How old is the roof?
A quality older organic-based asphalt shingle roof can be expected to last between 20 and 25 years. The new generation of fiberglass constructed shingles should last between 40 and 50 years. Some factors that affect the lifespan are ventilation, whether the roof was installed over one or more existing roofing layers, the weather and its proximity to trees.
Curling or clawing shingles
Excessive heat and aging can cause your shingles to curl upward, or claw downward. These shingles are highly susceptible to wind uplift and ice damage, can break easily and lose tab edges.
Broken or missing shingles
The most common causes of shingle damage are excessive wind and physical damage. Trees can help break the wind, providing vital protection in windy areas, but branches that tear loose can also do serious damage. Missing or broken shingles weaken the roofs ability to shed water and can become an entry point for water.
Shingles that have buckled result in waved distortions that will typically run vertically up the roof slope. Buckled shingles are very susceptible to both wind and ice damage, and can be torn off in a storm. Deterioration with age, or being subjected to a lot of very wet weather, can result in shingles buckling, as can improper installation of underlayment when the roof was installed.
Missing granules and bare spots
Aging or physical damage can lead to bare spots and loss of granules. Also, lack of eavestrough, improperly placed downspouts, or poorly designed valley drainage can result in a continuous waterfall effect that can wash granules away over time.
When the protective granules of the shingles are lost, they begin to harden from sun exposure. Granule loss on a roof system can lead to shingle decay, accelerate aging and present an entry point for water. You can check for areas where the granule surface appears thin, or there is an inconsistent or darker colour, as well as the gutters. If you’re seeing a buildup of “sand” in the gutters, that’s a bad sign.
Moisture, rot and mould
Dark, dirty-looking areas on the roof could indicate that your roof is under attack. Mould, algae, fungi and bacteria can grow very quickly, within only 24 to 48 hours of a water-related problem. If you do come across these symptoms, note that the wet spot may not be directly below a faulty shingle or flashing; water can travel down to its lowest point before it drips.
If you notice a spongy feel or bounce when you walk across the roof, the underlying decking could be weekened from moisture. Chances are, there will be some accompanying moisture in the insulation as well. While you’re in the attic, you’ll want to check for signs of water damage, and any daylight showing between roof boards.
Damaged or improperly installed flashings
Your roof is not only subjected to the elements, but also ongoing expansion and contraction as it’s heated and cooled during each daily cycle. The flashings around chimneys, stacks, wall details, rakes, eaves, valleys and skylights are subject to separation over time. Caulking can dry out and fasteners may become loose, allowing water to find its way underneath.
Eaves and overhangs
Inspect the eaves and overhangs for damage that could indicate there’s water leakage. If you find warpage, swelling, decay, mould or paint blistering, you’ll want to track down the source of the problem.
Excessive energy costs
Insufficient attic ventilation, compromised insulation and a failing roof system can drive energy costs up. Where the cost of heating a home is unusually high, replacing a roof can sometimes make sense, even if it’s still keeping the weather out.
If you notice any of the conditions described above, your roof should be inspected by a qualified roofer. If the damage is localized, you may only require a quick repair. It’s important to get on it immediately, before a small problem becomes a large one.
If shingle damage like granule loss or buckling are evident in a large area, or across the roof, the shingles may be approaching the end of their useable life.