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Archive for the ‘Masonry Water Repellents’ Category

Liberty Memorial

The most prominent feature of Kansas City’s Liberty Memorial is arguably its 217-foot-tall tower. Photo courtesy of Structural Engineering Associates

This year marks the beginning of the centennial observance of World War I, 1914-1918. The heart of that observance stands in the heartland — at Kansas City’s Liberty Memorial, a registered National Historic Landmark and home of the officially designated World War I museum of the United States.

So to call a project to clean and restore such a monument a great undertaking is… greatly understated. And it also takes time.

One iteration of the monument’s restoration began in 2000, when subcontractor Mid Continental Restoration Co. (along with general contractor JE Dunn Construction and a bevy of architects and engineers) used PROSOCO products to clean the memorial. They installed about 13,000 cubic feet of new stone, and cleaned and replaced around 24,000 cubic feet of existing limestone.

By this time, Liberty Memorial was a well-known site to PROSOCO. Its representatives had conducted surveys on the stone and also removed graffiti in the 1980s.

So when an army of designers and contractors undertook a $1.35 million masonry restoration project in 2012 to clean and protect the mostly limestone exterior of the complex, PROSOCO was ready for the call.

If you haven’t ever visited, put the Liberty Memorial on your list the next time you’re in Kansas City. Its stunning aesthetics have been part of the town’s cityscape since its dedication by President Calvin Coolidge in 1926.

The Liberty Memorial overlooks downtown Kansas City.

The Liberty Memorial overlooks downtown Kansas City. Photo courtesy of National World War I Museum at Liberty Memorial

The monument, designed by Harold Van Buren Magonigle in an Egyptian Revival architectural style on 47 acres, includes a 217-foot-tall tower, two Assyrian sphinxes, the 488-foot-by-48-foot Great Frieze on the North Wall, the Dedication Wall and many more elements constructed of limestone.

Under a design team led by Gould Evans and in conjunction with General Contractor JE Dunn Construction, two Kansas City firms — Structural Engineering Associates and Susan Richards Johnson & Associates — worked in collaboration to complete the limestone restoration. That included cleaning and sealing of the main entry, tower, General’s Wall and fountains, south entry courtyard, sphinxes, and the Great Frieze on the North Wall.

A variety of sources and types of limestones comprising the massive structure complicated the scope of the project. There was limestone old and new, buff and variegated, from different sections of quarries and varying grades. But it wasn’t too much for PROSOCO’s EnviroKlean ReKlaim (formerly known as BioKlean), ReVive (formerly known as BioWash), OH100 Consolidation Treatment, SureKlean Weather Seal Natural Stone Treatment and more.

Liberty Memorial tower

Photo courtesy of Structural Engineering Associates

Kirk Matchell, restoration project manager and associate at Structural Engineering Associates, said that PROSOCO products were specified almost exclusively in the publicly bid restoration job.

“We had worked with PROSOCO’s products for many many years,” Matchell said. “(The products) did wonderfully. They took care of all of the stain issues, and we (applied) a really good water repellent. It’s holding its color, and it’s done what we’ve asked for it to do.”

For Julie Garvey, project designer of Susan Richards Johnson & Associates, familiarity with PROSOCO’s cleaning and protective treatments played a crucial role in those products getting into the specs.

Mike Dickey of Dickey Sales LLC, a manufacturer’s sales rep for PROSOCO, had volunteered to perform a test sample for the firm, “so that we could determine the efficacy of the product… and make sure that no damage or detriment would be seen with the product on the stone in the long term,” Garvey said.

The sample, conducted a full year before construction began, tested 10-year-old Indiana limestone that had been experiencing severe discoloration due to mildew and staining. On the right-hand side of the sample (pictured), the control was power-washed with warm water. The left side of the sample was cleaned with ReKlaim, followed by an application of EnviroKlean Revive (formerly known as BioWash). On the lower half of the left side, a consolidant (OH100) and PROSOCO’s SureKlean Limestone & Masonry Afterwash was applied to demonstrate that “the product would not discolor or darken the stone in any way.” Garvey and others from the firm, including Project Architect Angie Gaebler, watched the three sections as they were left exposed to the elements for a full year.

Test panel at Liberty Memorial

The test panel at Liberty Memorial included the control panel (right), which was power-washed, and the left-side panel, which was treated with PROSOCO’s ReKlaim and ReVive cleaners. They were found to safely remove biological and atmospheric staining on the limestone. Photo courtesy of Susan Richards Johnson & Associates

A year later, Garvey said they “saw significant improvement in the overall appearance of the stone, it was not discolored, and the area was remaining clean longer. There were no detrimental effects of the water repellent or cleaning treatments, and we approved those for the Liberty Memorial.”

Construction started in 2012 and was completed late last year, but the work of everyone involved didn’t go unnoticed. The restoration of the memorial’s Wall of Dedication earned a 2012 Preservation Award in the conservation category from Historic Kansas City, a nonprofit dedicated to preserving the city’s buildings of “historical, cultural or architectural significance.” This wall commemorates the five allied leaders — Lt. Gen. Baron Jacques of Belgium; Admiral Earl Beatty of Great Britain; Gen. Armando Diaz of Italy; Marshal Ferdinand Foch of France; and Gen. John Pershing of the U.S. — who attended the memorial’s groundbreaking ceremony in 1921.

In addition, the overall masonry repairs of the memorial garnered an award of merit from the International Concrete Repair Institute in the historic category.

But it didn’t take international awards for the project’s architects to take pride in the finished product. “It was a labor of love,” Garvey of Susan Richards Johnson & Associates said. “We’re truly honored to have been part of such a significant historic property here in town.”

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Built in 1997 to resemble ancient Mesopotamian ziggurats, Sacramento, Calif.'s Ziggurat recently got a protective coating of Sure Klean Weather Seal Natural Stone Treatment WB Plus.

Built in 1997 to resemble ancient Mesopotamian ziggurats, Sacramento, Calif.’s Ziggurat recently got a protective coating of Sure Klean Weather Seal Natural Stone Treatment WB Plus. photo by Tim Sinnott, Sinco Sales

The design is one of the oldest in the world. The technology used to protect it from weather is one of the newest.

This 10-story stepped pyramid in Sacramento, known as the Ziggurat, is HQ for California’s Department of General Services. Though the Ziggurat was constructed in 1997, it hearkens back to 3,000 BC when ziggurats first appeared as platforms for temples in Mesopotamia.

We know that area now as adjoining parts of Iran, Iraq, Syria, Turkey and Kuwait.

Ancient ziggurats were usually made of sun-baked bricks faced with fired bricks glazed in different colors.

Sacramento’s Ziggurat, designed by E.M. Kado Associates, Sacramento, is faced with Minnesota Gray Buff limestone.

Project Manager Chris Hill, WSP Roofing & Waterproofing, Sacramento, oversaw cleaning and weatherproofing of the pyramid in autumn and winter 2012 and spring 2013. His crew stripped out and replaced bad caulk joints and pressure-washed to remove traces of biological staining.

To ensure the staining stayed gone, he treated the cleaned stone with Weather Seal Natural Stone Treatment WB Plus, one of PROSOCO’s newest masonry water repellents. Keep out water, of course, and you keep out the problems water brings, like biological staining, as well as wet-dry and freeze-thaw cycling.

The treatment made the shortlist of three candidates for the project, Chris said, after he asked the quarry that supplied the stone for suggestions. Chris got an unqualified endorsement for PROSOCO protective treatments. He asked Manufacturer’s Representative Tim Sinnott, Sinco Sales, Danville, Calif., to suggest a specific PROSOCO product.

Tim recommended PROSOCO’s newest water repellent for limestone and other stone masonry after consulting with PROSOCO’s Lab.

“Natural Stone Treatment WB Plus provides better water-repellency and bonds much more tenaciously to calcareous stone than the standard water-based water-repellents,” says PROSOCO Research and Development Chemist Chris Moore. “It does it without the blushing or whitening sometimes associated with these water-based products.

“It’s a modified siloxane, but it’s modified in a way that no one has ever tried before, to my knowledge,” says Chris, who created the new protective treatment in 2012.

The Lab tested the new treatment according to ASTM C97, among other tests, which measures by weight how much water a piece of treated stone absorbs after being immersed for 24 hours, compared to an untreated control.

“I expected about an 84 or 85 percent improvement compared to the untreated stone,” Chris says. “I knew we had a winner when it showed a 96.6 percent improvement. We pulled the treated stone out of the water after 24 hours and it was practically dry.”

In addition to effectiveness, the penetrating, breathable water repellent met two other checkpoints. It complied with California’s strict Volatile Organic Compound (VOC) regulations, and it had no effect on the stone’s appearance.

