Calculate Gutter Size Uk

If you ve got a simple gable end roof then it s easy you only need to know two figures one for either slope.

Calculate gutter size uk.

That will show how much water a gutter will have to drain. 6 inch 7 960 square feet. For a typical gutter run up to a maximum of 10m the ratio of gutter lengths is calculated from. Choosing the right size of gutters and downpipes step 1.

Calculate the square footage by getting up there with a tape measure. Divide the inch per hour watershed of the roof by the 5 minute rainfall intensity. Gutter ratio l1 l1 l2 where. 5 inch 5 520 square feet.

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. Geographical location and rainfall intensity maps. Change the style of gutters to one with a greater capacity. Increasing the capacity of your gutter system.

Then use the chart below to see what size gutter you need. 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. Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.

Add a fall to the gutters which we recommend you do anyway. 15 m is a practical maximum gutter length to be served by a downspout. Determine the rainfall intensity for your location. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

2000 contains maps showing. British standard bs en 12056 3. Using the 5280 square feet example from step 6 you will choose a gutter size that can handle at least 5280 square feet. That is how much rain a roof can drain during the most intense rainfall.

Calculate the number of outlets per. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Move the outlet downpipe from the end of the gutter to the middle. Ask gutter suppliers what size gutters will be needed to handle that amount.

Frequency and positioning of outlets downpipes.