Roof Drains


At this time there are several distinct varieties of roof drains and roof drain pvc in Huntsville, AL and each is an unique solution to the wide range of roof types and their drainage issues. You must take into consideration the kind of roof, its size, and the roof pitch to be able to pick the correct drain. You also may want to take into consideration the site of the drain, what amount of rainwater is anticipated and safety when choosing a roof drain for a house or business structure.

Gable, dormer, mansard and hip roofs shed rainwater water because of gravitational force. Flat roofs, conversely, accumulate water. Until this water is guided out and away from the flat roof structure, it will develop pools that could eventually leak and the accumulated weight may subsequently result in damage to the structure. That is why roofs with a pitch of less than two percent should have roof drains situated at the lowest areas on the roof in which water pools and need to be evenly spaced all throughout the roof top.

Kinds of Roof Drains


There are several distinct variations of roof drains. They basically fall into two categories: pitched roof drains and flat roof drains. Pitched roof drains usually comprise gutters that collect rainwater that passes via gravity down to the roof periphery. Gutters transport this water in the direction of downspouts which direct the water flow down and away from the structure or in to sewer lines. Flat roof drains can be one of three main types: scuppers, inner drains or siphonic drains.

Roof Drain Scuppers


Scuppers are situated on the 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 water can flow out and drain the roof surface. Scuppers can attach to a downspout, or can be lengthened so that water is directed away from the building sides and foundation.

Inner Roof Drains


There are many types of inner drains for flat roofs. These are installed at low areas on the roof and attach to inner drainage pipes that drive water outdoors or into a sewer system. Several versions of internal roof drains have domes, strainers or covers that prevent trash from obstructing the roof drain pipe. These kinds of drains operate 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 effective substitute for gravity drainage. Traditional flat roof drainage permits both air and water to enter 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 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 draws water off the roof siphonically. Though used mainly for flat roofs, siphonic drains can also be set up on angled roofs.

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