How our decision rules are derived.

Decision rules

Each rule is expressed as IF condition THEN action. Conditions use measurable thresholds (age in years, damage percent of surface, repair-to-replacement cost ratio). Actions resolve to one of: repair, replace, tarp, inspect, file claim.

Cost ranges

Cost ranges are national US averages from current contractor estimates, normalized to a 2,000 sq ft home with 6/12 pitch and one tear-off layer. Regional multipliers (coastal, mountain, high cost-of-living metros) add 15–35%.

Risk thresholds

Severity tiers (Low / Moderate / High / Critical) follow contractor and adjuster practice: Low = cosmetic; Moderate = act within 7 days; High = act within 48 hours; Critical = tarp now, replace within 30 days.

Material lifespans

Lifespan figures use manufacturer-warranted service life with a 15% real-world deduction for ventilation, climate, and installation quality.

Expert review methodology

Licensed roofing contractors, building-envelope engineers, and public adjusters are invited to submit evidence supporting, refining, or dissenting from our decision rules. Each contributor's credentials and license are verified against state databases before approval. Submissions enter a pending queue and become visible on a decision page only after editorial approval.

When approved experts disagree, we surface the range rather than picking a single voice — for example, "reviewed experts generally recommend replacement between 18–22 years depending on ventilation, climate, and extent of deterioration." Expert input informs and validates the deterministic decision rules; it does not override them. Real-world performance data (Search Console, call telemetry, post-decision outcomes) sits above expert consensus in the truth hierarchy.

Review cadence

Cost ranges are reviewed quarterly. Decision rules are reviewed annually or whenever IRC code or major insurance-carrier guidance changes. See sources for primary references.