Roof Pitch For Water Runoff

Every roof needs drainage.

Roof pitch for water runoff.

High pitch roof pros. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. 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. This can be located at the edge or in the middle of the roof.

An example for a steep sloped roof is 8 12. A small roof with a shorter length on the other hand will not collect a lot of water within a short period of time and will work just fine with the minimum roof slope for drainage. This means that the rise of the slope goes up or down 8 inches for every 12 inches. My own house with a metal roof of course is a 12 12 pitch and everything is just fine.

To put it in perspective the angle of this slope would be around 30 degrees. Roof pitch refers to the slope which the rafter creates. Therefore attic space can be at a premium with a low pitch roof. A 4 12 slope is enough to accommodate water runoff but is not suitable for regions that are affected by heavy snowfall.

How water sheds off a roof depends on how much rain falls in that location and how quickly it needs to drain. Care must be given so that debris does not collect and thus cause damage. While a 4 12 pitch roof has enough slope for water runoff it s often too low for regions with heavy snowfall which can put considerable weight on the roof s structure. Often you express roof pitch as the ratio between the rise and the run in the form of x 12.

A wide roof with a steep slope will lead to faster runoff hence necessitating a slightly steeper slope for effective discharge of the rain water. The ratio between width and height is much smaller with a low pitch roof. Since the pitch of the roof is lower it can act as a catch all for tree limbs and other debris. I do suggest hanging gutters as high as possible so that water does not over shoot them.