Roof Rafter Sizes Uk

Span tables for purlin supporting rafters to bs 5268 7 6 imposed loads of 0 75 kn m snow load are applicable to most areas where the altitude does not exceed 100 metres refer to bs 6399 3 imposed loads of 1 kn m snow load are applicable to most areas where the altitude exceeds 100 metres but does not exceed 200 metres but excluding.

Roof rafter sizes uk.

Clear span on plan. Here the number is 1166 66 inches. This is the distance between rafter centres. For pitched roofs flat roofs and ceiling joists.

Rafter is a sloping beam usually wood that supports a pitched 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. 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. The full version allows any size.

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. 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. Usually 400 450 or 600mm but any value can be used up to 610mm max. To establish the rafter length we calculate the following.

2 175m is your rafter length. Surveyors span tables for designing roof rafters. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Rafter slope min 15 max 45 degrees.

Maximum clear span of rafters in metres for roof pitches of between 15 and 45 degrees roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm. Here the number is 941 86 inches. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more.

4 8 2 2 4 for one half of your roof s width b skip this step if you already know what measurement half the width of your roof is. There could be many rafters supporting a roof. This calculator helps you make the rafters of the suitable sizes required for your roofing. This demo version is fixed at 1m clear span.

It is one of a series of sloped structural members that extend from the ridge or hip to the wall plate designed to support the.