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.
How toselect a roof drain.
Buried or underground roof drainage downspout defects clogging overflowing holes corrosion leaks that cause wet basements or crawl areas proper installation of buried downspout extensions proper installation of french drains seepage pits at flat sites gutter downspout defects cause wet basements crawl areas questions answers about installing maintaining repairing buried roof.
Clogged roof drains ponding water sagging roofs.
The roof structure may sag due to the added weight of ponding water.
The clamp tite small bowl commercial drain and value drains are designed to meet 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.
This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table.
Sizing the drains for each system including the number of drains required is based on.
Calculate drains needed.
The pitch of your roof also helps determine the type of materials that can be used on your roofing system.
Take the roof s total square footage and divide by the total square footage handled by one drain.
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.
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.
Ipc provides four steps to size the roof drains on a building.
Roof drains for flat or low slope roofs come in a few standard types.
The primary reason roof pitch exists in the first place is to redirect water.
When selecting a roof drain note.
Roofing materials are designed specifically to be compatible with the pitch of the roof.
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.
In that case you would use one of our smaller bowl drains.
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 above sizing data is offered as a guide only.
To select the proper roof drain the following information must be deter mined by the designer specifier.
To select the proper roof drain the following information must be known.
