Roof Drains


There are several distinct varieties of roof water drains and roof drain system in Semmes, AL and each one is a specific approach to the variety of roof types and their drainage challenges. You must take into consideration the kind of roof, its size, and its roof pitch to be able to choose the correct drain. You also may want to think about the location of the drain, how much rainwater is expected and safe practices when choosing a roof water drain for a home or commercial structure.

Hip roofs, dormers, gable and mansard roofs shed water due to gravity. Flat roofs, on the other hand, collect water. Until this water is routed out and away from the flat roof , it will most likely develop 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 below 2% ought to have roof drains located at the lowest spots on the roof where water pools and need to be evenly spaced all throughout the roof surface.

Roof Drain Types


There are a number of different alternatives of roof drains. They basically fall into two categories: flat roof drains and pitched roof drains. Pitched roof rainwater drains usually comprise gutters which accumulate rainwater that travels by means of gravity down to the roof periphery. Gutters transport this water towards downspouts which route the water flow down and away from the structure or in to sewers. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on the roof's perimeter. Scuppers can also be put in on a balcony or terrace. Small openings are cut in the side of the roof structure so that rain water can flow out and drain the roof surface. Scuppers can hook up to a downspout, or can be extended so that water is directed off of the structure sides and foundation.

Inner Roof Drains


There are many kinds of inner drains for flat roofs. These are positioned at low places in the roof and attach to interior drainage pipes that drive water outdoors or in to a sewer system. Several models 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 efficient substitute for gravity drainage. Traditional flat roof drainage allows both air and water to enter 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 body it creates a siphonic drain which removes air from the system and allows for smaller sized pipe diameters to be used. When all of the air is eliminated, a negative air pressure in the tail piece of the drain is established which pulls water off the roof siphonically. Though used primarily 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 system in and around Semmes, Alabama, give us a call. We'd be glad to help.