Unable to penetrate, water beads up on limestone treated with Natural Stone Treatment WB Plus at the Ziggurat in Sacramento.  The water, and the crepe myrtle blossoms, fell during a rain storm the previous night. -- Chris Hill photo

Unable to penetrate, water beads up on limestone treated with Natural Stone Treatment WB Plus at the Ziggurat in Sacramento. The water, and the crepe myrtle blossoms, fell during a rain storm the previous night. — Chris Hill photo

H.D. Supply/White Cap Construction Supply, Roseville, Calif., supplied the Natural Stone Treatment WB Plus, and Chris Hill and crew sprayed it onto the dense stone, then backrolled it, stone by stone. They weatherproofed from the top down, treating each level’s North, East, South and West elevations in turn.

Portions of the odd-shaped building were hard to reach, Chris said, such as the recessed ridges over the entrance and rear exit. To reach those with their sprayers and rollers, WSP crew members used an all-terrain lift with basket. In other places they had to harness up like mountaineers.

“We used lots of scaffolding,” Chris said. “After we finished each level, we had to disassemble it, hand it down to the next level and reassemble.

By project’s end, Chris and his team had weatherproofed 61,250 square feet of limestone pyramid with PROSOCO’s new Natural Stone Treatment WB Plus — a new technology for an ancient design. ###

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photos courtesy MSI General and County Materials

Behold the power of cheese! The new Mars Cheese Castle, Kenosha, Wis., cheese retailer, is protected from the often harsh Wisconsin climate by Sure Klean Weather Seal Blok-Guard & Graffiti Control.

As you’d guess from its name, the Mars Cheese Castle, owned by the Ventura family, and located in Kenosha, Wis., has specialized in selling cheese since its opening in 1947. The cheese retailer and gift shop offers more than 300 cheeses from around the world, along with a bakery and a tavern.

The business, which opened in new medieval-style digs in Spring 2011, now has the architecture to go along with its name.

“We had some fun designing this,” said Project Architect Tony Zulli, MSI General Corporation, Oconomowoc, Wis. “It was an opportunity to investigate a type of architecture you don’t see anymore.

“The corbeled arches near the top of the turret and on the main building, for instance; you might see that in brick work from the 1930s and 40s. We really had to think through how to do that with 8-inch concrete block on a single-wythe wall.”

Not exactly standard in contemporary architecture, corbeled arches made with 8-inch block on single-wyth walls took some “thinking through,” Mr. Zulli said.

Stone would’ve been the ideal material for a castle, Mr. Zulli said. However, staying in budget while taking the castle theme as far as possible was also part of what made the project fun.

County Materials, Marathon, Wis., created a custom-colored split-faced block using a castlerock mold specifically for the Mars Cheese Castle, Mr. Zulli said.

County Materials also supplied the water-repellent for weatherproofing the custom block. Specifying a water-repellent was a necessity, Mr. Zulli said — “We didn’t want any problems with water getting into the block.”

Dick Ciotti, Ruffalo Painting, also of Kenosha — their headquarters is about two miles North of the Cheese Castle — used airless sprayers and a 60-foot lift to apply PROSOCO’s Sure Klean Weather Seal Blok-Guard & Graffiti Control.

While the Cheese Castle’s design and construction took some resourcefulness, Mr. Ciotti said applying Blok Guard & Graffiti Control was problem-free.

Buttressed walls add to the Mars Cheese Castle’s medieval appearance.

“I’ve used it before, mostly on schools,” Mr. Ciotti said. “So I knew it worked fine.”

Applying from bottom to top in swaths about 8 feet wide, Mr. Ciotti started with the castle’s south elevation, then moved to West, North and East.

The silicone-based treatment imparts water-repellency to the block by filling the microscopic masonry pores with water-repellent molecules. Unable to penetrate, water simply beads up and rolls off. However, water already in the block can evaporate out, a characteristic known as “breathability.”

The filled pores also make it hard for graffiti media like spray paint to get a grip on treated surfaces. When paint, ink and other media can’t penetrate, they can be cleaned off much more easily than they could on unprotected surfaces.

Mr. Ciotti said he spent about two to three weeks weatherproofing the building in October 2010, toward the end of construction. Good weather added to the ease of the application, he said. Temperatures stayed in the 50s and 60s, and rain stayed away.

“That’s not always the case,” he added.

Turrets, arches, a drawbridge-style entrance and the castle’s other medieval details weren’t the only things Mr. Zulli said he enjoyed about the project.

“We were lucky enough to have clients who let us do what we wanted, while trusting us to look out for their interests,” he said. “I’m proud of the design. It worked out well for everyone.”

The Wisconsin Masonry Alliance echoed that assessment. At its recent Excellence in Masonry Awards event, the organization named the Mars Cheese Castle “Best of Show,” and “Best of Concrete Masonry” 2012.

