Roof Drains


There are a few different kinds of roof drains and roof drain dome in Birmingham, AL and each one is a specific answer to the variety of roof types and their drainage concerns. You need to consider the kind of roof, its size, and its roof pitch to be able to select the right drain. You also may want to think about the site of the drain, how much rainwater is anticipated and safety when choosing a roof drain for a home or business building.

Gambrel, dormers, hip and gable roofs shed rainwater water thanks to gravity. Flat roofs, on the other hand, collect rain water. Unless the water is routed out and away from the flat roof structure, it will most likely develop pools that could inevitably leak and the accumulated weight will subsequently cause damage to the structure. That is why roofs with a pitch of less than two percent should have roof drains situated at the lowest places on the roof in which water pools and should be evenly spaced all throughout the roof top.

Roof Drain Kinds


There are several distinct variations of roof drains. They basically fall into two categories: pitched roof drains and flat roof drains. Pitched roof rainwater drains usually consist of gutters that accumulate rainwater which passes via gravity to the roof edge. Gutters transport this water in the direction of downspouts which direct the water flow down and far away from the structure or into sewer lines. Flat roof drains can be one of three primary types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on a roof's perimeter. They can also be installed on a balcony or terrace. Small holes are cut in the side of the roof structure so rain water can empty and drain the roof top. Scuppers can connect to a downspout, or could be extended to make sure that water is guided off of the structure sides and foundation.

Inner Roof Drains


There are quite a few different types of inner drains for flat roofs. They are installed at low areas on the roof and attach to interior drainage pipes that route water outside or in to a sewer system. Several models of inner roof drains have domes, strainers or covers which prevent debris from blocking the roof drain pipe. These kinds of drains operate via gravitational force channeling standing 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 alternative to gravity drainage. Traditional flat roof drainage allows both air and water to go into 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 creates a siphonic drain that eliminates air from the system and permits smaller sized pipe diameters . When all of the air is removed, a negative air pressure in the tail portion of the drain is set up which attracts rainwater off the roof siphonically. Although used mainly for flat roofs, siphonic drains can also be installed on angled roofs.

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