Metric Roof Pitch Formula

A arctg h l or a arcsin h s h l tg a.

Metric roof pitch formula.

Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. S h sin a. You can also calculate roof pitch even without using a roof slope calculator. For example if a roof has a pitch of 4 12 then for every 12 inches the building extends horizontally it rises 4 inches.

When calculating the length of the rafter from the center of the ridge beam you ll need to take half of the ridge beam thickness and subtract it from the length of the top end of the rafter. Roof pitch angle in degrees and slope length formulas. Use the following formula which also describes a right triangle. Hip backing angle 10 5.

Calculate the roof pitch as the proportion of rise and run. For instance if the roof rises 4 feet and has a span of 16 feet then the roof pitch will be 4 16 or 1 4. Pitch rise run 1 5 6 25. Purlin lip cut angle 7 6.

The rise is the height of the roof and the run is the horizontal span as pictured above. Calculate the rafter length substituting these values into the following formula. Let s say it is equal to 1 5 m. Measure the rise of your roof.

Hip roof framing center join diagram with options for square roof 1. Here are the equations you may use to solve for the length of the slope and the rafter. Outside top plate edge to ridge top edge common 3108. Accordingly all quantities can be found.

Rafter rise run this formula is from the pythagorean theorem. The roof pitch is the slope of the rafter.