As with gutters a downspout s capacity must match or exceed the expected runoff.
Gutter slope per foot.
For example if you have 30 feet of guttering the calculation is 1 4 x 3 0 75 i e.
Rules of thumb for gutters.
1 sq in downspout cross section per 100 sq ft of roof drained.
The above recommendations assume that you have properly sized downspouts every 40 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.
Max run per downspout of 40 feet.
There are two factors that go into determining gutter position on the eave the pitch of the gutter and the roof slope.
At the ends of the gutters are 4 inch diameter corrugated aluminum downspouts 1 75 per linear foot which were ordered in white to match the house trim.
Ranch house with roof of 5 12 pitch 48 feet long with a small gable extending out over a porch at one end.
This means the downspout end of the gutter should be set 3 4 of an inch lower than the other end.
Increasing the pitch increases a gutter s handling capacity but the gutter may look askew over a long run.
So if you have a 25 foot section of guttering you should set the downspout end of the gutter 5 8 of an inch lower 1 4 x 2 5 5 8 than the other end.
Gutter should be pitched 1 16 or greater per foot for proper drainage.
The standard is about inch per 10 feet.
So what s the ideal amount of slope for your gutters.
Plenty of rain but not usually much snow.
Slope 1 8 inch per running foot.
The standard slope for rain gutters is half of an inch for every 10 feet.
As a general rule gutter slope is set at 1 4 inch per 10 feet of guttering.
Your supplier should have these simple facts or at least a brochure at the.
This means that your gutter should be a half inch lower in height at every 10 foot mark until you reach the downspout.
Modern roofing care and repair creative homeowner press.
Gutter can be run level for appearance but addition downspout will be necessary see section on proper gutter and downspout sizing.
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.
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.
I m reading a lot of different recommendations for the pitch slope of gutters on fascia anywhere from 1 8 per foot to 1 4 per 10 feet or to completely level.