How Toselect A Roof Drain

It is an essential element to ensure water drains properly off of your roof.

How toselect a roof drain.

Roofing materials are designed specifically to be compatible with the pitch of the roof. The result is the number of drains needed. Sizing the drains for each system including the number of drains required is based on. 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.

To select the proper roof drain the following information must be known. 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. First and foremost be sure to comply with all local plumbing codes. The roof structure may sag due to the added weight of ponding water.

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. Clogged roof drains ponding water sagging roofs. 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 above sizing data is offered as a guide only.

Roof drains for flat or low slope roofs come in a few standard types. Ipc provides four steps to size the roof drains on a building. To select the proper roof drain the following information must be deter mined by the designer specifier. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table.

The old bowl may be a little or a lot too shallow for this. 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. Calculate drains needed. The primary reason roof pitch exists in the first place is to redirect water.

The pitch of your roof also helps determine the type of materials that can be used on your roofing system. When selecting a roof drain note. In that case you would use one of our smaller bowl drains. 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.