How Toselect A Roof Drain

To select the proper roof drain the following information must be deter mined by the designer specifier.

How toselect a roof drain.

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 local code authority desired rate of drainage. The pitch of your roof also helps determine the type of materials that can be used on your roofing system. 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 old bowl may be a little or a lot too shallow for this.

To select the proper roof drain the following information must be known. The above sizing data is offered as a guide only. 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. Floor drains or area drains when used to drain exterior areas should have an open area equal to twice the transverse area of the connecting pipe table 1 see roof drain section for rainfall and sizing data table 1 recommended grate free areas for various outlet pipe sizes.

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. Ipc provides four steps to size the roof drains on a building. Take the roof s total square footage and divide by the total square footage handled by one drain. In that case you would use one of our smaller bowl drains.

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. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. The result is the number of drains needed. Clogged roof drains ponding water sagging roofs.

The roof structure may sag due to the added weight of ponding water. It is an essential element to ensure water drains properly off of your roof. Calculate drains needed. When selecting a roof drain note.

Roofing materials are designed specifically to be compatible with the pitch of the roof. The clamp tite small bowl commercial drain and value drains are designed to meet this. The zurn roof drains and drain accessories represent more than 100 years of experience in supplying engineered roof drainage equipment to the construction market. The primary reason roof pitch exists in the first place is to redirect water.

Sizing the drains for each system including the number of drains required is based on.