Roof Drains


There are several different varieties of roof water drains and roof drain pan in Piedmont, AL and each is an unique solution to the wide range of roof types and their drainage concerns. You must think about the type of roof, its dimensions, and the roof pitch to be able to choose the correct drain. You also should think about the location of the drain, how much rainwater is expected and safe practices when selecting a roof drain for a residence or business structure.

Hip roofs, dormers, gable and mansard roofs shed water due 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 develop pools of water that may eventually leak and the accumulated weight will eventually cause structural damage. That is why roofs with a slope of under two percent should have roof drains positioned in the lowest spots on the roof in which water pools and should be evenly spread throughout the roof top.

Roof Drain Types


There are several different alternatives of roof drains. They generally fall into two categories: pitched roof drains and flat roof drains. Pitched roof drains usually consist of gutters that collect rainwater which travels via gravity down to the roof periphery. Gutters direct this water towards downspouts which route the water flow down and away from the building or into sewers. Flat roof drains can be one of three primary types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


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

Inner Roof Drains


There are quite a few different kinds of inner drains for flat roofs. They are installed at low places in the roof and attach to interior drainage pipes that route water outside or into a sewer system. Several versions of inner roof drains have domes, strainers or covers which prevent trash from blocking the roof drain pipe. These kinds of drains operate via gravitational force funneling pooling 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 effective alternative to gravity drainage. Traditional flat roof drainage allows 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 produces a siphonic drain which eliminates air from the system and permits smaller pipe diameters to be used. When all of the air is eliminated, a negative air pressure in the tail portion of the drain is set up which attracts rainwater off the roof siphonically. Although 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 Piedmont, Alabama, give us a call. We'd be glad to help.