Roof Downpipe Design

Roof drainage systems should be designed and detailed by a suitably qualified trade or professional in accordance with the bca and the australian standards.

Roof downpipe design.

Designing the roof as an integral component of the overall building design will ensure roof drainage is not compromised. 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. Design of eaves gutters box gutters downpipes to the australian national plumbing code as nzs 3500 3. Roof systems limtied showroom corner of carlos wrightson road woodbrook port of spain trinidad and tobago.

They determine the roof area slope and rainfall intensity. They also influence the use of gutters and downspouts roof drains and scuppers. A downpipe is typically vertical and extends to ground level. In many instances though not necessarily always you will want the gutter and downpipe sizes to be the same for all gutters and downpipes on the project.

Approved document h suggests that to achieve this roofs should be designed with a suitable fall towards either a surface water collection channel or gutter that surface water to vertical rainwater downpipes which in turn connect the discharge to the drainage system. The bca specifically provides standards for the design and construction of downpipes and gutters and calls up the as nzs 3500 3. Quantity and placement of downpipes. The building type its appearance and location have a direct influence on the design of the roof drainage system.

And the provision of appropriate overflow devices. The process of calculating the required size of gutters and downspouts involves. Calculators for designing eaves gutters box gutters downpipes pipes and open channels etc to australian standards. This is particularly important with 2 storey designs where upper floor walls intersect lower storey roofs and drain water onto the roof increasing the total roof catchment area.

Particular reference should be made to the correct sizing of gutter. For roof slope less than 12 5 degs design as a box gutter. Builders plumbers and roof plumbers installing roof drainage systems should be fully aware of all the factors for consideration requirements and options available.