What Is a Roof Estimate?

What a roof estimate is

An estimate is the roofer's plan for your roof, written as a price. It says what they will remove, what they will install, what they will charge, and on what terms. People also call it a quote, a bid or a proposal. The words vary; what matters is what the paper says.

A short estimate can be a single line with one total. A good one breaks the job into parts, so you can see each choice the roofer made. That matters, because two roofers can look at the same roof and plan quite different work.

One may replace all the flashing; another may reuse it. One may count two old layers to tear off; another may assume one. The totals only make sense once you see those choices.

An estimate is not a contract. Once you sign, the agreed scope and price become a contract, and many states set rules for what that contract must include.

How a roofer builds an estimate

The roofer starts with the size of the roof. They measure it on site, or order a measurement report from aerial images, and work out the area in roofing squares, each 100 square feet of roof surface. They also measure the edges and lines in linear feet: eaves, rakes, ridges, hips and valleys.

Next they look at what is on the roof now: how many layers, what material, and how worn the deck looks from the attic. They count the penetrations, such as pipes, vents, chimneys and skylights. Then they choose the products and the method, and price each part.

Finally they add the costs that are not on the roof itself: the permit, the dumpster and disposal, the crew's travel and setup, and their overhead and profit. Many show these as separate lines; some fold them into a per-square price.

Each step leaves a line on the paper, so a bid that skips one usually shows up as a missing line when you compare it with the others.

Types of line item on a roof estimate

Most lines are priced per square, per linear foot, per piece, or as a flat item. Knowing which is which lets you check the numbers.

Measured squares vs waste

The square count is the biggest number on most estimates, so check it first.

Ask for two figures: the measured squares, which is the real area of the roof surface, and the waste allowance, which is extra material added for cuts at valleys, hips, dormers and edges.

A plain gable roof wastes little. A roof full of valleys and dormers wastes much more.

If one bid shows far fewer squares than another, ask why. Usually it is waste, or a missed plane such as a porch roof.

A count lower than the measured area is a warning sign: the crew will run short, or the bill will grow.

You can check the size yourself with our roofing squares calculator, from the footprint and pitch.

Tear-off layers and the deck underneath

On a replacement, the old roof comes off first. Tear-off is usually priced per square and per layer, so a two-layer roof costs more to strip and haul away than a one-layer roof.

The layer count also decides what is allowed. The 2021 International Residential Code, section R908.3.1.1, does not allow a new roof over the old one when the existing roof already has two or more layers, or when it is water soaked or deteriorated ⁴.

Ask each roofer how many layers they found and how they checked.

Once the old roof is off, the crew can see the wooden deck. Rotten or damaged sheets have to be replaced before new roofing goes on, and nobody knows how many until then.

That is why a good estimate gives a price per sheet of roof sheathing up front, and says whether any sheets are already included. Without that line, the extra cost after tear-off is open-ended.

Where the edges and details show up: flashing, drip edge and ridge

The edges and joins of the roof are where cheap bids often save money. Drip edge is a metal strip at the eaves and rakes.

The 2021 IRC, section R905.2.8.5, requires it on shingle roofs, overlapped at least 2 inches between pieces and fastened at not more than 12 inches apart ⁴. If drip edge is missing from a shingle estimate, ask why.

Flashing seals the roof where it meets walls, chimneys, skylights and valleys.

Section R908.5 of the same code says damaged flashings, edgings, outlets and vents must be replaced on a reroof ⁴.

Some bids reuse old flashing that is still sound; others replace it all. Either can be fine, but the estimate should say which.

Starter strip at the eaves and ridge cap along the ridges and hips are separate products from the field shingles, priced by the linear foot. They are easy to leave off a low bid and add back later.

Worked example: two bids side by side

An illustrative comparison of two estimates for the same house. No prices are shown; the point is the scope.

Bid B will almost always look cheaper, but it prices a smaller job. If the roof really has two layers, Bid B's price grows on day one. Ask Bid B to quote the same scope as Bid A before you compare totals.

Permits, warranty terms and payment schedule

Permits. Most areas need a permit to replace a roof. The estimate should say who pulls it. California's contractor board lists permit responsibility among the things a home improvement contract should state ¹.

Warranty. There are usually two: the maker's warranty on the materials, and the roofer's warranty on their work.

The estimate should name both, with the term and what they cover, and say who registers the maker's warranty. California's board says warranty information should be in writing ¹.

A spoken "lifetime warranty" with no document is not something you can rely on.

Payments. The estimate or contract should set out when you pay, and how much at each stage.

California requires a written payment schedule in the contract and caps the down payment at 10 percent of the price or a fixed limit set in law, whichever is less ¹.

Connecticut's consumer protection department advises keeping deposits to no more than a third, paying by card or check rather than cash, and tying later payments to progress ².

Why a detailed estimate helps

What an estimate cannot tell you

• It cannot know the deck condition for sure until the old roof is off.
• It does not prove the roofer is licensed or insured. Check those separately.
• It does not tell you about workmanship. Two crews can install the same products very differently.
• It is not the final price if it has allowances or per-sheet items. Read those as ranges.

What drives the total on an estimate

This page does not give prices.

The total is driven by a handful of clear factors: the number of squares, the material, the pitch (steep roofs need more safety gear and time), the number of old layers to remove, how cut-up the roof is, the number of penetrations, the amount of deck replaced, local permit and disposal fees, and the season.

