How to compare roofing quotes

The instinct is to sort by total price. The problem is that a roofing total is only meaningful alongside the scope it buys, and scope is exactly what varies between bids. Work through these steps in order; most homeowners find the ranking changes by the end.

Step 1: Confirm all three are pricing the same roof

Look for the roof area, in squares. If two bids say 24 squares and one says 21, someone measured differently — or someone is excluding a section, like a porch or detached garage. Ask each contractor what area they used. If nobody states it, that is your first question, and it usually explains a surprising share of the spread.

Step 2: Normalise to price per square

Divide each total by its roof area in squares. Now you are comparing rates rather than totals, and a larger measured roof stops looking like an expensive contractor. Our quote checker does this conversion for you and places the result against a typical range for your inputs.

Step 3: Compare tear-off treatment

Check each bid for the number of layers being removed and whether disposal is included. A roof-over (installing on top of the existing layer) is a genuinely cheaper job and a genuinely different product — shorter life, hidden deck condition, and often reduced manufacturer coverage. Do not compare it to a full tear-off on price alone.

Step 4: Compare the underlayment and edge details

The parts that keep water out are not the shingles; they are the ice-and-water membrane at eaves and valleys, the drip edge, the valley method (open metal versus woven versus closed-cut), and the flashing at chimneys and walls. A bid that says “re-use existing flashing” is cheaper today and is the most common cause of a leak two winters from now.

Step 5: Compare ventilation

Ridge vent, box vents or powered — and crucially, whether intake ventilation at the soffits is being addressed. Exhaust without intake does not work. Ventilation is also a warranty condition for many manufacturers, so a bid that ignores it may be quietly buying you a shorter guarantee.

Step 6: Compare the decking clause

Every bid should name a price per sheet of replacement decking and state how many sheets, if any, are included. Unpriced decking is an open-ended cost that surfaces on the second day of work.

Step 7: Compare the two warranties

There are always two: the manufacturer’s material warranty, and the contractor’s workmanship warranty. The second one is the one that matters in the first decade, because most failures are installation failures. Get its length in writing, and understand it is only as durable as the business offering it.

Step 8: Compare what is excluded

Read the exclusions section last and hardest: skylight replacement, gutter removal and reinstallation, satellite dish handling, solar panel detach and reset, structural repair, permit fees, and dumpster placement. The cheapest bid frequently wins by excluding two of these.

What to do with the result

Once the scopes match, put the middle bid through the quote checker and compare it to an independent range from the calculator. If everything lands in the same neighbourhood, the remaining decision is about people: references, tenure, insurance certificates and how they handled your questions. Our quote checklist covers exactly what to ask before signing.