Roof Drains


At this time there are several different types of roof drains and cast iron roof drain in Mobile, AL and each one is an unique solution to the variety of roof types and their drainage issues. You must look at the type of roof, its dimensions, and its roof pitch to be able to select the right drain. You also need to take into account the site of the drain, what amount of rainwater is expected and safe practices when selecting a roof drain for a home or commercial building.

Gambrel, dormers, hip and gable roofs shed rainwater water thanks to gravitational force. Flat roofs, on the other hand, accumulate rain water. Until this water is guided out and away from the roof , it will most likely develop pools of water that may inevitably leak and the amassed weight may eventually cause damage to the structure. That is the reason that roofs with a pitch of under 2% should have roof drains located at the lowest places on the roof where water puddles and need to be uniformly spread all throughout the roof top.

Roof Drain Types


There are several different variations of roof drains. They basically fall into 2 groups: pitched roof drains and flat roof drains. Pitched roof rainwater drains usually comprise gutters which accumulate rainwater that passes via gravity to the roof edge. Gutters channel this water towards downspouts which direct the water flow down and far away from the building or into sewers. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


Scuppers are situated on a roof's perimeter. Scuppers can also be placed on a balcony or terrace. Small holes are cut into the side of the roof structure so that rain water can empty and drain the roof surface. Scuppers can hook up to a downspout, or could be extended so that water is directed away from the structure sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. These are installed at low spots in the roof and connect to interior drainage pipes that direct water outside or in to a sewer system. Many designs of inner roof drains have domes, strainers or covers which prevent debris from obstructing the roof drain pipe. These types of drains operate via gravity funneling pooling water thru the roof drain system. They are made from PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient substitute for gravity drainage. Conventional flat roof drainage permits both air and water to enter the drain system creating pipe space which is occupied by both air and water. By incorporating an engineered baffle to the sump of the drain system it produces a siphonic drain which eliminates air from the system and permits smaller pipe diameters to be used. When all of the air is eliminated, a negative air pressure in the tail portion of the drain is set up which attracts water off the roof siphonically. Though used mainly for flat roofs, siphonic drains can also be installed on pitched roofs.

If you need more information about flat roof drain or cast iron roof drain in and around Mobile, Alabama, give us a call. We'd be glad to help.