Roof Rafter Spacing Australia

Dead load weight of structure and fixed loads 15 lbs ft 2.

Roof rafter spacing australia.

This is set by the roof use you selected in the previous screen and cannot be modified. Member span is not suitable for rafter spacing greater than 600mm. 3 4 5 x 12 pitch rises that much per foot of distance on the ceiling joist. 1 ft 0 3048 m.

The maximum overhang of house rafters or trusses shall not exceed 750 mm from outside of top plate to end of rafter truss. Loads are calculated in accordance with table 3 1 of as nzs 1170 1 2002. Rafters 12 ceiling joists 15 hanging beams member16 underpurlins 17 strutting beams 18 roof beams 20 verandah beams 22 garage roof. Use these two tables for roof rafters with a slope of 3 in 12 or less.

Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. Live load is weight of furniture wind snow and more. 1 psf lb f ft 2 47 88 n m 2. The same concept holds true for roof trusses.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. 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. 3x12 pitch 12 feet. 2 denotes 600 mm rafter spacing only.

Measure the ceiling joist to a point or to center and then plumb to the rafter and do the math. 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. 2 are indicated below. Pitching beams 23 common installation details 25 notches cuts and holes in beams.

Tables such as those for rafters. So the space between rafters can be greater without reducing the maximum span. 1 refer to general notes for information that is relevant for all span tables. Design of single span rafters in roofs in houses office buidlings schools and other structures.

3 for design parameters refer to figure 6 22 as1684 2 and 3. Wind classification 1 n2.