What Is Flashing?
The flashing on your roof is essentially another shingle but because it is usually found at intersections where the component parts of your roof join they are prone to damage. Roof leaks caused by bad flashing are a common problem. Some roof leaks occur because the flashing was installed incorrectly, but it is also feasible that the flashing on your roof has been battered and bruised by the elements. Proper maintenance and early repair are both vital to preventing roof leaks caused by bad flashing.
Flashing installation
Flashing works in the same way your shingles do and should overlap the first shingle below. This is so that water can run down the outside of your roof and not drip down the inside. If your flashing is damaged or removed you face a real risk of your roof leaking.
Inspecting your flashing
Most roof leaks caused by bad flashing can be identified before they occur or at least early in their damaging lives. If you have a roof leak either check the flashing yourself or employ a professional roofing contractor to look it over properly. The first step is to look for areas of the flashing that have pulled away from the roof. This will cause cracks in the roof; cracks that water can get through and cause damage to your home inside.
Checking your own roof flashing
If the roofing cement has become damaged or eroded it is vital to replace it because this will likely be the cause for flashing coming away from the roof and eventually causing a leak. If any of the flashing itself is damaged you should also replace this. Flashing can be made from a number of different materials ranging from sheet metals to rubber. One of the most popular choices at present is aluminum because it is durable, malleable and affordable. If you are in any doubt as to how to apply the roofing cement and flashing yourself then you should pay someone to do this for you because poorly applied flashing will easily lead to roof leaks.
The types of roof flashing
There are two types of flashing. If you have open valley flashing, the type you can clearly see when looking at the valley where roofs meet, you can usually check for any damage very easily but if you have closed valley flashing it is virtually impossible to check its condition for yourself. Regardless of the type of flashing you have on your roof and whether you believe you can check it yourself you should consider using a professional roofing contractor to look at it. This way you can be certain you're doing everything possible to prevent roof leaks caused by bad flashing.
December, 2004
by Steven Briesemeister. Reprinted courtesy of Roofer 911.com, roofing contractor serving Long Island, Queens, Brooklyn, NY and northern Virginia.