What is the '50% rule' for California roofs?

California Title 24 Part 6 mandates that if more than 50% of a roof area is replaced or repaired in any 12-month period, the entire roof must meet current Title 24 cool-roof requirements. This means a full reroof with CF1R + CF2R energy compliance documentation. The 50% rule is what stops contractors from doing partial replacements to dodge cool-roof code — it's enforced at municipal building permit inspection.

How can I tell if my California roof needs full replacement?

Eight signs: (1) age over 20 years, (2) granule loss visible on shingles (look in gutters), (3) curling, blistering, or buckling shingles, (4) multiple leaks in different locations, (5) sagging roof deck, (6) daylight visible through attic boards, (7) flashings deteriorated at chimneys/valleys/vents, (8) repeated repair failures at the same spot. Any 3+ of these usually means replace. A free 21-point inspection confirms.

Will insurance pay for full replacement if only part of my roof is damaged?

Usually yes if damage exceeds 30% of the roof and color match isn't possible (existing shingle discontinued). Most major carriers in California follow a similar rule: significant damage that makes matching impossible triggers full replacement coverage. Some policies (especially newer ones) include 'matching' language explicitly. TMC provides a written inspection report with photos that you can share with your carrier; we do not file or manage claims on your behalf.

How long should I expect a quality roof repair to last?

A quality targeted repair on a sound roof should last 5–15 years. The variable is the rest of the roof's age: if you're repairing a 5-year-old roof, the repair will likely outlast that age difference. If you're repairing a 20-year-old roof, the repair is buying time before replacement is inevitable. TMC's workmanship warranty on repairs runs 1–5 years depending on the work.

Is it cheaper to repair multiple times vs replace once?

Usually no, once you're past 2–3 repairs at $1,500+ each. The math: 3 repairs over 5 years at $2,000 each = $6,000, and you still have the old roof underneath that's failing in more places. Versus replacement: $15,000–$28,000+ one time and you have a new warranty starting from year 0. Past the third repair, replacement is almost always cheaper per year of remaining roof life.

Comparison · The 50% rule · Insurance triggers · Age math

Roof Repair vs Replace: 8 Signs You're Past Repair

How to know whether you should repair or replace your roof. The 50% rule, age math, water-damage triggers, and what insurance typically covers. By a licensed C39 contractor.

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Choose roof repair when damage is under 30% of the roof, the underlying decking is sound, the roof is under 15 years old, and the existing material is still in production. Choose full replacement when damage exceeds 30–50% of the roof, the roof is over 20 years old, the existing material has been discontinued (color match impossible), or you're already over the Title 24 50% reroof trigger which mandates a full replacement at California permit. When in doubt, get a free 21-point inspection — it's the only way to know exactly where you stand.

The Verdict

Which one wins?

Use the 50% rule: when you're over 50% damaged OR over 50% of expected lifespan, replacement is almost always the right financial call. Under those thresholds, targeted repair is usually fine.

Choose Roof Repair when…

Damage is localized (single area, single cause), roof age is under 15 years, underlying deck is sound, and the existing material is still in production (color match available). Repair preserves remaining lifespan.

Choose Roof Replacement when…

Damage exceeds 30% of the roof, multiple repair attempts have failed, the roof is past 20 years old, the existing material is discontinued, or any combination triggers Title 24's 50% reroof rule.

Feature-by-feature

Roof Repair vs Roof Replacement — full comparison

Feature	ARoof Repair	BRoof Replacement
Typical cost range	$300–$4,000+ Winner: A	$15,000–$50,000+
Roof age threshold	Under 15 years	Over 20 years usually	Tie
Damage percentage threshold	Under 30%	Over 50% triggers Title 24 full reroof in CA	Tie
Warranty restart	No — original warranty continues	Yes — full new warranty (e.g., Golden Pledge 25/50) Winner: B
Underlayment refresh	No — same old underlayment stays	Yes — new underlayment installed Winner: B
Title 24 paperwork required	No (if under 50%)	Yes — CF1R + CF2R filed	Tie
Permit required	Usually no	Yes	Tie
Insurance claim payout potential	Partial (covers repair cost)	Full (covers replacement) Winner: B
Resale impact	Neutral if disclosed	Adds value with new warranty transfer Winner: B
Time to complete	Hours to 1 day Winner: A	1–7 working days
Tear-off required	No — targeted repair only	Yes (or overlay if code permits)	Tie

Context: what the numbers don't show

The single most important variable in repair-vs-replace is California's Title 24 50% reroof rule. Once a roof project replaces more than 50% of the roof area in any 12-month period, it triggers a full reroof — meaning the entire roof must be brought up to current Title 24 cool-roof code with CF1R + CF2R documentation. This can effectively force a full replacement on what started as a repair.
Repair makes economic sense when the damage is localized (single leak, missing shingles from a wind event, isolated tile slippage) and the underlying decking is sound. A quality repair can extend the life of a 10-year-old roof by another 10+ years.
Replacement becomes inevitable when: (1) the roof is over 20 years old and showing multiple failure points, (2) the underlying decking is rotted in multiple areas, (3) the existing roofing material has been discontinued and color match isn't possible, (4) repeated repair attempts have failed at the same spot — usually indicating an underlying flashing or design issue.
Insurance carriers in California generally support repair for storm damage under 30% of the roof area. Once damage exceeds 30%, carriers commonly approve full replacement claims. The threshold varies by carrier and policy — State Farm, Allstate, Farmers, and Mercury all have slightly different rules. TMC provides a thorough written inspection report you can share with your carrier when filing; we do not file or manage claims on a homeowner's behalf.
There's a financial trap with repair: if you spend $3,000 on a repair and the roof needs full replacement within 5 years anyway, you've effectively added $3,000 to your replacement cost. A good inspector tells you when repair is throwing good money after bad.

Roof Repair vs Roof Replacement — common questions

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