Given pitch and a horizontal area measurement multiply the horizontal area by a correction factor corresponding to pitch provided in the table below to determine the actual area of the roof to be used in the roofing material calculator.
How to work out pitch of roof australia.
Calculate the roof pitch as the proportion of rise and run.
The slope of the roof which is diagonally across from the 90 angle is the hypotenuse of the triangle.
Drag sliders to animate the results and diagram.
For many people working out the roof pitch angles can be a bit of a nightmare especially if you are going to do it yourself and try to manage it all on your own.
First enter the value of the rise and choose the unit of measurement from the drop down menu.
Extend it upward so it is perpendicular to the level.
Then enter the value of the run and choose the unit of measurement from the drop down menu.
Let s say it is equal to 1 5 m.
Depending whether the roof area is measured horizontally possibly from a drawing or photograph a correction factor is necessary to determine the actual area of the roof.
A right angled triangle is made up of three sides.
Enter run the flat level length then click pitch angle or rise to select then enter other known dimension angle or pitch.
Now mark 2 inches onto the timber which is a 1 4 of 8 alternatively if metric hold 200mm across and mark where 50mm falls.
To calculate the pitch of a particular section of the roof you need to picture that section of roof as a right angled triangle.
Move the tape measure along the the roof until it hits the level at exactly the 12 inch mark.
In the example above the total catchment entering the box gutter would be a b c d.
Naturally this does not go down particularly well without the right tools knowledge and assistance.
Pitch rise run 1 5 6 25.
The triangle diagram will be re drawn to scale with all dimensions marked.
Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.
Visit this page using a phone or tablet to directly measure pitch and angles.
Finally enter the value of the rafter length and.
Calculate the rafter length substituting these values into the following formula.
Common rafter elevation if you are calculating rafter length from the center of the ridge beam as shown below you will need to subtract half of the thickness of the ridge beam from the top end of the rafter.
Measure the vertical distance from roof to level.
Hold the 0 mark of the tape measure against the roof.
Hold the tape measure across the width of the timber and keeping the zero end in place pivot the other end of the tape round until the 8 inch mark meets the timber.
The opposite side the adjacent side and the hypotenuse.
The effect of the roof slope is allowed for by entering the angle of the roof in the programs.
Measure the rise of your roof.