Roof Drains


At this time there are several different varieties of roof water drains and roof drain dome in Opelika, AL and each one is an unique answer to the variety of roof styles and their drainage concerns. You need to take into consideration the kind of roof, its size, and its roof pitch to be able to select the most suitable drain. You also may want to take into consideration the site of the drain, what amount of rainwater is anticipated and safe practices when selecting a roof drain for a residence or commercial building.

Gable, dormer, mansard and hip roofs shed water because of gravitational force. Flat roofs, conversely, collect rain water. Unless the water is routed out and away from the roof structure, it will most likely develop pools that may eventually leak and the accumulated weight will eventually result in compromising the integrity of the structure. That is why roofs with a pitch of below 2% should have roof drains situated at the lowest spots on the roof in which water puddles and should be evenly spaced all throughout the roof top.

Roof Drain Types


There are a number of different variations of roof drains. They generally fall into 2 categories: flat roof drains and pitched roof drains. Pitched roof drains usually consist of gutters which accumulate rainwater that passes by means of gravity to the roof periphery. Gutters transport this water in the direction of downspouts which route the water flow down and away from the building 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 situated on a roof's periphery. They can also be placed on a balcony or terrace. Small openings are cut into the side of the roof structure so rain water can empty and drain the roof surface. Scuppers can connect to a downspout, or could be extended so that water is directed away from the building sides and foundation.

Inner Roof Drains


There are quite a few different kinds of inner drains for flat roofs. These are positioned at low spots in the roof and attach to interior drainage pipes that route water outside or into a sewer system. Many styles of inner roof drains have domes, strainers or covers that keep trash from obstructing the roof drain pipe. These kinds of drains work via gravitational force funneling standing water thru the roof drain system. They are made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more effective alternative to gravity drainage. Traditional flat roof drainage permits both air and water to enter the drain system producing pipe space occupied by both air and water. By adding an engineered baffle to the sump of the drain system it produces a siphonic drain that eliminates air from the system and allows for smaller pipe diameters to be used. When all of the air is removed, a negative air pressure in the tail piece of the drain is set up which pulls rainwater off the roof siphonically. Though used primarily for flat roofs, siphonic drains can also be installed on pitched roofs.

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