Pros and Cons of Flat Roof Drain systems
Flat roofing systems offer a number of benefits, giving you more space for storage of unsightly equipment or even rooftop gardens. Flat roofing is also ideal for warmer climates as opposed to areas where there is a lot of rainfall. As with all roofing systems, flat roofing has its good and bad qualities, and there are often problems with the drainage that you should be aware of.
The name may imply that roofing is flat, but there is always a slight slope towards the drain. Gravity allows the drainage system to work, so the water needs to have a natural flow away from the roof. This is essential for preventing water from collecting on the surface. Despite this, common drainage problems can occur associated with flat roofing.
- Foundation problems
- Infiltration of water into living spaces
- Water damage to walls and casings
Even though these drainage problems can occur, there are numerous advantages to having flat roofing and there are several options for drainage systems to help keep water off your roof.
- Inner drains: These sit towards the center of the roof. A pipe system below the drain shuttles the water away. Often these can form pools of water on the surface if there are any clogs to this system. If this happens water can eventually find a way into the building. These systems are more expensive but they are great for colder climates because the pipes do not freeze.
- Scuppers: These are small boxed drains that exit through the parapet wall. The slight slope of the roof allows water and debris to move along the roof and out the scupper. These can become clogged easily with debris from outside. If water pools near the roof edge and if they are not connected to a downspout, then collected water can damage your foundation and cause erosion. These drains are not very expensive and are easier to maintain than other systems.
- Gutters: These metal structures sit along the edge of the roof, collecting water as it flows down the slope. These protect your foundation and help to control the flow of water away from the roof. This is important for flat roofing as water can pool easily on those surfaces. They are inexpensive and are the best way to protect your foundation, basement and nearby soils from erosion.
Flat roofing is an economical choice for any building, so long as you have an appropriate drainage system in place too. Make sure you discuss all options with an experienced roofer and learn the pros and cons to each drainage type. Find your professional commercial roofer and they will help you find the right drainage system for your flat roof.