Measuring Slope Of Roof

Write the roof slope as the ratio of rise over run or vertical distance over horizontal distance.

Measuring slope of roof.

Calculate the rafter length substituting these values into the following. Calculate the roof slope. This ratio is always expressed as inches per foot. 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.

The rise is the height of the roof and the run is the horizontal span as pictured above. The traditional method of measuring roof pitch is to display it as a ratio of x 12. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. Locate the level s 12 inch mark.

Use a level against the underside of the rafter you re measuring to get the most accurate value. So for our example the half roof area is as follows. The roof slope height is 6 98m. Divide the height of your roof by the width not the full width if you ve measured the full width wall to wall divide this by 2 first h w to get your pitch as a percent.

If you re using a 1 ft 0 30 m level the pitch is the distance between the edge of the level and the roof s surface. This is done by measuring the number of inches a roof rises vertically for every 12 inches it extends horizontally. The length of the roof is 8 7m for this square house as 8 7m x 8 7m is 76m total floor space. Measure the rise of your roof.

For example if your tape measure found a 6 inch vertical distance to the 12 inch mark on your level the slope is 6 12 or 6 in 12. A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. The roof pitch is the slope of the rafter. If you re using a 2 ft 0 61 m level divide the distance between the level and the roof by 2 to get the true pitch.

Because this is only one half of the roof we will need to double this number to find the entire roof area 121 45m. 8 7m x 6 98m 60 73m. The most precise way to find the roof s slope is by measuring it from the underside. Slope is the incline of the roof expressed as a ratio of the vertical rise to the horizontal run where the run is some portion of the span.

A distance of 7 inches 18 cm for example would mean your roof has a pitch of 7 in 12. How do you calculate the slope of a roof. This is simple to do and you ll need the same tools and access to your roof space as above. Let s say it is equal to 1 5 m.

Access one of the rafters then take.