Then use the information below to see what size gutter you need.
How to size box gutters.
Pick any size box gutter that fits on the relevant graph and determine the depth and the rain water head sizes.
For example by going up to a 6 inch from a 5 you are increasing the amount of water the gutters can hold by 40.
5 inch 5 520 square feet.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
For square footage up to 3 840 feet 1 170 m use 6 in 15 cm half round gutters.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
Sides must be vertical.
If the adjusted square footage is equal to or less than 2 500 feet 760 m choose 5 in 13 cm half round gutters.
Box gutters must be straight no bends.
6 inch 7 960 square feet.
Must have a constant slope between 1 40 and 1 200.
Sizes the depth shown of the box gutter is the depth at the upstream end.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
Gutters come in k style and half round style.
6 inch 7 960 square feet.
Choose the size that corresponds with the adjusted square footage.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
5 inch 5 520 square feet.
While a smaller commercial building might be able to get away with 5 inch box gutters we generally recommend that you start by looking at the 6 inch sizes.