Lean to roof timber dimensions

47×170 mm c24 size of timber as roof joists allows spans up to 3 meters for permanent loads are assumed to be 50 kg/m2 and imposed load of 150kg/m2 when spaced 400mm apart, allowing for the likelihood of the extra weight of heavy snow come winter.

The size of timber required for a lean-to roof with a span of 3m will depend on a few factors, such as the pitch of the roof and the distance between the supports. However, as a general rule, the following sizes can be used for a simple lean-to roof with a pitch of 5 degrees: Roofing joists: 100mm x 50mm (4 inch x 2 inch) timber, spaced at 400mm (16 inches) centres. Ridge board: 150mm x 50mm (6 inch x 2 inch) timber. Wall plate: 100mm x 50mm (4 inch x 2 inch) timber. It's important to note that these sizes are for guidance only, and the specific size of timber required will depend on the load capacity required for your particular application. If you're unsure about the appropriate size of timber, it's always best to consult with a structural engineer or a qualified builder who can advise you on the correct specifications for your specific project.

6x2