When you replace it, you need to be careful. Be very careful when lifting or removing the shingles so as to avoid damaging them. Another thing you can do is that as long as the Fascia board is removed from the roof you can inspect and have a look at the roof and the flashing. They can be prevented from rotting and damaging by taking extra care of the roof trim simply by regularly cleaning the gutters and preventing the water from accumulating at one part of the roof. Regular maintenance is the key to a long life for both the roof and the Fascia board trims.