At this time there are several distinct varieties of roof drains and roof drain cover in Grand Bay, AL and each is an unique answer to the variety of roof styles and their drainage issues. You should consider the type of roof, its dimensions, and the roof pitch to be able to select the right drain. You also should think about the site of the drain, what amount of rainwater is anticipated and safe practices when selecting a roof drain for a house or business structure. Gable, dormer, mansard and hip roofs shed water due to gravitational force. Flat roofs, conversely, collect water. Unless the water is guided out and away from the flat roof structure, it will most likely develop pools of water that could inevitably leak and the amassed weight may eventually result in compromising the integrity of the structure. That is the reason that roofs with a pitch of under 2% should have roof drains situated in the lowest areas on the roof in which water pools and should be evenly spaced throughout the roof surface.
Roof Drain Types
There are a number of distinct variations of roof drains. They generally fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof drains normally comprise gutters that accumulate rainwater that passes via gravity to the roof edge. Gutters transport this water towards downspouts which steer the water flow down and far away from the building or into sewer lines. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.
Roof Drain Scuppers
Scuppers are situated on the roof's perimeter. Scuppers can also be installed on a balcony or terrace. Small holes are cut in the side of the roof structure so that rain water can flow out and drain the roof top. Scuppers can connect to a downspout, or can be lengthened to make sure that water is directed off of the building sides and foundation.
Inner Roof Drains
There are many kinds of inner drains for flat roofs. These are positioned at low areas in the roof and attach to interior drainage pipes that drive water outdoors or in to a sewer system. Many designs of inner roof drains have domes, strainers or covers which prevent trash from clogging the roof drain pipe. These kinds of drains work via gravitational force funneling pooling water thru the roof drain system. They are made from PVC, cast iron or cast aluminum.
Siphonic Roof DrainsSiphonic roof drains are a more effective alternative to gravity drainage. Standard flat roof drainage permits both air and water to go into the drain system creating pipe space occupied by both air and water. By incorporating an engineered baffle to the sump of the drain system it produces a siphonic drain which removes air from the system and permits smaller sized pipe diameters to be used. When all of the air is removed, a negative air pressure in the tail portion of the drain is established which attracts water off the roof siphonically. Though 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 cover in and around Grand Bay, Alabama, give us a call. We'd be glad to help.