Roof Drains


There are a number of distinct types of roof drains and roof drain pipe in Piedmont, AL and each is an unique solution to the variety of roof types and their drainage challenges. You must think about the type of roof, its dimensions, and the roof pitch to be able to choose the right drain. You also may want to take into consideration the location of the drain, how much rainwater is anticipated and safety when choosing a roof drain for a house or business structure.

Gable, dormer, mansard and hip roofs shed water because of gravitational force. Flat roofs, on the other hand, accumulate rain water. Unless 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 may subsequently cause damage to the structure. That is why roofs with a pitch of under 2% ought to have roof drains located in the lowest spots on the roof in which water pools and should be uniformly spaced all throughout the roof top.

Roof Drain Types


There are several distinct variations of roof drains. They generally fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof rainwater drains normally comprise gutters that accumulate rainwater that travels by means of gravity to the roof edge. Gutters channel 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 Drain Scuppers


Scuppers are located on a roof's periphery. Scuppers can also be installed on a balcony or terrace. Small openings are cut in the side of the roof structure so that rain water can empty 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 many types of inner drains for flat roofs. They are positioned at low spots in the roof and connect to interior drainage pipes that drive water outdoors or into a sewer system. Several models of internal roof drains have domes, strainers or covers that keep debris from clogging the roof drain pipe. These kinds of drains operate via gravity funneling standing 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 effective alternative to gravity drainage. Traditional flat roof drainage allows both air and water to enter the drain system creating pipe space occupied by both air and water. By adding an engineered baffle to the sump of the drain system it produces a siphonic drain that removes air from the system and allows for smaller sized pipe diameters to be used. When all of the air is removed, a negative air pressure in the tail piece of the drain is set up which pulls rainwater off the roof siphonically. Although used mainly 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 pipe in and around Piedmont, Alabama, give us a call. We'd be glad to help.