By Best Roofing Pasadena — Licensed Contractor | Pasadena, CA
After inspecting hundreds of leaking roofs across Pasadena, San Marino, Arcadia, and Altadena, we see the same causes come up over and over. Here are the 8 most common reasons Pasadena roofs leak.
1. Failed Pipe Boot Seals
Plumbing vent pipes exit through your roof and are sealed with a rubber boot collar that lasts 10–15 years before cracking. Replacement cost: $200–$400.
2. Damaged or Missing Shingles
Pasadena’s Santa Ana winds strip shingles off roofs, especially in foothill neighborhoods like Altadena. A single missing shingle exposes the underlayment to direct rainfall.
3. Cracked or Broken Roof Tiles
Pasadena’s Spanish and Mediterranean homes have clay or concrete tile roofs that crack from thermal expansion, foot traffic during HVAC servicing, or hail impact.
4. Failed Chimney Flashing
The metal flashing where your chimney meets the roof is one of the highest-risk leak points on any Pasadena home. It expands and contracts with temperature changes and eventually the sealant cracks.
5. Valley Leaks
Roof valleys channel the highest volume of water on your roof. If the valley liner is inadequate or improperly installed, concentrated water flow finds its way under shingles or tiles.
6. Skylights and Penetrations
Any penetration through the roof surface is a potential leak point. Skylights, solar panel mounts, and attic vents all require proper flashing and sealing that degrades over time.
7. Clogged Gutters
When gutters clog with debris, water overflows and backs up under the roof edge, causing rot in the fascia board and eventually water into the attic.
8. Aging Underlayment
The waterproofing layer beneath your tiles or shingles has a lifespan of 20–30 years. When it fails, even intact tiles above won’t keep water out. Common on Pasadena tile roofs from the 1980s and 1990s.
When to Call a Professional
If you notice any ceiling staining or visible damage after a storm, call a licensed Pasadena roofer before the next rain. Best Roofing Pasadena provides free inspections across Pasadena CA. Call (626) 645-9292.