Updated September 2026 by Chris Horton. A method for reading bids, not a verdict on contractors. How we estimate costs
Two roofing bids arrive. One is 9,000 dollars higher. The instinct is to ask which one is right. The better question is whether they describe the same work at all, because most of the time they do not, and the gap is hiding in fields neither bid filled in. This page is the list of those fields, and a plain way of saying how two bids differ.
Four words that do the work
Comparing bids goes wrong when the only available verdict is better or worse. These four labels let you be precise about a difference without pretending to judge the price.
Most homeowners find that their first pass produces far more Unknowns than anything else. That is the useful result. Every Unknown is a question you can send back in writing, and a bid that fills them in is a bid you can actually hold someone to.
What a written bid should spell out
Work through it once per bid. The right-hand column is what to watch for.
The roof itself
| Line | What to look for |
|---|---|
| Roof area | A number in squares or square feet, and how it was measured: on the roof, from the ground, or from satellite imagery. Different methods produce different numbers. |
| Pitch and complexity | Slope, stories, and whether the roof is simple or cut up with valleys and dormers. This sits inside the labour price rather than on its own line. |
| Sections included | The whole roof, or only certain slopes. Detached garages and additions should be named explicitly. |
| Low-slope areas | Flat sections over a porch or addition need a membrane, not shingles. A bid that ignores them is not a whole-roof bid. |
Removal and disposal
| Line | What to look for |
|---|---|
| Tear-off or overlay | Stated explicitly. These are different products with different lifespans and different warranty consequences. |
| Number of layers | One, two or more, and whether that is confirmed or assumed. An assumption should come with a stated price if it turns out to be wrong. |
| Disposal | Dumpster and landfill fees included, excluded, or capped by an allowance. |
The deck underneath
| Line | What to look for |
|---|---|
| Deck inspection | A stated visual inspection after tear-off, and what happens if problems are found. |
| Replacement allowance | How many sheets are included, at what thickness and material, and the price per sheet beyond that. As needed with no unit price is the single highest-risk phrase on a roofing bid. |
The layers you will never see again
| Line | What to look for |
|---|---|
| Underlayment | Felt or synthetic, and ideally the product. They are not interchangeable. |
| Ice and water barrier | Where it goes: eaves, valleys, penetrations, and roughly how much. Per code means the local minimum, which varies by jurisdiction. The ice and water shield roof quote decoder lists every location and distance to ask about. |
| Starter strip | A manufactured starter at eaves and rakes, or cut-up field shingles. It affects wind performance and warranty eligibility. |
| Flashing | New or reused, named piece by piece: valley, step, chimney, skylight, drip edge. Seal as needed is not a specification. |
| Penetration boots | New boots for plumbing stacks and vents, with a count. |
| Skylights | Replaced, reflashed or excluded. If one bid excludes them and another replaces them, the totals are not comparable. |
The roof you will see
| Line | What to look for |
|---|---|
| Field shingles | Manufacturer, product line and colour. A brand alone, or a warranty length alone, leaves the most price-relevant field blank. Treat it as Unknown, not as equivalent to a named line. |
| Hip and ridge cap | A manufactured ridge cap product, or field shingles cut up on site. Different cost, different appearance, sometimes different warranty standing. |
| Nailing pattern | Four nails or six, and any enhanced install pattern. Some wind warranty coverage depends on this. |
| Accessory system | Whether the underlayment, starter, ridge and ventilation come from the same manufacturer. This is frequently what unlocks an upgraded warranty tier. |
Ventilation
| Line | What to look for |
|---|---|
| Exhaust | Ridge vent or other exhaust product, named. |
| Intake | Soffit vents, baffles, and whether existing intake is adequate. Exhaust without intake does not ventilate. |
| Balance claim | Any statement that the finished system is balanced, since inadequate ventilation is a named exclusion in manufacturer warranty documents. |
Paperwork, warranty and terms
| Line | What to look for |
|---|---|
| Permits and inspections | Who pulls, who pays, and whether inspection is included. |
| Code or programme claims | Any claimed compliance, including voluntary resilience programmes, should name the standard and edition. |
| Manufacturer warranty tier | The specific tier being provided, not just the word warranty. |
| Registration | Who registers the warranty, and by when. An unregistered warranty can sit at a lower tier than the one you were sold. |
| Workmanship warranty | How many years, and who stands behind it: the contractor alone, or the manufacturer. |
| Wind and algae terms | Stated limits, or silence. |
| Licence and insurance | Licence number, general liability and workers compensation, with certificates available on request. |
| Certification tier | Any claimed manufacturer certification. Verify it on the manufacturer’s own contractor locator rather than taking the logo at face value. |
| Property protection and cleanup | Landscaping protection, magnetic nail sweep, final walkthrough. |
| Timeline | Start window and days on site. |
| Price and unit pricing | The total, plus any per-square or per-sheet rates that let you price a change. |
| Allowances and exclusions | An explicit list. What is excluded is more informative than what is included. |
| Change orders | Whether written approval is required before extra work proceeds. |
| Payment schedule | Deposit, progress payments, final payment, and what triggers each. |
| Lien waiver | Whether final documentation is mentioned at all. |
The Roof Quote Analyzer walks one bid through this checklist in six steps and writes the questions out for you. Nothing you type is stored.
Five rules for comparing two bids
- If the removal scope differs, stop. Overlay against tear-off, or one layer against two, is not a price difference. Ask for a rebid on the same removal scope before you compare totals.
- An unnamed product line is Unknown, not equivalent. Architectural shingle does not make two bids the same. Manufacturers sell several architectural lines at different prices under the same brand. The architectural shingles quote decoder shows how to normalize two shingle bids line by line.
- Decking as needed with no unit price is Unknown and high risk. Ask for an included quantity and a rate.
- Silence on ventilation is Unknown, and it is a warranty flag. Ask what the intake and exhaust plan is before you decide anything else.
- Compare totals last. Area basis, removal scope, material system, flashing, ventilation and warranty tier come first. Until those are aligned or explicitly differenced, the totals are measuring different projects.
What this checklist deliberately does not do
It does not label a bid fair, high, cheap or a rip-off. It cannot: those judgements need a local labour market, a site visit and your own priorities, none of which a checklist has. It also does not rank contractors, and it does not cover insurance or storm-damage claims, which are a different subject with different rules.
What it does is convert a vague sense that something is missing into a specific list of things that are missing, which is what you need in order to ask a useful question.
Common questions
Is it rude to send a contractor a list of questions?
A contractor who intends to do the work described will usually be glad to write it down, because a specified bid protects them from arguments later too. A reluctance to put scope in writing is itself informative.
What if only one bid answers everything?
Then you have learned something useful, though not necessarily that the other contractor is worse. Send the same questions to everyone and compare the answers, not the eagerness.
How many bids should I get?
Enough to see the range, which is usually two or three. Beyond that you mostly add scheduling work rather than information, unless the bids you have are wildly apart, which normally means scope rather than price.
Do you have a tool that does this automatically?
Not for roofing. This page is the method written out, and working through it by hand on your own paperwork is genuinely the exercise that pays off.
About the author
Chris Horton writes UpgradeWorth’s homeowner decision guides. He covers how replacement projects are scoped, quoted and warrantied, with a bias toward what a homeowner can verify in writing rather than what a salesperson says at the kitchen table. UpgradeWorth does not sell leads, rank contractors or accept placement fees.
Next: what the cost drivers behind these lines actually are, and what the warranty lines really mean. Comparing two standing seam metal bids? Use the standing seam roof quote decoder. Start over at the Roofing hub.