Roof Drains


At this time there are a number of different kinds of roof water drains and roof drain system in Mobile, AL and each one is a specific solution to the variety of roof types and their drainage challenges. You need to consider the kind of roof, its size, and the roof pitch to be able to pick the right drain. You also should think about the location of the drain, how much rainwater is expected and safe practices when choosing a roof drain for a house or commercial structure.

Hip roofs, dormers, gable and mansard roofs shed rainwater water because of gravitational force. Flat roofs, conversely, collect water. Unless this water is directed out and away from the flat roof structure, it will create pools of water that may eventually leak and the accumulated weight may eventually cause compromising the integrity of the structure. That is the reason that roofs with a pitch of under 2% ought to have roof drains positioned in the lowest areas on the roof in which water pools and need to be evenly spread all throughout the roof top.

Kinds of Roof Drains


There are a number of distinct 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 collect rainwater that travels by means of gravity to the roof periphery. Gutters channel this water in the direction of downspouts which steer the water flow down and 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 Drain Scuppers


Scuppers are situated 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 rain water can flow out and drain the roof surface. Scuppers can hook up to a downspout, or could be extended to make sure 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 outside or in to a sewer system. Several styles of inner roof drains have domes, strainers or covers that prevent trash from obstructing the roof drain pipe. These kinds of drains operate via gravity channeling pooling water thru the roof drain system. They are made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient alternative to gravity drainage. Conventional flat roof drainage allows both air and water to go into 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 produces a siphonic drain that removes air from the system and allows for smaller pipe diameters . When all of the air is removed, a negative air pressure in the tail portion of the drain is established which draws water off the roof siphonically. Although used mainly for flat roofs, siphonic drains can also be installed on pitched roofs.

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