Roof Drains


There are several distinct varieties of roof drains and roof drain system in Hartselle, AL and each one is an unique answer to the variety of roof types and their drainage challenges. You should think about the type of roof, its dimensions, and the roof pitch to be able to choose the right drain. You also may want to take into consideration the site of the drain, how much rainwater is expected and safe practices when selecting a roof water drain for a residence or commercial building.

Gambrel, dormers, hip and gable roofs shed rainwater water because of gravitational force. Flat roofs, conversely, accumulate water. Unless this water is routed out and away from the roof structure, it will most likely create pools that may eventually leak and the accumulated weight will eventually result in damage to the structure. That is the reason that roofs with a pitch of less than 2% should have roof drains situated in the lowest places on the roof in which water puddles and should be evenly spread all throughout the roof top.

Roof Drain Kinds


There are several distinct variations of roof drains. They generally fall into 2 groups: flat roof drains and pitched roof drains. Pitched roof drains usually comprise gutters which accumulate rainwater that travels via gravity down to the roof edge. Gutters direct this water in the direction of downspouts which direct the water flow down and far away from the building or in to sewer lines. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on a roof's periphery. They can also be installed on a balcony or terrace. Small holes are cut in the side of the roof structure so rain water can flow out and drain the roof top. Scuppers can connect to a downspout, or can be extended so that water is directed off of the building sides and foundation.

Interior Roof Drains


There are quite a few different kinds of inner drains for flat roofs. These are positioned at low places in the roof and attach to inner drainage pipes that direct water outdoors or in to a sewer system. Several versions of internal roof drains have domes, strainers or covers that keep trash from clogging the roof drain pipe. These types of drains operate via gravity 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 substitute for gravity drainage. Conventional flat roof drainage allows both air and water to enter 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 system it produces a siphonic drain which removes air from the system and permits smaller sized pipe diameters to be used. When all air is eliminated, a negative air pressure in the tail portion of the drain is set up which attracts rainwater 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 system in and around Hartselle, Alabama, give us a call. We'd be glad to help.