Roof Rain Water Down Pipe

Rainwater calculations on face value guttering installation is a piece of cake but it is amazing how many installers get it wrong.

Roof rain water down pipe.

Water collected by a rain gutter is fed usually via a downpipe also called a leader or conductor from the roof edge to the base of the building where it is either discharged or collected. Down pipe size not listed a few of the uncommon pipe sizes are not listed eg sizes smaller than 90mm 125mm dia etc. Other roof outlets include stainless steel rainwater outlets cast iron rainwater outlets flat roof drainage outlet solutions and brand specific aco roof outlets and caro roof outlets. Downspouts are most commonly seen attached to the corners of home or building.

Calculating effective roof areas where gutter angles are installed. The down pipe can terminate in a shoe and discharge directly onto the surface but using modern construction techniques would be connected through an inspection chamber to a drain that led to a surface. Rainwater pipe sizes with the exception of the deepflow150 gutter system which has an 82mm diameter downpipe all other marley pvcu gutter systems incorporate outlets suitable for 68mm circular or 65mm square rainwater pipes. The first step in sizing a roof drain is to calculate the surface area of the roof that the drains will be covering as well as the average hourly rainfall rate at the building location.

This is where the rainwater is lead away from the building s foundation so that no rainwater is able to pool around the building. This size of downpipe has been selected as it has the necessary capacity to accommodate the maximum flow from any. The formula in qudm is designed for field inlets and not roof outlets. Roof rain water outlets rwo s are much smaller and seem to have a greater resistance to the flow.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. This can be calculated by using the following formula see diagram below. The building regulation s part h drainage and water disposal requires that adequate provision is made for rainwater to be carried from the roof of buildings. A rainwater downpipe is a pipe that is used to direct rainwater away from a building typically from roof guttering to a drainage system it is sometimes also referred to as a downspout drain spout roof drain pipe or leader.

Ring seals are epdm and natural rubber complying with the requirements of bs 2494 1976. Sizing a roof water drain. Downpipe fittings and connectors are used to join sections of downpipe together or to connect them to other parts of the guttering system they form waterproof and durable seals ensuring that rainwater is effectively drained away.