What goes into a roof estimate

  1. The measurements, the job’s takeoff. The roof’s area in squares (100 square feet each), its pitch, and the length of every edge: eaves, rakes, ridges, hips and valleys.
  2. The tear-off. Taking the old roof off down to the deck and hauling it away, by the square, more for each extra layer. A new roof can’t go over a roof that already has two layers (IRC R908.3.1.1).
  3. The shingles, by the square with waste for cuts. Most come three bundles to a square (GAF).
  4. Underlayment over the whole deck (IRC R905.1.1), and an ice barrier at the eaves where ice dams form (IRC R905.1.2).
  5. Drip edge on the eaves and rakes (IRC R905.2.8.5), starter at the eaves, and ridge cap on the ridges and hips, all by the foot.
  6. Flashings: pipe jacks, valleys, walls and chimneys.
  7. Vents, where the attic needs them.
  8. Labor, priced into each line or listed on its own, with more for steep or high roofs.
  9. Overhead and profit, commonly 20% on a contractor’s estimate.
  10. Sales tax on the materials.

How a roofer works it out

  1. Measure the roof. From the ground with the pitch, on the roof plane by plane, or from a report ordered by the address. The guide to measuring a roof covers each way.
  2. Turn it into squares and add the waste: about 10% on a plain gable, about 15% on a hip roof, more where valleys and dormers cut it up. The roofing calculator does the math, bundles and edges included.
  3. Price each line at the local price for the work and the material, from the tear-off to the ridge cap.
  4. Add overhead, profit and tax, and send it with the measurements so the client sees where the numbers come from. Quoting tools such as SumoQuote build branded quotes from your own price list.

What typical roofs come to

The same one-story houses with plain 6/12 gable roofs, priced the way a contractor’s estimate is priced:

House Architectural shingles 3-tab shingles
1,200 sq ft $8,200 to $12,100 $7,700 to $11,400
1,800 sq ft $11,800 to $17,400 $11,200 to $16,400
2,500 sq ft $15,700 to $23,250 $14,800 to $21,750

Totals include the contractor’s overhead and profit (20%) and the state’s average sales tax. The roof replacement cost guide has them by state, and the metal roof cost guide has the same houses in steel panels.

Writing roof estimates faster

For one written by hand, the free contractor estimate template has the parts laid out, as a PDF or an Excel sheet that adds itself up.

Most of a roof estimate is the measurement and the same dozen lines priced for the ZIP code. BluMatrix measures the roof from the address, with an EagleView report or a satellite sketch, and puts the squares, pitch and every edge straight into the estimate, written line by line at current prices for the ZIP code. The client signs it online, and it exports as an ESX file that opens in Xactimate when the carrier asks for one.

Common questions

How much does it cost to replace a 1,000 sq ft roof?

For a one-story house with a 1,000 sq ft footprint and a plain gable roof, about $6,500 to $9,800 in architectural shingles, by the footprint figure in the roof replacement cost guide.

How much does a roof measurement report cost?

From about $13 to $19 at the low end, as RoofSnap, Roofr and GAF list them. The roof measurement apps page compares them.

What does a 10/12 roof pitch mean?

The roof rises 10 inches for every 12 inches it runs: a 39.8° angle, with 1.302 times the footprint’s area on the slope. The guide to finding a roof’s pitch has every pitch.

How many shingles for a 10 by 12 roof?

120 square feet is 1.2 squares; with 10% waste, 1.32 squares, which is 4 bundles at three bundles a square.

Will insurance pay for a roof?

When a covered event such as hail or wind damages it, a homeowner’s policy usually pays to repair or replace the damaged roof, less the deductible and subject to the policy’s terms. The adjuster’s estimate itemizes the work.