Roof Drains


At this time there are several distinct kinds of roof drains and roof drain pipe in Moulton, AL and each is a specific solution to the wide range of roof types and their drainage concerns. You must look at the type of roof, its dimensions, and its roof pitch to be able to pick the correct drain. You also need to take into account the location of the drain, how much rainwater is expected and safety when choosing a roof drain for a home or commercial building.

Gable, dormer, mansard and hip roofs shed rainwater water due to gravity. Flat roofs, conversely, accumulate rain water. Until the water is guided out and away from the roof structure, it will most likely develop pools that could eventually leak and the accumulated weight may eventually cause compromising the integrity of the structure. That is the reason that roofs with a slope of below 2% should have roof drains positioned at the lowest areas on the roof where water pools and need to be evenly spread all throughout the roof surface.

Roof Drain Types


There are several different alternatives of roof drains. They basically fall into 2 groups: pitched roof drains and flat roof drains. Pitched roof drains normally comprise gutters that accumulate rainwater that passes by means of gravity down to the roof edge. Gutters transport this water towards downspouts which steer the water flow down and away from the structure or in to sewers. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are located on the roof's periphery. They can also be placed on a balcony or terrace. Small openings are cut in the side of the roof structure so water can empty and drain the roof top. Scuppers can hook up to a downspout, or can be lengthened so that water is directed off of the structure sides and foundation.

Inner Roof Drains


There are quite a few different types of inner drains for flat roofs. These are installed at low spots on the roof and connect to inner drainage pipes that drive water outside or in to a sewer system. Many models of inner roof drains have domes, strainers or covers which keep trash from obstructing the roof drain pipe. These kinds of drains operate via gravitational force funneling standing water through 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 allows both air and water to enter the drain system producing pipe space which is occupied by both air and water. By incorporating an engineered baffle to the sump of the drain body it produces a siphonic drain which eliminates air from the system and permits smaller pipe diameters . When all air is removed, a negative air pressure in the tail portion of the drain is set up which pulls water off the roof siphonically. Although 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 pipe in and around Moulton, Alabama, give us a call. We'd be glad to help.