How Long Do Asphalt Shingles Last in Los Angeles? — Seasonal Guide
How long an asphalt shingle roof really lasts in North Hollywood, as opposed to what the wrapper claims.
The number on the wrapper and the number you get are two different things. In North Hollywood, an asphalt shingle roof realistically gives eighteen to twenty-five years in this climate, which is short of the number printed on the wrapper, and the gap between that and the printed figure is explained by conditions the manufacturer never tested for.
What decides how long it lasts
A shingle roof is a water-shedding system, not a waterproof one. Every course relies on the course above it and on the underlayment beneath, so the covering and the layer under it fail together and have to be judged together. Asphalt ages from the top down. The granules on the surface are the sunscreen; once ultraviolet has stripped enough of them the mat underneath goes brittle, curls at the edges and starts to crack. Granules in the gutter are the earliest honest signal, and they show up years before a leak does.
Why the warranty number is not the answer
A warranty is a commercial document, not a life expectancy. It covers the product against manufacturing defect, and manufacturing defect is not what ends roofs here. The starter course and the drip edge are where cheap work shows first. A starter strip laid the wrong way round, or an eave with no metal under the first course, will wick water back into the fascia no matter how good the shingles above it are. Installation and ventilation decide the real number, and neither of them appears in the warranty document.
How North Hollywood changes the answer
North Hollywood takes the full inland summer with very little relief after dark, and the ultraviolet load on a south-facing slope here is as hard as anywhere in the county. Asphalt ages from the top down under it: once the granules have gone the mat underneath turns brittle and starts to crack. Mostly single-storey post-war housing with later additions, which puts a transition detail in the middle of the roof where two eras of workmanship meet.
What we look at on an inspection
- Granule loss across the field, and how much is sitting in the gutters
- Curling, cupping or cracking, particularly on the sun-facing slopes
- Nail placement and whether shingles have begun to back off the deck
- Sherman Oaks construction, and whether it is woven, closed-cut or metal-lined
- Flashing at every wall, chimney, skylight and pipe penetration
- Deck condition underfoot, checked by walking rather than by eye
- Attic ventilation, both intake at the eave and exhaust at the ridge
Common questions
Does a longer warranty mean a longer life?
Not by itself. Warranties cover manufacturing defects, and manufacturing defects are not what ends most roofs. Installation and ventilation decide the actual service life.
Can I extend the life of what I already have?
Often, yes. Clearing drainage, renewing sealant and fixing small failures early adds years, and it is far cheaper than the alternative.
The honest summary
Shingle roofs rarely fail suddenly. They give years of warning through granule loss and edge curl, and the difference between a planned replacement and an emergency one is usually whether anybody was looking. In North Hollywood the thing to watch is granule loss on the sun-facing slopes, and the junction where an addition meets the original roof.
Free inspection, drone photography where access is difficult, and a written estimate with deck repair priced per sheet. No obligation.
More on Shingle Roofing
- Choosing a Shingle for Southern California UV Load — Signs to WatchShingle Roofing
- Cool-Rated Shingles and Universal City Attic Heat — Signs to WatchShingle Roofing
- Nail Pops and What They Signal — Budget PlanningShingle Roofing
- Ventilation: The Leak That Is Not a Leak — The Short AnswerShingle Roofing