Roof Drains


At this time there are a few different varieties of roof drains and roof drain cover in Anniston, AL and each one is a specific approach to the wide range of roof types and their drainage challenges. You must consider the type of roof, its size, and its roof pitch to be able to select the right drain. You also need to take into account the site of the drain, how much rainwater is expected and safe practices when selecting a roof drain for a house or commercial structure.

Gambrel, dormers, hip and gable roofs shed water due to gravitational force. Flat roofs, on the other hand, accumulate water. Until the water is directed out and away from the roof structure, it will develop pools of water that may inevitably leak and the amassed weight may eventually result in structural damage. That is the reason that roofs with a slope of under 2% should have roof drains situated in the lowest spots on the roof where water pools and need to be uniformly spread all throughout the roof top.

Roof Drain Types


There are several different variations of roof drains. They generally fall into two groups: flat roof drains and pitched roof drains. Pitched roof rainwater drains normally comprise gutters that accumulate rainwater that travels by means of gravity down to the roof edge. Gutters channel 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 situated on the roof's perimeter. Scuppers can also be placed on a balcony or terrace. Small openings are cut into the side of the roof structure so rain water can flow out and drain the roof surface. Scuppers can connect to a downspout, or could be lengthened so 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 positioned at low places in the roof and attach to interior drainage pipes that route water outside or in to a sewer system. Many styles of internal roof drains have domes, strainers or covers that keep trash from blocking the roof drain pipe. These types of drains work via gravity funneling standing water thru the roof drain system. They can be made of PVC, cast iron or cast aluminum.

Siphonic Roof Drains

Siphonic roof drains are a more efficient substitute for gravity drainage. Standard 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 creates a siphonic drain that eliminates air from the system and allows for smaller sized pipe diameters . When all air is removed, a negative air pressure in the tail portion of the drain is established which pulls rainwater off the roof siphonically. Though 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 cover in and around Anniston, Alabama, give us a call. We'd be glad to help.