# # #

Inside the Mars Cheese Castle, the cheese waits.

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This totally permeable cheesecloth, treated with masonry water-repellent Weather Seal Siloxane PD, illustrates what protective treatments are all about. Liquid water cannot go through the treated cloth, porous as it is, and beads up on the surface. Water vapor can go through, however, as the rising steam shows.

I first learned about penetrating water-repellents for masonry, a PROSOCO specialty, when I arrived here at PROSOCO 13 years ago in July.

These remarkable treatments seemed completely magical to me then, and still do. It’s amazing to me how these substances — many of them water-based themselves — can bar entry of liquid water into the substrate, while permitting water vapor to evaporate out.

Newbie though I was then, I could still see the advantages. Water can’t get in, to freeze and expand, and crack and spall the masonry — or to make a moist environment for mold. Moisture already in isn’t trapped within the microscopic pores and capillaries of the brick, stone or concrete — it can evaporate out.

That characteristic is often referred to as “breathability.”

My first thought was — if moisture can get out, but not in, wouldn’t the masonry eventually get so dry that it would crumble into dust? However, this dire circumstance has never come to pass. Evidently, the laws of physics don’t work that way.

The opposite problem — too much water getting into unprotected masonry does create dire circumstances.

The black gunk is mold on the (then) 100-year-old limestone of the North elevation of the Douglas County Courthouse here in Lawrence.

One of those problems is biological growth. If you think the preceding photo looks bad, you should’ve seen it in person. Eventually they cleaned the building, using PROSOCO products, natch. The cleaning contractor recommended a penetrating water repellent for the cleaned courthouse, but I don’t know if that ever got done.

North elevation, Douglas County Courthouse after cleaning, with PROSOCO products, natch. But without a water-repellent, the biological staining will come right back.

If it didn’t the biological staining will be back.

Here’s another North elevation shot. This is historic Allen Fieldhouse at the University of Kansas, getting cleaned for its 50th b-day in 2005.

Allen Fieldhouse got treated with a masonry-strengthening water repellent Weather Seal H-40, and the black gunk hasn’t returned.

North elevations are particularly susceptible because they seldom see direct sunlight. So once wet, they often stay wet, which is just how mold likes it.

Put a penetrating water repellent on that masonry, and the water can’t soak in to provide a moist environment for mold.

I poured water on this limestone sample after treating three-quarters of it with Natural Stone Treatment, a water-repellent specially made for limestone.

Here’s an example. Water beads up, unable to penetrate this limestone where I treated it with a water-repellent. Mold won’t find that a good place to thrive, because of lack of moisture. The water soaked right into the untreated edge, making it more susceptible to biological growth.

Water penetration has popped the faces off this bark-faced brick. There’s also plenty of dirt and mold.

In the photo below, water penetration has popped off the faces of the bark-faced brick in this retaining wall. The damage could have been caused by freeze-thaw cycling, or by the build-up of salts within the masonry fabric (subflorescence). Water penetration causes both problems, so either way, keeping water out of the masonry prevents the damage, as well as the mold growth.

This graphic shows how penetrating water repellents line the pores of masonry substrates with hydrophobic molecules.

Penetrating water repellents work by soaking in and lining the pores of masonry substrates with water-repellent molecules. Visualize a molecule with an umbrella on top and hooks on the bottom. The hooks chemically bond the water-repellent to the substrate. The net effect of all those little molecular umbrellas is to create a surface tension that keeps liquid out of the pores.

There’s not a thing in the world, however, to stop vapor from evaporating out, if it needs to.

Because the treatment does its job from beneath the surface, there’s seldom, if any, change to the look and feel of the masonry. That’s particularly important to restoration professionals.

They’re right to be concerned. Film-forming water-repellents, which try to protect the masonry by forming an impermeable layer over the masonry, can seriously degrade a building’s appearance.

Here’s a close-up of a failed film-forming protective treatment. The force of the moisture evaporating out caused the coating to debond.

Because they’re not “breathable,” these treatments trap moisture within the substrate until it breaks out. The results are ugly. Where the coating fails, more water gets in. Where the coating stays intact, it traps the additional moisture, so the problem gets worse and worse faster and faster.

The only solution is to remove the failed coating, and replace it with a penetrating water-repellent.

A failed film-forming coating is removed from the orange brick at the historic Folly Theater in Kansas City. Guess which side has yet to be cleaned.

That’s what happened at the historic Folly Theater in downtown Kansas City. You can read the full story here.

