Timber Framer's Rafter Gauges are a pair of stainless steel stair gauges made for laying out rafters on a framing square. Clamp one at your rise and one at your run, and every rafter in the frame, or every stringer in a set of stairs, lays out at the same angle.
Nut-style stair gauges sit proud of the square, so the mark never quite meets the edge of the timber. At 12 in 12 the error cancels out. The shallower the pitch, the bigger it gets, and the fix is to loosen, pivot and reset every time. Ours land on the mark the first time. Teeth on the end seat right into a score line, so you can carry a line onto the next face of a big timber without the gauge covering it.
Each gauge is machined from stainless steel, so it won't rust or dent easily, and chamfered on every edge so it won't bite your hands. A knurled brass thumbscrew locks it to the square. They come as a pair in a fitted box.
Shelter has been tracking down tools good enough for our students since 1974. This time the stair gauge we relied on had gone out of production, so we made our own. It took two years and four prototypes, each one tested in our timber frame shop. Are these overbuilt? Absolutely. Do most people need these? Absolutely not. Most off-the-shelf stair gauges do a fine job. We made them selfishly, for one very specific job: accurate timber frame rafter layout. Made in the USA.
