APT DC Blog
I was honored to have received the 2019 Emerging Professional Sponsorship to attend the Preservation Trade Network’s (PTN) International Preservation Trades Workshop (IPTW) in Stirling, Scotland this September. The event took place at The Engine Shed, an adapted early 20th-century goods transfer shed, which now serves as Historic Environment Scotland’s (HES) central hub for building and conservation professionals and public discourse and learning (Figure 1). HES is the lead Scottish “public body established to investigate, care for and promote Scotland’s historic environment.”
Workshops covered fascinating topics, from familiar subjects such as historic brick masonry joint profiling, stone carving (Figure 2), carpentry, steel and leaded glass window restoration, traditional timber framing, and decorative wood finishes to more obscure specialized subjects such as traditional and modern scagliola, thatched roofing, and earthen construction. All presentations I attended included hands-on demonstrations.
Gerard Lynch, an animated mason from outside London, demonstrated several different traditional English mortar joint profiles, and explained that masons prior to the beginning of the 17th century “pencilled” crushed calcium carbonate (called “whiting”) onto their joint profile for an exaggerated aesthetic (Figure 3). Until the 19th century, masons also applied an ochre color wash to the brick and mortar on the primary facades of buildings which created a vibrant orange and consistent appearance. It was not until the 19th century when kiln technology advanced that bricks with relatively uniform color could be produced.
David Hayles offered modern and traditional scagliola demonstrations in between sharing anecdotes from his world-wide cycling trip. The modern technique includes placement of dyed silk and flowable pigmented plaster in a mold to create a marble column reproduction (Figure 4). The traditional technique involved a moldable pigmented plaster mix, where layers of pigmented plaster were folded and molded into a column plinth form.
James Turner and Andrea Sevonty from Detroit (near my hometown) demonstrated the restoration of a steel window with leaded glass—a captivating program (Figure 5). They showed that two linear feet of rust on steel frame windows could be removed in roughly a minute using a “needle-scaler” followed by a grinder with a metal wire brush attachment and that dutchman repairs can be performed on leaded glass window panes. Sevonty also demonstrated a window pane replacement and polished the lead using calcium carbonate (“whiting”).
The most memorable feature of my time in Scotland was the scaffolding tour of Doune Castle (Figure 6), backdrop for Game of Thrones (Episode 1), Outlander, and Monty Python. HES masons gave guided tours of their ongoing masonry conservation work focusing on moisture infiltration from the head of the exterior masonry walls. HES methodology included mortar and stone analysis and installation of an NHL 5 (natural hydraulic lime) mortar at the top of the walls with an NHL 3.5 mortar several feet down. The idea is that the harder NHL 5 mortar will limit absorption of moisture at the top of the wall and slow moisture-related deterioration of the wall.
IPTW concluded with a “Ceilidh” (Scottish social gathering) in the Great Hall of Stirling Castle (Figure 7), featuring an auction to support PTN, traditional Scottish fare (including haggis and tablet dessert), dancing, and music (complete with bagpipes). The kilt-wearers and whisky gave a rousing ending to a marvelous educational opportunity! I had the pleasure to sit next to two Scottish HES masons-turned-project managers and the head of the US-Scottish Consulate, so talk centered on Scottish traditions and the work ongoing to preserve cherished Scottish monuments. I loved every moment of this opportunity to meet and talk to tradespeople from all over the US and UK!
The sun-drenched Biscayne Bay served as the backdrop for this year’s APTI Conference in Downtown Miami. Hundreds of international preservationists congregated at the Intercontinental Miami Hotel to engage in workshops, view presentations, and connect with the global preservation community. The subtropical climate and turquoise ocean waters contrasted with some of the serious-minded conference themes this year, including climate change, sustainability, and the socio-economic challenges faced within the context of heritage sites. Heavy-handiness aside, the general vibe was upbeat as attendees explored Miami’s rich cultural history and global inﬂuence. Having never attended an APTI conference, or any conference for that matter, my arrival to Miami was met with nervousness and excitement. Not knowing what to expect, I began the conference with the mindset of meeting new people and learning from the experiences of others.
The ﬁrst ﬁeld session I attended was the Downtown Miami Historic Architecture Walking Tour guided by Cheryl Jacobs, Executive Vice President of AIA Miami and the Miami Center for Architecture & Design. We toured Miami’s collection of Art Deco, Neoclassical Revival, and Art Moderne styled buildings. I was most impressed by the second-ﬂoor lobby of the Alfred i. DuPont building. Brass adorned ﬁnishes with tropical motifs and an entire wood coﬀered ceiling with hand-painted depictions of the Seminole Tribe were the small details in a open space ﬁlled with natural light.
