There are a few different varieties of roof drains and roof drain pipe in Anniston, AL and each one is a specific answer to the wide range of roof styles and their drainage challenges. You need to look at the kind of roof, its size, and the roof pitch to be able to pick the correct drain. You also need to take into account the site of the drain, how much rainwater is anticipated and safety when selecting a roof drain for a house or commercial building. Hip roofs, dormers, gable and mansard roofs shed water because of gravity. Flat roofs, conversely, collect water. Until the water is guided out and away from the roof structure, it will develop pools of water that could eventually leak and the amassed weight will subsequently cause damage to the structure. That is the reason that roofs with a pitch of below 2% ought to have roof drains positioned in the lowest spots on the roof where water puddles and should be evenly spread all throughout the roof surface.
Types of Roof Drains
There are several different variations of roof drains. They generally fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof drains usually consist of gutters which accumulate rainwater that passes via gravity down to the roof edge. Gutters transport this water in the direction of downspouts which direct the water flow down and far away from the structure or into sewer lines. Flat roof drains can be one of three primary types: scuppers, inner drains or siphonic drains.
Roof Drain Scuppers
Scuppers are situated on the roof's periphery. Scuppers can also be installed on a balcony or terrace. Small openings are cut in the side of the roof structure so water can flow out and drain the roof top. Scuppers can hook up to a downspout, or could be lengthened so that water is guided off of the structure 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 attach to inner drainage pipes that direct water outdoors or into a sewer system. Many styles of inner roof drains have domes, strainers or covers that keep trash from clogging the roof drain pipe. These types of drains operate via gravitational force funneling standing water through the roof drain system. They are constructed from PVC, cast iron or cast aluminum.
Siphonic Roof DrainsSiphonic roof drains are a more effective substitute for gravity drainage. Traditional flat roof drainage permits both air and water to go into the drain system producing pipe space which is occupied by both air and water. By incorporating an engineered baffle to the sump of the drain body it produces a siphonic drain that removes air from the system and allows for smaller pipe diameters to be used. When all air is eliminated, a negative air pressure in the tail portion of the drain is established 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 pipe in and around Anniston, Alabama, give us a call. We'd be glad to help.