Roof Rafter Spacing Uk

Surveyors span tables for designing roof rafters.

Roof rafter spacing uk.

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. 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. For pitched roofs flat roofs and ceiling joists. But they do tend to space rafters in one of several industry standard increments typically.

If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. 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. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

If you enter a value for. Usually 400 450 or 600mm but any value can be used up to 610mm max. Builders aren t bound by standard rafter spacing measurements. For instance 2 grade 2x4s at 16 on center will span just over 9.

Suitable for uk building regulation approval. Here the number is 1166 66 inches. This is the distance between rafter centres. Here the number is 941 86 inches.

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. There are several variables to consider when determining the proper rafter size. This sizing guide for roof rafters will help determine what you need for your small project. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.

There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. Includes result for hip valley factor slope factor and the roof slope in degrees. 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. Are there any brittle finishes e g.

Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.