Water penteration into masonry and concrete causes plenty of other problems besides mold growth and surface damage. Lime run and efflorescence are two other common problems. As a matter of fact, uncontrolled water causes more damage to buildings than anything else.

Though they’re major components, water-repellents are still only one part of the system for stopping water damage. Expertise, structural integrity and a reliable, tested water repellent all work together. Still looks like magic to me, though.

One of my favorite photos. I treated this brand-new masonry With Weather Seal Siloxane PD, then hit it with the garden hose, then got the photo on a sunny summer day. Love this job!

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Can you identify this project, which was cleaned, inside and out with PROSOCO products? More than 50 readers of last issue's PROSOCO News got it right in that edition's installment of the "Can You Identify This Project" contest.

It’s Union Station, Kansas City, Mo.

You probably already knew that.

We run the “Can You Identify This Project” contest in each edition of our flagship newsletter the “PROSOCO News.” Sometimes I put easy ones in there like — well, like Union Station, or Frank Lloyd Wright buildings (love that Prairie Style). Other times they’re more obscure, like the national headquarters of some big corporation or other.

PROSOCO News -- This cover story won an "honorable mention" for writing in a Publications Management newsletter contest in 2005, but I just like the design. Click on the image to go our archive of PROSOCO News newsletters.

One thing all the mystery projects have in common — contractors used PROSOCO products, natch, to clean, protect and/or maintain the buildings in some way.

When our readers, who are the elite of the construction industry, imho, equalled only in brilliance by the readers of this blog, e-mail, fax or call me with the correct answer, I publish their names and companies in the “Can You Identify This Project” winner’s column in the very next issue.

I ask permission first of course. In all the years I’ve been running the contest, only one person asked me to not put his name into print.

Winners also get some sort of fabulous prize — usually a PROSOCO ball cap. Even better, they get the “You sure know your stuff” certificate.

The "You sure know your stuff" certificate, awarded to winners of the "Can You Identify This Project" contest constitutes absolute documented proof that the holder knows his or her stuff.

This valuable certificate can come in pretty handy. Let’s say you’re in an argument with some rude person who declares “You don’t know what you’re talking about!” You just whip out the certificate, which clearly states that you sure know your stuff. Argument over.

The certificate template was created by our graphic designer Stephen Falls, and each winner’s award is filled out by Systems Support & Training Specialist Candy Monroe. Candy really did correctly identify the Medtronics HQ as stated in the certificate; it’s not just done for example’s sake.

The only drawback to the Can You Identify This Project contest is that sometimes I get more correct responses than I have room to print in the PROSOCO News. The last time it happened was for a Frank Lloyd Wright building near Chicago. I think the entire state of Illinois responded to that one.

So we printed as many winners as we could in the newsletter, alphabetically by first name, and published the full list on a special webpage. That was in the days before blogs. Now that we’re in the days OF blogs, I can publish the full list of last issue’s winners right here, since there’s far too many to put in the print edition of PROSOCO News.

And truly it’s an honor to have the names of these architecturally aware and constructionally knowledgeable building professionals gracing this blog. Here they are for last issue’s “Can You Identify This Project” — Union Station, KCMO. I wouldn’t be surprised if you spot someone you know in their ranks.

Andy Vohs
Chamberlin Contracting
Kansas City, MO

Angela Myler
Univar USA
Kansas City, MO

Bill Morris, AIA
Augusta, KS

Bill Neville
Chamberlin Contracting
Kansas City, MO

Billy Vicic Jr., RLA
Newman, Jackson, Bieberstein
Dallas, TX

Brian Pape
Historic Preservation & Green Architect
New York, NY

Chelsie Booker
RIM Architects
Anchorage, AK

Ching-Ya Yeh
Historic Preservation & Green Architect
New York, NY

Connie Watkins
Scott Rice Office Works
Lawrence, KS

Daryl Carter
ACI/Boland
Kansas City, MO

Doug Kouba
Kouba + Knoop Associates
St. Louis, MO

Elliott E. Dudnik
Elliott Dudnik + Associates
Evanston, Ill.

