Roof Pitch Formula Australia

For more on calculating roof pitch and understanding how pitch and slope are different read on.

Roof pitch formula australia.

Rafter rise run this formula is from the pythagorean theorem. Being able to quickly and accurately calculate roof pitch is important for a number of reasons. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.

In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. Roof pitch calculator results explained. 48 10 4 8. This type of roof is the most popular in australia.

Here are some of the most common ones used in australia. The incorrect roof pitch and panel angle will mean that the panels won t be able to self clean in the rain meaning that you ll have to manually clean them more often and the panels may not be effective if incorrectly installed. Pitch rise run 1 5 6 25. In australia roof pitch is most accurately expressed in degrees as an angle.

After measuring the slope estimate the roof pitch by dividing the slope by 2 if you have a simple gable roof. Angle the angle of a roof is the same as the roof s slope except instead of being. The pitch of this roof is 4 8 12. It is often compared to slope but is not exactly the same.

Calculate the roof pitch as the proportion of rise and run. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Measure the rise of your roof. Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run this is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.

Standard roof pitches in australia are usually either 15 degrees or 22 5 degrees depending on the materials used in the roof. The calculator above can handle much of this math. For instance a 7 12 roof pitch means that the roof rises 7 inches. Roof pitch places limitations on design and materials in a roof.

Calculate the rafter length substituting these values into the following formula. However if you have a more complex roof you may need to calculate pitch section by section. Hip a hipped roof has three four or more pitched planes depending on the shape of the house and all planes slope downwards from a ridge at the top of the roof. Since pitch is the rise over a 12 inch run divide the run by 12 to get the multiplier in this case 120 12 10.

Here are the equations you may use to solve for the length of the slope and the rafter. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. You can also calculate roof pitch even without using a roof slope calculator.