Challenging Reroofing Project

Easing Congestion on Doctors Hospital of Manteca Roof

by Jay Thomas, director of marketing, Sika Sarnafil


From Western Roofing May/Jun ’13


The roof at Doctors Hospital of Manteca located in Manteca, California, defines the word “congested.” The facility’s mechanical equipment, electrical service, duct work, and roof pipes are all on the roof, creating a large network of equipment that would make any reroofing project a challenge. Add 1,750 double pipe support posts which had to be booted and flashed and you have an installation that would scare off many roofing contractors. Fortunately, that was not the case with Waterproofing Associates of Mountain View, Calif. “Waterproofing Associates knew what they were getting into during the bidding situation, but they were not shaken,” said Ernest Magana, president of Magnum Builders, Inc. of Lomita, Calif. Added John Ravetti, project manager at Waterproofing Associates, “We knew that this could be the most difficult job we’ve ever tackled, and it was.”

Waterproofing Associates was awarded the job after submitting a bid with the Sarnafil roofing membrane system. “We chose to go with Sika Sarnafil because of our relationship with them,” Ravetti explained. “We’ve been working with Sika Sarnafil for more than ten years and felt confident this was the right system for the job.”

“I took into consideration the existing construction, the low flashing heights, and the potential for some ponding water, and elected to specify a single-ply membrane,” stated Alvin Nunnikhoven, senior consultant at Benchmark, Inc. roofing consultants in Cedar Rapids, Iowa. “I actually wrote the spec for the Sarnafil roofing system, though we also considered bids for a KEE membrane. We look for proven performance and you get that with Sika Sarnafil roofs.”


Down on Their Knees

The reroofing project started with removing a four-ply BUR over a plywood substrate, mechanically fastening a gypsum roof board, and then adhering the 80-mil Sarnafil membrane. Since all of the equipment on the roof was about 12” above the deck, most of the crew were on their hands and knees for a good portion of the roof installation. “These guys were on their bellies for over a year,” Ravetti remarked. “They only stood up to take a break.”

In addition, some mechanical units on the roof were being replaced, as well as some ductwork, piping, and electrical service. “We had to manage approximately 1,750 new duct support pipe stanchions,” Ravetti said. “These stanchions had to be inspected every day which required temporary patching of all supports.”


Patience Eases Patient Discomfort

The 73-bed hospital remained in operation during the entire installation, which limited Waterproofing Associates to the areas they could work on each day. “The coordination of this project was unbelievable,” Ravetti stated. “Nothing was done until all parties, including the hospital staff, architect, owner’s representative, and general contractor, agreed on which areas of the hospital could be shut down for the roof removal and installation.”

“We worked closely with the facility manager to make sure this work was not disruptive to the patients or staff,” said Magana. “Some areas, like the mammography department couldn’t be closed down, so, we could only work over those areas during the weekends.”

“Waterproofing Associates were very responsive to us if we needed them to stop work because of an emergency,” added Gary Modlin, director of plant operations at Doctors Hospital of Manteca. “I couldn’t ask for a better crew than the people at Waterproofing Associates and Magnum Builders. They really worked well together in keeping any disturbance to a minimum.”

Because of the constraints mentioned above, Waterproofing Associates was usually limited to less than 300 sq.ft. of tear-off per day. “Sometimes we could only do 75 sq.ft. a day. It was like doing a tear-off with a spoon,” Ravetti remarked. They also had to make sure each area was watertight at the end of the day, which was especially important during the punishing rainy season. “Throughout that entire process we didn’t have one leak,” Nunnikhoven pointed out.

“Despite a learning process dealing with miles and miles of ductwork, Waterproofing Associates handled this job with precision,” Magana added.


The Value of Teamwork

Ravetti attributes the great teamwork between Benchmark, Magnum Builders, and Sika Sarnafil as important factors in the success of the project. “Benchmark was great and always on-site, and Magnum Builders made our job a lot easier for us,” he stated. “And Sika Sarnafil representatives helped us by approving special flashing clearances for under the duct work on the pipe stanchions, and working hand-in-hand with us on details that were out of the norm.”

Magana also credited Tenet Healthcare for having the foresight to assemble such a dynamic team. “Every great project begins with a great client,” he remarked. The influence of Waterproofing Associates president, Dennis Ryan, also played a role. “Ryan is a great guy and was always available to help us when needed,” Ravetti said. “He’s going to be the next, and best president of the Western States Roofing Contractors Association (WSRCA) because of his eagerness, spontaneity, and caring nature.”

Ryan states, “This is the type of project in which we specialize. It’s a challenge, but by no means impossible. I knew our team was up to the task.”

Magana added, “Ryan will be a great asset to the WSRCA because of his dynamic and outgoing personality. He will take the time required for the betterment of the organization. His leadership skills and attention to detail are a direct result of his success in building Waterproofing Associates.”

With this leadership, professionalism, and attention to detail it is no surprise that Waterproofing Associates won First Place in Sika Sarnafil’s 2012 Contractor Project of the Year, Low Slope Category.


A Favorable Prognosis

Today the roof is leak free and is expected to perform well for many, many years. “This is the best product we’ve ever installed,” Magana stated. “We’ve already recommended it to another hospital.”

“Would I specify the Sarnafil system again?” Nunnikhoven asked. “Yes, in a heartbeat!”

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