Guide

How to read a roofing estimate

A roofing estimate is readable when it names the area, the shingle, the tear-off, the underlayment, the flashing, who pulls the permit, and where the old roof goes. One line that says “composition shingle — $27,500” is a total. It is not an estimate you can compare to the next bid.

This is a reading aid, not a price check. It will not tell you whether that number is fair for your ZIP or postcode. Two roofs on the same street can differ because one has two layers to strip, a rotten deck, or a chimney the other bid quietly left out.

Start with the area, not the total

In the US, roofers usually measure in squares. One square is 100 square feet of roof, not of the house footprint. A quote that never says how many squares is asking you to trust a number you cannot check. In the UK the same idea is square metres of roof, including the pitch. Steeper roofs use more material than the floor plan suggests.

Ask them to write the count on the page. If two bids disagree by a square or two, that is a measuring question, not a personality test.

Tear-off and the dumpster

Tear-off means they take the old roof off. Haul-away or a dumpster means someone pays to get rid of it. Cheap bids often skip one of those, then the dumpster shows up as a change order after you have already said yes.

The estimate should also say how many existing layers they will remove. One layer is a different job from two. If the page is silent, ask. “We’ll see when we get up there” is how a $9,000 bid becomes a different job on day one.

Underlayment, ice and water, flashing

Shingles are the part you can see. The bid often goes wrong underneath them.

• Underlayment is the sheet under the shingles. “Felt” and a named synthetic are not the same product. The estimate should say which.
• Ice and water shield is the sticky membrane at eaves, valleys, and sometimes around penetrations. In cold climates it is not a luxury line. If it is missing, ask whether your roof needs it and who pays if it does.
• Flashing and drip edge keep water out at walls, chimneys, skylights, and the edge of the roof. “Re-use existing flashing” can be fine or it can mean the leak stays. Get that choice in writing.

The shingle has a name

“Architectural shingles” is a category, not a product. A serious line names the manufacturer, the product or series, and the color. It also says whether the manufacturer warranty and the workmanship warranty are included, and for how long.

An allowance for shingles is a placeholder, not a price. If you pick a different color or a heavier shingle, you pay the difference. Ask what product that allowance assumes.

Decking is where the surprise lives

Plywood or OSB decking is often rotten in spots you cannot see from the ground. Good estimates do not pretend they know every sheet. They give a unit price: a price per sheet to replace bad decking, or a small allowance plus that unit price.

“Decking as needed” with no price is the vague line. You want the rate before they are standing on your roof with the old shingles already in the truck.

The small lines that still leak

Pipe boots, chimney flashing, ridge vent, and bathroom or kitchen vents are easy to leave off a one-line bid. If the house has a skylight, it should be its own line: reflashed, replaced, or excluded. Excluded means you still have a skylight problem after the new roof is on.

Ventilation belongs on the page too. A new shingle over a roof that cannot breathe is a warranty argument waiting to happen. If they are adding a ridge vent or replacing box vents, it should say so.

Permit, who is on it, and the deposit

Someone pulls the permit, or the job is unpermitted. The estimate should say who, and whether the fee is inside the total. Unpermitted roof work shows up when you sell or when you file a claim.

A modest deposit to order materials is normal. Fifty percent before anyone is on the roof is a lot of leverage to hand over. Ask for a milestone schedule and a last piece after the walkthrough, when you can see flashing, vents, and cleanup — not only the shingles from the street.

If they will not itemize

Some roofers send a short number and a longer contract later. Do not sign the short number. Ask for labor, materials with product names, tear-off, dumpster, permit, and the per-sheet decking rate. If they refuse to separate those, you cannot tell whether the cheap bid skipped the work the other bid included.

“As discussed” does not count. If it was said on the driveway, it is not in the deal until it is on the PDF.

Then still get a second bid

Line the two estimates up on the same work: squares or square metres, layers removed, underlayment, ice and water, flashing, shingle name, decking rate, permit, dumpster, warranty. The lower total is only cheaper if those lines match.

If you already have the PDF, the free briefing on Explain My Quote will flag vague wording and common gaps in your browser. The file stays on your device on that pass. It will not say the price is fair, and it will not replace a second roofer.

More on the general case: how to read a contractor quote.