Roof Drains


At this time there are a few different types of roof drains and roof drain downspout in Jacksonville, AL and each is a specific approach to the variety of roof types and their drainage issues. You must take into consideration the type of roof, its size, and the roof pitch to be able to pick the right drain. You also should think about the location of the drain, what amount of rainwater is expected and safety when choosing a roof drain for a home or commercial building.

Hip roofs, dormers, gable and mansard roofs shed rainwater water due to gravitational force. Flat roofs, alternatively, collect rain water. Until the water is routed out and away from the roof , it will most likely create pools that could inevitably leak and the amassed weight will eventually result in compromising the integrity of the structure. That is the reason that roofs with a pitch of less than 2% should have roof drains located at the lowest areas on the roof where water pools and need to be uniformly spaced throughout the roof top.

Roof Drain Types


There are a number of different alternatives of roof drains. They basically fall into 2 categories: flat roof drains and pitched roof drains. Pitched roof drains usually comprise gutters which collect rainwater which travels via gravity down to the roof edge. Gutters channel this water in the direction of downspouts which route the water flow down and far away from the structure or into sewer lines. Flat roof drains are one of three primary types: scuppers, inner drains or siphonic drains.

Roof Rainwater Drain Scuppes


Scuppers are located on a roof's periphery. Scuppers can also be installed on a balcony or terrace. Small openings are cut into the side of the roof structure so that water can flow out and drain the roof top. Scuppers can attach to a downspout, or could be lengthened so that water is directed away from the building sides and foundation.

Inner Roof Drains


There are quite a few different types of inner drains for flat roofs. They are installed at low places in the roof and attach to inner drainage pipes that direct water outdoors or in to a sewer system. Many models of inner roof drains have domes, strainers or covers that keep trash from clogging 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 effective substitute for gravity drainage. Standard flat roof drainage allows both air and water to enter the drain system creating 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 which removes air from the system and permits smaller pipe diameters . When all air is eliminated, a negative air pressure in the tail portion of the drain is established which draws 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 downspout in and around Jacksonville, Alabama, give us a call. We'd be glad to help.