Roof Rafter Spacing Uk

Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak.

Roof rafter spacing uk.

These spans were calculated using our flat roof joist calculation. This span table is to the format and methodology given in bs 5268 7 2. Plasterboard on the underside of the rafter. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.

Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall. Usually 400 450 or 600mm but any value can be used up to 610mm max are there any brittle finishes e g. Here the number is 941 86 inches. For pitched roofs flat roofs and ceiling joists.

Click on a span to generate a full calculation you can adjust the exact span. Find the column for your dead load and spacing and the row for your timber size to find the permissible clear span in metres. But they do tend to space rafters in one of several industry standard increments typically either 12 16 or 24 inches apart. It is always better to have a large rafter rather than be concerned with a sagging roof.

Mm this is the distance between rafter centres. Here the number is 1166 66 inches. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. Surveyors span tables for designing roof rafters.