How to Compare Roofing Quotes Line by Line

Two roofing quotes are comparable only when they price the same roof: the same squares, the same number of layers torn off, the same underlayment and flashing, and a stated price for rotten decking found after tear-off. Add what each quote leaves out before you compare totals, because the lowest bid can change once the gaps are priced.

The work is mostly a spreadsheet exercise. Put every quote on one sheet, mark what each includes, price what each omits, and only then look at the bottom line.

Start Every Bid From the Same Request

Unequal quotes start with unequal requests. If one roofer heard “replace the shingles” and another heard “full tear-off with new flashing and vents,” their prices answer different questions.

Decide the material tier first, such as a specific architectural shingle line, so bids are not split across product grades. Then send every roofer the same written request that asks for:

• the number of squares the price is based on, and how the roof was measured;
• the number of existing layers to be removed;
• product names for shingles, underlayment, ice barrier, starter, ridge cap and drip edge;
• which flashing will be replaced and which, if any, reused;
• a unit price for each sheet of decking replaced after tear-off;
• permit, debris removal, warranty terms, and start and completion dates.

That list goes beyond the Federal Trade Commission’s floor in How To Avoid a Home Improvement Scam, which says a written estimate should include “a description of the work to be done, materials, completion date, and the price.” The National Roofing Contractors Association’s Selecting a Contractor advice is to “insist on a written proposal,” and it adds that “price is only one criterion.”

Compare the square counts as soon as the quotes arrive. If they differ by more than a rounding gap, ask each roofer how it measured; how roof area is measured in squares shows how to sanity-check the figure.

Line Up the Scope Item by Item

Build one row per scope item and one column per quote, then mark each cell: included and named, included but vague, priced as an option, or missing. If a quote uses a term you cannot place, the glossary of estimate and contract terms defines it.

Hypothetical example: three quotes laid out on a comparison sheet.

Every “missing,” “not mentioned” or “vague” cell becomes a written question to that roofer. Send all bidders the same gap list, so each one answers the same items. Keep each question short and closed: “Your quote does not mention chimney flashing. Is new chimney flashing included? If not, what is the price to add it?” A yes or a price is easy to compare; a paragraph of reassurance is not.

On an insurance claim job, add one more column: the insurer’s estimate. If the insurer’s scope lists an item a quote leaves out, ask the roofer why. If a quote includes work the insurer did not list, ask whether the roofer plans to request it from the insurer as a supplement, and get that answer in writing before you sign.

Some of those rows are not optional. The re-roof rules your city enforces, drawn from whichever edition of the International Residential Code (IRC) it adopted, can require items such as an ice barrier, drip edge and removal of old layers once a roof reaches its layer limit. Lincoln, Nebraska’s Re-Roof Policy, based on the 2018 IRC, is one example. Amendments change the list: the City of Bloomington, Minnesota reroofing sheet notes that the 2020 Minnesota Residential Code it cites does not require drip edge unless the shingle manufacturer does. A quote that leaves out a required item is not cheaper; it is incomplete. Which code items apply to a re-roof explains how to confirm the list with your building department.

Allowances and Unit Prices

Decking is the biggest unknown in a re-roof quote, because its full condition shows only once the old roof is off. A quote handles that unknown in one of three ways: a fixed price that includes all deck repairs, a unit price per sheet, or a vague “as needed” that leaves the price open.

Turn every quote into the same form with one formula:

Adjusted total = quote price + (expected deck sheets times the quoted unit price) + the price of any excluded items you need.

Use the same expected sheet count for every quote. If an attic check or a roofer’s inspection gave you a number, use it; if not, pick one figure and apply it to all bids, so the comparison stays fair even if the number is a guess. Ask any roofer with an “as needed” line for a unit price in writing before you compare.

Hypothetical example: The numbers are illustrative inputs, not typical prices. Quote A is $15,200 with all deck repairs included. Quote B is $14,300, plus $95 per replaced sheet, and lists drip edge as an option at $400. Assuming eight sheets for both, Quote B’s adjusted total is $14,300 + (8 times $95) + $400 = $15,460. The lower bid is now the higher one.

A fixed price moves deck risk to the roofer, who builds it into the base. A unit price keeps the base lower and leaves your final number open. The formula puts both on the same footing for comparison, but only the fixed price caps what you will pay for decking. What drives roof replacement price covers the cost factors behind each line.

Terms Outside the Price

Two quotes with the same adjusted total can still differ in what you are buying.

• Exclusions. Read every “by others,” “if required” and “not included” line, and price the ones you need.
• Workmanship warranty. NRCA’s Resources page says there is no industry standard for workmanship coverage, though many contractors offer one or two years. Compare the stated years and what each covers.
• Manufacturer warranty level. GAF’s Roofer Certification page states that “only contractors certified by GAF can offer GAF enhanced warranties.” If a quote promises an enhanced warranty, confirm the roofer’s tier before you count it.
• Product line. Two quotes that both say “architectural shingles” can name different product lines with different warranty terms. Ask each roofer for the line by name and compare like with like.
• Dates. A start date months away has a cost if the roof is leaking now. Also note any date after which a quote’s price no longer holds, and get an extension in writing if you need more time.
• Payment terms. A quote that wants a large share up front carries more risk than one that pays against delivered work, so note what each payment is tied to.
• Permit. Know who pulls it, and whether the fee is in the price.

Picking the Quote Once the Numbers Are Even

After the adjustment, if two totals are close, choose on the terms: the clearer scope, the stated deck unit price, the longer written workmanship warranty, and the better vetting results. If one quote is still far below the others, ask that roofer in writing what it is leaving out or doing differently, and wait for the answer before you accept.

Then send the winning roofer your gap list one last time, confirm every answer is in writing, and move to the clauses the contract should carry. If you have not finished checking the roofers themselves, go back to the license, reference and red-flag checks first.

This guide is general information for U.S. homeowners, not legal, insurance, tax, or engineering advice. Codes, laws, and policy terms vary by location and change over time; confirm details with your local building department, your insurer, or a licensed professional.

Sources

• How To Avoid a Home Improvement Scam, Federal Trade Commission
• Selecting a Contractor, National Roofing Contractors Association
• Re-Roof Policy, City of Lincoln, Nebraska Building and Safety
• Reroofing information sheet, City of Bloomington, Minnesota
• Resources (warranties, maintenance, weather events), National Roofing Contractors Association
• GAF Roofer Certification, GAF