Franklin Consulting Uses Multi-Step Process for Waterproofing Parking Facility

Case History: Franklin Consulting Services, LLC. 

An existing waterproof and insulation membrane system installed decades ago over a below-grade parking facility had failed. The owner‘s roofing and waterproofing contractor, WeatherTight Installations, worked closely with FCS (Franklin Consulting Services) to develop a scope of work. It included the removal of existing soil, vegetation, EPDM single ply membrane and channel insulation board stock. The exposed substrate consisting of numerous precast panels was swept clean and pressure washed. Inspection noted numerous open joints connection–one panel to another.

Once the precast panels were clean, dry, and stable, any major open joints were treated using a backer rod to seal the gaps. Any pre-existing EPDM membrane adhered onto vertical surfaces had to be removed as well as any counter flashing both on the vertical plywood and brick wall substrates. Weather delays and re-drying of substrate had to be done several times.

Some areas of adjoining brick walls were treated using urethane caulking sealing for missing mortar in the joints. It was now time to mix and apply the Seal/Primer applications. This would seal the precast concrete from possible moisture drive from the parking deck below and the substrate surface porosity. The product utilized was Oak Ridge Foam and Coatings, Inc. E-41 primer. It was applied at a minimum rate of 300 sq. ft per gallon in two applications and allowing for sufficient dry time between coats.

When the seal/prime coats had fully dried, the vertical/horizontal transitions, and the two precast panel seams that ran the full length of the seven-thousand feet deck, were treated using a 12 oz. geotextile fabric. The fabric was installed to provide a totally adhere and sealed membrane bridging the gaps. The surfaces were flashed using Oak Ridge’s OR 80 WPM pure Polyurea. Within 19 seconds, the geo was laid into the polyurea.

A final layer of Polyurea was installed encapsulating the geotextile and onto the sealed/primed deck surfaces. With all the gaps, elevation transitions and longitudinal precast panel joints sealed, the overall applications of the OR 80 WPM pure polyurea could begin. This waterproofing membrane system would involve three individual applications applied in alternating directions, insuring a uniformed monolithic membrane throughout the area of the deck substrate. At the start, it was noted that minor pinholes began to appear. It could not ensure that these did not extend directly to the concrete surfaces. Several methods and technique in applications were introduced to reduce the pinhole appearances. A total of 100 dry mils of the Polyurea was applied to the overall deck surface. A tack coat was used to tie into the previously applied polyurea coating when the recoat window had expired or as added insurance when installing new polyurea to previously installed.

Monitoring and inspection of the applications was conducted. At the completion of the polyurea applications, additional inspections were conducted noting any deficiencies in the membrane applications. Any noted suspicious appearing cracks, holes, pinholes were treated using a urethane caulking product. WeatherTight felt that as added insurance to any possible missing pinhole treatment, he would install an additional coat of a topcoat of silicone coating and back roll over the polyurea coating. This project had experienced substantial rainfall during its installations; however, more rain was in the forecast. This would be a good water test of the installed membrane system. As expected, the rains came and since there was little drainage on this flat surface and that the upper roof elevations of the adjoining buildings dumped their water onto this deck, no points of water leaks were noted. The loading of the deck could now begin.

Case History Author: Richard Franklin, Franklin Consulting Services, LLC.

PROJECT SIZE: 7,000 SQ. FT.

CONTRACTOR: WeatherTight Installations, Inc. Livonia, NY

CONTACT: Steve Ezard, Manufacturer: Oak Ridge Foam and Coating Systems, Inc.  Green Lake, WI

PROJECT SCOPE DEVELOPMENT: Franklin Consulting Services, LLC. 380 Hill Road Hilton, New York 14468 (585) 314-4063