When you check your shingles for damage after a storm or as a routine home maintenance task, don't forget to look at the metal flashing around your roof and pipe vents. Even if you check your roof from the ground, you can look at the flashing for lifted areas or signs of rust discoloration.
If you see something suspicious with the flashing, call a residential roofer to take a closer look and make repairs if they're needed. Here is a look at the purpose of metal flashing, how it leads to a roof leak, and the repairs a roofer might need to make.
Why Your Roof Has Metal Flashing
It may seem odd that your roof has metal parts to it, but flashing is necessary around things like chimneys and vents, as well as in valleys, to prevent roof leaks. Shingles protect your roof from leaks because they overlap each other so rain rolls right off them. However, in valleys and around the chimney, the shingles can't overlap as well, especially next to the chimney or pipe.
The flashing is put in place to keep water from reaching the deck. The flashing fits snugly against the chimney or pipe, and it is secured in place so water rolls down it rather than seeping on the wood deck and causing water damage.
Why Flashing Starts Leaking
Since flashing is made of metal, it can rust as the years pass. Rust eats holes through metal, and the holes allow water to drip through and cause a roof leak. Flashing can sometimes work loose if the adhesive used to hold it down gets old and ineffective. If the edges of the flashing lift up, rain might leak through.
How A Roofer Makes Repairs
If the flashing is rusted, the roofer will probably pull it off and replace it with new flashing. Some flashing comes already formed, but other times the roofer forms the flashing on the spot from a small sheet of metal.
If the flashing is just loose and it doesn't have any damage, the roofer might just put roofing adhesive under the metal so it is secured to the roof again. Depending on where the flashing is used, it may be overlapped with shingles. The roofer might have to remove several of the shingles, or at least lift them, so the hidden part of the flashing can be seen and so the flashing can be removed if necessary.
Since metal can last a long time, you might never have a problem with your roof flashing. However, leaks around flashing are common, so you should always look the flashing over as best as you can so you spot problems before a roof leak and water damage develop. Call a residential roofer for additional advice.