Rafter Spacing For Corrugated Metal Roof Australia

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 spacing for corrugated metal roof australia.

A purlin is a horizontal piece of timber or metal which supports the roof s rafters or decking and helps to prevent your roof from sagging. This is set by the roof use you selected in the. Rafters are sloped beams that run from the roof s ridge to the eaves. Since 1 nominal lumber and solid decking are thinner they provide somewhat lower pullout values.

The most common measurement used for rafter spacing is either 16 or 24 inches. 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. Alternatively design in a specific timber or steel material type. Correctly measure the spacing of furring strips for a metal roof to further decrease condensation.

So the space between rafters can be greater without reducing the maximum span. When placing rafters for a tin roof also frequently referred to as corrugated metal or steel it is common to set the distance between rafters based on the size of the roofing panels. This allows the panels to be securely attached to the rafters for maximum stability. Pullout values decrease if the fasteners protrude completely through the purlins.

Roof purlin single span. Twenty four inches is a common spacing of furring strips for a metal roof. Determining rafter s spacing is as important as setting the metal roof purlins spacing. Design of single span rafters in roofs in houses office buidlings schools and other structures.

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. In some cases however the exact spacing of the rafters doesn t matter if the roof has other means of supporting the metal panels. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. When using purlins fabral recommends a maximum spacing of 24 on center note that 5v requires solid decking.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. You have to take the width of your roofing panel into the considerations. Use these two tables for roof rafters with a slope of 3 in 12 or less. Pick list all suitable timber and steel sections to design across all timber and steel sections.

The same concept holds true for roof trusses.