FM Issue: Recipe For Roof Coatings
By Richard Catley and Joseph W. Mellott
Published in the January/February 2013 issue of Today's Facility Manager
According to experts in the field, more than 20% of restaurants fail in the first year of business. Further, statistics indicate greater than 60% of these establishments will be out of business within three years. The reasons are many and varied, but most relate to deficiencies in planning, forethought, and execution. Like restaurants, rooftop coating and restoration solutions also require proper planning and execution to deliver maximum performance. And as with restaurants, there are several steps facility managers (fms) can take for long-term success of rooftop coating and restoration projects.
Location, Location, Location
Just as scouting out the best location for a restaurant is critical to its success, understanding the rooftop conditions prior to specifying a coating is critical for fms. There are many factors that affect the long-term performance of an applied coating. Fms should refer to information provided by the manufacturer or consult a roofing professional prior to use. However, several things for fms to consider up front are:
Slope of the roof. Positive slope that eliminates stagnant (ponded) water is a key to any roof’s success. For coatings, this can be even more critical. Wet roof areas can be very difficult to clean, and gaining good adhesion is difficult. Further, some coatings under long-term ponded conditions can fail prematurely. Water in ponded areas should be dealt with prior to the application of a coating by creating proper slope. If this is not done, adhesion can be an initial issue, and underwater exposure can present a long-term problem.
Wet substrate. While coatings can serve to prolong the life of a roof system, these cannot solve substrate moisture issues. Performing an infrared roof (IR) scan, using moisture meters, or making core cuts can help determine if current moisture conditions exist. Removing and mitigating moisture issues prior to coating or restoration is critical to long-term success.
Know the substrate. Many roofing systems are easy to identify while others can be more difficult. For example, an APP modified bitumen roof can look similar to an SBS modified bitumen roof. TPO, PVC, and KEE roof systems can look alike, as well. Fms should be sure of the substrate characteristics, so they know what is being coated before deciding on a system.
Environmental conditions. Knowing the eventual environmental conditions of the rooftop can help with coating selection as well. If exposure to chemical or material emissions is a possibility, an intimate understanding of what and how much exposure may occur is necessary. Some rooftop emissions can be highly caustic or acid and may lead to product failure.
Know The Market
Once the restaurant location (or roof condition) has been scouted out, the next step is to know the “customer.” This is best done through market research. By knowing what they are looking for, fms will be able to select the right solution. The following two factors should be examined when selecting a coating or restoration:
Coating or waterproofing? The primary role of a coating product is to protect the substrate underneath. Meanwhile, waterproofing products can serve as a substantial secondary layer to resist water intrusion into a facility. If the roof is watertight and in good condition, an fm may choose to apply a coating to extend the system’s life. If there is an indication that there have been some leaks or water intrusion, a better course of action may be to remove any wet roofing (including insulation) and apply a waterproofing surface system. Both product types serve to protect the roofing system below but the expectation for each may be somewhat different.
Energy enhancement. Reflective white and metallic (aluminum pigmented) coatings can offer the additional benefit of providing energy savings as a result of keeping the rooftop cooler. In warmer climates, it has been shown that using these products can significantly reduce cooling demand on HVAC units. Fms should consider the overall potential energy impact of installing a reflective surface.
A lack of preparation, inadequate training, and poor product can kill a restaurant’s opening night, and the same is true for a roof coating and restoration solution. Preparation is the single most important step in applying a liquid coating product.
Making sure the roof surface is clean is the difference between success and failure. Many manufacturers recommend power washing prior to installation; some recommend the use of cleaners and soaps as well. Getting the surface clean is certainly important, but the removal of any cleaners used is just as critical. Soap and cleaner residues can act as bond breakers. After power washing and cleaning, those doing the work should make sure the roof is dry and residue-free.
An adhesion test (seen in photo at right) is an additional step that can be performed by the roofing professional or a member of the fm’s staff. In its simplest form, this test involves applying a small amount of the coating to the roof substrate with the concurrent placement of a 1" wide x 10" long strip scrim or fabric.
These materials should then be allowed to cure (dry) per the manufacturer’s recommendation. The strip should be removed at a 90° angle while constant pressure is applied (there should be reasonable resistance to removal). A scale can be used as well to perform a quantitative test. The coating manufacturer should be consulted for recommended performance values.
Prior training and material preparation is also an important element to success, and the fm should be sure the installation team understands how to use the product. Installers should strictly follow any mixing and blending procedures and closely monitor the application rate through volume by square footage application measurements or, better yet, using a mil gauge. In the absence of a mil gauge, a comparative tool like a razor blade (23 mils) or a credit card (30 mils) can provide some insight during coating application (shown below).
Finally, it should be ensured that environmental conditions are appropriate for the work to be performed, since many products have temperature limits for proper application. It should not be too hot or too cold for proper application. Checking the weather forecast is also useful; many products have expected cure times, and rain events can cause improper curing, or worse, rooftop wash off.
Well, the “restaurant” is in business. All the preparation and knowledge has worked out, but clearly the work does not stop there. Keeping the roof clean and communicating with facility staff as well as suppliers makes good business sense. Frequent rooftop inspections help identify problems before they might become major issues. A strong preventive maintenance program can help prolong the life of the roof system even further. With proper planning, selection, installation, and training, coating and restoration decisions can significantly extend the life of a facility’s overall roofing system.
Catley is a six year veteran of the construction industry and collaborates in numerous construction and sealant industry organizations. He is the sealants & accessories product manager at The Garland Company, Inc., a Cleveland, OH-based manufacturer of high performance solutions for the total building envelope.
Mellott holds several patents for roof related innovations and received the 2006 Industry Statesman Award from the Roof Coatings Manufacturers Association (RCMA) for his work in advancing roof coatings industry technology. A graduate of Case Western Reserve University, he holds a BS in Engineering. Mellott has served as the technical chair, and is a past president of the RCMA; is on the board of the Cool Roof Rating Council (CRRC); and is a member of the Roof Consultant Institute (RCI) and the National Roof Contractors Association (NRCA).
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