Tile roofs: relay, not replace?
Clay and concrete tile can last 100-plus years, per InterNACHI, but the underlayment under it wears out far sooner. A common South Bay fix is to remove the tiles, install new underlayment and flashing, and relay the sound tiles. The code doesn't allow a new roof over existing tile (CRC R908).
Shingle tracts
Homes from the 1970s and 80s in San Jose, Sunnyvale and Santa Clara are often on their second roof. Summer heat in climate zone 4 bakes shingles, so look for:
- bald patches and heavy granules in gutters,
- curled or cracked tabs on south and west slopes,
- brittle shingles that crack when lifted.
Eichler and other flat roofs
Water that sits for days, blisters, and split seams around skylights are signs the membrane is failing. A partial patch rarely lasts on an old membrane.
The rule that changes with replacement
Replacing more than half the roof brings in the 2025 cool-roof requirement in climate zone 4 (CEC). Repairs generally don't.
Every roofer we work with is licensed, insured and highly reviewed by Bay Area homeowners.
Get a free replacement quoteFrequently asked questions
Can I keep my tile and replace only the underlayment?
Often yes, if the tiles are sound. It's a common South Bay approach.
Does a repair require a cool roof?
The cool-roof rule applies when more than half the roof is replaced.
Can I put a new roof over my tile?
No. The California Residential Code doesn't allow recovering over tile.
Sources
- InterNACHI: life expectancy of roofing materials
- California Residential Code R908 (reroofing)
- CEC 2025 Single-Family Compliance Manual, ch. 9
Sources reviewed November 11, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.