We are often the middle quote of three, and homeowners want to know why the spread is so wide. It is almost never the shingle. Four things move the number, and only one of them is visible from the street.
One: how much comes off first
A tear-off costs more than an overlay, and it is worth every dollar. Laying new shingles over old traps heat, hides rot, voids most manufacturer warranties, and doubles the tear-off cost for whoever comes next. If a quote is unusually cheap, check whether it includes a full tear-off to the deck.
Also check how many layers it accounts for. Plenty of houses in this area are carrying two, and the second one is not always visible from the eave.
Two: what happens to bad decking
Nobody knows how much sheathing is rotten until the old roof is off. Honest quotes give you a per-sheet price up front — ours is at cost — and a rough allowance. Quotes that stay silent on decking are the ones that produce an uncomfortable phone call on day one.
Three: the parts you never see
Underlayment, ice-and-water in the valleys and at the eaves, new step and counter flashing, drip edge, and a properly sized ridge vent. This is where the money quietly disappears from a cheap quote. Reusing old flashing saves a few hundred dollars and is the single most common cause of a leak on a brand-new roof.
Four: the roof itself
Pitch, height, and complexity. A steep roof needs staging and slows a crew down. Every valley, dormer, chimney and skylight is a detail somebody has to flash by hand. Two houses of identical square footage can differ by thirty percent on geometry alone.
Comparing quotes properly
Put them side by side and check they describe the same job: layers removed, decking terms, underlayment type, flashing replaced or reused, ventilation, warranty length, and who carries the workmanship. Once those match, the remaining difference is the real difference — and it is usually far smaller than it first looked.
