Roof Drains


There are a few distinct kinds of roof drains and roof drain pan in Moulton, AL and each is a specific answer to the wide range of roof styles and their drainage concerns. You must look at the kind of roof, its dimensions, and the roof pitch to be able to pick the correct drain. You also need to take into consideration the location of the drain, what amount of rainwater is anticipated and safe practices when selecting a roof water drain for a home or business building.

Hip roofs, dormers, gable and mansard roofs shed rainwater water thanks to gravitational force. Flat roofs, conversely, collect water. Unless this water is routed out and away from the flat roof structure, it will most likely develop pools that could inevitably leak and the accumulated weight will eventually cause compromising the integrity of the structure. That is why roofs with a slope of below two percent should have roof drains located at the lowest spots on the roof where water pools and should be evenly spaced throughout the roof top.

Types of Roof Drains


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 rainwater drains normally consist of gutters which collect rainwater which travels via gravity down to the roof edge. Gutters channel this water towards downspouts which direct the water flow down and far away from the building or into sewers. Flat roof drains are one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are situated on a roof's perimeter. Scuppers can also be put in on a balcony or terrace. Small holes are cut in the side of the roof structure so water can flow out and drain the roof surface. Scuppers can hook up to a downspout, or can be extended so that water is directed off of the structure sides and foundation.

Interior Roof Drains


There are quite a few different types of inner drains for flat roofs. They are positioned at low spots on the roof and connect to inner drainage pipes that drive water outdoors or in to a sewer system. Many versions of internal roof drains have domes, strainers or covers which keep debris from clogging the roof drain pipe. These types of drains work via gravity channeling 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 efficient alternative to gravity drainage. Standard flat roof drainage allows both air and water to go into the drain system producing pipe space occupied by both air and water. By incorporating an engineered baffle to the sump of the drain system it produces a siphonic drain that removes air from the system and allows for smaller sized pipe diameters . When all of the air is eliminated, a negative air pressure in the tail portion of the drain is set up which pulls rainwater off the roof siphonically. Although used primarily for flat roofs, siphonic drains can also be set up on pitched roofs.

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