How to Figure Roof Pitch on a New Building

The pitch of a new building's roof is a numerical measurement of its slant or steepness. The main reason for pitch for a roof is to help the redirection of rain, sleet and snow. Determining the pitch of a new roof is essential in the process of laying the shingles or slates for the roof. The pitch of a roof is obtained by dividing its vertical rise by the measured horizontal span. Put another way, pitch is the distance a roof rises vertically over a 12-inch horizontal distance.

Things You'll Need

• Ladder
• Square
• Level

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Instructions

1. • 1

     Place the ladder against the side of the new building and climb it to access the roof's vertical rise and down slope.

   • 2

     Set the framing square on the vertical rise with the tongue facing up.

   • 3

     Hold the level flush plumb against the roof and the square's tongue.

   • 4

     Shift the square so that the long ends meet the roof edge at the 12-inch mark, then level the square in the horizontal position. The rise is the vertical arm of the square and the run is the 12-inch measurement. A roof with the vertical measurement of 7, would have a pitch of 7/12.