Pitched Roof Timber Span Tables

For pitched roofs flat roofs and ceiling joists.

Pitched roof timber span tables.

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. All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. Span tables for solid timber joists. Span calculator for wood joists and rafters also available for the android os.

Continuing on from part 3. Surveyors span tables for designing roof rafters. For timber floors between homes. Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Also available for the android os. Here we have a wood framed gable roof. Tables 1 and 2 in this chapter are derived from the trada technology ltd.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. 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. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. 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.

Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3. Eurocode 5 span tables for solid timber members in floors ceilings and roofs for dwellings 3rd edition. The section sizes are based on regularised als or cls timber. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

Let s consider a basic gable wood roof framing design. Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof.