Evidence and methods

Our roofing content methodology

See how At-Cost separates sources, calculations, examples, and operating experience.

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Evidence and methods

Source record

These sources support the factual guidance on this page. Project documents and current official records control when facts change.

Every factual roofing page should show where its claims came from, what varies by property or date, and whether the statement is manufacturer data, public law, local procedure, or At-Cost operating policy.

See how a claim earns publication

  • Product review evidence — See how product documents, tests, tradeoffs, and unknowns are handled.
  • Roof price inputs — Separate quoted, measured, calculated, and still-unknown amounts.
  • Roof-condition documentation — Keep observations, measurements, photographs, and conclusions distinct.
  • Project records — See which contract, change, installation, permit, invoice, payment, and warranty records a homeowner can verify.