Laying Out Unequally-Sloped Gables

AUGUST JLC 1998 Unequally-sloped gable roofs can be difficult to lay out, but the job is a lot easier if you have a proven method. Complicated mathematical calculations that use “inverse cotangents,” “secants,” and “adjacent angles” may be accurate, but they’re not easy to teach to novice tradespeople. As one carpenter I know put it, “I don’t want to learn any ‘friggonometry’ — I just want to cut rafters that fit.” For a layout method to earn a five-star rating, it must be accurate, fast, and easy to understand. Over the years, I’ve developed a layout method that works without having to bother with any heavy math. To use my method, you only need to