Roof Drains


At this time there are a few different varieties of roof drains and roof drain pipe in Montgomery, AL and each is an unique approach to the variety of roof styles and their drainage issues. You should think about the kind of roof, its size, and its roof pitch to be able to select the right drain. You also may want to think about the site of the drain, how much rainwater is expected and safe practices when selecting a roof drain for a house or commercial structure.

Hip roofs, dormers, gable and mansard roofs shed rainwater water because of gravity. Flat roofs, alternatively, collect rain water. Until the water is directed out and away from the roof structure, it will most likely develop pools of water that could 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 below two percent should have roof drains located in the lowest spots on the roof in which water puddles and should be evenly spread throughout the roof surface.

Roof Drain Types


There are a number of distinct alternatives of roof drains. They basically fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof drains usually comprise gutters that collect rainwater that travels via gravity to the roof edge. Gutters channel this water towards downspouts which route the water flow down and far away from the building or in to sewers. Flat roof drains can be one of three main 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 holes are cut into the side of the roof structure so rain water can empty and drain the roof surface. Scuppers can connect to a downspout, or can be lengthened to make sure that water is guided away from the structure sides and foundation.

Inner Roof Drains


There are many kinds of inner drains for flat roofs. They are positioned at low places on the roof and attach to interior drainage pipes that direct water outside or in to a sewer system. Many versions of inner roof drains have domes, strainers or covers which keep debris from clogging the roof drain pipe. These types of drains work via gravitational force channeling pooling water through the roof drain system. They can be made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient substitute for gravity drainage. Conventional flat roof drainage allows both air and water to go into the drain system creating pipe space which is occupied by both air and water. By incorporating an engineered baffle to the sump of the drain system it creates a siphonic drain which eliminates air from the system and permits smaller sized pipe diameters to be used. When all air is removed, a negative air pressure in the tail portion of the drain is set up which pulls water off the roof siphonically. Although 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 Montgomery, Alabama, give us a call. We'd be glad to help.