The Easiest Way to Cut Rafters (No Math Required)

If you’re building a shed roof, how do you cut perfect rafters and birdsmouth joints without calculating angles? In this video, I show a simple layout method for cutting rafters using only your roof’s rise and run — no trigonometry, no angle charts, and no math formulas. This technique works for a 6/12 pitch (and other roof pitches) and allows you to cut identical rafters with clean, flat birdsmouth seats every time. You’ll learn: • How to lay out rafters using peak height and run • How to mark and cut accurate birdsmouth joints • How to avoid cutting past the heel (a common framing mistake) • How to set up a cutting jig to produce identical rafters • How to assemble rafter pairs with gussets • How to frame a shed roof accurately and repeatably This method is ideal for shed building, small cabin framing, workshop roofs, and DIY roof construction. If you’ve struggled with rafter angles, framing math, or getting birdsmouth cuts to sit flat on the top plate, this approach simplifies the process. Tools used for this shed build are linked below (Amazon affiliate links help support the channel). 🛠️Metabo HPT Framing Nailer https://amzn.to/3Zlzllo 🛠️2000 Count 21 Degree Framing Nails, 2-1/2" x 0.120" https://amzn.to/3NWavGs 🛠️Flexzilla Air Hose, 3/8 in. x 50 ft https://amzn.to/3M6hw6U 🛠️7 Inch Speed Square https://amzn.to/3ZQJXsC 🛠️WORKPRO 6" Clamps https://amzn.to/3Zjzl5r 🛠️WORKPRO 12" Clamps https://amzn.to/4avyXXL 🛠️WORKPRO 12-Inch Steel Bar Clamps https://amzn.to/4kn89fU 🛠️MILWAUKEE 25Ft Tape Measure https://amzn.to/4bx8rOR 🛠️Milwaukee 12V Extended Batteries https://amzn.to/4qZStlb 🛠️Milwaukee 12V Impact Driver https://amzn.to/4rxKGuJ 🛠️Milwaukee 12V Sawzall https://amzn.to/4qWgU2G 🛠️Milwaukee 12V 3/8-Inch Drill Driver https://amzn.to/3Zhqstc 🛠️Milwaukee 12V Battery Charger https://amzn.to/4a8DY7f If you’re building a shed roof and want consistent, professional-looking rafters without complicated calculations, this method works. Many images used from Free Pik: https://www.freepik.com I get most of my sound effects from https://pixabay.com/ Disclaimer! Mike does stuff to entertain you, not for you to try some of the stupid things he does and get you hurt. Affiliated with Mike the Backyard Mechanic. 00:00 How to build perfect birdsmouths and rafters 00:50 Preplanning, or planning for a plan 01:46 Getting the Rafter Dimensions 02:36 A setup to Help Cut Rafters 03:35 A setup for Perfect Birdsmouths 06:58 Assembly Fixture for Rafters 07:31 Alaska! 08:13 Rafter Assembly 09:10 Conclusion #diy #shed #rafters #birdsmouth