Frank Halsey
Mid-Continental Restoration
Fort Scott, KS

Gary Becker
Hesston, KS

Gerald Morgan
University of Missouri
Mexico, MO

Gerard Alba
Studio 804
Lawrence, KS

Gerri Kielhofner
Butler Rosenbury & Partners
Springfield, MO

Howard Langner
Texas Historical Commission
Austin, TX

Jack O’Roark
BAC Local #15 MO/KS
Overland Park, KS

James W. Rhodes, FAIA
PRESERVATION DESIGN
Croton-on-Hudson, NY

James Warren
New York State Historic Preservation Office
Waterford, NY

Jessica Gates
Sherwin Williams
Independence, MO

Jim O’Neill
Contractors Supply
East Providence, RI

John E. Heckman, AIA
Heckman & Associates, P.A. Architects
Independence, KS

Jonas Packer
AECOM
Chicago, IL

Jonathan Brooks
PBA Architects, P.A.
Wichita, KS

Joseph Le Pique
New York City Department of Design + Construction
Long Island City, NY

James R. (JR) Baron Jr., RA, CSI
Norcross, GA

Karen MacCannell
The McIntosh Group
Tulsa, OK

Kathleen Alberding, AIA, CSI, LEED AP
Heller & Metzger, PC
Washington, DC

Keith Anderson
WRA Architects, Inc.
Dallas, TX

Ken Kaiser
Ken Kaiser Restoration
Des Moines, IA

Kevin L. Jarman, AIA
Johnson Cartwright Jarman Architects, P.A.
Tampa, FL

Kimball L. Hales, AIA, LEED AP
Hufft Projects
Kansas City, MO

Kirk Delzer, AIA
Integrated Design Solutions
Troy, MI

Larry Lisbona
Lisbona Architects, Inc.
Shawnee, KS

Lurita Blank
Walter P Moore
Kansas City, MO

Mark Critchfield
Columbia,MO 65203

Mary Beth Oberlin, AIA, LEED AP
Bond Wolfe Architects
St. Louis, MO

Michael Morley
Sipsmart Building Systems
Lawrence, KS

Milton Grenfell
Milton Grenfell Architecture
Washington, DC

Norman Sneed
Allen & Hoshall
Memphis, TN

Paul J. Sanders, Associate AIA, Project Designer, LEED AP
Burns & McDonnell
Kansas City, MO

Phillip Schuler, AIA, CDT, LEED AP
Cannon Design
Boston, MA

Rebecca Davis
RBS Design Group Architecture
Owensboro, KY

Rich McGuire, PE
Structural Engineering Associates
Kansas City, MO

Richard J. Schuetz, AIA
Arlington, VA

Robert Dye, FSCI
Overland Park, KS

Scott Slimp
Intrepid Enterprises, Inc.
Harvey, LA

Shannon Pollard
hollis & miller architects
Lee’s Summit, MO

Terri Heitzman
Station Nineteen Architects, Inc.
Minneapolis, MN

Thomas McKenzie
Agile Pursuits Franchising, Inc.
Olathe, KS

Timothy G. Carlson
HGA Architects & Engineers
Minneapolis, MN

William J. Richardson, AIA
URBAN DESIGN GROUP
Dallas, TX

If you would like to receive the PROSOCO News and participate in the “Can You Identify This Project” contest, just shoot me an e-mail and I’ll get you signed up.

gary

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EPIC

Photos courtesy Carl Stein, Elemental Architecture

Shepard Hall (1907) City College of New York, clad in dark gray, locally quarried Manhattan Schist, features nearly 72,000 individual units of GFRC trim and ornamentation replacing failing terra cotta pieces.

There’s something grand about every high-profile restoration project, but Shepard Hall, City College of New York, with work spanning more than a quarter-century and $100 million, is truly epic in scope.

The project began in 1986 when the award-winning Stein Partnership, New York City, now Elemental Architecture, took on the job of determining how to save the 1907 Gothic Revival centerpiece of the college — if indeed it could be saved.

The building, designed by George Browne Post (1837-1913), was in dire condition inside and out, said Carl Stein, FAIA, one of the firm’s founders. Carl, author of Greening Modernism, published by W. W. Norton, has overseen the Shepard Hall restoration from the beginning.

Structural terra cotta, unable to cope with decades of freeze-thaw cycling and building movement had been failing for 60 years. In some places chunks, falling from the building, were replaced with brick and mortar.

“It wasn’t very pretty,” Carl said.

Of the 72,000 separate terra cotta pieces on the building, a third were already missing from the building and another third were badly damaged. Craftsmen, studying vintage photographs, replaced 65,000 with GFRC replicas.

In the process, they recreated nearly 10,000 different shapes of which 3,000 are sculptures ranging from floral decoration to larger-than-life-sized human figures, gothic grotesques and gargoyles.

GFRC castings wait for installation. They are replicas of original terra cotta ornaments, created by craftsmen after studying vintage photos of the originals.

Correcting the flaws of the original design, Carl specified a substrate using a traditional masonry structure with the GFRC replicas bolted on to it using a steel framing system that accommodates adjustment in all three planes.

