Therefore this roof should be equipped with 6 inch k style gutters.
How many feet are my gutters.
Doubling the number of downspouts halves the required capacity for each.
If the adjusted square footage is equal to or less than 2 500 feet 760 m choose 5 in 13 cm half round gutters.
The bigger your roof and the more rain you get the bigger your gutters will need to be.
As with gutters a downspout s capacity must match or exceed the expected runoff.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of.
Multiplying that number by the local maximum rainfall intensity 6 8 inches per hour yields an adjusted square footage of 7 480 square feet.
Size downspouts to fit the gutter.
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.
Always inspect ladders before using them and make certain the feet of the ladder are secure before climbing up.
Next you ll need to choose your material.
For downspouts a good rule of thumb is one for every 40 feet of guttering.
The most common residential gutter size is five inches.
There is a simple and accurate way to measure and calculate linear feet for gutters that doesn t require climbing all the way up on the roof.
The above recommendations assume that you have properly sized downspouts every 40 feet.
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 square footage up to 3 840 feet 1 170 m use 6 in 15 cm half round gutters.
Use the chart below to figure out how many extra downspouts you need.
Step 1 position a ladder at one end of a wall with a gutter or where one is to be installed.