How Much Drop Should A Gutter Have

All guttering must slope toward the nearest downspout.

How much drop should a gutter have. As a general rule gutter slope is set at 1 4 inch per 10 feet of guttering. Calculate the gutter slope by dividing the length of the gutter needed by 10. This allows the water to flow gently but. If the length of the gutter is 10 5 metres 35 feet the amount of slope required is 1 25 cm 1 4 inch multiplied by 1 metres 3 5 feet which when rounded up is 2 5 cm 1 inch.

The standard is about inch per 10 feet. Gutters should slope an inch or two for every 40 feet. The minimal slope needed for proper gutter drainage is 1 25 cm 1 4 inch for every 3 metres 10 feet of gutter. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.

That said gutters need to be completely level from front to back or water could spill over either edge. Gutter does not need very much grade slope to work properly. This brings up another important rule to keep in mind. Most contractors tend to set the slop at one quarter inch per ten feet of guttering.

Size downspouts to fit the gutter. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. To ensure the adequate drainage your gutters should be pitched approximately inch per 10 feet. For example for every 10 feet of gutter they need to drop 1 2 inch from the high end to the downspout.

For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e. Doubling the number of downspouts halves the required capacity for each. A subtle slope is b. This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.

Click show more for more information contact information and update notes. Downspouts are commonly 2 x 3 inches and 3 x 4 inches in size or 3 or 4 inches in diameter. Increasing the pitch increases a gutter s handling capacity but the gutter may look askew over a long run.