Four Ways to Waterproof your Commercial Roof

4 ways to Waterproof

There is a unique challenge that comes with waterproofing a flat surface. Unlike pitched roofs, gravity needs additional help to direct water to drainage systems. Most roof systems do have a slight pitch to guide water to gutters, scuppers, and drains, but without proper maintenance, some factors can build up over time and affect the performance of your roof system.

Many factors can contribute to the leakage on the roof:

  • Clogged gutters that cause water to pool with nowhere to escape
  • Dirt, debris, plant-life prohibiting the proper water flow off of the roof
  • Hail damage allow small pockets and rivets for water to pool into over time
  • Small cracks can cause significant damage due to repeating water seeping through
  • Deteriorating flashing around joints, skylights, and HVAC equipment

Over time, as roofing materials degrade because of the hot sun, harsh winters and lack of maintenance, your roof can become more prone to leaks. To prolong the life of your roof, it is crucial to perform annual maintenance to ensure that your roof system is functioning as it should. Adding a waterproof coating to your roof is also part of a good preventative maintenance program.

This article will provide you with information on you four waterproofing options along with the projected lifespan of each one.

Liquid Applied or Spray Waterproofing Coating

Pros – Seamless and joint-free coating

Cons – A careful balance of the number of coats needs to be achieved. Too few coats render the coating too fragile.

Spray applied waterproofing is a more recent development in the roofing industry. The application is simple, and once the coating has dried completely, it can provide a reflective barrier against the hot sun.

Projected lifespan – 10+ years

Elastomeric Coating

Pros – The added benefit of an insulated coating that prevents heat loss

Cons – Roof must be in good shape before applying and completely free of debris

The elastomeric coating has the advantage of stretching and moving to fit tight with your buildings expanding and contracting. This type of coating can be used on many types of roof materials such as bitumen, modified bitumen, EPDM, metals, or concrete roofs.

Projected lifespan – 10+ years

Siloxane Coatings

Pros – Ideal for treating brick, concrete, and stone

Cons – May slightly darken treated surface while creating a water-beading effect

Derived from the silicone family, siloxanes are not commonly used as a stand-alone product but to maximize their potential they are typically blended with silanes. 

Projected lifespan – 7-10 years

Waterproofing Sealant Products


Pros – Affordable and relatively simple installation when professionally installed.

Cons – Can deteriorate over time when exposed to the elements.

Flashing is usually strips of metal that create a barrier at the junction of the roof with another surface. It is crucial in waterproofing because it directs water away from penetrable seams and joints. The flashing applied is only as good as its installation and the adhesive used to allow for expanding and contracting of the roof.

Projected lifespan – Varies depending on the type of material used and the weather condition in your area. Typically 5-7 years.

When choosing a waterproofing option for your commercial roof, keep in mind the aspects of the Oklahoma weather. Your roof will be exposed to UV rays, heavy rain, hail, freezing temperatures and the usual expanding and contraction of the building, not to mention general wear and tear.

Waterproofing that is performed by a professional who is manufacturer-certified, waterproofing can add 20 to 30 years of warranted protection for your commercial roof. Waterproofing can also save you a considerable amount of money when compared to the cost of a complete roof replacement.

Schedule a free, no-obligation commercial inspection today for a professional and honest analysis on the condition of your commercial roof. 

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