Roof Drains


There are a number of distinct types of roof water drains and cast iron roof drain in Pelham, AL and each one is an unique solution to the variety of roof styles and their drainage challenges. You should think about the kind of roof, its size, and the roof pitch to be able to select the right drain. You also may want to take into consideration the site of the drain, what amount of rainwater is expected and safe practices when selecting a roof water drain for a house or business structure.

Hip roofs, dormers, gable and mansard roofs shed water because of gravity. Flat roofs, alternatively, accumulate rain water. Unless the water is directed out and away from the roof structure, it will create pools of water that could eventually leak and the accumulated weight will subsequently result in structural damage. That is why roofs with a pitch of below two percent ought to have roof drains situated in the lowest places on the roof in which water pools and should be evenly spread throughout the roof surface.

Types of Roof Drains


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 usually consist of gutters that accumulate rainwater which travels via gravity to the roof edge. Gutters direct this water towards downspouts which route the water flow down and away from the building or into sewers. 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 periphery. Scuppers 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 surface. Scuppers can connect to a downspout, or can be lengthened so that water is directed away from the structure sides and foundation.

Inner Roof Drains


There are many kinds of inner drains for flat roofs. These are installed at low places on the roof and connect to interior drainage pipes that route water outside or into a sewer system. Many models of internal roof drains have domes, strainers or covers which keep debris from obstructing the roof drain pipe. These kinds of drains work via gravitational force channeling standing water thru 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 alternative to gravity drainage. Traditional flat roof drainage permits both air and water to enter 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 system 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 set up which pulls rainwater off the roof siphonically. Though used primarily for flat roofs, siphonic drains can also be set up on pitched roofs.

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