How Toselect A Roof Drain

Roof drains for flat or low slope roofs come in a few standard types.

How toselect a roof drain.

The result is the number of drains needed. In that case you would use one of our smaller bowl drains. The roof structure may sag due to the added weight of ponding water. Drain by gravity to a seepage pit or catch basin located on the property see french drain below.

The zurn roof drains and drain accessories represent more than 100 years of experience in supplying engineered roof drainage equipment to the construction market. 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. The water weight compresses roof insulation leading to more ponding. Drain by gravity to a nearby storm drainage system.

Clogged roof drains ponding water sagging roofs. Sizing the drains for each system including the number of drains required is based on. 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 clamp tite small bowl commercial drain and value drains are designed to meet this.

The above sizing data is offered as a guide only. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. 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. 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.

The old bowl may be a little or a lot too shallow for this. 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. Any clog in the internal drain or scuppers leads to ponding where water simply sits on your roof. Pump roof runoff from a collecting basin or pit at the building to a remote seepage pit storm sewer or catch basin.

Take the roof s total square footage and divide by the total square footage handled by one drain. 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. To select the proper roof drain the following information must be known. Calculate drains needed.

When selecting a roof drain note. To select the proper roof drain the following information must be deter mined by the designer specifier. In these conditions typical solutions to disposing of roof runoff include.