If a roof s various drainage areas call for different size gutters go for the biggest one k style.
Calculate gutter size uk.
Total roof area also affects runoff.
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.
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.
Depending on building type a safety factor should be allowed for the sizing of internal gutters.
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.
Gutter ratio l1 l1 l2 where.
Gather some basic weather information to calculate the proper size for gutters and downspouts for a house.
For a typical gutter run up to a maximum of 10m the ratio of gutter lengths is calculated from.
5 inch 2 500 square feet.
6 inch 7 960 square feet.
An inch of rain is not much but it if falls in half an hour it could flood a gutter.
5 inch 5 520 square feet.
Calculate the area of a roof to work out how much guttering is required.
Match your downspouts to the gutter size you chose in step 7.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
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.
Then use the chart below to see what size gutter you need.
The total rainfall and how rapidly it falls will affect the runoff from the roof.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
Roof drainage layout and calculations.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
That part of the gutter in which the angle obstructs the flow.
Determine the size of your downspout.
Refer to bsen 12056 part 3.
Then use the information below to see what size gutter you need.
Calculate effective maximum roof area b c 2 x length of roof area in m installation.
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.
These figures are based on a rainfall intensity of 75mm hr roof pitch not exceeding 50º gutters running full.
Refer to the gutter packaging or specification for the recommended downspout size.
6 inch 7 960 square feet.
For accurate project specific advice on rainwater flow calculations contact our friendly knowledgeable team on 0800 644 44 26.