Roof Drains


There are several different types of roof water drains and roof drain pipe in Semmes, AL and each is an unique approach to the wide range of roof types and their drainage issues. You must take into consideration the type of roof, its size, and its roof pitch to be able to choose the correct drain. You also need to take into account the site of the drain, what amount of rainwater is anticipated and safety when choosing a roof 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. Unless the water is routed out and away from the roof structure, it will most likely create pools of water that may inevitably leak and the amassed weight may subsequently result in compromising the integrity of the structure. That is the reason that roofs with a slope of less than 2% should have roof drains located at the lowest places on the roof in which water pools and should be evenly spaced all throughout the roof surface.

Kinds of Roof Drains


There are a number of different variations of roof drains. They basically fall into 2 groups: pitched roof drains and flat roof drains. Pitched roof rainwater drains usually comprise gutters that accumulate rainwater which travels by means of gravity down to the roof edge. Gutters channel this water in the direction of downspouts which direct the water flow down and away from the building 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 situated on a 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 empty and drain the roof surface. Scuppers can hook up to a downspout, or could be lengthened to make sure that water is directed away from the structure sides and foundation.

Interior Roof Drains


There are many types of inner drains for flat roofs. These are positioned at low areas in the roof and connect to inner drainage pipes that direct water outdoors or into a sewer system. Many designs of inner roof drains have domes, strainers or covers which keep debris from clogging the roof drain pipe. These types of drains operate via gravity 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 efficient alternative to gravity drainage. Conventional flat roof drainage permits both air and water to go into 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 body it produces a siphonic drain that removes air from the system and permits smaller pipe diameters to be used. When all of the air is removed, a negative air pressure in the tail piece of the drain is established which attracts water off the roof siphonically. Though used mainly for flat roofs, siphonic drains can also be set up on pitched roofs.

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