How long does a roof last in the Bay Area?

Asphalt shingles last 20 to 30 years. Tile roofs go 40 to 60 years. Metal roofs last 50 to 70 years. These numbers assume normal Bay Area conditions and regular maintenance. Coastal homes in fog-heavy areas may see shorter lifespans due to constant moisture exposure.

Can I put a new roof over the old one?

California building code allows a second layer of asphalt shingles over the first. But we rarely recommend it. The added weight stresses the structure, hides existing damage, and shortens the new roof lifespan by 20 to 25 percent. A full tear-off costs more upfront but performs better long-term.

How much does a roof replacement cost in the Bay Area?

For a typical 1,800 square foot home, expect $12,000 to $22,000 for asphalt shingles, $25,000 to $45,000 for tile, and $20,000 to $35,000 for metal. The exact cost depends on roof complexity, pitch, access difficulty, and the number of layers to remove. We provide free detailed estimates.

Does a new roof increase home value?

Yes. A new roof typically returns 60 to 70 percent of its cost in added home value. In competitive Bay Area markets like Palo Alto and Saratoga, a new roof can be the difference between a fast sale and a price reduction. Buyers here pay attention to inspection reports.

Blog / 7 Signs You Need a New Roof

7 Signs You Need a New Roof

Published April 2026 · 6 min read

Most homeowners do not think about their roof until water comes through the ceiling. By then, you are past "repair" territory and into full replacement. Here are seven signs to catch before that happens.

1. Your Roof Is Over 20 Years Old

Asphalt shingle roofs last 20 to 30 years in the Bay Area. If yours was installed in the early 2000s or before, it is approaching end of life regardless of how it looks from the ground.

Check your home improvement records or ask your inspector when the current roof was installed. If nobody knows, a professional can estimate its age based on shingle condition and wear patterns.

Homes in Sunnyvale and Santa Clara built in the 1990s housing boom are hitting this window right now. If that is your home, schedule an inspection soon.

2. Granules in Your Gutters

Asphalt shingles are coated with ceramic granules that protect against UV damage. As shingles age, these granules loosen and wash into your gutters.

Some granule loss is normal, especially on a new roof. But if you are finding handfuls of gritty, sand-like material in your gutters or at the bottom of your downspouts, your shingles are wearing out. Without those granules, the asphalt underneath deteriorates fast.

3. Shingles Are Curling or Buckling

Look at your roof from the street. Healthy shingles lay flat. If you see edges curling upward or shingles buckling in the middle, the material is failing.

Curling happens from heat cycling. The Bay Area's inland cities like Livermore and San Ramon see summer temperatures above 100 degrees. That kind of heat accelerates curling, especially on south-facing roof slopes.

A few curled shingles can be replaced individually. If the curling is widespread across multiple sections, the whole roof is aging out.

4. Daylight Through the Roof Boards

Go into your attic on a sunny day. Turn off the lights and look up. If you see pinpoints of light coming through the roof decking, water is getting through too.

Small light spots indicate gaps where shingles have shifted or where flashing has failed. This test also reveals soft spots in the decking. While you are up there, step carefully on the boards. They should feel solid. Spongy or soft areas mean moisture damage has already started.

5. Sagging Roof Deck

A roof should follow straight, clean lines. If you notice a dip, sag, or wave in your roofline, there is a structural problem underneath.

Sagging usually means the decking has been wet for a long time and is rotting. In severe cases, it means the rafters or trusses are compromised. This is not something to watch and wait on. A sagging roof is a safety issue that needs immediate professional assessment.

6. Moss and Dark Streaks

Moss is not just cosmetic. It holds moisture against your roof surface 24 hours a day. Over time, that constant moisture breaks down shingles and works its way under the edges, lifting them away from the deck.

Dark streaks are algae. They are less destructive than moss but signal that moisture is staying on your roof too long. Homes in fog belt areas like Pacifica, Daly City, and the San Francisco coast deal with this constantly.

Moss can be professionally removed if caught early. But if it has been growing for years and the shingles underneath are damaged, replacement is the better investment.

7. Rising Energy Bills

Your roof is part of your home's thermal envelope. When it fails, your attic heats up in summer and loses heat in winter. Your HVAC works harder, and your bills climb.

If your energy costs have been creeping up without a clear explanation, poor roof ventilation or insulation failure could be the cause. A professional inspection can check ventilation, insulation condition, and identify whether the roof is contributing to energy loss.

What to Do Next

If you are seeing two or more of these signs, get a professional opinion. A qualified roofer can tell you whether you need spot repairs or a full replacement. They can also estimate how much usable life your current roof has left.

Do not wait for a leak. Water damage to your attic, insulation, and ceilings costs thousands more than catching the problem early. A 30-minute inspection can save you $10,000 or more in preventable repairs.