Roof Drains


At this time there are several distinct kinds of roof water drains and roof drain downspout in Alabaster, AL and each one is an unique solution to the variety of roof styles and their drainage concerns. You need to look at the type of roof, its size, and the roof pitch to be able to choose the correct drain. You also may want to take into account the location of the drain, how much rainwater is expected and safety when selecting a roof water drain for a house or business structure.

Gable, dormer, mansard and hip roofs shed water due to gravitational force. Flat roofs, conversely, collect rain water. Unless this water is routed out and away from the flat roof , it will create pools of water that could inevitably leak and the accumulated weight will eventually cause damage to the structure. That is why roofs with a pitch of less than two percent should have roof drains positioned at the lowest areas on the roof where water pools and should be evenly spread throughout the roof surface.

Roof Drain Kinds


There are several distinct alternatives of roof drains. They basically fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof rainwater drains usually consist of gutters that collect rainwater which travels by means of gravity down to the roof periphery. Gutters transport this water in the direction of downspouts which steer the water flow down and away from the structure 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 located on a roof's perimeter. They can also be installed on a balcony or terrace. Small openings are cut in the side of the roof structure so water can flow out and drain the roof top. Scuppers can connect to a downspout, or could be extended so that water is guided off of the structure sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. They are positioned at low spots on the roof and attach to inner drainage pipes that direct water outside or in to a sewer system. Many versions of inner roof drains have domes, strainers or covers that keep debris from obstructing the roof drain pipe. These kinds of drains work via gravity funneling standing water through the roof drain system. They can be made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient alternative to 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 body it produces a siphonic drain which eliminates air from the system and allows for smaller sized pipe diameters . When all air is removed, a negative air pressure in the tail portion of the drain is set up which pulls rainwater off the roof siphonically. Though used mainly for flat roofs, siphonic drains can also be set up on angled roofs.

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