Curling and bucking of shingles
To know whether the shingles are curled, you need to look at the slopes of your home that have direct sunlight. If you take a look and you see that the shingles are curling and losing granules, it means that the shingles are past their life expectancy. It's also an indication that the roof is defective.
To determine if the roof is effective in its working, you should take a look at the valley of your house. If there are any missing shingles in this area, you most definitely need a new roof. This is because valleys are one of the most important areas of the roof; therefore, if their condition is compromised, it means that the roof will be leaking a lot.
Dark spots on the roof
If some areas of the roof are darker than others it means that your shingles have lost granules that protect them from being broken down by the sun. As a result of this the shingles are unprotected and weather extremely quickly.
To prevent water from leaking into the house, you should replace these shingles as soon as possible.
Excessive moss growth
Moss digs its roots into shingles and as the moss grows, the roots expand and as a consequence they pull shingles apart. When the roofing materials are apart, they are usually at high risk of being blown off by the wind.
Although, some moss can be cleaned off, it can sometimes be necessary to tear the roof off and replace it with a new one. To prevent the moss from growing in the future, you should spray the roof once a year with a moss killing chemical.
Chimney flashing
If your flashing consists of roof cement and tar, you need to replace it with a long term and water tight flashing. An ideal flashing to have is a metal flashing system.
Roof age
Most experts agree that a typical roof should have a lifespan of 20-25 years after which you should replace it. If your roof was installed over another layer or layers and it's older than 20 years, chances are that you need a new roof.
