ShingleTallySquares, bundles and everything else a roof needs, counted properly.

Shingles & Squares

Bundles, squares and waste for a roof of a given size and pitch.

Roofing material is sold by the square — 100 square feet of roof surface. Not 100 square feet of ground, and that distinction is where most estimates fail.

A 40 × 30 ft house covers 1,200 ft² on the ground. The roof over it, at an 8/12 pitch, is 1,442 ft². That is two and a half squares of shingle nobody ordered.

The pitch factor is not an estimate

factor = √(1 + (rise ÷ 12)²)

4/12 gives 1.054. 6/12 gives 1.118. 8/12 gives 1.202. 12/12 gives 1.414. It is the hypotenuse of the roof triangle and there is no judgement in it — which makes it the most reliable number in the whole estimate.

Waste is a property of the roof shape

Ten percent on a simple gable, where the only cuts are at the rakes. Fifteen on a hip roof, which cuts along every hip. Twenty on anything with valleys and dormers, where a fifth of what you buy ends up in the dumpster.

Quoting one waste figure for all roofs is how a cut-up roof comes up short.

The two lines that get left off every estimate

Starter course along every eave and rake, and hip and ridge cap along the top. Both are separate products. Cutting up field shingles to use as starter voids most manufacturers' wind warranties, and that is discovered at the claim rather than at the register.

Tear-off is half the job

A single layer of asphalt shingle weighs 200–350 lb per square. A 30-square roof is around four tons of material to strip, carry down and skip — and on a second layer, double it. That line belongs in the budget before the shingle line does.

The one thing to check before anything else

Whether you can stand on it. Above 8/12 most people cannot, and roof jacks or scaffolding change the economics of doing it yourself more than any material price does.

20 articles

How much does a 25-square roof replacement cost in Federal Way, WA?

A full asphalt shingle roof replacement in Federal Way, WA
$16,182
25 squares · typical range $10,980 – $26,006
Typical total$647 per square$16,182
Range you should see in bidsthree bids on the same scope normally land inside this$10,980 – $26,006
Labor portion60% of the job — this is the part that moves by city$9,709
Material portion40% — bought at national prices$6,473
Roofers pay near Federal Wayabout $35/hr · Seattle-Tacoma-Bellevue, WA metro$73,240/yr
U.S. mean for the same tradeSOC 47-2181$58,140/yr
Versus the national pricetrade pay here runs +26% against the U.S. mean+$2,182
Ice barrier requiredFederal Way designs to 25°F, so IRC R905.1.2 ice barrier applies — two courses of membrane at the eaves, typically $60–$120 per square added—

Notes

  • Where the number comes from. The national price for a full asphalt shingle roof replacement is $560 per square — installed asphalt shingle pricing published for 2026, $3.50–$10.00 per ft² of roof. Labor is about 60% of that. Roofers near Federal Way, WA average $73,240 a year against a U.S. mean of $58,140 — a factor of 1.26 — so the labor half is scaled by that and the material half is not. Source: BLS OEWS May 2025 for the Seattle-Tacoma-Bellevue, WA metro area, SOC 47-2181.
  • Why the city matters, not just the state. Trade pay moves inside a state as much as it does between states. Crews do not commute across a state to bid a job, and materials ship at national prices either way — so a metro wage is the honest input here and a state average quietly rounds four different cities into one number.
  • Ice barrier required. Federal Way designs to 25°F, so IRC R905.1.2 ice barrier applies — two courses of membrane at the eaves, typically $60–$120 per square added.
  • What is in the price: tear-off of one layer, synthetic underlayment, architectural shingles, starter, ridge cap, drip edge, nails, disposal and labor.
  • What is not: decking replacement, chimney or skylight flashing rebuilds, structural repair, and permits. These are the lines that turn a $16,182 quote into a $20,227 invoice, so ask about each one before signing.
  • Use this as a bid check, not a quote. It prices an average job in average condition. Difficult access, the state of what is being replaced, the season, and a crew booked out three months all move the real number, and none of them are in a per-unit average.

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