Eaves Gutter Sizing

The gutter outlet capacity should suit the downspout capacity.

Eaves gutter sizing.

Roof drainage systems should be designed and detailed by a suitably qualified trade or professional in accordance with the bca and the australian standards. If a roof s various drainage areas call for different size gutters go for the biggest one k style. An inch of rain is not much but it if falls in half an hour it could flood a gutter. Total roof area also affects runoff.

Residential sizing samples are available to check the optimal fit but in most cases the 5 half round gutter requires standard gutterbrush for 5 gutters 4 25 dia while the 6 half round gutter requires oversized gutterbrush for 6 gutters 5 25 dia. The program will calculate the size and number of downpipes downspouts leaders required and the eaves gutter sizes for any roof. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. 5 inch 5 520 square feet.

6 inch 7 960 square feet. Gutter downspout sizes are 3 to 6 inches. 5 inch 5 520 square feet. 6 inch 7 960 square feet.

Most downspouts are rectangular but they can also be round or square. The size of the downspout should be constant through out its length. Particular reference should be made to the correct sizing of gutter. And the provision of appropriate overflow devices.

Then use the chart below to see what size gutter you need. You can choose a downpipe size and calculate the number required and the corresponding eaves gutter size. You should have enough gutter downspouts to effectively handle the size of your entire gutter system. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

There is no limit to downpipe size or eaves gutter size. Then use the information below to see what size gutter you need. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. Quantity and placement of downpipes.

Learn more how to storm water design for building sites. The total rainfall and how rapidly it falls will affect the runoff from the roof. If a roof s various drainage areas call for different size gutters go for the biggest one k style. Offset of more than 10 ft 3 0 m can affect drainage capacity.

The larger a gutter downspout the more water it can drain quickly. The code limit is 150mm for dp s and 26 800 sq mm for flat eaves gutters.