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Span tables roof purlin spacing australia.
Use recommended minimum roof pitches as specified by roof sheet supplier.
Joists crippled over supports shall be considered as single span joists.
The safe spans below are suitable for sheds and class 1 structures with the following assumptions.
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.
From span table c the maximum allowable single span is 2160mm.
Cpe 0 9 and cpi 0 2.
Cleated or bracketed fixing only no flange bolting.
Spantec has prepared these tables for use by people skilled in the design and specification of the.
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.
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.
Rafter or uss spacing w lintel span sheet roofing tiled roofing roof load width rlw mm 1500 2100 4500 7500 1500 2100 4500 7500 maximum span of lintel mm.
If the space between posts is greater than 8 feet then brace is needed to avoid buckling.
High pressure zones kl 1 5 and 2 0 included.
The tables include a comprehensive range of span configurations.
Purlins near roof edges or changes of roof slope are subject to higher wind forces than interior purlins.
Table assumes a maximum flooring mass of 40kg m2.
All spans to have 1 row of bridging.
Required size for a given span.
Max roof span allowed 12m.
Roof load width rlw and floor load width flw can be determined from as1684 or from the images below.
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.
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.
Safe roof purlins spans.
Reading off the empty under table with h 5m hc 2 5m span table c will be used to determine the spans.
For 2x6s purlins the posts are spaced in 6 feet distance.
Spacing should be interpreted as the centre to centre distance between adjacent parallel members.
If you want to know how to support roof purlins they are usually supported by 2 4 or 2 6 struts or posts.
