Slope Roof Snow

If your roof is pitched enter the length and width of the flat area covered by the roof.

Slope roof snow.

Even in these arid regions so called flat roofs are still installed with a slight pitch to keep water from pooling on top of the structure. I e 4 inches of rise per 12 inches one foot of run. 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. What exactly is roof slope.

The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions. Roof pitch is the measurement of roof steepness. The sloped roof snow load p s shall be obtained by multiplying the flat roof snow load p f by the roof slope factor c s. Intuitively this is the number of inches of snow on your roof in the place where the cover is the thickest.

A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible. 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. In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. There are some opinions that standing seam metal roof minimum slope is 12 but it increases the possibility of leaking on the few first days of snow arrival.

In general determining the pitch of an existing roof is a simple calculation. Roof slopes are most commonly defined by the rise over run ratio. This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally. The way pitch also known as roof slope is measured is rise over run.

You can enter this value either as a ratio x 12 or as an angle whichever suits you better. Importance of a roof pitch. For example a roof with a 6 inch 12 pitch is one where it rises 6 inches vertically for every 12 inches of the horizontal run. So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12.