Roof Drains


At this time there are several different kinds of roof drains and roof drain dome in Florence, AL and each one is a specific solution to the variety of roof styles and their drainage concerns. You need to consider the kind of roof, its size, and its roof pitch to be able to pick the right drain. You also need to take into consideration the site of the drain, what amount of rainwater is expected and safe practices when choosing a roof water drain for a house or commercial building.

Gable, dormer, mansard and hip roofs shed rainwater water due to gravity. Flat roofs, on the other hand, collect water. Unless the water is routed out and away from the flat roof structure, it will develop pools of water that may eventually leak and the accumulated weight will subsequently cause structural damage. That is why roofs with a pitch of under two percent should have roof drains located in the lowest spots on the roof where water puddles and need to be uniformly spaced throughout the roof surface.

Roof Drain Kinds


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

Roof Rainwater Drain Scuppes


Scuppers are located on the roof's periphery. Scuppers can also be placed on a balcony or terrace. Small holes are cut into the side of the roof structure so water can flow out and drain the roof top. Scuppers can connect to a downspout, or could be extended so that water is guided away from the structure sides and foundation.

Inner Roof Drains


There are many kinds of inner drains for flat roofs. They are positioned at low spots in the roof and attach to interior drainage pipes that drive water outside or in to a sewer system. Several designs of inner roof drains have domes, strainers or covers which keep debris from blocking the roof drain pipe. These kinds of drains operate via gravity channeling 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 efficient substitute for gravity drainage. Traditional 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 creates a siphonic drain which removes air from the system and permits smaller pipe diameters to be used. 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. Though used primarily for flat roofs, siphonic drains can also be installed on angled roofs.

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