Many homes in the Seattle area were built with an internal gutter system otherwise known as an internal gutter system. The internal gutter system is made up of a gutter lining material, a metal drop scupper and a fascia board that has been installed more than two inches above the roof deck. The common gutter lining is either a hot mop built up roofing, a torch down membrane or a PVC/TPO single ply. The built-up and torch down roofing will last about as long as the average twenty year steep slope roof and the PVC/TPO liners, if installed correctly, could last as long as the thirty year steep slope roof. If you have a roof that is expected to last between twenty and thirty years you can then expect to replace the gutters when you have the roof changed.
What about for those who installed a roof that is expected to last forty years or more? If your roofing contractor was really looking out for you then he would have suggested installing a continuous external gutter system. Those roofs that are expected to last more than forty years will out live the internal gutters leaving you to a very expensive gutter replacement bill or worse yet, replacing the roof before the it’s time, which defeats the purpose of why you chose the roof that will last a lifetime.
There are many reasons why a continuous external gutter makes sense. 1) External gutters are made of aluminum or steel and with proper maintenance these gutters can last as long as the high life expectant roof you choose. 2) When an internal gutter fails it will usually cause damage to the structure of your home leaving you with an expensive repair bill. 3) External gutters are separate from your roof and don’t need to be changed when you change your roof, or vise versa. 4) External gutters cost less to install especially if you compare the cost over time against the internal gutter. 5) If an external gutter gets full of debris and clogs in many cases it will not cause a leak into your home whereas an internal gutter can.
The next time you choose a roof that is expected to last more then twenty years and you have an internal gutter system you might want to consider switching to an external gutter system. The cost will be slightly higher than just going back to the internal gutters but the outcome will pay for itself over time.