The total rainfall and how rapidly it falls will affect the runoff from the roof.
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.
These figures are based on a rainfall intensity of 75mm hr roof pitch not exceeding 50º gutters running full.
5 inch 2 500 square feet.
Picking your gutter size.
6 inch 7 960 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.
An inch of rain is not much but it if falls in half an hour it could flood a gutter.
Now finally you can find the appropriate gutter size by looking at the following figures showing the relationship between different gutter systems and the roof area they ll be able to drain.
Depending on building type a safety factor should be allowed for the sizing of internal gutters.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
Determine the size of your downspout.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
6 inch 7 960 square feet.
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.
Refer to the gutter packaging or specification for the recommended downspout size.
Roof drainage layout and calculations.
Gutter ratio l1 l1 l2 where.
For accurate project specific advice on rainwater flow calculations contact our friendly knowledgeable team on 0800 644 44 26.
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.
Then use the chart below to see what size gutter you need.
For a typical gutter run up to a maximum of 10m the ratio of gutter lengths is calculated from.
5 inch 5 520 square feet.
For example a 5 inch gutter system requires at least 2 x 3 downspouts and a 6 inch gutter system requires 3 x 4 downspouts.
5 inch 5 520 square feet.
That part of the gutter in which the angle obstructs the flow.
Refer to bsen 12056 part 3.
5 inch 5 520 square feet.
Calculate effective maximum roof area b c 2 x length of roof area in m installation.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
Then use the information below to see what size gutter you need.
Choose gutter outlets according to published flow rate capacities.
