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Estimating guide · Roofing

How to estimate a roofing job

Roofing estimates are measured geometry: slope-adjusted area, edges, ridges, valleys, and penetrations. Get the measurements right and the material math follows.

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A repeatable process

  1. Measure roof planes and adjust for pitch

    Footprint area is not roof area. Measure each plane or apply the pitch multiplier, and record eaves, rakes, ridges, valleys, and penetrations.

  2. Confirm the existing condition

    Layer count, deck condition, and ventilation status decide tear-off scope, deck-repair allowance, and code items.

  3. Take off field and accessory materials

    Squares and bundles from area; starter from eaves plus rakes; drip edge from the same edges; ice and water where code or exposure requires; ridge vent from ridge length; boots and flashing from penetrations.

  4. Price tear-off, disposal, and install labor

    Tear-off and install carry different production rates. Dumpster and haul are explicit lines, not rounding error.

  5. Review the whole scope before sending

    Accessory omissions are the classic roofing margin leak. A readiness checklist catches them before the customer sees the number.

Where roofing estimates go wrong

  • Pricing from footprint area

    A 6:12 roof has roughly 12% more surface than its footprint; steeper roofs more.

  • Skipping accessory lines

    Starter, drip edge, and flashing kits are small lines that add up across every job.

  • One waste number for every roof

    Cut-up roofs with valleys waste more than simple gables.

Certified benchmark · 2026-08-21

In 520 certified profile-mode generations across 26 supported Instant assemblies on Windows (profile/AOT) and an Android API 36 emulator, supported jobs became editable estimates in a median of 0.028 seconds (rounded); the measured 95th percentile was 48.008 milliseconds (approximately 0.048 seconds), with 0 generative-AI provider calls.

median, supported jobs
0.028 sec
certified generations
520
supported assemblies
26
failures · 0 AI provider calls
0

Certified supported jobs only. Editable output; contractor pricing and field verification remain in control. Full methodology and results

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