St. John the Divine, New York

Even as church officials hurried to reopen the historic building for Christmas services and the annual New Year’s peace concert, they were thankful that no lives were lost in the five-alarm fire. And, firefighters were persuaded not to break the main roof or stained-glass windows to get at the blaze.

By not venting the fire, though, smoke penetrated deep into the cathedral’s interior stonework, particularly with large areas of granite and limestone. In total, the cathedral – the seat of the Episcopal Diocese of New York – suffered more than $40 million of damage.

Fortunately, before the fire, cathedral officials commissioned a preservation and site-improvement plan; the team assembled for that work was able to shift gears into a restoration plan that still took almost seven years to complete and execute.

At rededication of facilities late last November, every square foot of interior stone been cleaned and restored – in a project described by the construction manager as, “like no other.”

SETTING THE TABLE

As with the great cathedrals of Europe, the construction history of St. John the Divine spanned more than a century – a schedule perhaps not surprising, considering it’s the largest cathedral in the United States, and among the top five church buildings in the world.

Work on the cathedral began in 1892 and completed in stages, but services weren’t held in the main sanctuary until just before the bombing of Pearl Harbor in 1941. Located on Manhattan’s Upper West Side, initial construction was slowed by unexpectedly soft soils; 15 years after the groundbreaking, the original concept of a domed Romanesque structure was replaced with a 601’ Gothic design featuring a limestone sanctuary 124’ high.

Work slowed virtually to a stop during World War II, restarted in the mid-1970s with the addition of 55’ to the South Tower through a unique on-site apprenticeship program, and stopped again during the recession of the 1990s. Cathedral officials believe it could take another 100 years or so to finish up.

Nor is the cathedral the only building on the 11.5-acre close. Stephen Facey, the facility’s executive vice president, explains that one of the other structures is a building that served as an orphan asylum when the diocese purchased the property.

“It’s the oldest building in Morningside Heights, and it was half torn down as they were building the cathedral,” he says. “It sits where ultimately the south transept will go, but it was the restoration we were working on at the time of the fire.”

Preservation and site-improvement are important parts of Facey’s job, and he’s been working on it for about 15 years now with the help of locally-based Polshek Partnership Architects.

“To begin the planning process we engaged Polshek to be the architects for the cathedral and to develop a plan,” he says. “Polshek Partnership is one of the premier firms in New York that works in all kinds of buildings, and we hired them to figure out the planning we wanted to do.”

He adds that Polshek, in turn, brought in other consultants, most notably Building Conservation Associates Inc. (BCA), which specializes in building conservation, with a focus on stonework and masonry.

The fire began in the cathedral’s north transept – not surprisingly, an area that wasn’t quite finished (including a temporary wood roof) – and destroyed it.

“Its full footprint had been built out, but only to a height of about 40’,” Facey says. “They stopped building in World War II, and that was where our gift shop was. However, it blew into the cathedral because of a massive ‘temporary’ wall that had been put up while they were building the north transept.”

Typically, church fires are fought from outside the building by going through the roof and windows. However, despite being in different styles and from different times, the bulk of the cathedral roof is concrete. And, the New York Fire Department agreed not to blow the cathedral’s stained-glass windows, most notably its 1,240-ft² rose window.

“The fire department was great, but we had a huge amount of soot damage that really penetrated, particularly all the limestone,” Facey says. “We knew we had to clean it or it would have gradually deteriorated. Fortunately we had our team of construction people on board as a result of the work we were doing.”

MASSIVE SCOPE
One member of the team is Claudia Kavenagh, director of BCA’s New York office, who started working on the cathedral in the mid-1990s.

“Even before the fire, it was an interesting case,” she says. “At one end you had areas that were in need of restoration well before the fire. At the other end, it isn’t complete. It’s an interesting combination of issues.”

Until the fire, Kavenagh says BCA had done several smaller projects at the site. As part of Facey’s team, BCA was then called in soon after the blaze was extinguished to discuss both short- and long-term issues.

“Right after the fire, they went in and did an initial cleaning out of the smoke from the building so it could be opened for the holidays,” says Kavenagh. “Steve was smart and had a crew come in and do basic work using methods that weren’t going to damage materials or get in the way of any permanent solutions. When we started our evaluation, it wasn’t an emergency, which allowed more time to investigate solutions.”

One of the first things BCA and other teams members were called upon to do was to help the cathedral settle with its insurance carrier. One answer BCA helped provide was whether smoke and soot had traveled through the entire building.

