What decides the cost of a roof replacement

Two houses on the same street, same square footage, and the quotes come back thousands apart. Usually that is not one roofer being greedy and another being generous. It is that they are quoting different jobs.

Here is what actually moves the number.

Pitch

A roof you can walk on and a roof that needs staging are different labor entirely. Past roughly 7:12 a crew slows down, harnesses come out, and material has to be carried rather than moved.

Pitch also drives waste: steeper roofs need more cutting at the hips and valleys, and the offcut does not go back in the bundle.

The number of planes

This is the one homeowners underestimate most.

A simple gable roof is two planes and one ridge. A roof with four dormers, two valleys and a porch tie-in might have the same area and three times the linear feet of flashing — and flashing is where roofs leak, so it is where the careful hours go.

When a quote looks low on a complicated roof, the question to ask is what is happening at the valleys and the sidewalls.

Penetrations

Every pipe, vent, chimney, skylight and satellite mount is a hole in the roof that has to be made watertight and stay that way through thermal movement.

Ten penetrations is a normal house. Twenty-five is a different job.

What is under the old roof

Nobody knows until the old roof is off. Decking that is soft, delaminated or rotted at the eave has to be replaced, and it is not optional — new shingles over bad decking is a new roof that fails early over a problem you paid to cover up.

A good estimate says what the decking allowance is and what replacement costs per sheet beyond it. A quote that is silent about decking is a quote that will change on the day.

Access

Can a truck get close? Is there a driveway to stage on, or is everything carried around the house? Are there mature trees, a pool, or a neighbor's fence within falling distance of every tear-off bundle?

Access changes the crew size and the clean-up time, and both are real money.

Layers to tear off

One layer comes off fast. Two or three layers is double or triple the disposal weight, the dumpster capacity and the labor hours before a single new shingle goes down.

Material, which is the part people focus on first

It matters, but it is rarely the biggest variable between two quotes on the same house. Moving from asphalt shingle to standing-seam metal or Brava synthetic changes the number substantially — but two shingle quotes on the same house differ because of everything above, not because of the shingle.

How to compare two estimates honestly

Put them side by side and check that they say the same thing about:

1. Tear-off — how many layers, and disposal included?
2. Decking — what allowance, and what per sheet beyond it?
3. Underlayment — synthetic or felt, and ice-and-water where?
4. Flashing — new, or reusing the existing metal? Reusing is where a cheap quote gets cheap, and it is the part that leaks.
5. Ventilation — are the intake and exhaust being corrected, or just replaced like for like?
6. Who is on the roof — the company's crew, or a subcontractor they met this season?

If two quotes differ by thousands, one of those six is different. It is worth finding out which before choosing on price.

Why we do not publish a price per square

Because it would be a number we would then have to defend on a roof we have not seen, and every honest exception to it is one of the seven things above.

What we do instead is put the scope, materials and timeline in writing after the inspection, so the number you are given is the number you pay.

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Want a real estimate rather than a range? Call (615) 418-6087 or request an inspection. We get on the roof — a windshield estimate is a guess, and you would be comparing guesses.