Span Tables Roof Purlin Spacing Australia

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.

Span tables roof purlin spacing australia. If you want to know how to support roof purlins they are usually supported by 2 4 or 2 6 struts or posts. Spantec has prepared these tables for use by people skilled in the design and specification of the. Posts these span tables are designed for a minimum post size of 50 x 50 x 2 5mm up to a maximum height of 3 0m. Step 4 assume the wind classification for the area is n1 and the roofing profile is stramit corrugated cladding 0 48mm bmt thickness in a single span configuration.

The safe spans below are suitable for sheds and class 1 structures with the following assumptions. Max roof span allowed 12m. High pressure zones kl 1 5 and 2 0 included. Flat roof span tables allow for a maximum roof pitch of 5º.

Spacing should be interpreted as the centre to centre distance between adjacent parallel members. Required size for a given span. Use recommended minimum roof pitches as specified by roof sheet supplier. Cpe 0 9 and cpi 0 2.

For 2x6s purlins the posts are spaced in 6 feet distance. Joists crippled over supports shall be considered as single span joists. Safe roof purlins spans. Cleated or bracketed fixing only no flange bolting.

Roof load width rlw and floor load width flw can be determined from as1684 or from the images below. For 2x4s purlins the posts are spaced in 4 feet distance. They have been generated using the latest version of the purlin and girt software developed by the centre for advanced structural engineering at the university of sydney and cover the full range of stratco z and c sections from 75mm through to 400mm depth. If the space between posts is greater than 8 feet then brace is needed to avoid buckling.

29 norfolk close tuncurry nsw 2428 phone. 02 6554 6422 email. From span table c the maximum allowable single span is 2160mm. All spans to have 1 row of bridging.

As per as1684 and as4055 spanman adopts a nett pressure coefficient applied along the full length of the purlin of cpn 2 0 for non cyclonic zones n1 to n6 and cpn 2 5 for cyclonic zones c1 to c4. 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. Purlins near roof edges or changes of roof slope are subject to higher wind forces than interior purlins. Reading off the empty under table with h 5m hc 2 5m span table c will be used to determine the spans.