Calculating Gutter Sizes Uk

Determine the surface area of your roof.

Calculating gutter sizes uk.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Downspout sizes must not exceed the bottom width of the gutter. Use the formula a l x w where a is area l is length and w is width. 15 m is a practical maximum gutter length to be served by a downspout.

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. 6 inch 7 960 square feet. 5 inch 5 520 square feet. British standard bs en 12056 3.

If a roof s various drainage areas call for different size gutters go for the biggest one k style. 2000 contains maps showing rainfall intensity in litres second per m2 for 1 5 50 and 500 year storms of 2 minute duration. 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. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

The total rainfall and how rapidly it falls will affect the runoff from the roof. 5m x 4m x 4 2 40 square metres. 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. All external gutters designed for 1 year.

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. Geographical location and rainfall intensity maps. To limit the effects of thermal expansion in gutters 50 ft.

Downpipes are available in four. All gutter systems in the uk should be designed to bs en 12056 3 2000 gravity drainage systems inside buildings. Then use the information below to see what size gutter you need. Where an angle occurs in a length of gutter served by two outlets the reduction factor of 0 85 should only be applied to.

For example if your roof is 40 feet long and 20 feet wide you area will be 800 square feet. Calculating effective roof areas where gutter angles are installed effect of angles if a length of eaves gutter includes an angle the flow in the gutter will be impeded and its capacity reduced by 15. Design area effective area 5 x 10 x 1 29 64 5m run off 64 5m x 0 022 l s per m 1 42 l s from chart 125 x 100 gutter with 76 ø downpipe appears suitable but check. Then use the chart below to see what size gutter you need.

100mm 125mm 150mm 190mm and rectangular 136mm. As a consequence sizing the gutter spout is key to properly sizing a gutter system. Gather some basic weather information to calculate the proper size for gutters and downspouts for a house. Rainline gutters are available in two shapes and five sizes.

Roof drainage layout and calculation amd 17041 2000.