“It sounds like an obvious thing, but the fire was concentrated in the north transept,” she says. “The first thing we did was a round of forensics to take samples from the entire interior and document what was in them.”

Aiding that effort: the north transept’s roof wasn’t concrete, but wood with a bitumen coating.

“The fingerprint of the fire soil was already unique, and as we’d take samples and look at them under the microscope, we could pick out that fingerprint of charred wood with little globules of melted bitumen,” Kavenagh says. “Even 500’ away and 100’ in the air, we found that same fingerprint.

“It was a pretty clear-cut case, and it allowed them to move forward more rapidly,” she adds.

However, in a case such as this, rapidly is a relative term. Another important member of Facey’s team – even before the fire – is JS Mitchell & Sons Inc., the locally based firm founded in 1888 that served as construction managers and helped lead the work on the insurance settlement.

“We basically spent two years putting an estimate together that was arguable with the insurance company,” says James Patterson, Mitchell’s project manager. “It’s a massive project that takes not only time to create drawings to have people bid on work, but you have to explain it to them, and you have to explain it to the insurance company and have them approve it.”

TESTING, TESTING
Finding the best solutions wasn’t always an easy task. Take the matter of cleaning the interior stone.

Kavenagh explains that under any circumstances, her company does a comprehensive round of testing to determine the best methods for cleaning. However, in this case, options were limited because of the need to keep the cathedral open during the clean-up.

The cathedral’s Facey says not only did the selected method need to be able to clean a large selection of different stone types, with an emphasis on limestone and granite, but any system using abrasives was dismissed for air-quality concerns.

“We couldn’t wet-clean the interior because underneath the damaged spaces we have classrooms and gymnasiums and program space,” he says. “We couldn’t contain the massive amount of water you’d use for an exterior cleaning, or even methods using high-speed compression.”

During negotiations with the insurance company, however, a new method of cleaning called Arte Mundit, from Belgian firm FTB-Remmers, was suggested.

“It’s a liquid latex you spray on the stone,” explains BCA’s Kavenagh. “Sometimes it has a chemical additive in it and sometimes not. You allow it cure on the stone, then peel it off after it’s cured to a rubbery consistency. Then, you scrub the stone and wipe it down with a sponge and water. However, you avoid the greater amounts of water you’d need for a typical wet-chemical method.”

At that time, Arte Mundit was being used on a restoration of St. Paul’s Cathedral in London (“Restoring a Nation’s Icon,” Stone Business, Jan. 2006), but had not yet been used in the United States. Kavenagh says it was suggested the method be tested on St. John the Divine.

“It was so new, and the project was going to cost so much money, that we wanted to be really sure what we were up against and what other people felt about using the product on a large scale,” she says. “We went to London and met with the architect and the contractors working at St. Paul’s. We watched them work and did a lot of our own testing as well, and ended up specifying the product.”

Among those traveling with Kavenagh was Andrew Wilson, executive vice president and project manager for Nicholson & Galloway Inc. The Glen Head, N.Y.-based firm has been cleaning stone for more than a century, and had worked with both BCA and JS Mitchell previously.

“This is a contractor we sought out,” says Mitchell’s Patterson. “The architect puts the project down on paper, but they leave it to the construction manager to find the contractors. It’s our job to separate the contractors who say, ‘Yeah, we can handle anything,’ from those with real expertise.”

Wilson says his firm had originally bid the job using a micro-abrasive system that would have required a lot of cleanup. What he likes about Arte Mundit is that it’s very cost-effective because there’s no dust and only minimal cleanup involved.

“It required a lot of testing on our part,” says Wilson. “We had to bring pump sprayers and the product over from Europe. We also had to really learn the system, and we brought a trainer in to train our crew. However, once we learned it, it was very versatile.”

AN OPPORTUNITY
The ease of doing the work was also important, given the working conditions. Staging was left to JS Mitchell and Sons, and Patterson says the sheer size of the cathedral helped with that situation.

“We were able to shut down sections of it, and it didn’t affect the flow of traffic through the building,” he says. “It did reduce the number of displays that were available for the public to see. We felt bad shutting down some of the chapels, but the work had to get done.”

Also daunting was that some of the work had to be done 120’ in the air. BCA’s Kavenagh says once the scaffolding was in place, the scope of the project expanded.

“We had the opportunity to look at surfaces that in some cases hadn’t been examined since they were installed,” she says. “What started as primarily a cleaning project ended up being a cleaning and repair project. Once we got up to the vaults and the ribs and the upper walls we discovered a good bit of damage that simply couldn’t be observed from the floor. We added to the project a pretty large quantity of repairs.”

