Calculate Gutter Size Uk

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.

Calculate gutter size uk.

That is how much rain a roof can drain during the most intense rainfall. The most logical way to choose your gutter size would be according to the area of your roof. Divide the inch per hour watershed of the roof by the 5 minute rainfall intensity. 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. British standard bs en 12056 3. 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. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.

If a roof s various drainage areas call for different size gutters go for the biggest one k style. Add a fall to the gutters which we recommend you do anyway. 5 inch 5 520 square feet. Determine the rainfall intensity for your location.

Frequency and positioning of outlets downpipes. Ask gutter suppliers what size gutters will be needed to handle that amount. Choosing the right size of gutters and downpipes step 1. Change the style of gutters to one with a greater capacity.

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. Using the 5280 square feet example from step 6 you will choose a gutter size that can handle at least 5280 square feet. Move the outlet downpipe from the end of the gutter to the middle. Gutter ratio l1 l1 l2 where.

That will show how much water a gutter will have to drain. For a typical gutter run up to a maximum of 10m the ratio of gutter lengths is calculated from. Geographical location and rainfall intensity maps. Calculate the number of outlets per.

Then use the chart below to see what size gutter you need. If you ve got a simple gable end roof then it s easy you only need to know two figures one for either slope. 15 m is a practical maximum gutter length to be served by a downspout. Increasing the capacity of your gutter system.

2000 contains maps showing.