Roof Drains


At this time there are several distinct types of roof drains and roof drain strainer in Dothan, AL and each is an unique answer to the wide range of roof types and their drainage concerns. You should think about the type of roof, its size, and the roof pitch to be able to select the most suitable drain. You also may want to think about the location of the drain, how much rainwater is expected and safe practices when selecting a roof water drain for a residence or commercial building.

Hip roofs, dormers, gable and mansard roofs shed rainwater water due to gravity. Flat roofs, conversely, accumulate rain water. Until the water is guided out and away from the flat roof , it will most likely create pools of water that may eventually leak and the accumulated weight may subsequently cause compromising the integrity of the structure. That is why roofs with a slope of less than 2% should have roof drains positioned in the lowest places on the roof where water pools and need to be evenly spread throughout the roof top.

Roof Drain Types


There are several different variations of roof drains. They generally fall into two categories: pitched roof drains and flat roof drains. Pitched roof drains usually consist of gutters that accumulate rainwater that passes via gravity to the roof edge. Gutters direct this water towards downspouts which steer the water flow down and far away from the structure or in to sewer lines. Flat roof drains are one of three primary types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


Scuppers are located on the roof's periphery. They 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 flow out and drain the roof surface. Scuppers can connect to a downspout, or can be extended to make sure that water is directed away from the building sides and foundation.

Inner Roof Drains


There are quite a few different kinds of inner drains for flat roofs. These are positioned at low areas on the roof and attach to interior drainage pipes that direct water outside or in to a sewer system. Several versions of internal roof drains have domes, strainers or covers that prevent debris from blocking the roof drain pipe. These types of drains operate via gravitational force channeling 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 effective alternative to gravity drainage. Standard flat roof drainage allows both air and water to enter the drain system creating 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 allows for smaller sized pipe diameters to be used. When all air is eliminated, a negative air pressure in the tail portion of the drain is set up which draws rainwater off the roof siphonically. Though 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 strainer in and around Dothan, Alabama, give us a call. We'd be glad to help.