A flat roof is used for many different types of architecture. Most commonly seen on warehouses and large businesses, many homes also use this type of roofing. Overall, it's an easy-to-maintain design. However, you may encounter ventilation and draining issues if the roof is not installed and maintained properly.
A flat roof will only have so many types of ventilation possible. A traditional pitched roof will give you many more options. The ventilation is still important though, regardless of the type of roof you have. You need to allow for cross ventilation to avoid excess moisture from building up. This excess moisture can cause mold, mildew, and decay. Having a pop vent and a ventilator installed on opposite ends of the roof will resolve this problem.
A flat roof building in an area of the country that sees a lot of rainfall is not always the ideal scenario. Since the rain will not have anywhere to drain, it will just sit on the roof. This can lead to leaks, and worse, the entire roof failing. If you have a flat roof in one of these areas, you will need to install some type of drain system. This is easiest when the roof is being constructed. The best placement for a drain would be the center of the roof, at the lowest point. From there a drain pipe that leads back down the exterior of the home will allow a place for the water to go without damaging your roof or your structure.
Improper Roof Coatings
Make sure you understand the best coating system for the region you live in. An epoxy-based roof coating in a high rain or humidity area can be dangerous. The epoxy itself can curl up on itself, and bring the roof with it. This will cause major leaks, lead to major damage to your roof, and quite the roof can fail. Make sure you get the right coating to avoid these serious issues down the road.
If you are not experienced at installing flashing, trying to install it yourself on a flat roof is not a wise idea. A flat roof requires much more attention to detail when it comes to the flashing. Sloppy installation can lead to water damage that will not be seen until it's too late. One of the most common mistakes in flat roof construction is the use of roofing tar or cement in the joints. This is not water-tight, and water will penetrate these joints over time, causing extensive damage to your structure. This damage is usually not seen until another major structural issue happens, such as water spots on the interior walls. By the time this has happened, you are looking at an expensive repair job. Installing a flat roof is not for the fault of heart. In most cases it's best to have a professional roofing company with experience in your area perform the installation. If you choose to self install, just be prepared for a big job that requires craftsmanship and attention to detail.