As a general rule gutter slope is set at 1 4 inch per 10 feet of guttering.
Gutter pitch angle.
As long as there is enough slope the water will naturally run out.
There s no hard rule on the angle of the slope.
This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.
Calculate the gutter slope by dividing the length of the gutter needed by 10.
Technically speaking the slope also called the pitch of the gutters is the amount by which the gutters slant downward along the path of the water flow.
Gutters should be placed below the extended roof line so that snow and ice can slide clear.
If the gutter continues around a corner cut the appropriate angle typically 45 degrees on that end.
There are two factors that go into determining gutter position on the eave the pitch of the gutter and the roof slope.
Gutters need to be pitched at a 5 degree angle.
If you have a length of gutter that is more than 35 feet long the center point should be the highest elevation and each side should pitch down toward the downspouts on either end.
Measure from the roof edge at both ends of the gutter if you want to be sure.
For example for every 10 feet of gutter they need to drop 1 2 inch from the high end to the downspout.
Place the line spirit level on the string.
Gutter should be pitched 1 16 or greater per foot for proper drainage.
Gutter can be run level for appearance but addition downspout will be necessary see section on proper gutter and downspout sizing.
If the run requires two sections of gutter overlap them by 8 inches and use a 3 8 inch long self tapping stainless steel screws or pop rivets in two rows of four each to join them.
To get started measure the side of the house directly under the gutter to determine its length in feet.
For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e.
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.