When it comes to your roofline, the fascia boards are often the first thing to go. The fascia boards are very vulnerable because they are directly exposed to the sun and rain without hardly any protection. Furthermore, some fascia boards have the gutter hanging from them. This puts more pressure and weight on the board and can cause it to sag. Making small repairs to your fascia board is possible, but it is often easier to just remove the entire board and replace it. This article explains how to do this.
Remove the Damaged Board
The seams between individual fascia pieces will usually be caulked or glued together. First you need to find this seam. In some cases, this line will be very obvious and easy to see. If the installer did a good job joining the boards and the seams aren't damaged, you just need to look closely. Once you find the seam, you need to separate the boards. A utility knife usually does the trick. You don't need to cut through the entire chunk of glue. Instead, just score it so the board will snap off in that spot. Usually, the job is easiest if you just hit the backside of the fascia boards with a hammer.
Prepare the Eaves
Before you can attach the new fascia board, you need to prep the eaves. First, make sure there is no serious damage to the eaves. You need to make sure they can still hold the weight of the fascia board. Depending on the design of your roof, replacing eave supports can be very easy or very hard. If you can tell that you eaves need to be replaced, don't risk it. Call in a professional roofer.
Attaching the New Fascia Board
Attaching the new fascia board is much easier if you have a pneumatic nail gun. Trying to nail it up by hand is going to be hard unless you have experience framing homes. Don't try to make the fascia level; just make sure it is tight and flush with roofline. You don't want any gaps in between the roofing material and the fascia boards. Once the new board is installed you can either paint or stain it. You will need to repaint the entire fascia, not just the boards that you replaced.
Visit a site like http://www.allamericanroofing.com to learn about roofing services you may need if you know that more than your fascia boards are damaged.