Rafter Spacing For Slate Roof

Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.

Rafter spacing for slate roof.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Usually 400 450 or 600mm but any value can be used up to 610mm max. Surveyors span tables for designing roof rafters. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.

If your local building authority has a rafter spacing code you may not space rafters wider than required by code. But they do tend to space rafters in one of several industry standard increments typically. Builders aren t bound by standard rafter spacing measurements. The boards creating the slope of the roof are wider than lumber used to build trusses 2x8s 2x10s and 2x12s are most common in rafters vs.

Other imposed loads roof snow load and short term point load altitude not exceeding 100m. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. 0 75 kn m snow load 0 9 kn. For pitched roofs flat roofs and ceiling joists.

Rafter and roof joist spacing is only one part of a complex roof design that works together to form a structure that meets building codes and can hold up the weight of the roof and roof load. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. Wider panels allow for greater spacing between rafters.

Rafters must be strong enough to hold the roof sheathing and the shingles. As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. In finished space insulation is placed between the rafter boards and drywall or other material is fastened to the face. Rafter spacing is based on the width of the metal roofing panels.