Calculate Gutter Size Uk

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

Calculate gutter size uk.

Then use the chart below to see what size gutter you need. Calculate the square footage by getting up there with a tape measure. Choosing the right size of gutters and downpipes step 1. Change the style of gutters to one with a greater capacity.

Determine the rainfall intensity for your location. 6 inch 7 960 square feet. To limit the effects of thermal expansion in gutters 50 ft. If you ve got a simple gable end roof then it s easy you only need to know two figures one for either slope.

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. Calculate the number of outlets per. Add a fall to the gutters which we recommend you do anyway. 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.

That will show how much water a gutter will have to drain. Ask gutter suppliers what size gutters will be needed to handle that amount. Downspout sizes must not exceed the bottom width of the gutter. 5 inch 5 520 square feet.

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. 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.

Divide the inch per hour watershed of the roof by the 5 minute rainfall intensity. The most logical way to choose your gutter size would be according to the area of your roof. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist. 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.

Move the outlet downpipe from the end of the gutter to the middle. That is how much rain a roof can drain during the most intense rainfall. Increasing the capacity of your gutter system. Frequency and positioning of outlets downpipes.

15 m is a practical maximum gutter length to be served by a downspout.