Calculate Gutter Size Uk

Geographical location and rainfall intensity maps.

Calculate gutter size uk.

2000 contains maps showing. 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. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.

Calculate the number of outlets per. 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. Then use the chart below to see what size gutter you need. Frequency and positioning of outlets downpipes.

Using the 5280 square feet example from step 6 you will choose a gutter size that can handle at least 5280 square feet. Ask gutter suppliers what size gutters will be needed to handle that amount. That is how much rain a roof can drain during the most intense rainfall. Calculate the square footage by getting up there with a tape measure.

Move the outlet downpipe from the end of the gutter to the middle. If you ve got a simple gable end roof then it s easy you only need to know two figures one for either slope. Gutter ratio l1 l1 l2 where. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

For a typical gutter run up to a maximum of 10m the ratio of gutter lengths is calculated from. Change the style of gutters to one with a greater capacity. That will show how much water a gutter will have to drain. 15 m is a practical maximum gutter length to be served by a downspout.

Add a fall to the gutters which we recommend you do anyway. To limit the effects of thermal expansion in gutters 50 ft. L1 l2 selecting gutter size there is no standard rate of rainfall in the uk so for accurate calculations refer to an approved weather authority to get a site specific rainfall level. Divide the inch per hour watershed of the roof by the 5 minute rainfall intensity.

Choosing the right size of gutters and downpipes step 1. Downspout sizes must not exceed the bottom width of the gutter. The most logical way to choose your gutter size would be according to the area of your roof. 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.

British standard bs en 12056 3.