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