I'm removing a header board which is attached to a home at about 7' high. The board itself is a 2x5 and is 16' long. I require a saw or cutter that will allow me saw through it in a straight away fashion. This way I can remove it in sections. I tried my saw zaw but it didn't work well. I also have a ROTOZIP which does allow me to cut through the header board but the bit isn't long enough and I cannot locate longer bits. Can someone recommend a tool?