We ll use satellite imagery and trigonometry to calculate your roof s measurements.
Roof measurement formula.
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.
Pitch measurement method 1 1.
This is only important for gable roofs as the calculator uses a specific formula to estimate roof run length of gable.
If your house has a hip roof then it does not matter which side is the length and which is the width for an accurate result.
Roof reports and wall reports made easy.
So if you divide your answer of a product of length times height by two you will get the area of a triangle.
Includes result for hip valley factor slope factor and the roof slope in degrees.
Roof pitch refers to the slope which the rafter creates.
Calculate unit rise for the roof rise.
Measure both the width gable side and the length eave gutter side.
If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.
Make sure to document the number of chimneys skylights or other obstructions and include dormers in your measurements.
If this distance measures 4 inches you have a 4 in 12 pitch.
Total rise total run in feet x rise per foot the tan value for my 9 degree slope roof tan 9 0 1583.
It is often compared to slope but is not exactly the same.
On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof.
See the diagram.
You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof.
To calculate total rise if i knew the total run say we had made an on roof measurement we take the following steps.
Calculating an area of a triangle when estimating a roof.
The length l times the height h of a triangle is twice its area a2.
Often you express roof pitch as the ratio between the rise and the run in the form of x 12.
If you re going to use an area calculator you can do this separately for each level of the home to ensure a more accurate calculation.
0 1583 rise run.
Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.
1 roof square 100 square feet.
First measure the length and width of each surface on the roof then multiply these values to get the square footage of that surface.
