Degraded shingles can curl, loose their surface gravel protection, and eventually break apart completely. Knowing the causes of degradation can help you spot issues and take steps to repair the roof.
1. Hail Damage
Hail storms cause roof damage that isn't always immediately visible. The hail strikes compress the shingles and knock off the weatherproofing granules. This results in increased UV damage and moisture absorption, which speeds up the deterioration of the shingles. You may be able to spot hail damage by checking your shingles for shiny spots or the gutters for the gravel granules that come off the damaged shingles.
2. Flashing Failure
Flashing seals rooftop penetrations, like the chimney and vent stacks, to the shingles so that water doesn't leak at the joints. If the flashing begins to fail, such as by developing pinprick leaks or peeling up, water can seep beneath it. This water can then leak under the shingles through the joint, causing them to deteriorate from the underside. You may not notice the issue until there is an interior leak or the shingles are so damaged they pull up.
3. Roof Moss
Moss on the roof can look charming, but it acts like a sponge that absorbs moisture from the air, dew, and rain. This moisture sits right up against the shingle, where over time it can begin to break down the surface waterproofing. The shingles will eventually begin to deteriorate, which means they will begin to develop leaks and the edges will curl up and break the watertight seal.
4. Poor Ventilation
If a roof doesn't ventilate the trapped moisture and heat in the attic properly, it can actually lead to shingle damages. The trapped heat raises the temperature of the shingles, and the underside is not typically designed for high heat gain. Moisture in the attic can also be absorbed by the roof sheathing panels, which can then be transferred to the underside of the shingles. Poorly ventilated roofs are more prone to ice dams, as well, which can damage and deteriorate shingles.
5. Sun Exposure
Although shingles are made to be exposed to the elements, including the sun, over time the constant barrage of UV light will causes the shingles to deteriorate and break down. This issue is worse in some climates where long, clear summer weather maximizes UV levels. You can slow the process down by choosing UV resistant shingles. There are also treatments that can be applied to help prolong the UV resistance.
Contact a residential roofing repair service such as New Roof if you suspect that shingle degradation is affecting your roof.