Three contractors looked at the same 28-square roof this summer and came back with $11,400, $15,200, and $21,300. The homeowner assumed the middle bid was the honest one and the other two were a lowballer and a gouger. That was roughly right, but not for the reason she thought. The spread wasn't markup. It was scope — three different jobs wearing the same two-word description.
Below is the $15,200 bid broken into its actual line items, with the real 2026 unit costs behind each one. Once you can read a quote this way, comparing three of them takes about fifteen minutes instead of a week of second-guessing.
The house: 2,800 sq ft of roof surface (28 squares), 6:12 pitch, two stories, one layer of existing architectural shingles, a masonry chimney, two sidewall intersections, two valleys, and four plumbing penetrations. Northeast climate zone, so an ice barrier is in play.
Squares, waste, and why the measurement comes first
A roofing square is 100 square feet of roof surface. Not floor area — roof area, which on a 6:12 pitch is about 12 percent larger than the footprint underneath it. Every material on the job is priced per square, so if two bidders disagree about the square count, nothing else in the two quotes is comparable.
Then there's waste. Shingles get cut at rakes, valleys, hips and around every pipe, and the offcuts go in the dumpster. A plain gable roof runs 7 to 10 percent waste. This one — two valleys, a chimney, a cut-up perimeter — orders at 10 percent, so 28 squares of roof buys 31 squares of shingles. That gap is real money, and a bidder who quotes exactly 28 squares of material is either running short on day three or isn't planning to cut anything the way it should be cut.
The materials side: $8,797
| Line item | Quantity | Cost |
|---|---|---|
| Architectural shingles (GAF Timberline HDZ) | 31 sq @ $148 | $4,588 |
| Ice barrier membrane, eaves + valleys | 8 rolls @ $135 | $1,080 |
| Step, counter & valley flashing | chimney + 2 walls | $640 |
| Drip edge, eaves and rakes | 190 lf @ $3.25 | $618 |
| Hip & ridge cap shingles | 105 lf | $390 |
| Starter strip | 190 lf | $372 |
| Synthetic underlayment | 3 rolls @ $115 | $345 |
| Ridge vent (material) | 42 lf | $294 |
| Pipe boots | 4 @ $65 | $260 |
| Fasteners, sealant, misc. | — | $210 |
| Materials subtotal | $8,797 |
Notice the proportions. The shingles everyone shops for are 52 percent of the material cost. The other 48 percent is the unglamorous stuff nobody asks about in the sales appointment — and it's where quotes diverge.
The ice barrier is bigger than most homeowners expect
IRC Section R905.1.2 requires an ice barrier in regions with a history of ice forming at the eaves, running from the lowest roof edge to a point at least 24 inches inside the exterior wall line. On a house with a 16-inch overhang and a 6:12 pitch, "24 inches inside the wall line" measured along the slope lands past the first three-foot course of membrane. That's two courses at the eaves, not one. Eight rolls here covers the eaves properly plus both valleys. A bid with three rolls on the same roof is either not meeting code or is measuring from the wall instead of past it.
Flashing is the line item that decides whether you leak in 2029
Step flashing is woven into the shingle courses as they go up a sidewall — one piece per course, lapped. Which means you cannot reuse it without leaving the old pieces bedded in the old sequence while new shingles go over the top. "Reuse existing flashing" on a quote saves the contractor about $640 and costs you a wall leak somewhere around year three. If a quote doesn't mention flashing at all, that's the same thing said quieter.
Drip edge is not optional and not decorative
IRC R905.2.8.5 requires drip edge at eaves and rakes on asphalt shingle roofs, lapped at least 2 inches, fastened 12 inches on center. It's $618 on this roof. Older homes in Connecticut, New Jersey and upstate New York frequently have none, because it wasn't enforced when they were built — which means a quote that says "reinstall existing drip edge" on a 1962 house is describing something that isn't there.
The labor and site side: $6,394
| Line item | Basis | Cost |
|---|---|---|
| Install labor | 28 sq @ $105 | $2,940 |
| Tear-off, one layer | 28 sq @ $68 | $1,904 |
| Disposal — two 20-yard dumpsters | — | $980 |
| Deck repair allowance | 6 sheets 7/16 OSB @ $95 installed | $570 |
| Labor & site subtotal | $6,394 | |
| Quote total | $15,191 |
A 28-square tear-off produces roughly 6,500 pounds of debris per layer. Two 20-yard containers isn't padding; one 20-yard container means a second trip or an overweight fee that shows up later as a change order.
The deck allowance is the line to read twice. Sheathing condition is invisible until the shingles come off, so every honest quote carries an allowance with a stated unit price beyond it — "six sheets included, additional at $95 installed." A quote that says "deck replacement billed as needed" with no unit price is an open checkbook, and tear-off day is a bad day to negotiate. On two-story homes with a 6:12 pitch, expect the second story to carry a pitch and height premium of 10 to 20 percent on labor; anything steeper than 8:12 adds staging cost on top of that.
Where the $11,400 bid found its savings
Same roof, same shingle brand on the front page. The differences were all on page two:
- Three rolls of ice barrier instead of eight. Saves $675, fails R905.1.2 on a house that needs it.
- Felt underlayment instead of synthetic. Saves about $180 and tears when a crew walks it wet.
- Existing flashing reused. Saves $640, guarantees a future callback the contractor may or may not still be around for.
- Cut three-tab shingles as starter and as ridge cap. Saves roughly $500 and voids the manufacturer's enhanced wind warranty, which requires the matching starter and cap products.
