Asphalt shingle roofs don't usually fail overnight — they decline over a span of years. The trick is recognizing the difference between a roof that has another 5 good years and a roof that needs to be replaced before next winter. Repair the wrong roof at the wrong time and you've thrown money at a system that's already past saving.
Here are the five warning signs that mean it's replacement time, not repair time, on a residential asphalt shingle roof.
1. Granules in the Gutters
Asphalt shingles are coated in mineral granules that protect the asphalt below from UV. As the roof ages, those granules wash off into the gutters with every rain. A handful is normal. A heavy layer covering the bottom of the gutter — especially after just a few months — means the shingles are nearing the end of their UV protection and the asphalt underneath will start cracking soon.
2. Curling, Cupping, or Clawing Shingles
Healthy shingles lie flat against the roof. Aged shingles curl up at the edges (cupping) or in the centre (clawing). Once curling starts, wind catches under the shingles and rips them off in storms — and water finds its way under the curl in heavy rain.
A few curled shingles can be replaced individually. Widespread curling across multiple slopes is a replacement signal — the whole field is failing at once.
3. Bare Patches and Bald Spots
If you can see the dark asphalt mat through worn-away granules — particularly on south-facing slopes that get the most sun — you're looking at shingles that have lost their UV protection entirely. Once the asphalt is exposed, it cracks within a few BC winters.
4. Daylight Through the Roof Deck
Go into the attic on a sunny day with the lights off. Any pinholes of daylight through the roof deck mean water can get in. This usually shows up around vents, chimneys, and at the ridge — and it usually means the underlayment has failed too, which is a tear-off-and-replace job, not a patch.
5. Age
BC asphalt shingles last:
- 3-tab shingles: 15–20 years on the BC coast
- Architectural (laminated) shingles: 25–30 years
If your roof is in or past those windows, plan replacement before a leak forces your hand. Pre-emptive replacement is roughly 30–40% cheaper than emergency replacement after interior water damage.
Repair or Replace? The 30% Rule
A practical rule of thumb: if more than 30% of the field is showing the warning signs above, replace the whole roof. Spot repairs on a roof that's broadly failing usually buy you 12–24 months at most, and the dollars are better spent on the new roof you'll need anyway.
What to Expect From a Replacement
- Tear-off: existing shingles and (usually) underlayment removed to the deck
- Deck inspection: rotten plywood replaced (usually 1–3 sheets on a typical home)
- New underlayment: synthetic on the field, ice-and-water shield at eaves and valleys
- New flashings: all roof penetrations re-flashed
- New shingles: typically architectural with a 30-year warranty
- New ridge cap, vents, and drip edge
Typical BC residential replacement runs $8,000–$18,000 depending on size, slope, complexity, and material choice. Most jobs complete in 1–3 days.
The Bottom Line
Watch for granule loss, curling, bald patches, and daylight through the deck. If you see two or more of those signs — or your roof is past its rated lifespan — it's time to budget for a replacement. Repairing a dying roof is the most expensive way to delay the inevitable.