A king rafter has hip rafters jutting from either side of where they meet the ridge beam. It extends from the edge of the ridge beam down to the center of the wall, making it perpendicular to the common rafters. King RafterĪlso known as a “king common”, the king rafter is the center rafter between two hip rafters. They also make sheathing and adding roofing material a bit more difficult due to the added angles on your roof. These rafters require extra measurement to mesh the hip gable to the ridge beam properly. They extend diagonally so that one end, or both, of a rectangular shed roof, is slanted perpendicularly to the gable roof in the midsection of the shed. Hip rafters, when used, are beams that sit on two or all four corners of a shed wall and extend upward to meet the ridge beam. Hip RafterĪ hip rafter works in tandem with a common rafter, but when used, it creates a more visually appealing roofline but creates less interior space. Lean-to rafters then connect to a ledger board against a wall of another shed or house.

When to use common rafters? You can use common rafters on any shed roof, but they make the most sense when constructing a gable roof or lean to-type shed roof where they can sit on or attach to top plates of a wall. However, our instructions include making shed rafters with a ridge beam. Some shed rafters do not incorporate ridge beams, either due to small size or lack of technical know-how. A ridge beam runs the length of the shed roof, connecting every pair of rafters. Each beam is notched at the bottom, called a birdsmouth, so that it rests flat on top of each wall.Īt the top, where the rafters meet, they are either angled to meet at a point or attached to a horizontal ridge beam. Common RaftersĪ common rafter comprises two beams that extend upwards from the top plate of either side of a shed wall. We’ll take a look at some of the most common shed rafter types and why you might or might not consider them in your next shed project. Shed rafters come in many different designs, depending on the design of the shed and the shed roof. Trusses are held together with steel gussets and are staples of home construction. Trusses use “webs” of 2x4s within the truss structure to support the roof. A rafter beam is usually larger than a 2×4 – large homes may have rafters that are 2×12 or more!Ī truss, on the other hand, is only made up of 2x4s and is often pre-fabricated in a factory. Rafters typically use larger wood beams and do not have any sort of framework other than the beams themselves. It rests on top of your wall framing and, when done properly, serves to keep your shed walls in place while supporting a roof. More specifically, it is a beam that goes from the peak of your roof down to the eve. What Is the Standard Shed Roof Rafter Spacing?Ī rafter is the frame of your roof.Additional Steps for Roofs without a Ridge Beam.Cut the First Rafter Tail and Ridge Cuts.Tools and Materials Needed to Build Shed Rafters.What Size Lumber Should Be Used for Roof Rafters?.It's too small, it might squeek in at a 6圆. I also changed the span in the calc to 140' then entered this info assuming the same species. The fail in deflection shows it would make for a bouncy floor but a passable roof board.Ĥ0square feet of roof bearing on a purlin X 40lbs per square foot= 1600lbs load bearing on each 4圆 purlin. I looked at it as a simple beam in flatways bending I'd call the adjusted Fb-1125psiĪssume a 6' wide board spanning the 40'=1.66 square feet X40psf=67lbs load I would bump up the Fb by 15% for short term loading(snow), 15% for repetitive member use, and you could take 15% more for flat use but I don't think I would. Add 10psf for dead load so 40psf total load. Your building department can give you the snow load for your area, I'm guessing it will be 30psf. Roughly then, 4' centers on an 8/12 with 4' wide purlins is going to give a clear horizontal span of about 40'. The horizontal clear span from plumb to plumb would be the way the NDS measures the span. The codebook doesn't alter sheathing, rafters or purlins based on pitch.

Rafter spacing for metal barn roof