Flat roofs are a popular choice for commercial buildings, but they come with their own set of problems. Exposure to the elements, water accumulation, and poor installation can all lead to leaks, mold, and other damage. In this article, we'll discuss the most common flat roofing problems and how to avoid them. One of the most common issues with flat roofs is leaks.
The flat surface makes them more susceptible to water accumulation, which can cause deterioration of the exterior and shorten the lifespan of the roof. Unless the roof is completely level or drainage systems have been installed, rainwater and runoff can build up in any pothole or hole in the roof. In addition to the fact that leaks will eventually compromise the integrity of your commercial building, they can also cause mold and mildew to grow. Most flat roofs aren't really flat; they have enough inclination (or slope) to drain water.
However, there isn't much room for error. If the flat roof is damaged in any way or if ice covers it, water can start to accumulate in small ponds and cause more serious problems. The lack of slope also allows leaves, branches, and other debris to more easily accumulate on a flat roof and block the drain. In addition, a large pile of uncleaned leaves retains moisture that can freeze, thaw, and refreeze during the winter.
This cycle will wreak havoc on the roof below. Another common problem with flat roofs is “alligatoring”. This term refers to a flat roof that has begun to crack and bubble due to exposure to the sun over time. If left untreated, a flat alligator roof can cause additional cracks, leaks inside the house and a total failure of the roofing system. Homes settle and change over time, which can cause displacement of the membrane between a house and the roofing material. Since the membrane of a flat roof is a continuous sheet, this displacement can cause it to bend.
A poorly installed flat roof can also contribute to deformations, which can also cause major problems. Roofs must be able to withstand the elements, especially wind. Because flat roofs are a single sheet of material, a little wind damage can turn into a lot of wind damage with just a few additional gusts. The entire roof can fail and require immediate replacement. Leaks can also develop without any of these problems. For example, damaged gaskets can cause leaks just as easily on a flat roof as on a sloped roof.
Poor installation, substandard materials, or simple age can also be factors that cause flat roofs to leak. Waterproofing is an important characteristic of a flat roof. Asphalt shingles and other surfaces are porous, increasing the chance of leaks if the roof has poor drainage. However, a waterproof sealant can protect your roof. In fact, many flat roofs are sealed with water resistant coatings. Stagnant water is another common problem with both sloped and flat roofs.
If water accumulated on the flat roof does not drain within 72 hours, it's likely that either the roof is too flat or there isn't sufficient drainage. Otherwise, water that has accumulated on the roof can damage its structure. Opening issues such as lightning strikes, freezing, hail or wind damage are also common with flat roofs. Poor installation or substandard materials may also contribute to opening issues. A well-installed flat roof should last at least 15 years and up to 30 years - shorter than an asphalt shingle roof but longer than cedar or metal roofs. New owners of existing homes should anticipate that replacing their flat roof may not be too far off in the future. To prevent your flat roof from leaking, you should schedule annual inspections with your local roofing contractor.
Your contractor can identify weak spots in your flat roof and repair them before they start to leak. Debris is another issue that's unique to flat roofs; it's easy for debris such as leaves and branches to get trapped in them. Therefore, it's important to inspect your flat roof more frequently - ideally twice a year - and clean off any debris that has accumulated. You should also look for signs of alligatoring or deformations due to displacement or poor installation; these should be investigated by a professional immediately. Small defects such as cracks can be repaired yourself with roof putty and wire mesh. Finally, make sure your flat roof is sealed with an asphalt membrane designed to protect it from UV radiation and water damage. This will help ensure that your commercial building stays safe from leaks for years to come.
