I have a question about a Woodpecker?

Alright, so I live in Fort Worth Texas, and although I'm out in the country Woodpeckers are very rare here, but we have the same Woodpecker that comes around frequently and he keeps pecking on my roof (along with our neighbors in the area, because I hear him)! Why the hell is he pecking on my roof? I thought they pecked on trees! Could he damage my roof? Also, how do I get him to stop? He sounds like a flipping jackhammer!