Roof Slope 3 12

Roof slopes are most commonly defined by the rise over run ratio.

Roof slope 3 12. The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow. Roofers like to express the roof pitch ratio in inches and for simplicity they always use a run of 12 inches. 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. Roof pitch designations are comprised of two numbers indicating a ratio.

For example if you measure 4 inches the pitch of your roof is 4 12. If this isn t practical then perform the same measurement on the underside of the roof. The fraction 4 4 equals 1 so it doesn t change the value of the pitch and it produces a pitch of 4 12. A roof slope of 7 12 is also good and can provide the additional benefit of helping minimize the effects of wind driven rain.

Or the colon can replace the slash as in 2 12 or 7 12. If a roof rises 3 in a length of 12 this is 3 12 roof pitch. The combination of two numbers are used to display or show the roof pitch. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Image 1 12 to 12 12 roof pitch 7 12 pitch. To express a slope of 1 3 as a roof pitch you would multiply by 4 4 to produce 12 in the denominator of the ratio. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.

What exactly is roof slope. We included a roof pitch chart below the 7 12 example image and the calculator below that. Roof pitch degree table. The ratio can be indicated by a division slash separating the numbers such as 2 12 or 7 12.

However from the wind uplift mitigation perspective a 7 12 roof slope can be considered as a two story building due to the higher overall steepness and profile of the roof. Roof pitch defined and explained. I e 4 inches of rise per 12 inches one foot of run. 3 12 roof pitch angle 14 04 degrees.

If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. Roof pitch is a term describing how steep or flat your roof slope is.