Drainage Systems for Flat Roofs

Flat Roof Drainage System

Flat roofs in the United States have a long history, in particular in commercial buildings. Flat roofs are, though, highly dependent on adequate rain and snow drainage to maintain integrity. Otherwise, water pools may occur and lead to leaks, roof membrane deterioration and the formation of seasonal ice. These types of drainage systems are best suited for flat roofs, and you can ask about it from our roofing contractor in Tulsa.

The main task is to ensure proper drainage with flat roofing. Unlike other sloped or sloped roof types, flat ones must be equipped with an integrated drainage system to remove moisture and waste. Poor drainage can lead to severe flat roofing problems, from leaks to building damage.


Scuppers are outlets on the borders of the roof that project water out of the building's roof. They keep the building walls dry and avoid destabilizing the foundation with too much water exposure. They work better if all water is directed towards them with a containing insulating system or an inclined structure toward indoor drains. They are cost effective. This is a good solution for areas where heavy rain often occurs, but it's not ideal for snow melting.

A Roofer settling the Gutter


Open pipes attached to the corners of the roof are gutters. They collect and carry water from the building as it drains off the roof. In general, they are the most cost-effective drainage solution as they can be attached without changing the roof. The variable levels of rain and snow are good for them too. As with drains and scuppers, they must be cleaned regularly to maintain proper operation.

Internal Drains

Internal drainage systems are another affordable solution that can also connect with existing drainage systems. They require aluminum or copper inserts to be installed in roof areas where water is common. Spring systems are attached to the drainage inserts to lead the water through a side wall outside of the building. Pipes run down inside the wall and hung under the roof. To be effective, a licensed plumber must install this system.

Eavestrough Drainage

While the drainage system is no longer commonly used, if you have an older large flat industrial or commercial roof, an eavestrough is a good option. In the lower isolated areas drainage ditches are created on the roof. These ditches guide water in the direction of the eaves.

Step Sloped Insulation

Step sloped insulation is an affordable approach to a flat roof, where multiple layers will be installed under the roof membrane, mounted in steps on and around the drains, to guide the flow. Then the insulation on the roof membrane is installed.

Contact our Tulsa roofing contractor at Elliott Roofing for a drainage system implementation to your flat roof.