Perfect Roof Rafters
Focus your efforts on the pattern rafter, and the rest of the roof falls into place easily.
Synopsis: Taking lessons learned from timber framing, Sam Koerber uses chalklines, a framing square, and knife lines to carefully lay out pattern rafters, ensuring that his roof rafters line up nicely without the need to trim and shim them once in place. Online Extra: Behind the Scenes: How Fine Homebuilding Articles are Captured.
My process for framing a roof starts the same as anybody else’s: laying out and cutting a pattern rafter, which I then use as a template to cut the rest of the rafters to make up the roof frame. Just like everybody else, I choose a flat, straight, and dry piece of stock for the pattern rafter, which I crown so that any natural arch is facing up when installed, and I set the piece atop a pair of sturdy sawhorses that are at a comfortable working height. From there, I get a bit more fussy than most with the layout, which I believe pays off big time in terms of the quality of my frames.
Lessons learned from timber framing
Most of the time, framers use a 6-in. rafter square to lay out the plumb and seat cuts of a rafter. But two practices on recent jobs have convinced me to change up my approach. First, I’ve begun to incorporate components of timber framing into otherwise stick-framed houses; second, I do exposed rafter tails on most builds. Timber framing has taught me to use chalklines and a framing square for accurate layout on boards that don’t have a reliable straight edge for reference. It also has taught me that a knife makes crisper layout lines than a pencil. Those same layout techniques have improved the consistency of the exposed rafter tails, ensuring that they not only look crisp and uniform but that they line up…