How to Prepare Waterproof Parking Structure?
Nash was under pressure to complete the rooftop parking structure at Saddleback Memorial Medical Center during one of Southern California's hottest and longest-lasting heat waves. Did they beat the heat and get the job done. Saddleback Memorial Medical Center is a world-class medical center located in southern Orange County, California. Saddleback was recently named one of the top 100 hospitals in the United States by Thomas Reuters, an independent health research organization, and is ranked Best Hospital in several medical specialties by U.S. News & World Report. But according to John the heat wave brought unseasonably high temperatures for weeks on the end. Nash of Nash Deck Coatings, the three-level parking structure at the medical center was no living up to expectations.
"There was severe peeling and flaking of the existing top coat on the access ramps and roof deck of the parking structure," explains Nash." It seems like an inferior product was put down very thin on the deck, and it was peeling pretty badly."
Something needed to be done to the 15,000-square -foot access ramp and roof deck area to restore safe and functional parking. This is where Polycoat Products' Polyprime U And Poly-I-Gard 246SC came into the picture.
HOT TIRES, GOOEY MESS
A peeling top coat was not the only issue with the roof deck. Send had not been broadcast into the existing coating system, making the deck extremely slippery when wet.
"When it rained, cars and people would go skidding and sliding around," Nash says. ," In addition, the hot tires of the cars that drove up the access ramps and onto the roof deck took the material with them, leaving a peeling and slippery mess. To make sure everyone remained safe, the top level of the parking structure had to be closed whenever it rained."
While Saddleback Memorial Medical Center staff felt it necessary during inclement weather to close the roof of the parking structure to ensure patient and visitor safety, they realized doing so was not an acceptable solution.
Nash performed a number of adhesion tests to make sure that the Polyprime U and Poly-I-Grad 246 SC would properly adhere to the existing urethane base coat. "If we had adhesion tested it and the primer lifted, we would have had a problem," says Nash. "But that was definitely not the case with the saddleback project."
Since the polycoat products coatings passed the adhesion tests by adhering to the existing urethane base coat, it was determined that only the top coat needed to be completely removed the base coat could remain on the concrete substrate - thus saving the client a great deal of money and time.
"At that point in time, we were ready to apply Polyprime U directly to the existing base coat," says Nash
Adriaan van der capellen, southern California sales manager for polycoat, agrees that Polyprime U was the right choice for the job.
"Polyprime U is an intercoat adhesion primer for existing urethane systems," explains van der capellen. "It really takes a hold of and bites in to the existing urethane."
According to Nash during the late summer and early fall of 2012 there were many days temperatures soared to above 100 F (37.78 C) in southern Orange County, California, which is quite an unusual occurrence.
"It was 109 F (42.78C) outside, and the temperature would be even higher on the roof deck, " says Nash. " It was ridiculously hot." It was decided that postponing the job might be the best option. By the end of the two week period, Nash and his crew were eager to get started on the job, not to mention eager for the weather in southern California to return to normal. With no end the heat wave in sight, Nash had to pull the trigger.
"We had to go in on the third week regardless of the heat wave," Nash says. "The job had to get done!"
After making the decision to go ahead with the job. Nash and his five man crew began the surface preparation. The entire roof deck area and all access ramps were power washed using a power washer.
"We power -washed the deck on the Sunday before we started surface prop and coatings," says Nash. He and his crew needed to be finished with the job within five working days, so they took advantage of the slower vehicular and pedestrian traffic on the weekend to get a jump on the first step of the process.
"Since the hospital never closes, the parking structure needed to remain open," Nash says. "The two lower levels were open even while we were doing work on the roof.
Once the deck was power-washed, the crew got down to the business of removing the existing top coat using a grinder. The deck was divided into three sections and each section was prepped, repaired (if necessary), primed, and coated before moving onto the next section.
"The very last section was into he worst condition", says Nash." It was the largest section and had the most traffic come across it, so it makes sense that it was the most damaged".
In all the sections, the crew made concrete repairs as necessary before moving on to priming and coating. Depending on the severity of the cracks, the crew used gun-grade urethane, embedded carbon fiber tape, and/or caulking to bridge the gaps.
With surface prep and repairs made, the crew was ready to apply the Polyprime U.Using squeegees and rollers, the Nash Deck crew applied the high-solids primer to the roof deck at 3 mils (76.2 microns), DFT. Under typical circumstances, Polyprime U should be coated within 12 hours after it has becomes tack-free; however, because of the extreme heat, the primer cured much faster.
"We were able to apply the Poly-I-Gard 246 SC within three hours after we laid down the primer," Nash explains.
Poly -I-Gard 246sc is a single component ,moisture- cured, aromatic polyurethane waterproofing -I-Gard 246SC is designed for use in Southern California to meet the region's low volatile organic compound (voc) requirements.These requirements are set forth and regulated by the South Coast Air Quality Management District (SCAQMD),which encompasses most of Los Angeles, san Bernardino ,Riverside, and all of Orange Counties. The SCAQMD regulates all sources of stationary sir pollution for the aforementioned regions.
The crew poured and rolled the Poly-I-Gard 246 SC at a thickness of approximately 10 mils (254 microns).Nash credits the Polycoat materials for performing incredibly well under unusual circumstances.
"I was a little worried about gassing because of the high temperatures," Nash says." It wasn't a problem with the polycoat Products coatings. There were no
bubbles and no gassing." Nash did, however, make some adjustments. Both the Polyprime U and the Poly-I-GARD 246SC are sensitive to heat, so Nash was very careful with batch sizes, especially the primer." I mixed the two-part Polyprime U primer in half batches-we mixed two-and-a-half gallons, sometimes less, at a time instead of the usual five gallons." Nash says.
NO DAY AT THE BEACH!
Working feverishly, the Nash Deck crew broadcast Cemex-brand Lapis Luster 2/16 sand onto the wet coating.
"We needed to have a fairly aggressive non-skid component added to the coating system," says Nash. In the highest traffic areas, there was a double broadcast, ensuring excellent non-skid properties. Two final coats of 10 mils (254 microns), DFT, of Poly-I-Gard 246sc were then laid on the entire deck area. In the areas of highest vehicular traffic, the coating systems has a thickness of over 40 mils (1016 microns) that protects the existing urethane base coat and underlying concrete substrate. The non-skid component of the system ensures that cars and pedestrians do not slip and slide in wet conditions.
"We finished on Friday and the stripers came in on Monday,"Nash says." The roof deck of the parking structure was open to pedestrians and vehicles on Tuesday." Throughout the project, Nash and his crew followed all standard safety procedures.
THEY BEAT THE HEAT
Polycoated Van Der Capellen is extremely happy with the outcome of the job.
Nash is quick to point out he is impressed with the coatings and his crew.
"I've been doing this a long time -25 years -and I am really happy with the way the Poly-I-Gard 246SC performs," says Nash. Although this was Nash Deck Coatings first job for Saddleback Memorial Medical Center, with the way his crew beat the heat to recoat and reopen the parking structure, Nash bets it will not be the LAST!