There are a number of different types of roof drains and roof drain system in Athens, AL and each is an unique answer to the variety of roof styles and their drainage issues. You need to consider the type of roof, its dimensions, and its roof pitch to be able to pick the right drain. You also need to think about the location of the drain, what amount of rainwater is expected and safety when choosing a roof drain for a residence or commercial building. Gambrel, dormers, hip and gable roofs shed water due to gravity. Flat roofs, conversely, accumulate water. Until this water is guided out and away from the roof structure, it will develop pools of water that could inevitably leak and the accumulated weight will eventually result in structural damage. That is the reason that roofs with a pitch of less than 2% should have roof drains situated in the lowest spots on the roof in which water puddles and should be evenly spaced throughout the roof surface.
Roof Drain Types
There are a number of distinct variations of roof drains. They generally fall into two categories: flat roof drains and pitched roof drains. Pitched roof drains usually consist of gutters that accumulate rainwater which travels by means of gravity down to the roof periphery. Gutters channel this water in the direction of downspouts which direct the water flow down and far away from the structure or in to sewers. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.
Roof Drain Scuppers
Scuppers are situated on the roof's periphery. They can also be put in on a balcony or terrace. Small holes are cut in the side of the roof structure so that water can flow out and drain the roof top. Scuppers can hook up to a downspout, or could be lengthened to make sure that water is directed off of the building sides and foundation.
Interior Roof Drains
There are quite a few different types of inner drains for flat roofs. They are installed at low spots on the roof and attach to interior drainage pipes that route water outdoors or in to a sewer system. Many versions of inner roof drains have domes, strainers or covers that prevent trash from obstructing the roof drain pipe. These types of drains work via gravity funneling pooling water thru the roof drain system. They can be made of PVC, cast iron or cast aluminum.
Siphonic Roof DrainsSiphonic roof drains are a more effective substitute for gravity drainage. Conventional flat roof drainage allows both air and water to enter the drain system creating pipe space occupied by both air and water. By incorporating an engineered baffle to the sump of the drain body it creates a siphonic drain which eliminates air from the system and allows for smaller pipe diameters . When all air is removed, a negative air pressure in the tail portion of the drain is established which pulls 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 system in and around Athens, Alabama, give us a call. We'd be glad to help.