Industrial flat roofs are prone to a condition known as ponding. Ponding water significantly decreases the lifespan of an otherwise well-built roof by several years. Pooled water puts continuous stress on roof membranes and accelerates thermal and ultraviolet degradation of roof components, contributing algae growth and degradation of roofing components. All of which increase the likelihood of a roof failure.
There are several root causes for ponding. These include: structural deflection, blocked or undersized outlets, improper maintenance, and rarely, ponding may be caused by repair work slowly settling. Not identifying the reason for ponding can lead one to think that creating additional falls in the flowing direction of the roof is the answer. This is completely false. It’s possible that the peak of water collection does not have a fall to funnel the water to the outlets of the roof. So if no remedy for insufficient roof falls is applied, the poor drainage capacity of the roof will be as useless as the ponding on the roof.
Design and Drainage Solutions
For roofs with genuine design faults, tapered insulation systems are one of the most effective long-term solutions. These have built-in slopes that direct water to the drainage points of a roof system without compromising the original roof line. This makes them an ideal roofing option for retrofitting during the re-roofing process, since complete structure rebuilds are unnecessary.
There are certain things that take maintenance on a building-by-building basis, and outlets and gutters are some of those things. On an industrial building, the roof is large relative to the number of drains. Because of that, an outlet can fill up with moss, twigs, other debris, or even nests rather quickly. If you don’t clear them regularly, they’ll start creating water pooling problems at the time of heavy rains. Having a maintenance plan with a clear outlet cleaning schedule is recommended.
Why Early Action Matters
Most facilities managers do not treat the ponding water problem until leaks start to appear on the building’s ceiling. Still, it is important to consider that standing water starts to damage the roof membrane, which can lead to the failure of the roof during a storm. A roof survey can help identify locations on the roof where standing water can accumulate and help the manager understand the underlying issues. Waiting for water to fill a building to show the location of a leak means that a bad situation will only be worse.
It’s more cost-effective to address ponding water due to inadequate drainage, insulation, or an unstructured maintenance plan to avoid internal damage from leaks, than to wait for leaks to happen and address the situation later. Industrial flat roofs are an investment for any business. Drainage should be a priority over an afterthought. It protects both the building and the business as well as the materials and equipment housed beneath it.