Shepard Hall’s dark gray Manhattan Schist, which was quarried from the very ground where Shepard Hall now stands, bore up under the decades much better than the terra cotta, but still had problems in places. Damaged stones were replaced with similar-looking granite.

Dark gray Manhattan Schist and newly installed GFRC await cleaning and weatherproofing with PROSOCO products on Shepard Hall, during its ongoing restoration.

Where cleaning was needed, the preferred method was simply brush and water. When tougher measures were called for workers used Sure Klean Restoration Cleaner.

The technicians used Restoration Cleaner for areas of heavy carbon staining, a common problem on buildings from the coal-fueled early 20th Century.

Sure Klean Weatherseal SL100 Water Repellent was and is specified to weatherproof the cleaned and repaired sections of the building. The protective treatment is designed specifically for dense substrates like schist and GFRC.

“We chose SL100 because it’s highly breathable, and doesn’t create any appearance change,” Carl said. Along with short-circuiting the freeze-thaw cycle by blocking water penetration, the protective treatment also makes the surface easier to keep clean by stopping contaminants from soaking in, he added.

Work proceeded in nine separate phases, with a 10th and final phase set to kick off in late 2011.

Each phase addressed its own portion of the building, the order driven by severity of deterioration. “Life-threatening” conditions topped the list. With its four turrets beginning to bend outward, in danger of catastrophic failure, Shepard Hall’s main tower was first to get attention.

“We dismantled and rebuilt the upper 65 feet of the tower,” Carl said. This included the installation of four, 56-foot-tall structural post-tensioned precast concrete “masts” which were entirely clad with GFRC replicas, faithfully reproducing the original terra cotta forms.

Newly rebuilt, the upper 65 feet of Shephard Hall’s Main Tower awaits installation of GFRC.

A three-story bay window, one of six on the building, that had torn loose and collapsed led to another priority project. Investigation showed that all of the steel in these areas had deteriorated to the point of imminent failure. All six bay windows were carefully removed and replaced.

Inside, the building’s Great Hall, a cathedral-sized space 63 feet high, 185 feet long and 89 feet wide, was equally at risk. In its time, the hall boasted appearances by Albert Einstein, presidents William Howard Taft, Woodrow Wilson, and Franklin D. Roosevelt, and other luminaries.

Authorities closed the Great Hall in the 1980s because of the risk of masonry falling from upper parts of the window surrounds and other dangers. It stayed closed for 10 years.

By 1997, Carl and his team had put the Hall back in business, with a new limestone floor, new ventilation, lighting, acoustics, and voice and data systems — and restored stained glass windows with new surrounds. That work netted the firm a coveted Lucy G. Moses Preservation award.

Falling masonry and other safety hazards closed Shepard Hall’s cathedral-sized Great Hall for 10 years until it was restored with a new limestone floor, new window surrounds and more.

People caused some of the deterioration. In the 50s and 60s, Carl said, wooden doors and windows were replaced with aluminum. One of the building’s main entrances was taken for a concrete truck dock, which was later abandoned.

The entrance is now restored. Handsome oak door and window frames matching George Post’s original specifications have replaced the deteriorating aluminum frames.

Original oak doors were replaced with aluminum in the 50s and 60s, but were themselves replaced with new replicas, like this entrance to the Bell Tower, matching architect George Browne Post’s original specifications, during Shepard Hall’s epic restoration.

But weather, architectural flaws and human disregard for aesthetics aside, the biggest cause for the building’s descent into near-ruin was neglect, Carl said.

Several New York City budget crises, going back to the 50s, back-burnered maintenance for decades. With nothing to oppose it, weather found the weaknesses in the design and exploited them. By 1986, Shephard Hall was at a turning point where something had to be done — demolition or restoration.

Carl and his associates envisioned a 10-year plan to save the building. Its owners, the Dormitory Authority for the State of New York and City University of New York, agreed. The architects structured the plan to proceed as money became available.

While the vagaries of public funding have stretched the project out to more than two-and-a-half times its intended length, the work has methodically continued to where Shephard Hall, if not complete, is at least out of danger.

During the decades-long project, Elemental and nearly a dozen general contractors worked around building occupants, explored dozens of options for terra cotta replacement, and navigated a complex and constantly changing political and financial landscape to keep the epic project on track.

The payoff is that this landmark building, centerpiece of a campus that has produced more Nobel Laureates (nine) than any other public college, that has hosted presidents, will be around for a long time to come, Carl said.

“I look forward to seeing it completed,” he added.

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This long shot shows Shepard Hall’s Main Tower under reconstruction during the building's epic, ongoing restoration.

