Should You Repair or Replace Your Roof?
A practical way to decide, plus what the often-quoted "25% rule" actually is and which California rules apply instead.
Quick decision guide
| Situation | Usually |
|---|---|
| One leak or one damaged area; roof otherwise sound | Repair |
| A few cracked tiles from foot traffic | Repair |
| Tile roof 20–30 years old, leaking in several spots, tiles intact | Lift and relay (new underlayment) |
| Shingles curling, cracking or bald across most of the roof | Replace |
| Soft or sagging deck in several areas | Replace |
| Planning solar and the roof is older | Consider replacing first |
| Selling soon, roof has some life left | Inspect, repair, document |
Roof age and lifespan
InterNACHI's life-expectancy chart lists architectural asphalt shingles at about 30 years and 3-tab at about 20, and notes that hot climates reduce asphalt life (InterNACHI). Tile is different: the tiles can last 100+ years, but standard underlayment has a useful life of about 25 years (AWS Consultants). Age alone isn't a reason to replace, but an older roof with spreading problems usually is.
The "25% rule" explained
The rule people search for comes from the Florida Building Code: no more than 25% of a roof could be repaired, replaced or recovered in any 12-month period unless the entire roof was replaced to current code (Florida Roofing / FRSA). Florida narrowed it in 2022 so newer roofs only need the damaged portion repaired.
In California, the triggers are different:
- Fire rating: when more than 50% of the total roof area is replaced within one year, the whole roof covering must meet the fire-rating class required for its area (Health & Safety Code §13132.7).
- Cool roofs: in climate zone 12 (East Contra Costa), steep-slope reroofs replacing more than 50% of the roof or more than 2,000 sq ft, whichever is less, generally need a cool-roof-rated product, with exceptions including heavy roofs such as most concrete tile (Energy Code Ace).
- Permits: re-roofing generally needs a permit in East County cities and in unincorporated Contra Costa County (Contra Costa County).
Some California cities add local amendments, so confirm with your building department or contractor.
Questions that tip the decision
- Is the damage in one area, or showing up across the roof?
- How old is the roof, and how much life does an inspection say it has?
- On tile: is it the tiles or the underlayment that's failing?
- Will a repair now just delay a replacement by a year or two?
- Are you adding solar, selling, or staying long term?
- What do two written bids say, for repair and for replacement?
Sources
- InterNACHI — Standard Estimated Life Expectancy Chart (accessed Oct 2026)
- AWS Consultants — Lifetime Tile Roofs: Fact or Fiction (C. Brown, RCI) (May 2012)
- Florida Roofing (FRSA) — Florida Building Code's 25 Percent Rule (Jun 21, 2018)
- California Health & Safety Code §13132.7 (accessed Oct 2026)
- Energy Code Ace — Roof Alterations (Title 24) (accessed Oct 2026)
- Contra Costa County — Residential Re-Roof Requirements (2022 codes)
Repair vs replace questions
What is the 25% rule for roofing?
It's a Florida Building Code provision: historically, no more than 25% of a roof could be repaired or replaced in a 12-month period unless the whole roof was brought up to current code. Florida narrowed it in 2022 for newer roofs. California has no statewide equivalent.
Does California have a rule like the 25% rule?
Not the same one. California Health & Safety Code §13132.7 requires the entire roof covering to meet the fire rating for its area when more than 50% of the roof is replaced within one year. Title 24's cool-roof rules can also apply to steep-slope reroofs that replace more than 50% of the roof or more than 2,000 sq ft. A few cities have local amendments, so check with your building department.
How old is too old for a roof?
InterNACHI's chart lists architectural asphalt shingles at about 30 years and notes hot climates shorten asphalt life. Tile itself can last far longer, but its underlayment often needs replacement after roughly 20–30 years.
Request a roofing estimate
Tell us what's going on with your roof. We pass your request to an independent local roofing contractor serving East Contra Costa, who contacts you to inspect and quote. There's no cost to send a request.
- Takes about a minute
- No obligation to hire
- Ask for a written, itemized estimate