Minnesota Commercial Building Roofing: What You Need to Know About Low Spots on Your Flat Commercial Roof

If you own a commercial building with a flat roof, then you may be worried about low spots forming on your roof and the problems that this can cause down the road. In case you are unaware, low spots on your roof can lead to water ponding on your roof after a storm. When water is allowed to pond on a flat commercial roof, this can cause your roof to leak, and it can even compromise your roof’s structural integrity. This makes it imperative that you occasionally check your roof for low spots and ponding water so that you can have these problems fixed as soon as possible before they become more extensive. However, you may still have questions about low spots on flat commercial roofs such as: “what causes these low spots?”, “can they be prevented?”, and “how can they be fixed?” To help you answer these questions, here is a quick overview of everything you need to know about low spots on your commercial roof.  

Potential Causes:

Inadequate or Obstructed Roof Drains

One of the most common causes of low spots on flat commercial roofs is improper drainage. If your roof is not draining, whether because your drains have become blocked, or your roof did not have proper drainage in the first place, water may then collect on your roof after a storm. If even a small amount of water is left on your roof for a couple of days, a slight depression can form on your roof. This low spot will then grow, and become more problematic, with each passing storm.

Your Building is Settling/Shifting

Another common cause of low spots on flat commercial roofs is your building shifting or settling. Over time, it is natural for a building to settle into its foundation as it sinks into the ground. However, in large buildings with flat roofs, this can result in low spots forming on your roof. Additionally, it is not uncommon for the ground beneath a large building to shift as this ground expands and contracts with changes in temperature. This can exacerbate problems caused by your building settling, and can result in the formation of additional low spots on your roof.

Saturated Insulation

Low spots can also form on your roof if your insulation becomes saturated. If a leak forms in your roof, then your roof’s insulation can quickly become saturated with water, and if you have ever seen wet roofing insulation, you will know that it becomes compressed quickly. However, where this compression occurs, low spots will likely form on the roof above it.

How Low Spots Can Be Prevented and Fixed

By now you may be wondering what you can do to fix low spots on your commercial roof, and if there is anything you can do to prevent these low spots from forming in the first place. Unfortunately, there is very little that can be done to prevent low spots from forming on your roof as a result of your building shifting. However, you can prevent low spots from forming due to leaks and drainage issues by ensuring that your roof has the right membrane and drainage systems installed. However, if you do discover a low spot on your roof, you will want to have these issues professionally corrected in order to ensure that water does not collect on your roof in the future. Contact us to find out about having the low spots on your commercial roof corrected, as well as to find out more about the other commercial construction and roofing services that we offer, and how we can help you with any of your construction needs.