The second half of the conference was comprised of paper sessions typically structured with four presenters led by a session chair. I found myself checking the conference schedule and hopping between presentations of interest. The Zero Net Carbon Collaborative for Existing and Historic Buildings (ZNCC) Session led by Carl Elefante was both fascinating and shocking at the same time. Larry Strain (Siegel & Strain Associates) presented on building reuse and its role as a critical climate action strategy. He made a compelling point when he stated that any new net-zero buildings are not enough to combat climate change and if we are to make any signiﬁcant progress, building reuse is the solution. This presentation changed my perspective on what it means to be a preservation engineer. I originally saw myself as structural engineer whose goal was to preserve the beauty and cultural signiﬁcance of historic buildings. I now realize that I need to expand my career beyond just historic buildings and include transforming the more mundane building stock into something fresh and modern.
I began the APTI conference seeking to connect with other preservationists and to learn more about preservation. I am leaving with a renewed energy and purpose in my career as a structural engineer. I would like to express my sincere gratitude to the patrons of the APT DC Chapter who donated to make this experience a possibility for me.
Emily Garrison, one of this year's recipients of APT DC's Emerging Professionals Sponsorships, attended the 2018 IPTN Workshop in Frederick, Maryland. The following is her summary of the workshop.
I recently had the opportunity to attend the International Preservation Trades Workshop in Frederick Maryland through the Emerging Professionals Sponsorship Program. The workshop features craftsmen and women as well as other professionals in the preservation industry. The workshop included many demonstrations and hands-on sessions, ranging from how-to presentations of a specific repair/preservation method to presentations on projects and advocacy. As a structural engineer it was a great opportunity to observe the aspects of preservation construction, as I am not on-site as structures are repaired.
I went to one session on the process of a dutchman repair. The mason presenter, from the National Park Service, who apart from detailing the process of dutchman repair, shared some of the repairs he conducted in the national parks. One such example was repairing a monument which was struck by a car. It was illuminating being walked through the process of fitting pieces of stone together to minimize the transition from old to new. Had it not been for the difference in color of the two pieces of the stone from age and weathering, it would have been hard to see the dutchman repairs. After explaining the process for a dutchman repair, he demonstrated varies parts of the process on a spare stone, identified his tools, and gave us the opportunity to experiment. I carved a piece of the stone and eventually got somewhat comfortable using the air chisel, after first carving out a very wavy line of stone.
Perhaps the brick mason keynote speaker, Dr. Gerard Lynch, was the best. On the first day of the workshop I walked by Dr. Lynch’s area as he was setting it up to give a presentation. Later, while heading to another session, I stopped as a large crowd was congregated waiting for the presentation to start. The workshop program didn’t include an explanation of the session, so it was not on my list I intended to attend. Witnessing half the workshop attendees were gathered around Dr. Lynch, I decided to stay. His session was a demonstration of tuck-pointing a masonry wall, interwoven with stories from his decades as a mason. He explained the history of tuck-pointing, and took everyone step by step through the process, explaining both tools and techniques.
Dr. Lynch explaining the process of tuck pointing before beginning the demonstration
Beginning the demonstration by grouting the joints
Tuck pointing the joints
Later, during his keynote address, he stressed the importance of apprenticeships and preservation training, emphasizing that modern training regimes often don’t equip craftsmen and women with the knowledge or skills to repair historic structures, as the materials and techniques can differ significantly from modern practices.
Rebecca Domingue, one of this year's recipients of APT DC's Emerging Professionals Sponsorships, attended the 2018 APTI Conference in Buffalo, New York. The following is her summary of the conference.
The 2018 Association for Preservation Technology International conference in Buffalo, New York offered a unique educational and cultural experience. The conference officially kicked off with the all-conference keynote on Sunday September 23rd. Set in the Ashbury Hall of Babeville (Figure 1) the conference was off to a great start.
Figure 1: Ashbury Hall served as the location of the Opening Keynote, located in Babeville, a 19th century gothic revival style church structure repurposed into an event space
The morning after the keynote my coworker, Nicole Ferran, and I presented a case study that closely followed the theme of the night before. Hoen, an industrial complex in Baltimore, Maryland has sat abandoned since the early 1980s. Our case study discussed the balance between preservation approaches and the importance of inhabitation. Work included both repair and localized reconstruction. The finished product preserves the rich history of the complex and will serve as a focal point of the revitalization of the East Baltimore neighborhood. Hoen has demonstrated resilient behavior- the complex had been over run and heavily damaged by nature, but the strength of the original construction persevered.
