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!