Here’s a quick way to get a tight joint with 3/4-in. thick rake boards where they meet at the roof peak. Tack your two rake boards in place on the gable end, letting them run wild at the top, one over the other, to form an X. Mark your plumb cut. Set the proper depth on your saw and your shoe angle at 7°, and cut through both boards at the same time. You want the bevel in the top board to be an undercut, as shown, so lap the boards accordingly. This will be a function of which way the shoe on your saw tilts, and whether you are cutting from above on the ridge or from below on a scaffold or ladder. This trick also works on straight cuts to join long runs of fascia.
Matthew Giordano, Plymouth, MI