COLONIAL WILLIAMSBURG, once the epicenter of British political power in North America, is considered the largest living history museum in the world. Located in Williamsburg, Virginia, a couple of hours south of Washington, D.C., the site’s 301-acre (122-hectare) historic area includes 88 original structures and nearly 500 reconstructed homes, shops, and public buildings that have the look and feel of their 18th-century predecessors. In addition to its many buildings, Colonial Williamsburg is home to a treasure trove of historical artifacts, including nearly 67,000 American and British antiques and works of art — furniture, paintings, tools, costumes, and more — and 5,000 pieces of folk art.
Protecting such treasures is a priority for the Colonial Williamsburg Foundation, which operates the site. Over the years, the foundation has installed sprinklers in nearly 50 of the buildings it oversees. (Benjamin Franklin, the forefather of the U.S. fire service, would have approved.) In 2001, when it was discovered that some of its dry-pipe sprinkler systems were corroding, resulting in pinhole leaks, the foundation began researching the issue. Its findings helped uncover a wider problem affecting sprinkler systems in cultural institutions around the world, which led, in turn, to new provisions in the 2010 edition of NFPA 909, Protection of Cultural Resource Properties — Museums, Libraries, and Places of Worship, that address the corrosion issue. These provisions were further refined for the 2013 edition of NFPA 909.
As Colonial Williamsburg’s director of security, safety, and transportation, Danny McDaniel played an important role in the evaluation and replacement of the problematic sprinkler systems and in the addition of new provisions to NFPA 909. McDaniel, an alternate member of the Technical Committee on Cultural Resources and a member of NFPA’s Standards Council, talked with NFPA Journal about that work.
From a property protection standpoint, why is Colonial Williamsburg a unique location?
We have buildings that are reconstructed on original sites that run the gamut in terms of occupancies — residential, hotel, office, retail — so we have a range of issues. Eighty-eight of the structures are original 18th-century buildings, mostly wood-frame construction. We also have the DeWitt Wallace Decorative Arts Museum, a single building of about 185,000 square feet (17,187 square meters), with 100,000 square feet (9,290 square meters) of exhibit space, as well as a collection storage and conservation facility that was built in 1995 and covers about 45,000 square feet (4,181 square meters).
When did you notice your sprinkler problems?
In 2001, we noticed pinhole leaks in the dry-pipe sprinkler system of our collection facility. We found significant corrosion and had to replace the system a year later. It cost about $500,000. It was a long, detailed operation to replace the sprinkler system with the collections in place. We finished in 2004.
We were at the tail end of that project when we started investigating similar issues at our art museum. Its dry-pipe sprinkler system was installed in 1985, but we found exactly the same problem. In 2005, we had to replace that system, too. That was a much bigger job. It took two years to complete and cost about $1 million.
Was anything damaged in these facilities?
There were about three or four paintings with watermarks on them. It was treatable but not the kind of thing you want to see.
You started researching similar issues at other cultural resource facilities. What did you find?
There was an article about the McNay Art Museum in Texas with a dry-pipe system that was two years old and leaking. That concerned us. As we continued to look into this, we found that these systems tend to start leaking in as few as 18 months after installation. We discovered an issue at the National Library of Scotland, which used stainless steel pipe that was found to have metallic corrosion. They were early users of stainless steel and had a ton of installation problems.
How did you address all of this?
In 2008, the Technical Committee on Cultural Resources, which maintains NFPA 909, brought in experts on NFPA 25, Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, and NFPA 13, Installation of Sprinkler Systems, as well as cultural resource folks for a day-long symposium on corrosion. We discovered a lot of [possible] reasons for corrosion [in the systems we were looking at] but were unable to nail down a single reason, except that trapped water in an oxygen-rich environment, similar to what’s found in a dry-pipe sprinkler system, tends to do it. However, if you look at very old dry-pipe systems in New England, they are pristine. There is no corrosion. Those of us on the committee feel something has changed.
What’s your opinion on the cause?
