Roof Drains


There are a few different varieties of roof water drains and roof drain pipe in Athens, AL and each is an unique solution to the variety of roof types and their drainage challenges. You need to consider the type of roof, its size, and its roof pitch to be able to pick the correct drain. You also need to take into consideration the site of the drain, how much rainwater is expected and safety when selecting a roof drain for a home or commercial structure.

Hip roofs, dormers, gable and mansard roofs shed rainwater water thanks to gravitational force. Flat roofs, alternatively, collect rain water. Until this water is guided out and away from the roof , it will most likely create pools that may eventually leak and the accumulated weight will eventually cause damage to the structure. That is the reason that roofs with a slope of less than two percent should have roof drains positioned in the lowest spots on the roof where water pools and need to be evenly spread all throughout the roof top.

Roof Drain Types


There are several different alternatives of roof drains. They basically fall into two groups: pitched roof drains and flat roof drains. Pitched roof drains usually consist of gutters which collect rainwater that travels via gravity to the roof edge. Gutters channel this water towards downspouts which steer the water flow down and away from the structure or in to sewers. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


Scuppers are located on the roof's perimeter. Scuppers can also be placed on a balcony or terrace. Small holes are cut into the side of the roof structure so water can empty and drain the roof top. Scuppers can attach to a downspout, or can be extended to make sure that water is directed away from the building sides and foundation.

Inner Roof Drains


There are many kinds of inner drains for flat roofs. These are positioned at low spots on the roof and connect to interior drainage pipes that drive water outside or into a sewer system. Several versions of inner roof drains have domes, strainers or covers which keep trash from blocking the roof drain pipe. These types of drains operate via gravitational force funneling standing water thru 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. Traditional flat roof drainage allows 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 body it produces a siphonic drain that eliminates air from the system and allows for smaller sized pipe diameters . When all of the air is eliminated, a negative air pressure in the tail piece of the drain is set up which attracts rainwater off the roof siphonically. Although used mainly for flat roofs, siphonic drains can also be installed on angled roofs.

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