Roof Drains


At this time there are a number of different kinds of roof water drains and roof drain downspout in Pelham, AL and each is a specific solution to the variety of roof styles and their drainage challenges. You must look at the kind of roof, its dimensions, and its roof pitch to be able to choose the most suitable drain. You also need to take into consideration the site of the drain, how much rainwater is expected and safe practices when selecting a roof water drain for a home or business building.

Hip roofs, dormers, gable and mansard roofs shed water due to gravity. Flat roofs, conversely, accumulate rain water. Unless the water is routed out and away from the roof structure, it will develop pools of water that could inevitably leak and the accumulated weight may subsequently result in compromising the integrity of the structure. That is why roofs with a pitch of below 2% should have roof drains positioned in the lowest places on the roof where water pools and need to be uniformly spaced all throughout the roof surface.

Roof Drain Types


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

Roof Drain Scuppers


Scuppers are located on the roof's perimeter. They can also be placed on a balcony or terrace. Small openings are cut in the side of the roof structure so that rain water can flow out and drain the roof surface. Scuppers can attach to a downspout, or could be lengthened to make sure that water is directed 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 places on the roof and connect to interior drainage pipes that route water outdoors or in to a sewer system. Several styles of inner roof drains have domes, strainers or covers which keep trash from obstructing the roof drain pipe. These kinds of drains work via gravity channeling standing water through the roof drain system. They can be constructed from PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more effective substitute for gravity drainage. Traditional flat roof drainage allows both air and water to go into the drain system producing pipe space occupied by both air and water. By incorporating an engineered baffle to the sump of the drain body it produces a siphonic drain that removes air from the system and permits smaller pipe diameters . When all of the air is eliminated, a negative air pressure in the tail portion of the drain is established which pulls rainwater off the roof siphonically. Though used mainly for flat roofs, siphonic drains can also be set up on pitched roofs.

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