Who will you choose for your roof maintenance in Portland Oregon?  Are you looking for the cheapest?  I was on the phone with a very bad customer the other day and he didnt understand anything but price.  I said if you want the cheapest price call Tweeker Roof Cleaning, they will come out and ruin your ro0f, maybe fall off and you will be liable because they are not licensed.  You end up saving money in the long run when you  have stuff done right by a licensed pro.