Hi i want to know if my builder is doing the right thing? I have a garage with felt roofing, and he is going to put the gutter on. What i want to know is that should the felt hang into the gutter or shall it be on top, my builder wants to put a piece of ply wood along the side and put felt over it which will be above the gutter is this a good idea or is dropping the felt into the gutter the proper way. Thanks.