The paper sessions I attended were captivating; enriching and broadening my insight into preservation techniques and practices. The case studies presented in Track 1 “Decline vs. Revival: Tempering the Impulse to Tear Down and Start Over” drew my attention and continued with the overall theme of resilience. One session, “Innovated or Unusual Reuse” described deconstruction and monitored collapse as two different approaches to preservation. Both were intriguing new ideas I had never considered before. The same paper session introduced me to baltimorebrickbybrick.com, a website that catalogs the deconstruction processes of Baltimore, Maryland’s abandoned buildings.
In addition to paper sessions I attended the Preservation Engineering Technical Committee (PETC) Meeting. The PETC meeting offered me the opportunity to meet and connect with other professionals who share similar interests to my own from all over the world. The enthusiasm of this group of people encouraged me to become more involved and as a result I volunteered to help organize the 2019 Student Design Competition to be held at the Miami conference.
Figure 2: Originally a mental hospital, this heavy stone Richardson building was renovated recently into a boutique hotel.
Figure 3: Louis Sullivan's Guaranty Building in downtown Buffalo, NY.
Figure 4: Upjohn’s gothic revival style church in downtown Buffalo. The exterior is impressive but the interior is absolutely breathtaking!
On March 19th, the Cosmos Club hosted APTDC and presentations on the preservation of the club were given by David Riccio of John Canning Preservation and Arthur Page of Page Conservation. For those who missed the presentations below are some notes from the evening!
-Cheap repairs in the mid-centurn allowed the existing plaster to deteriorate along the exterior wall
-Molds taken from other areas of the room were used to replace the damaged areas
-Where furring strips worked loose of the joists, blocking pieces were used to fill the space between the joists and furring strips with the plaster then reinstalled over the assemblage
-The original gilding was actually three different techniques including water gilding and roman gilding
-Paint analysis determined the original color of the room was a warm grey. Canning used two separate shades of gray to subtly enhance the ornamental plasterwork.
-To remove and restore the lunette panels above the doors, the door headers were carefully removed. When replaced, the screws (which were covered after re-installation) were carefully mapped to aid future repair work.
-The lunettes over the doors were overpainted by a decorator in the early 20th century
-To determine how much overpainting was performed the paintings are viewed under a specific lightsource where the overpainting comes off as dull and dark.
-When the lunette canvases were remounted a larger sheet of muslin was attached to the canvas with modified wax to make future removal from the stretcher easier
-Additionally a new stretcher system was used which will expand and contract less than the original wood stretcher
Thanks to the Cosmos Club, John Canning, and Arthur Page for a great event!
Kimberly Robinson, Museum Curator with the National Park Service, and Bryan Fisher, AIA, Historic Preservation Specialist at GWWO Architects guided two groups of APT DC and AIA DC members and guests through Arlington House, The Robert E. Lee Memorial, to provide an overview of preservation and rehabilitation efforts slated for construction beginning this spring and extending into next year. The project includes the restoration of the mansion house, dependencies, and grounds as well as the construction of a new structure to support the visitor experience.
On February 24th APT DC took over Open Works in downtown Baltimore to learn about new and different digital fabrication techniques. The following are just a few takeaways from each of the wonderful speakers:
Jordan Greco from Xometry, Inc. "3D printing Technologies and Applications"
· 3D printing can be used for both inexpensive rapid prototyping (to test ideas) and manufacturing processes (to create jigs/one-offs)
· Many museums/collections now using 3D printing to create copies of artifacts for display
· Several types of 3D printing:
o Selective Laser Sintering (SLS) - allows a high level of complexity in the object
o Fused Deposition Modeling (FDM) - most common type of 3D printing, but not good for small details
o Stereolithography (SLA) and Polyjet (PJ3D) - Good surface finish, but not durable; can print in a variety of materials
o Direct Metal Laser Sintering (DMLS) - Prints using a fine metal powder; requires more intensive safety equipment
Joe Nicoli from Direct Dimensions "Digital Restoration"
· Many types of laser scanners available to scan everything from a landscape to a building to a small object
· From the scan, can create 3D models that can be scaled to any size
· Have used SLS 3D printing before to create building elements that have been installed (like a ceiling medallion) or for reference for the artisan's use
· When scanning an element for restoration, they often use their 3D artists to "restore" the scanned model element and manipulate the 3D model to match the original design intent
Sean Wise from Repliform, Inc. "Tangible Artifacts from Electroplated 3D Printed Parts"
· 3D printed objects can be electroplated to make them durable, strong, and less flammable
· This is particularly useful when creating replicas of artifacts and/or when creating visually accessible exhibit designs
· Electroplating can also be used to add cosmetic finishes to 3D printed designs
Thank you to all of our speakers and Open Works for hosting and giving us a tour!
