How Toselect A Roof Drain

When the through building roof drain system has become clogged even if it does not burst and lead to building flooding it causes other building problems.

How toselect a roof drain.

To select the proper roof drain the following information must be known. Roof drains for flat or low slope roofs come in a few standard types. The drains must allow a large volume of water equal to the square footage of your roof times the number of inches of rain to drain quickly. Type of roof construction roof pitch maximum volume of expected rainfall and storm design criteria this information must be obtained from your local weather bureau and or.

Pump roof runoff from a collecting basin or pit at the building to a remote seepage pit storm sewer or catch basin. The best type for the application depends on several factors such as the size and slope of the roof the desired appearance and how much regular maintenance the drain system might need. The above sizing data is offered as a guide only. The zurn roof drains and drain accessories represent more than 100 years of experience in supplying engineered roof drainage equipment to the construction market.

In these conditions typical solutions to disposing of roof runoff include. First and foremost be sure to comply with all local plumbing codes. Determine 100 year 1 hour rainfall rate used for location of building select number of roof drains and calculate the roof area sloped to each drain size horizontal storm drainage piping size vertical storm drainage piping. The result is the number of drains needed.

The water weight compresses roof insulation leading to more ponding. Sizing the drains for each system including the number of drains required is based on. To select the proper roof drain the following information must be deter mined by the designer specifier. In that case you would use one of our smaller bowl drains.

Drain by gravity to a seepage pit or catch basin located on the property see french drain below. The new drain must fit flush on the roof surface inside the old drain bowl and the new outlet pipe must fit inside the old outlet pipe. Drain by gravity to a nearby storm drainage system. Calculate drains needed.

Clogged roof drains ponding water sagging roofs. Ipc provides four steps to size the roof drains on a building. The roof structure may sag due to the added weight of ponding water. Take the roof s total square footage and divide by the total square footage handled by one drain.

The old bowl may be a little or a lot too shallow for this. The clamp tite small bowl commercial drain and value drains are designed to meet this. Any clog in the internal drain or scuppers leads to ponding where water simply sits on your roof.