4 12 Roof Slope

The combination of two numbers are used to display or show the roof pitch.

4 12 roof slope. Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter. Modified bitumen membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. Most roof s have a pitch in the 4 12 to 9 12 range. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.

For example if you measure 4 inches the pitch of your roof is 4 12. A roof pitch of 4 in 12 4 12 has a rise of 4 and a run of 12. The roof s incline increases four feet for every 12 feet of horizontal measurement. The slope of the roof provides the rise and the run to be plugged into the equation.

Roof pitch is a term describing how steep or flat your roof slope is. This will give you the rise over run or pitch. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. A 4 12 roof pitch can also be expressed as 4 over 12 and when you re talking to a roofer this is the most common way you ll hear it explained because it s easy to say in conversation. Modified bitumen roofing minimum roof slope roof pitch r905 11 1. To find the total length of a common rafter consider the run to be the horizontal distance covered by the whole rafter.

Standing seam roof systems must have a minimum roof slope of 1 4 12 2 slope. Another way to express a 4 12 pitch is 4 and 12 in this pitch the four is your roof s rise and the twelve is the roof s run. The gentle slope of a 4 12 pitch roof falls. This means for every 12 horizontal units the roof must rise a minimum of one quarter vertical unit.