Some of that was the repair and replacement of the historic Akoustilith ceiling tiles (a porous cement-based product) installed by Rafael Gustavino, the man who invented the product and the process for installing them.

Kavenagh says the rapid expansion and contraction of crystals in the limestone and granite being exposed to high temperatures from the fire, and then hit with cold water from the fire hoses, also caused some cracking and spalling that was stabilized rather than restored.

“We did some limestone replacement, along with some grouting, pinning and pointing,” says Nicholson’s Wilson. “In the scope of things, it was all relatively minor.”

To give some further perspective, Wilson adds that Nicholson & Galloway spent three years on the site, with a crew ranging from 20-40 masons, depending on the phase. It was not uncommon, using Arte Mundit to clean a couple thousand square feet of stone a day.

However, in the end, it wasn’t the entire answer to the project.

“The crossing is granite,” he explains. “The Arte Mundit didn’t work well on the granite, so we had to chemically clean it with a vacuum-recovery pressure washer.”

Nor was Nicholson & Galloway the only firm cleaning stone in the cathedral. JS Mitchell’s Patterson explains that of the cathedral’s seven unique chapels, the St. Ambrose Chapel had finished stone that required its own cleaning. For that, and to do the floors, locally based Heritage Maintenance Inc. was brought on board.

Ron Jagusch, co-owner of Heritage, says most of that company’s work involved cleaning and restoring the floors in the chapels and nave, but the St. Ambrose Chapel required more-extensive wall work.

“It had more water-penetration issues due to some roofing problems that had been on-going,” says Jagusch. “A lot of the things we worked on were where moisture was bleeding out of the joints, giving it an efflorescent-type staining effect.”

Each of the chapels was designed individually; in St. Ambrose, there’s a mix of dark green and white marbles. Additionally, there’s what Jagusch describes as “a pinkish marble” that didn’t respond well to Arte Mundit.

“It cleaned the surface a bit too aggressively and bleached out the color,” he says. “We re-honed it and re-polished it to a satin luster. We also did some repairing of spalling and missing stone in the St. Ambrose Chapel.”

Jagusch adds that his company spent almost a year at the cathedral; because of its responsibility for the floors, the firm was one of the latter ones to finish work.

“Mitchell scheduled everything so we weren’t in anyone’s way; there was never any problem,” he says. “We were a little pushed at the end, but they gave us plenty of notice. We knew we were going to have a couple busy weeks, but we got it done.”

The cathedral was rededicated lastNovember, and everyone involved with the project says they’re pleased with the outcome. For instance, Jagusch notes his company received an award for its work, and Nicholson’s Wilson says, “It was a great project.”

Both Mitchell’s Patterson and BCA’s Kavenagh give plaudits to the contractors who did the work. Patterson says the craftspeople on the project were so enthused it was often difficult to get them to quit working during the services.

“We had to stop working for two services every day,” he says. “It wasn’t that they were disrespectful, but they wanted to go on working. People kept saying, ‘I just need five more minutes to finish this part.’ It wasn’t for any other reason than the pride in their work.”

“The workmanship is of very high quality,” agrees Kavenagh. “There were a large number of things that needed to be worked out in the field as we went along, but everyone worked well together and came up with a very high-quality job.

“You can see that as you walk through the building.”

The cathedral’s Facey is pleased, too. While he says the fire could have been catastrophic, after seven years the diocese has a clean cathedral. Additionally, with scaffolding in place, several million dollars of structural and preventative repairs were made to the stonework, a new roof was placed on the apse over the organ chambers, and plans and specifications for replacement of the nave roof are now in place, anticipating the need for that work in another 10-15 years.

“We also have the experience, and that gave us a leap ahead on our biggest piece of deferred maintenance,” Facey says. “It turned into a real opportunity. We know these things happen, and we were able to take advantage of it and move ahead.”

Client: The Cathedral Church of St. John the Divine, New York
Architect: Polshek Partnership Architects, New York
Restoration Consultant: Building Conservation Associates Inc. (BCA), New York
Construction Manager: JS Mitchell & Sons Inc., New York
Stone Cleaning and Restoration: Nicholson & Galloway Inc., Glen Head, N.Y.
Tile Floor Cleaning and Restoration: Heritage Maintenance Inc., New York

This article first appeared in the August 2009 print edition of Stone Business. ©2009 Western Business Media Inc.