Correct Rain Gutter Slope

Place the line spirit level on the string.

Correct rain gutter slope.

Multiply the number of feet by 1 16 inch to determine the total slope the gutter requires. For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e. For gutter runs longer than 40 feet it s best to pitch the gutter down from the middle to a downspout at each end. To get started measure the side of the house directly under the gutter to determine its length in feet.

For rainy climates where gutters will handle a larger amount of water for long periods they should have a maximum distance of 18 inches apart between them. 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. This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end. Gutter can be run level for appearance but addition downspout will be necessary see section on proper gutter and downspout sizing.

Or you can slope the gutters down from each end toward a single downspout placed in the middle of the run. First determine the location of each one of your downspouts. How to determine gutter slope the best way to calculate the slope of a gutter run before hanging it is to use a long string and a string level. To ensure that gutters drain properly make certain they slope inch for every 10 feet toward a downspout.

For spans longer than 40 feet it s wise to have a downspout on each end and start the high spot of the gutter in the center. Working out gutter slope as a general rule gutter slope is set at 1 4 inch per 10 feet of guttering. For example if the gutter is 16 feet long the end near the down spout must be 1 inch lower than the starting end. Then fasten one end of the string at the highest point of the gutter and the other at the spot where the downspout will be.

The standard slope for rain gutters is half of an inch for every 10 feet. Gutter should be pitched 1 16 or greater per foot for proper drainage. This means that your gutter should be a half inch lower in height at every 10 foot mark until you reach the downspout.