Maximum Roof Pitch Australia

In australia roof pitch is most accurately expressed in degrees as an angle.

Maximum roof pitch australia. Examples of valley gutters are shown below. For commercial and industrial applications tables are based on a maximum overall height of ten metres and a 500 year design return period. Eaves height of six metres roof pitch of 35 degrees and total roof height of 8 5 metres. Standard roof pitches in australia are usually either 15 degrees or 22 5 degrees depending on the materials used in the roof.

Most roof s have a pitch in the 4 12 to 9 12 range. Here are some of the most common ones used in australia. However from the wind uplift mitigation perspective a 7 12 roof slope can be considered as a two story building due to the higher overall steepness and profile of the roof. Conventional roofs are the easiest to construct and you can walk on them safely.

For a gothic style the rafters must equal the span 60 while an elizabethan style requires the rafters to be longer than the span. In snowy areas your roof should be at least 10 12 40 to allow snow to shed while the safest roof pitch in very windy areas is between 4 12 6 12 18 5 26 5. A roof slope of 7 12 is also good and can provide the additional benefit of helping minimize the effects of wind driven rain. Roof pitch places limitations on design and materials in a roof.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. One would have to assume that slates fixed on roofs with less than 20 degree pitches would need to be in very benign climates with large headlaps. Being able to quickly and accurately calculate roof pitch is important for a number of reasons.

Roofing calculations are based on cpe 0 9 and cpi 0 2 walling is based on cpe 0 65 and cpi 0 2. It has references to roof pitches as low as 17 5 degrees in relation to sarking requirements table 3. On a roof with a pitch more than 12 5 degrees must have a width of at least 400 mm with at least 150 mm of the roof covering overhanging past each side of the gutter. High pitched roofs often need extra fasteners and their pitch can be as high as 21 12.

The australian standards makes no recommendation for the minimum roof pitch for slate. You can also calculate roof pitch even without using a roof slope calculator.