RoofRangeBase

Methodology

Last updated: July 22, 2026

Estimate only — not a contractor quote, insurance valuation, or engineering stamp. Confirm materials, labor, permits, and deck condition with a licensed roofer before you sign.

How RoofRangeBase turns roof size and material into a low / mid / high dollar band. Defaults are US national installed starting points with an “as of” stamp. Override any $/square when a written local bid teaches a better unit rate.

Current stamp: 2026-07. Bands live in static rate tables under src/lib/rrb/. Update the table; keep the formula code. Arithmetic runs in a browser Web Worker when available.

Core formula

  • One roofing square = 100 sq ft of roof surface (not always downstairs footprint on a pitch)
  • total ≈ squares × (material $/sq + tear-off $/sq if enabled) × complexity
  • Low / mid / high come from the material and tear-off bands — not from inventing a fake exact invoice
  • Complexity defaults to 1.0 unless the UI exposes a multiplier for steep or cut-up roofs

Installed material bands (per square)

  • Asphalt — $350 / $500 / $700
  • Metal — $700 / $1,000 / $1,400
  • Flat (generic membrane) — $500 / $800 / $1,200
  • Tile — $800 / $1,100 / $1,600
  • Steel — $650 / $950 / $1,350
  • Standing seam — $900 / $1,200 / $1,600
  • Rubber (EPDM) — $450 / $750 / $1,100
  • TPO — $550 / $850 / $1,250
  • Commercial — $600 / $950 / $1,400

These are installed ballparks (typical crew + covering), not big-box materials-only aisle prices. Start: roofing cost per square.

Tear-off

When enabled: $100 / $150 / $250 per square. Replacement and redo pages default tear-off on; new-roof pages default it off. Overlay-only bids need a local code check — our redo mid assumes removal. Detail: roof tear-off cost.

Scene bands (not full-field re-cover)

  • Repair — $80 / $180 / $350 per square of affected area
  • Cleaning — $25 / $45 / $80 per square
  • Inspection — $15 / $30 / $55 per square (visit-fee proxy)

Do not multiply a whole-house field by the repair band and call it a redo. Scene tools and replacement tools answer different questions.

What we do not claim

  • No live ZIP-coded price feed or contractor marketplace
  • No insurance ACV, depreciation, or claim settlement math
  • No permit fee schedule, dumpster overages, or city surcharge table
  • No structural engineering, load calc, or deck stamp
  • No guarantee every local bid lands inside the rail

Stale band or a page that disagrees with a clear written bid? Contact with the URL and inputs.