At Colonial Williamsburg, the more we investigated, the more we found this was a fairly common problem. We spent a lot of money investigating the metallurgy of pipe. We discovered — and what NFPA’s Technical Committee on Cultural Resources eventually learned — that microbiologically influenced corrosion is a byproduct of this specific corrosion process but not the driver, in most cases. The driver in dry-pipe systems seems to be trapped water.
There were also issues of incompatible pipe in the sprinkler system installation at the museum and collection storage facility — sections of galvanized pipe had been put in that shouldn’t have been there.
In general, though, I feel the cause has something to do with the metallurgy of the pipe, though I can’t say what on earth it is.
You used chemical corrosion additives in the system. Did they help?
When we installed a new, standard wet-pipe system in our collection and storage facility, we put in a corrosion protection system that includes these chemicals. About 18 months later, we started seeing some crystals growing on the outside joints of the piping. I think the chemical was leaching and forming those crystals.
We have controlled humidity in the collection and storage facility, so we didn’t get dripping. What we found in the mechanical room of the facility, where the humidity increased, was that the crystals would go back into liquid form and drip. We had a nice fluorescent-blue puddle on the floor. I won’t put chemicals in the system again.
Chemical additives aside, are wet-pipe systems the answer to the corrosion problem?
In wet-pipe systems, you do see corrosion, but you don’t see the same level of corrosion. The oldest sprinkler system that we have was installed in 1977 in our data center. It’s a wet-pipe system and it has never leaked.
There are applications where these systems are not appropriate, such as unheated spaces in cold climates. However, in my opinion, where an option exists, wet-pipe systems are the best choice for cultural resource properties.
How have the 2010 and 2013 editions of NFPA 909 addressed the corrosion concerns?
We added language to the body of the code that includes protocols for dealing with corrosion if your water supply or your environmental conditions indicate that you’ll have an abnormal corrosion problem in a dry- or wet-pipe system. As a requirement, if you’re going to put in a wet-pipe or preaction system, you have to assume you have those conditions and you need a plan to address them.
NFPA 25 has protocols for inspecting and testing the system. NFPA 909 has taken this a step further to require an internal corrosion inspection every five years. There’s a significant amount of annex material telling you how to do that inspection.
We also added another section to the body of the code requiring that, where chlorinated polyvinyl chloride (CPVC) sprinkler pipe is used, it must be installed in accordance with the manufacturer’s instructions. We also require a plan to ensure that only materials that are compatible with CPVC are used on the system over time. If you’re going to use CPVC in a cultural resource facility, you have to have a plan in place to keep the incompatible materials away from the system so it doesn’t fail. There’s also a significant amount of annex material on that issue.
What role did you play in the development of these provisions?
I submitted the majority of the comments that went into the code, based on committee discussions and what I had learned while working at Colonial Williamsburg.
How was the committee’s stance on these submissions?
There were a lot of discussions on how to deal with interior pipe inspection. We posed the idea to the Technical Committee on Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, but they thought it was too restrictive for NFPA 25. It seemed more occupancy-specific to them, so they suggested we put it in our code, which is what we did.
What other changes to NFPA 909 have been relevant to your line of work?
We’ve been looking at NFPA 909 as an all-hazards document. Fire protection is an issue, but if you look at a cultural resources facility, there is a plethora of issues that can cause damage or loss of collections. Building and property protection is our primary concern. We’ve put a lot of emphasis in the 2013 edition on planning for damage limitation and damage mitigation.
We also added an annex that addresses a project by the Fire Protection Research Foundation on how fire extinguisher agents affect the types of materials we have in our collections. There have been some studies, but nothing looking at the broad range of fire extinguisher agents available. We’re hoping to publish a fairly simple table in a future edition of NFPA 909 that lists which agents can be used with which historic textiles.
What impact will these new provisions have on cultural resource institutions in the United States?
It certainly has raised awareness of the corrosion problem. The membership of the Technical Committee on Cultural Resources encompasses a wide range of folks with a lot of contacts who ask us about corrosion. The information has already trickled down.
— Interview conducted by NFPA Journal staff writer Fred Durso, Jr.