Over 
Call for FREE ESTIMATE 
Curling shingles on your roof may mean damage to your roofing system might have begun. you can hardly overlook the risk that damaged or curled shingles pose, so the problem should be addressed as soon as possible. Take note of the following factors that contribute to the deterioration of roofing shingles:
Life span matters
Harsh weather conditions take its toll on the shingles and cause them to curl up before their expected life span. Note that improper storage and installation of the materials affect the condition of the shingles before installation. As improper or defective installation of shingles can cause premature curling, especially when constantly exposed to moisture, it is important that roof repair in Sunnyvale must not simply be entrusted to the first name that comes out of your search.
When brand name comes into play
Brand names, with a long and prominent history behind each one, equates with high quality and trustworthiness, and established roofing companies like Shelton Roofing understand how to live up to their client’s standards. Still, homeowners need to be vigilant because even brand name materials are not entirely immune to weather assaults and may, over time, curl and get damaged.
As quoted from Ehow.com, curling shingles usually follow a pattern:
Curling can develop on the corner, in the middle or across the entire shingle. “Fishmouthed” roof shingles are those that curl in the middle of the shingle as a result of moisture buildup or ventilation problems. Walking across the roof to remove ice or conduct other repairs is a cause of shingle curling in the corners of shingles, as is extreme heat or cold. Poor or defective interior insulation, flashing or other roofing materials can cause curling across the bottom edge of a shingle.
Read the signs right
According to experts, curled shingles can also root from inadequate ventilation and poor building structure. Once you see obvious signs of deterioration, take action. Remember that curled shingles predispose the roof to further damage and the only way to minimize the problem is to have it fixed by a reputable Sunnyvale roofing contractor as soon as possible.
The DIY attitude in home repair may save you a lot of money, but it cannot guarantee quality craftsmanship. To get the best professional-grade work possible, seek out the services of a trusted Sunnyvale roofing contractor like Shelton Roofing. They offer roofing services in Sunnyvale, Menlo Park, and Palo Alto.
From eHow, What Causes Roof Shingles to Curl?