Should I Re-Coat with Acrylic, Silicone or Polyurethane?

Roof Coatings

Whether your structure is leaking, visibly decrepit or you have maintained immaculate records and they now show that your roof system is reaching the end of its life expectancy, a weighty decision lies ahead. Environmental concerns and the expense of a complete tear-off, have you now considering the option of re-coating your existing structure. Budgeting real dollars to replace or repair your existing roof structure is not a glamorous endeavor but a necessary one,  if you want to extend its life and possibly the warranty. There are several different types of elastomeric roof coatings that can be used and each will have inherently different chemically properties associated with their make-up. Taking into account the type of roof system that will be covered and deciding on a complimentary chemically formulated coating for the former can be an arduous task and more than you might want to bite off without the help of roofing professional. Coatings, like your existing roof structure are anything but equal. Some roofing structures can entertain almost any type of coating, while others should be only coated with a specific type. A free roof inspections or advice from a professional who will be doing the coatings is not only the preferred road to travel but in the end, the only way to go.


If your roof is already undergoing problems associated with moisture or is actually leaking then these problems need to be addressed before undertaking a new roof coating. A roof professional can inspect and identify roof damage and leaks, which are most often, found in flashings and roof penetrations and provide the necessary technical advice on how to proceed. If any moister is found or suspected in the insulation then a core cut or a non destructive infrared scan can identify locations of wet insulation. Wet insulation will need to be removed prior to a re coat. It is important to remember that if more than 30% of the underlying insulation is wet, than a complete tear-off is recommended.


Selecting the right roof coating and its accompanying chemistry can be a chore. It is important to select the most appropriate product based on your existing structure and the environment that will act on the new coating.


Some important roof conditions to consider when selecting a restoration coating include:


  • Current condition of the roof
  • Location
  • Slope
  • Ponding water
  • Chemical exposure
  • High heat exposure
  • UV exposure


Below are the most common elastomeric roof coatings:


  • Acrylic
  • Silicone
  • Polyurethane


Acrylic Roof Coatings
Acrylic coatings are very common; they are typically water-based products and can be the most cost effective in a re-coat process. Water-based acrylic roof coatings are environmentally friendly and are highly reflective. With this reflective nature comes the added benefit of cooling the roof and reducing the building’s energy costs as well as protecting the roof surface from UV exposure. Acrylic coatings are also very “elastomeric,” allowing for increased fluctuations in temperature without affecting the coating. One draw back to Acrylic coatings is they do not have a high tensile strength, and this can adversely affect the coating’s ability to resist typical wear and tear, making the roof restoration more susceptible to damage from ponding water.


Silicone Roof Coatings


Silicone roof coatings are permeable and are mostly used to cover and protect polyurethane foam (SPF) for this reason. Silicone coatings are also recommended for areas where extreme temperature fluctuations and high UV exposure is more frequent.  Silicone coatings need water to cure and do well in high humid areas.  Silicon coatings can be applied at or below freezing, which can not be done with other roof coatings. The drawback to Silicone Coatings is they can be a magnet to dirt and if the structure is visible and aesthetics is a concern then a silicon coating may not be the way to proceed. Once you apply a Silicon Coating then any repair or re-coat must be re-applied with a Silicon Coating. Silicon Coatings have a low tensile strength and very low abrasion resistance and should not be applied where heavy foot traffic or hail is a concern.
Polyurethane Roof Coatings 
Polyurethane coatings are becoming more common and are tough against hail because these Coatings have a high tensile strength. They provide a highly durable surface that protects the roofing system from a wide variety of conditions and are recommended in heavy traffic areas and in climates that require a more vigorous environment defense. Polyurethane Coatings work well around penetrations or on wall flashings where our structure endures the most abuse. The drawback to Polyurethane Coatings is that they can be the most expensive and can have an odor than can linger in the application area.

Consultation with a professional roof expert is highly recommended when deciding whether to re-coat and which type of coating is the best choice for your structure and the environment that will influence it. Roof warranties can usually be extended with the appropriate choice when applied by a qualified contractor, so do you due diligence. Jottan-Jorel has been offering a variety of commercial roofing solutions for your new or existing roofing needs for the past 40 years. Jottan-Jorel specializes in re-roof Coatings, preventive maintenance, emergency repair and service. If you would like to talk to someone about a FREE no obligation roof inspection then click on the form below

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