Roof Drains


There are several different types of roof water drains and roof drain system in Montgomery, AL and each one is an unique answer to the variety of roof types and their drainage challenges. You need to take into consideration the type of roof, its size, and the roof pitch to be able to choose the correct drain. You also may want to take into account the site of the drain, how much rainwater is expected and safety when choosing a roof drain for a house or commercial structure.

Gable, dormer, mansard and hip roofs shed rainwater water because of gravitational force. Flat roofs, alternatively, collect water. Until this water is directed out and away from the flat roof , it will most likely develop pools 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 spots on the roof where water pools and need to be evenly spread all throughout the roof top.

Kinds of Roof Drains


There are several distinct variations of roof drains. They basically fall into 2 groups: pitched roof drains and flat roof drains. Pitched roof drains normally consist of gutters that collect rainwater which travels via gravity down to the roof periphery. Gutters direct this water towards downspouts which direct the water flow down and away from the structure or in to sewer lines. Flat roof drains are one of three main 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 holes are cut in the side of the roof structure so water can empty and drain the roof surface. Scuppers can attach to a downspout, or can be lengthened so that water is guided off of the building sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. They are positioned at low places in the roof and attach to interior drainage pipes that route water outdoors or in to a sewer system. Several models of internal roof drains have domes, strainers or covers which prevent trash from clogging the roof drain pipe. These types of drains work via gravitational force funneling standing 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 substitute for gravity drainage. Standard flat roof drainage allows both air and water to go into the drain system producing pipe space occupied by both air and water. By adding an engineered baffle to the sump of the drain system it produces a siphonic drain which removes air from the system and permits smaller pipe diameters . When all air is eliminated, 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 installed on angled roofs.

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