Roof Drains


There are several different varieties of roof drains and roof drain system in Grand Bay, AL and each one is an unique solution to the variety of roof types and their drainage issues. You need to consider the type of roof, its size, and the roof pitch to be able to select the most suitable drain. You also need to take into account the site of the drain, what amount of rainwater is expected and safe practices when selecting a roof water drain for a house or commercial structure.

Hip roofs, dormers, gable and mansard roofs shed water thanks to gravity. Flat roofs, conversely, collect rain water. Unless this water is routed out and away from the flat roof structure, it will create pools that could eventually leak and the amassed weight will subsequently result in damage to the structure. That is why roofs with a pitch of less than two percent should have roof drains situated at the lowest areas on the roof in which water puddles and should be evenly spread throughout the roof surface.

Roof Drain Kinds


There are several distinct variations of roof drains. They basically fall into two categories: pitched roof drains and flat roof drains. Pitched roof drains normally comprise gutters which accumulate rainwater that passes via gravity down to the roof periphery. Gutters direct this water in the direction of downspouts which route the water flow down and far away from the building or in to sewers. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


Scuppers are situated on a 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 water can empty and drain the roof top. Scuppers can hook up to a downspout, or can be extended to make sure that water is directed away from the building sides and foundation.

Interior Roof Drains


There are quite a few different kinds of inner drains for flat roofs. They are installed at low spots in the roof and attach to inner drainage pipes that route water outdoors or in to a sewer system. Several versions of internal roof drains have domes, strainers or covers that prevent trash from obstructing the roof drain pipe. These kinds 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 Drains

Siphonic roof drains are a more effective substitute for gravity drainage. Standard flat roof drainage permits 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 removes air from the system and permits smaller sized pipe diameters . When all of the air is removed, a negative air pressure in the tail piece of the drain is set up which attracts water off the roof siphonically. Though used primarily 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 Grand Bay, Alabama, give us a call. We'd be glad to help.