Audrey Tepper, a Historic Architect with the National Park Service at the National Mall and Memorial Parks, and Tim Vandewalle, Superintendent at the Christman Company, both discussed their current and ongoing preservation efforts at some of our Nation's significant monuments at the Octagon House to a sold-out audience. Both presenters discussed the innovative technologies developed to appropriately restore and repair historic materials at National Monuments that spawned an informative Q&A discussion afterwards.
Our major takeaways from the presentations are as follows:
1. Increasing annual visitation numbers to our National Monuments are putting stress on our current historic resources. Aging visitor spaces need to be upgraded and many monuments are in need of restoration.
2. The aggressive bio-film found on the Thomas Jefferson Memorial has a unique biology, even different from a similar bio-film found across the Potomac at Arlington Cemetery.
3. Laser-cleaning was determined to be the only long-lasting solution for keeping the aggressive bio-film from growing back.
4. There are 4 methods of repairing cracked cast-iron
1. Heat (1000-1500 degrees Fahrenheit and is only successful when employed at corners of cast-iron)
4. In-kind Replacement
5. Lock-n-Stitch (a mechanical technique developed by Gary Reed) was chosen for the restoration of the Capitol Dome because it preserved the most material in-place among other significant reasons including limited heating processes to the already delicate historic cast iron.
6. Lock-n-Stitch developed a unique mechanical fastener for use on the Capitol Dome, which had a special profile to provide added strength to the low thread strength of in-place historic cast-iron.
7. Selective demolition and fit-up prior to commencement of cast-iron work is critical to the success of repairs.
8. Employ "magnetic particle inspection" after repairs have been completed to ensure no new cracks or discontinuities were formed.
9. Previous mid-century repairs to the Capitol Dome included heat-based repairs, which are irreversible and cannot be reworked or reheated.
Thanks to Kara Johnston for compiling these pointers and thank you to our presenters, we truly enjoyed learning about your experiences with our National Monuments!
Recently a small group of APT DC members were led on a tour of the exterior of the Sidney Yates building by representatives from Grunley Construction Company. The tour included discussions on the restoration techniques used at the windows and masonry units, and up-close viewing of these elements from the scaffolding at the south side and west sides of the building. A few key points from the project shared by Nick Patrick of Grunley include:
· 2 year project
· 130,000 LF of pointing (largest lime putty based repointing job in GSA’s building stock)
· Over 6400 brick replacements
· Over 1000 Jahn patches
· Over 60 new granite, bluestone, and brownstone stone replacements
· 1200 LF of new gutter installed
· Over 8000 LF of new flashing installed
· 568 windows restored
Thanks go out to Grunley for sharing the project with APT DC!
Moira Nadal, one of this year's recipients of APT DC's Emerging Professionals Sponsorships, attended the 2017 APTI Conference in Ottawa, Ontario. The following is her summary of the workshop.
I was thrilled to receive the scholarship to attend the APT-National Trust of Canada joint conference in Ottawa. Since I work for the National Trust in the United States (NTHP) I was interested to see the types of programming put on by the National Trust of Canada and how it was joined with the technical presentations from APT. There seemed to be two main points of focus for the conference; indigenous heritage and sustainability.
The conference was organized along the following tracks: Documentation and Diagnostics – Understanding Historic Places; Design – Planning the Conservation of Historic Places; Delivery – Intervening in Historic Places; Policy and Practice; Canada 150 – Indigenous Heritage, Diversity, and New Directions; Integrating Old and New – Buildings, Districts, and Landscapes; and Regeneration – Community, Economics, and Equitable Places. I attended a variety of sessions, some technical and some cultural. As some of the presentations were in French, the other national language of Canada, we were provided with headphones connected to simultaneous interpreters. It was very cool and made me feel like I was at the UN.
Several session topics were helpful for potential reviews that I may have to conduct for my position with NTHP. I learned about base isolation for seismic retrofitting of historic buildings, which is immediately useful as I monitor properties in California and Oregon. There were also several presentations where I learned more about testing historic windows in situ to demonstrate their performance under specific conditions and with different modifications to make informed comparisons of retention versus replacement. After having the opportunity to walk around the historic district near the conference hotel, I also appreciated getting to know more about Parliament Hill and the ongoing work at that complex of buildings.
In addition to the presentation panels, there was a very full demonstration hall. It was so valuable to be able to ask questions of the vendors on site and helped me to understand some of the newer products and methodologies I’ve been hearing about. I especially enjoyed the hands-on demonstrations by students from the Heritage Institute of Algonquin College. We shared desserts from the reception while planing molding profiles. Overall, the conference was a great mix of detailed technical presentations, larger cultural and theoretical discussions, and networking with professionals from throughout North America and 20 represented nations.
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