I told my carpenter I wanted to use screws and washers and he showed me these things he uses for roofing. They're kind of along the same idea, but they are a slightly threaded nail with a built in plastic washer, but it's all one piece and very easy to use. I asked where I could find them in case I need to repair, etc, and he said in roofing department of Home Depot. The one piece design makes it much quicker to use than actual separate washers.