
Days of work on site, and usually weeks of waiting before that — the timeline itself, and the scheduling lead time behind it, is [how long a roof replacement takes](/blog/how-long-does-a-roof-replacement-take/). What matters to a bid is that time is a labor input rather than a discount.
A steep or cut-up roof that needs an extra day of staging is charged for that day, and a dumpster parked on the driveway through a rain delay is still on rent. If one quote has the crew there half as long as another, the two are not scoping the same job.
Local context
How this applies in Portland, ME
Every article here is written from roofing work done in Portland and southern Maine, so the numbers reflect local labour, permit and material costs rather than a national average. Your own job can land either side of them depending on access, the condition of what is already there, and the materials you pick — self-adhered ice barrier membrane at eaves and in every valley, over-fascia intake vents slotted through sheathing instead of painted soffit, board sheathing overlay panel where plank gaps outrun a fastener's grip.
The way to turn any of this into a real answer is to have someone look at your actual situation. The free estimate is free, itemized and written down, with no deposit and no obligation. Call (866) 413-9856 or start on the Portland ME Roof Pros homepage.
Areas Portland ME Roof Pros covers
Portland first, then the surrounding communities of southern Maine. Each has its own page with local detail rather than a copy of this one:
- South Portland, ME — Cumberland County, population 26,498
- Westbrook, ME — Cumberland County, population 20,400
- Scarborough, ME — Cumberland County, population 22,135
- Gorham, ME — Cumberland County, population 18,336
- Windham, ME — Cumberland County, population 18,434
- Falmouth, ME — Cumberland County, population 12,444
Or jump to the full list of Portland services.
More from the Portland ME Roof Pros blog
- Roof Inspection Cost in Portland, ME: What You Get for the Money
A real roof inspection produces a photographed, slope-by-slope report. Here's what one costs in Portland, ME, and how to tell it from a sales visit.
- Metal Roof vs Shingles in Portland, ME: The Honest Comparison
Metal costs roughly two to three times what asphalt does and lasts two to three times as long. Here's when that math works in Portland, ME, and when it doesn't.
- How to Find and Fix a Roof Leak in Portland, ME
Water rarely enters where the stain appears. Here's how to trace a roof leak in Portland, ME, what you can fix yourself, and what needs a roofer.
The Portland ME Roof Pros Team
roofing specialists serving Portland, ME
Written by the Portland ME Roof Pros team — insured roofing pros serving Portland, ME and the surrounding area.