Insurance work and storm seasons can change demand and timing.

For sourced, dated prices, see our roofing cost guide, and try the roof cost calculator to see how size and material move the range.

How to compare bids

1. Get at least three written estimates. Connecticut's consumer protection department gives the same advice ².
2. Line them up item by item: squares, waste, tear-off layers, deck price, underlayment, drip edge, flashing, ridge, vents, permit, cleanup.
3. Mark anything one bid includes and another leaves out. Ask the others to price it.
4. Compare the products by name, not by grade words like "premium".
5. Compare warranty terms in writing, and who registers the maker's warranty.
6. Compare payment schedules. Be wary of a large payment before work starts.
7. Only then compare totals.

Keep the estimate after the job

File the signed estimate and contract with the permit, the warranty papers, the final invoice, and any change orders. Note the exact shingle name and color.

Years later, those papers help with storm repairs, insurance claims and selling the house. A repair crew can match the product, and an adjuster can see what was installed and when.

Red flags on an estimate

• One line, one total, with no breakdown.
• No square count, or a count well below the measured area.
• One layer of tear-off priced when you know there are two.
• No per-sheet deck price, so rot found later has no set cost.
• A large deposit or full payment up front, or a request for cash only.
• Pressure to sign today, or an offer to "cover your deductible". Ask your insurer before agreeing to anything like that ⁵.
• No licence or registration number on the paperwork in a state that requires one.

Rules for home improvement contracts

Federal. The FTC's cooling-off rule, 16 CFR Part 429, covers sales made at your home, such as a door-to-door roofing pitch. It requires the seller to tell you that you may cancel at any time before midnight of the third business day after the sale, and to give you a cancellation form ³.

California. The Contractors State License Board says a written contract is required for home improvement projects above a set dollar threshold.

The down payment may not be more than 10 percent of the contract price or a fixed cap, whichever is less.

The contract should list the work and products, a written payment schedule, permit duty, the completion date, the contractor's licence number and the warranty.

Changes in price or scope must be made by a written change order signed by both sides before the change ¹.

Connecticut. The Department of Consumer Protection says home improvement work needs a written contract that lists the contractor's registration number, the work and materials, start and finish dates, the costs and payment schedule, and the right to cancel until midnight of the third business day ².

Other states have their own rules, and some have none specific to roofing. Check with your state's contractor licensing board or attorney general.

Estimate vs quote vs contract vs inspection report

Common mix-ups

Myth The lowest bid is the best deal.

Reality Only if it prices the same work. A low total often leaves out tear-off layers, deck sheets, drip edge or flashing.

Myth An estimate is a contract.

Reality It is not binding until you sign a contract. Get the agreed scope written into it.

Myth A lifetime warranty means the roof is covered for life.

Reality Warranty terms vary widely. Read the actual document for both materials and workmanship.

Myth All roofers measure the same.

Reality Measured area should agree, but waste allowances differ. Ask for both numbers.

Sources: [1]

What changes by state and town

The parts of an estimate are much the same anywhere, but the rules around it are local. States differ on contractor licensing or registration, written contract rules, down payment limits and cancellation rights.

Towns differ on permits, inspection steps and disposal fees. Code editions vary too, which changes items like ice barrier and underlayment. We quote only California and Connecticut here because we read their rules directly.

Check your state's contractor licensing board and your building department before you sign.

Before you sign

1. Make sure the scope you chose is written into the contract, line by line.
2. Confirm the licence or registration number and the insurance.
3. Check the payment schedule and the deposit against your state's rules.
4. Get the warranty terms in writing.
5. Agree in writing how changes and extra deck sheets will be handled.

Our guide to choosing a roofer covers vetting, and a roof inspection report helps every bidder price the same problems.

Keep going

• Roof cost calculatorHow size and material move the range
• Squares calculatorCheck the square count on each bid
• Roofing cost guideSourced, dated prices
• Roof inspectionKnow the roof before you price it
• Roof plannerSee roof options for your house in a few steps

Related terms

Roofing Square

A roofing square is a unit of area equal to 100 square feet of roof surface, a 10-by-10-foot patch, and it is the unit in which shingles are sold and most roofing quotes are priced.

Roof Inspection Report

A roof inspection report is the written record of a roof inspection: what parts of the roof were looked at, how they were looked at, what defects were found, photos of those defects, and what the inspector recommends doing next.

Reroofing

Reroofing is the work of putting a new roof covering on a house that already has one, either by tearing the old covering off down to the deck (a replacement) or by laying the new covering over the old one (a recover, often called an overlay).

Roof Sheathing

Roof sheathing is the layer of plywood, OSB or wood boards nailed across the rafters or trusses.

Drip Edge

Drip edge is a strip of bent metal flashing installed along a roof's eaves and rake edges that carries water off the edge of the roof and away from the fascia and the deck beneath.

Roof Warranty

A roof warranty is a written promise to repair or pay for certain roof failures for a set time.

Roofing Contractor

A business that installs and repairs roofs. Licensing, insurance and warranty terms vary by state and company.

Roof Replacement Cost

The price of replacing a roof, driven by size, pitch, material, tear-off layers and deck repair.

Also referenced from: Roof Inspection Report, Roofing Square