Roof Drains


There are a few different kinds of roof drains and roof drain scupper in Birmingham, AL and each is an unique solution to the wide range of roof styles and their drainage issues. You should think about the type of roof, its size, and the roof pitch to be able to choose the right drain. You also may want to take into consideration the site of the drain, how much rainwater is anticipated and safe practices when choosing a roof drain for a residence or business building.

Gambrel, dormers, hip and gable roofs shed water due to gravity. Flat roofs, conversely, accumulate water. Until the water is directed out and away from the flat roof , it will develop pools that may eventually leak and the amassed weight will eventually result in structural damage. That is why roofs with a pitch of below 2% ought to have roof drains located at the lowest places on the roof where water pools and should be uniformly spaced throughout the roof top.

Types of Roof Drains


There are a number of distinct alternatives of roof drains. They basically fall into 2 categories: flat roof drains and pitched roof drains. Pitched roof drains normally consist of gutters that collect rainwater which passes via gravity down to the roof edge. Gutters direct this water in the direction of downspouts which route the water flow down and away from the structure or into sewer lines. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on the 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 flow out and drain the roof top. Scuppers can attach to a downspout, or can be extended to make sure that water is directed away from the building sides and foundation.

Inner Roof Drains


There are many types of inner drains for flat roofs. These are positioned at low places in the roof and connect to inner drainage pipes that direct water outdoors or in to a sewer system. Several designs of internal roof drains have domes, strainers or covers which prevent trash from obstructing the roof drain pipe. These types of drains operate via gravity funneling standing water thru 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 go into the drain system producing pipe space which is occupied by both air and water. By adding an engineered baffle to the sump of the drain body it creates a siphonic drain that removes air from the system and allows for smaller sized pipe diameters to be used. When all air is removed, a negative air pressure in the tail portion of the drain is set up which attracts rainwater off the roof siphonically. Though used primarily 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 scupper in and around Birmingham, Alabama, give us a call. We'd be glad to help.