How Many Downpipes Do I Need For My Roof

Choosing a contractor contractor checklist financing your roof re roof 101.

How many downpipes do i need for my roof.

Average catchment per downpipe roof catchment area. Size downspouts to fit the gutter. It is the roof area the pitch of the roof and the number of drops downpipes coming down from outlets in the guttering around the building determine the flow we will need to know these to calculate the flow capacity for you. Frequency and positioning of outlets downpipes.

Build your roof empowers you to select each layer and component that goes into your total protection roofing system so that you get. The average roll of 15 pound roofing felt covers about 400 ft 2 or 4 squares while the average roll of 30 pound roofing felt covers about 200 ft 2 or 2 squares. Determine the average catchment area per downpipe. You can choose a downpipe size and calculate the number required and the corresponding eaves gutter size.

Doubling the number of downspouts halves the required capacity for each. Per downpipe 223 8 47 4 76m 2 five downpipes are required round up to the next whole number step 6. Rolls of felt are 36 wide x 144 long for 15 and 72 long for 30. Always check the measurements of your building and work out exactly how much downpipe will be serving each gutter.

Downpipes should not serve more than 12 metres of gutter length for each downpipe. 6 inch 7 960 square feet. The program will calculate the size and number of downpipes downspouts leaders required and the eaves gutter sizes for any roof. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.

Roof area m gutter flow litres sec roof area m downpipe at centre half round 76mm 0 7 34 0 8 38 112mm 1 8 86 2 6 125 squareflo 3 2 154 3 8 182 125 68mm downpipe 3 8 182 4 6 221 82mm downpipe 4 0 191 4 9 235 regency 4 2 202 4 7 226 highflo 5 4 258 6 0 289 stormflo 110mm 11 1 534 12 4 598 160mm 12 5 601 14 0 673 downpipe at end half. Calculate the number of outlets per run. To calculate the average catchment per downpipe divide the roof catchment area by the number of downpipes. You do not want to put extra pressure on the system.

How many rolls of felt will you need roofing felt is sold by the roll. Storm damage how to spot a roof leak signs of roof damage signs that you need a new roof ice damming. Also the various styles of guttering that are available have different flow rates. 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. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. 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.