Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
Calculate gutter size uk.
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.
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.
Choose gutter outlets according to published flow rate capacities.
Gather some basic weather information to calculate the proper size for gutters and downspouts for a house.
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.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
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.
Roof drainage layout and calculations.
Refer to the gutter packaging or specification for the recommended downspout size.
Then use the chart below to see what size gutter you need.
Picking your gutter size.
Gutter ratio l1 l1 l2 where.
Calculate the area of a roof to work out how much guttering is required.
Then use the information below to see what size gutter you need.
An inch of rain is not much but it if falls in half an hour it could flood a gutter.
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.
Calculate effective maximum roof area b c 2 x length of roof area in m installation.
These figures are based on a rainfall intensity of 75mm hr roof pitch not exceeding 50º gutters running full.
6 inch 7 960 square feet.
5 inch 2 500 square feet.
5 inch 5 520 square feet.
That part of the gutter in which the angle obstructs the flow.
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.
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.
Determine the size of your downspout.
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.
Refer to bsen 12056 part 3.
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.
