There are many components to installing a new roof that will last and won’t cause you problems down the road. One key component is installing gutter edge metal. By the way, this is also known as gutter edge flashing. A roof is supposed to get water off of your house and into the gutters without anything getting wet. If your roof doesn’t do this then you will have rot or mold somewhere on your home.
One big problem especially here in the Seattle area is water dripping behind the gutters and soaking the soffit or eave of a house. To prevent this, make sure your roofing contractor installs gutter edge metal under the felt paper (aka tar paper/underlayment). This should be 26 gauge steel with a baked on enamel coating that matches the color of the roofing being installed.
Here is an up-close of the gutter edge metal:
Here is the finished installation:
(note how the bottom edge of the roofing lines up very straight and neat. This goes a long ways in getting a beautifully installed roof.)
This is one of many steps to make sure water doesn’t get somewhere it isn’t supposed to. There are a lot of precautions to take here in Seattle that in other parts of the country wouldn’t be a big deal.