- One dumpster. Saves $490 until the overweight ticket arrives.
That's about $2,500 in scope removed and another $1,300 in thinner labor allocation. Nobody lied. The bid just describes a different roof than the one you thought you were buying. The $21,300 bid, for what it's worth, was a legitimate quote from a company carrying higher insurance, a 25-year workmanship warranty and a synthetic-plus-full-deck-membrane spec — defensible, just more roof than this house needed.
Regional line items that change the math
Texas and the hail belt: the Class 4 impact upgrade (GAF Timberline AS II, Owens Corning Duration Storm, Malarkey Legacy) adds $45 to $75 per square — about $1,400 to $2,300 here. Most Texas carriers discount premium 10 to 25 percent for a Class 4 roof, so it typically pays back in six to nine years. If you're rebuilding after a storm, the claim mechanics matter as much as the spec; see our guides to Texas hail damage claims and the storm damage claim filing window, and compare vetted crews on our Texas roofing contractors page.
Florida and the coastal Southeast: no ice barrier line, but a secondary water barrier and enhanced nailing requirements apply, and roof deck attachment gets inspected. Budget for a re-nail of the existing sheathing to current fastening schedule — commonly $70 to $110 per square that Northeast quotes never carry. Our hurricane season roof prep checklist covers what inspectors and adjusters look for.
Northeast: ice barrier is the swing item, and attic ventilation is the one people skip. IRC R806.2 requires net free ventilating area of 1/150 of the attic floor, reduced to 1/300 when the intake and exhaust are balanced. A ridge vent with no soffit intake is decoration, and it's the reason a new roof sometimes ice-dams worse than the old one.
Get three roofing quotes you can actually compare
We pre-vet every roofer in our network for licensing, insurance and complaint history — and we tell you what to ask before you sign anything.
Compare roofing quotes →The fifteen-minute comparison
Put three quotes side by side and check six things, in this order:
- Square count. If they disagree by more than one square, someone measured wrong. Ask both for the measurement source.
- Ice barrier quantity in rolls (or "not applicable" with a reason).
- The word "new" in front of flashing. Not "reinstall," not silence.
- Starter and ridge cap named as products, not as cut shingles.
- Deck allowance with a per-sheet unit price.
- Warranty split — manufacturer material warranty and contractor workmanship warranty are two separate things, and the second one is worth exactly as much as the company's odds of still existing.
Six checks. If all three quotes clear them, then and only then does the lowest number win. And if you're still deciding whether you need the roof at all this year, our guide to vetting a licensed roofing contractor covers the licensing and insurance verification step that happens before any of this.
Frequently asked questions
What is a roofing square and why do quotes use it?
A roofing square is 100 square feet of roof surface — not floor area. A 2,800 square foot roof is 28 squares. Roofers price in squares because every material in the job (shingles, underlayment, starter, ice barrier) is sold and installed on that unit. If a quote gives you a lump sum with no square count, you cannot compare it to anything, because you do not know whether two bidders even measured the same roof.
Why is there a 10% waste factor on the shingles?
Shingles get cut at rakes, valleys, hips and around penetrations, and the offcuts are scrap. A simple gable roof runs about 7-10% waste. A cut-up roof with multiple valleys, dormers and a hip perimeter runs 12-18%. On a 28-square roof that's roughly 2 to 5 extra squares of material. A bidder who orders exactly 28 squares either plans to run short mid-job or isn't planning to cut anything correctly.
Is ice and water shield required by code?
In cold regions, yes. IRC Section R905.1.2 requires an ice barrier in areas with a history of ice forming along the eaves, extending from the lowest roof edge to a point at least 24 inches inside the exterior wall line. On a house with a wide overhang, 24 inches inside the wall line means two courses of membrane, not one. Connecticut, Massachusetts, New York and most of New Jersey are ice barrier territory. Florida and most of Texas are not, though valleys and low-slope sections still warrant it.
Should the roofer reuse my existing flashing?
No. Step flashing is woven into the shingle courses, so reusing it means the old pieces stay bedded in the old sequence while new shingles go over the top. It's the most common corner cut in residential roofing and the most common source of a wall leak two winters later. New step flashing on a chimney and two sidewalls is a few hundred dollars in material. If a quote says "reuse existing flashing" or doesn't mention flashing at all, ask before you compare prices.
What does a deck repair allowance mean on a roofing quote?
Sheathing condition is invisible until the old shingles come off, so quotes carry an allowance — a stated number of sheets included, with a per-sheet price for anything beyond that. A good quote reads like "six sheets of 7/16 OSB included, additional sheets at $95 installed." A bad quote says "deck replacement billed as needed" with no unit price, which is an open checkbook on change-order day.
How much of a roofing quote is overhead and profit?
On a legitimate residential re-roof, overhead and profit typically runs 18-30% of the total, embedded in the per-square labor rate rather than shown as a line. That covers general liability and workers' comp insurance, the truck, the warranty reserve, and the office. A bid priced 30% under two comparable competitors is usually not a better negotiator — it's a bid with no insurance cost or no warranty reserve in it.
Does a more expensive shingle change the total much?
Less than most homeowners expect. Stepping from a standard architectural shingle to a Class 4 impact-rated product such as GAF Timberline AS II, Owens Corning Duration Storm or Malarkey Legacy typically adds $45-$75 per square — about $1,400-$2,300 on a 28-square roof. In Texas hail country that upgrade often pays for itself through an insurance premium discount within six to nine years.