Where our numbers come from.
Cost ranges, lifespan figures, and risk thresholds across the site are reconciled against the following primary references.
- International Residential Code (IRC), Chapter 9 — Roof AssembliesCode-required ventilation, underlayment, and flashing.
- NRCA Roofing ManualIndustry-standard installation specifications and service-life guidance.
- Asphalt Roofing Manufacturers Association (ARMA) Technical BulletinsAsphalt-shingle lifespan and failure modes.
- Metal Roofing Alliance — Buyer's GuideStanding-seam vs exposed-fastener service life and pricing.
- Insurance Information Institute (III) — Homeowners CoverageCovered perils, claim filing windows, and matching-shingle rules.
- HomeAdvisor & RSMeans National Cost Data (current year)Per-square installed cost ranges by material and region.
- FEMA P-804 — Wind Retrofit Guide for Existing BuildingsWind-speed damage thresholds and roof hardening.
Reviewed by licensed professionals
Only approved experts appear here. Their input supplements — never replaces — the deterministic decision rules.
- 2 contributionsCarlos MendezPrincipal Inspector · 22y exp.Licensed Roofing Contractor (TX #RCAT-21884), HAAG Certified InspectorResidential asphalt & metal systems, storm damage assessment
- 2 contributionsJanelle Park, P.E.Senior Building Envelope Engineer · 17y exp.Licensed Professional Engineer (CA #C-78321), Building Envelope SpecialistVentilation, moisture, and assembly performance
- 1 contributionRenee AlvarezSenior Claims Consultant · 14y exp.Licensed Public Adjuster (FL #W654321), 14 years carrier-side claimsHail, wind, and matching-shingle disputes
See methodology for how these sources and expert contributions are reconciled into the rules and ranges on each decision page.