Roof Drains


At this time there are a few distinct kinds of roof water drains and roof drain pan in Helena, AL and each is a specific approach to the wide range of roof types and their drainage concerns. You should think about the kind of roof, its size, and the roof pitch to be able to choose the most suitable drain. You also may want to take into consideration the location of the drain, what amount of rainwater is anticipated and safe practices when selecting a roof drain for a home or business structure.

Hip roofs, dormers, gable and mansard roofs shed rainwater water thanks to gravity. Flat roofs, conversely, collect water. Unless the water is guided out and away from the roof structure, it will develop pools of water that could inevitably leak and the accumulated weight will eventually result in compromising the integrity of the structure. That is why roofs with a pitch of below two percent should have roof drains located in the lowest spots on the roof in which water pools and should be evenly spread all throughout the roof surface.

Types of Roof Drains


There are several distinct alternatives of roof drains. They basically fall into two categories: pitched roof drains and flat roof drains. Pitched roof rainwater drains usually comprise gutters that accumulate rainwater which passes via gravity to the roof periphery. Gutters transport this water towards downspouts which direct the water flow down and far away from the structure 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 situated on a roof's perimeter. Scuppers can also be put in on a balcony or terrace. Small holes are cut in the side of the roof structure so that water can empty and drain the roof top. Scuppers can attach to a downspout, or can be lengthened so that water is directed off of the structure sides and foundation.

Inner Roof Drains


There are many types of inner drains for flat roofs. These are installed at low places in the roof and attach to interior drainage pipes that drive water outside or into a sewer system. Many models of inner roof drains have domes, strainers or covers which keep debris from obstructing the roof drain pipe. These types of drains work via gravitational force funneling pooling water through the roof drain system. They are made from PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more effective alternative to 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 adding an engineered baffle to the sump of the drain system it produces a siphonic drain that eliminates air from the system and allows for smaller pipe diameters . When all air is eliminated, a negative air pressure in the tail piece of the drain is set up which pulls rainwater off the roof siphonically. Although used mainly for flat roofs, siphonic drains can also be installed on pitched roofs.

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