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The Amon Carter Museum of American Art is home to this 1872 Winslow Homer oil painting, "Crossing the Pasture." Sealant, Waterproofing and Restoration Institute members recently exercised their own arts to restore the museum's deteriorating exterior.

I’m writing up this project for entry in the SWR (Sealant, Waterproofing and Restoration) Institute’s Trinity Project Awards Program.

The Amon Carter Museum of American Art Exterior Restoration involved restoration cleaning, repair and improvement.

The 50-year-old museum is a Philip Johnson design. Mr. Johnson also designed the AT&T Building in New York City. Some might say Mr. Johnson’s museum is artistically significant as any of the fabulous paintings, photos and sculptures within.

Nevertheless, after half a century, you could expect to see some wear and tear.

SWR Institute members Harper-Brawner, LLC, Arlington, Texas; Mid-Continental Restoration, Fort Scott, Kan.; and PROSOCO, Lawrence, Kan., worked together this past year to shore up the museum’s deteriorating exterior.

The shellstone exterior of the museum's front elevation doesn't look too bad in this recent photo, but get up close and you can see why they called in the pros.

The major problems started with cracks in the shellstone front of the museum. In the above photo you get just a hint of the big granite addition to the museum, which Mr. Glass also designed. It had problems too.

Museum officials originally invited Harper-Brawner to review these cracks in the shellstone exterior. While there, they identifed a few other areas that could use some attention.

The silicone sealant joints bled and stained the polished granite panels — a stain, according to project architect Bland Harper, “not typically thought possible to remove.” Also, where the granite panels went below grade, they wicked up moisture, causing water stains in the beautiful stone.

Harper-Brawner’s assessment turned up a few other problems, too, including deteriorating concrete pavers at the museum’s front pavilion, and a front sidewalk graded the wrong way that directed rainwater into the front door. Those fixes came outside the time period for the award, so I acknowledged them in the award entry write-up, but didn’t include them for consideration with the other repairs.

As I wrote about these repairs, I realized that this restoration, like most involving both aesthetics and sustainability, has artistic elements — maybe not at the level of the original design, or the collections within — but could be considered restoration “art” nonetheless.

The staining around the joints, caused by oils bleeding out of the silicone sealant, is hard, if not impossible to remove.

Water wicked up by the below-grade portion of these granite panels caused these stains.

I thought the answer to the below-grade granite wicking up the water was particularly elegant.

Mid-Continental Restoration excavated around the base of the building and installed a concrete curb. The above-grade part of the curb directs water away from the building, and sends it into the ground, where the below-grade part of the curb blocks the water from wicking up into the granite and causing stains.

They dyed the concrete curb to fit in with the granite panels. I’ll leave it to you to decide if the curb is an improvement in appearance (I think it is), but there’s no arguing that it’s an improvement in building sustainability.

The new concrete curb goes below grade to keep water away from the granite panels.

After being dyed to match the granite, the new concrete curb awaits backfill.

The finished curb improves the building's sustainability by directing rain water away from the building and into the ground, and isolating the below-grade portion of the panels from the groundwater.

Saw cutting new expansion joints into cracking areas of the shellstone fabric, and making it look like it was always meant to be that way also has a touch of the artistic about it, too, in my humble.

The new expansion joint looks a like nasty scar here, before it's finished.

The finished expansion joint fits right into the building aesthetic. Looks like art to me.

Initially, Harper-Brawner told museum officials they might not be able to remove the staining from the bleeding silicone joints. But test panels with PROSOCO’s Sure Klean Dicone NC15 Gel silicone sealant & adhesive remover showed promise. In any case, the old sealant had to come out to stop further staining, and had to be replaced with a new, non-staining sealant.

In addition to mitigating the staining around the joints, Dicone NC15 softened up the old joints for easier removal.

Though it started out messy, in the end, the old joints were neatly removed. Note also the absence of stains around the empty joints.

The new, non-staining sealant is installed as neatly as the old sealant was removed.

Mid-Continental Restoration also gave the building a thorough washing with PROSOCO’s EnviroKlean BioKlean. It’s made for safely removing both biological and atmospheric staining, and was chosen, said Howard Kinsel of Mid-Continental Restoration, because there was plenty of both contaminants on the building.

This, of course, is just the merest bare-bones description of parts of a year-long project. But I think it clearly shows the “art” of restoration in action. After all, if people who restore historic paintings are artists, I believe the people who restore historic buildings housing those paintings are artists too.

Photos provided by Bland Harper, Harper-Brawner LLC.

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