Correct Rain Gutter Slope
To ensure that gutters drain properly make certain they slope inch for every 10 feet toward a downspout.
Correct rain gutter slope. Gutter should be pitched 1 16 or greater per foot for proper drainage. For gutter runs longer than 40 feet it s best to pitch the gutter down from the middle to a downspout at each end. The standard slope for rain gutters is half of an inch for every 10 feet. Or you can slope the gutters down from each end toward a single downspout placed in the middle of the run.
There are two factors that go into determining gutter position on the eave the pitch of the gutter and the roof slope. First determine the location of each one of your downspouts. 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. 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.
To get started measure the side of the house directly under the gutter to determine its length in feet. For example if the gutter is 16 feet long the end near the down spout must be 1 inch lower than the starting end. If you live in a warm place with sporadic rain you can hang gutter hangers close to the middle of the gutter with a spacing of no more than 36 inches or three feet apart from the center. 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.
This means that your gutter should be a half inch lower in height at every 10 foot mark until you reach the downspout. 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. Gutter can be run level for appearance but addition downspout will be necessary see section on proper gutter and downspout sizing. This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.
For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e. Multiply the number of feet by 1 16 inch to determine the total slope the gutter requires. Working out gutter slope as a general rule gutter slope is set at 1 4 inch per 10 feet of guttering.