Roof Drains


There are a few different kinds of roof water drains and roof drain system in Madison, AL and each one is an unique approach to the wide range of roof styles and their drainage issues. You must look at the type of roof, its size, and its roof pitch to be able to pick the correct drain. You also may want to take into consideration the site of the drain, how much rainwater is expected and safety when choosing a roof water drain for a residence or business building.

Hip roofs, dormers, gable and mansard roofs shed rainwater water due to gravity. Flat roofs, conversely, collect water. Until the water is directed out and away from the roof , it will create pools of water that could inevitably leak and the amassed weight will subsequently result in structural damage. That is the reason that roofs with a pitch of less than 2% should have roof drains positioned at the lowest places on the roof where water puddles and need to be evenly spread throughout the roof surface.

Roof Drain Types


There are a number of distinct alternatives of roof drains. They basically fall into two categories: pitched roof drains and flat roof drains. Pitched roof drains usually consist of gutters which collect rainwater which passes by means of gravity down to the roof periphery. Gutters direct this water in the direction of downspouts which steer the water flow down and far away from the building or in to sewers. Flat roof drains can be one of three primary types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on the 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 hook up to a downspout, or can be extended so that water is directed off of the building sides and foundation.

Interior Roof Drains


There are many kinds of inner drains for flat roofs. These are installed at low spots in the roof and connect to interior drainage pipes that route water outdoors or into a sewer system. Many designs of internal 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 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 effective substitute for gravity drainage. Conventional flat roof drainage permits 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 creates a siphonic drain which eliminates air from the system and permits smaller sized pipe diameters . When all of the air is removed, a negative air pressure in the tail portion of the drain is established which pulls 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 system in and around Madison, Alabama, give us a call. We'd be glad to help.