Polyurea & Urethane Over Concrete
Northwestern University in Natchitoches, LA was looking for a durable deck coating system that could withstand hundreds of students walking across the system daily. Plus, it needed to be flexible enough to waterproof sections of the deck that were causing leaks in the adjacent Student Union.
Working closely with an engineering firm, the contractor determined that a combination of polyurea and urethane would be the best solution. The 23,000 sq. ft. walking path and deck had over 15 years of service life, and was well past its prime. Even more challenging, this particular project had a contract requirement to be completed within 30 days.
The first step was to tear-off of the gravel surface to bring the substrate to a point suitable for coating. After tearing off the first layer they found several areas where a 24 hour curing structural concrete was needed to repair the existing deck. Aggressive power-washing and shot blasting was done to ensure the surface was clean. A water-block was then used in several areas to ensure ground moisture would not affect the new coating system.
First, 80 mils of American WeatherStar Polyurea 550 was applied to all seams, cracks, and transition areas. Next, a 50 mil base coat of Polyurea 550 was applied giving the system a durable, flexible, waterproof membrane that allowed for expansion and contraction. During the application of this base coat, 3M Roofing Granules were broadcast over the Polyurea 550 before it was able to dry.
Within 12-24 hours, a base coat of Urethane 510 was applied over the Polyurea 550 with another layer of 3M Roofing Granules was broadcast into the wet urethane. To complete the project, a top coat of the Urethane 510 was sprayed over the entire deck. In all, the deck has approximately 80-90 dry mils of combined polyurea and urethane coatings.
This combination polyurea and urethane coating system gave Northwestern University a durable, seamless, water-tight solution that would withstand heavy walking traffic. The urethane top coat helps the system maintain its color properties over the course of time.
Northwestern University in Natchitoches, Louisiana was looking for a deck coating system capable of withstanding heavy walking traffic. The system would also need to waterproof certain areas of the deck that were causing leaks in the surrounding buildings.
- Roof Type: Concrete Deck
- Size: 23,000 sq. ft.
- Location: Natchitoches, LA
- System: Polyurea & Urethane
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