Roof Drains


At this time there are a few distinct varieties of roof water drains and roof drain cover in Semmes, AL and each one is an unique answer to the variety of roof types and their drainage issues. You should look at the type of roof, its dimensions, and its roof pitch to be able to select the right drain. You also should think about the location of the drain, what amount of rainwater is expected and safe practices when selecting a roof water drain for a home or commercial building.

Hip roofs, dormers, gable and mansard roofs shed rainwater water because of gravitational force. Flat roofs, conversely, collect water. Unless this water is guided out and away from the flat roof structure, it will most likely create pools of water that could inevitably leak and the amassed weight may subsequently cause compromising the integrity of the structure. That is the reason that roofs with a pitch of below 2% ought to have roof drains situated in the lowest areas on the roof where water puddles and need to be uniformly spread all throughout the roof top.

Roof Drain Types


There are several distinct alternatives of roof drains. They basically fall into 2 groups: pitched roof drains and flat roof drains. Pitched roof rainwater drains normally consist of gutters which accumulate rainwater which travels via gravity to the roof edge. Gutters direct this water in the direction of downspouts which direct the water flow down and far away from the building 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 periphery. Scuppers can also be placed on a balcony or terrace. Small openings are cut in the side of the roof structure so rain water can flow out and drain the roof top. Scuppers can connect to a downspout, or could be lengthened so that water is directed off of the structure sides and foundation.

Inner Roof Drains


There are quite a few different types of inner drains for flat roofs. They are installed at low areas in the roof and connect to inner drainage pipes that direct water outdoors or into a sewer system. Several versions of internal roof drains have domes, strainers or covers which keep trash from clogging the roof drain pipe. These types of drains work via gravity funneling pooling water through the roof drain system. They are constructed from PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient alternative to gravity drainage. Standard flat roof drainage allows 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 body it creates a siphonic drain that eliminates air from the system and permits smaller sized pipe diameters to be used. When all air is eliminated, a negative air pressure in the tail portion of the drain is established which attracts rainwater off the roof siphonically. Although used mainly for flat roofs, siphonic drains can also be installed on angled roofs.

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