Roof Drains


There are a number of different types of roof drains and roof drain pan in Birmingham, AL and each one is an unique approach to the wide range of roof types and their drainage issues. You must consider the kind of roof, its size, and the roof pitch to be able to choose the most suitable drain. You also should take into consideration the site of the drain, how much rainwater is anticipated and safe practices when selecting a roof water drain for a home or commercial building.

Hip roofs, dormers, gable and mansard roofs shed water thanks to gravity. Flat roofs, alternatively, collect rain water. Unless the water is routed out and away from the flat roof structure, it will develop pools of water that could eventually leak and the accumulated weight will eventually cause compromising the integrity of the structure. That is why roofs with a slope of under two percent should have roof drains positioned at the lowest spots on the roof where water pools and need to be uniformly spaced all throughout the roof top.

Roof Drain Kinds


There are a number of distinct variations of roof drains. They generally fall into 2 categories: pitched roof drains and flat roof drains. Pitched roof rainwater drains normally comprise gutters that accumulate rainwater that travels by means of gravity down to the roof edge. Gutters channel this water towards downspouts which direct the water flow down and far away from the building 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 a roof's perimeter. Scuppers can also be installed 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 lengthened so that water is directed off of the structure sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. These are positioned at low spots on the roof and attach to interior drainage pipes that route water outside or into a sewer system. Many versions of internal roof drains have domes, strainers or covers which prevent trash from blocking the roof drain pipe. These kinds of drains operate via gravity funneling pooling water through the roof drain system. They are made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient substitute for gravity drainage. Standard flat roof drainage permits both air and water to enter the drain system producing pipe space occupied by both air and water. By adding an engineered baffle to the sump of the drain body it produces a siphonic drain which removes air from the system and permits smaller sized pipe diameters to be used. When all of the air is eliminated, a negative air pressure in the tail piece of the drain is set up which draws water off the roof siphonically. Although used primarily for flat roofs, siphonic drains can also be installed on pitched roofs.

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