Total roof area also affects runoff.
Calculating gutter sizes uk.
Downspout sizes must not exceed the bottom width of the gutter.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
For example if your roof is 40 feet long and 20 feet wide you area will be 800 square feet.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
Determine the surface area of your roof.
Gather some basic weather information to calculate the proper size for gutters and downspouts for a house.
An inch of rain is not much but it if falls in half an hour it could flood a gutter.
2000 contains maps showing rainfall intensity in litres second per m2 for 1 5 50 and 500 year storms of 2 minute duration.
Downpipes are available in four.
Where an angle occurs in a length of gutter served by two outlets the reduction factor of 0 85 should only be applied to.
5m x 4m x 4 2 40 square metres.
Roof length x half roof width x roof height 2 roof area calculate the area of a roof to work out how much guttering is required so for a roof that is 5 m long with a height of 4 m and the roof width is 8 m which makes the half roof width 4m we can calculate the effective roof area like this.
All external gutters designed for 1 year.
As a consequence sizing the gutter spout is key to properly sizing a gutter system.
Use the formula a l x w where a is area l is length and w is width.
5 inch 5 520 square feet.
Then use the chart below to see what size gutter you need.
6 inch 7 960 square feet.
All gutter systems in the uk should be designed to bs en 12056 3 2000 gravity drainage systems inside buildings.
This guide provides a basic method for calculating flow requirements or flow capacity.
Then use the information below to see what size gutter you need.
British standard bs en 12056 3.
Geographical location and rainfall intensity maps.
100mm 125mm 150mm 190mm and rectangular 136mm.
To limit the effects of thermal expansion in gutters 50 ft.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
The capacity of a sloped rectangular gutter may be approximated by using a gutter cross section area not less than that of a semicircular gutter and.
Roof drainage layout and calculation amd 17041 2000.
Lg 10 133 therefore reduction factor 0 86 d 0 1 gutter capacity x reduction factor 2 84 x 0 86 2 44 l s therefore the proposed system is suitable.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
15 m is a practical maximum gutter length to be served by a downspout.
5 inch 5 520 square feet.
The total rainfall and how rapidly it falls will affect the runoff from the roof.
