Roof Drains


There are a number of different types of roof drains and roof drain pan in Prattville, AL and each one is a specific answer to the variety of roof styles and their drainage challenges. You must think about the type of roof, its size, and the roof pitch to be able to select the most suitable drain. You also need to think about the location of the drain, what amount of rainwater is expected and safety when selecting a roof drain for a house or business building.

Hip roofs, dormers, gable and mansard roofs shed water thanks to gravitational force. Flat roofs, conversely, accumulate rain water. Until this water is guided out and away from the roof structure, it will most likely create pools of water that may eventually leak and the accumulated weight may subsequently result in damage to the structure. That is why roofs with a pitch of below two percent should have roof drains positioned in the lowest areas on the roof in which water puddles and should be uniformly spaced all throughout the roof surface.

Roof Drain Types


There are several distinct variations of roof drains. They generally fall into 2 categories: flat roof drains and pitched roof drains. Pitched roof rainwater drains usually consist of gutters which collect rainwater which travels via gravity down to the roof edge. Gutters direct this water in the direction of downspouts which direct the water flow down and away from the structure or into sewer lines. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on a roof's perimeter. They can also be placed on a balcony or terrace. Small openings are cut into the side of the roof structure so that water can flow out and drain the roof top. Scuppers can connect to a downspout, or can be extended so that water is directed away from the structure sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. These are positioned at low areas in the roof and attach to inner drainage pipes that drive water outside or into a sewer system. Several versions of internal roof drains have domes, strainers or covers which keep trash from obstructing the roof drain pipe. These kinds of drains operate via gravity funneling pooling water thru the roof drain system. They can be made from PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more effective alternative to gravity drainage. Conventional flat roof drainage allows both air and water to go into the drain system creating pipe space occupied by both air and water. By incorporating an engineered baffle to the sump of the drain system it produces a siphonic drain which eliminates air from the system and permits smaller pipe diameters . When all of the air is eliminated, a negative air pressure in the tail piece of the drain is set up which pulls water 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 pan in and around Prattville, Alabama, give us a call. We'd be glad to help.