By Kristian Foster
During our April travels, news reached us of the lead theft at St John the Baptist Church in Inglesham. The significance of this church to William Morris and the SPAB made it a particular talking point, and reinforced how devastating lead theft can be.
There’s the damage of losing such critical protection from the elements, the cost of the replacement materials, the insurance costs and the cost of alarms or additional security. When thinking about replacing the lost material one must consider the compromises to authenticity, detailing, appearance, workability and performance. Though there are alternatives to lead, we’ve grown to really appreciate how wonderful lead is.
Hands-on learning is one of the most rewarding elements of the Scholarship. It imbues us with a respectful understanding of the material, its detailing, workability and the skills of those crafting it. In just the last few weeks we’ve been fortunate to develop our understanding of lead.
We enjoyed several days with architect Ruth Blackman and family, of Birdsall Swash & Blackman Ltd, Norfolk. They’ve worked passionately for years to safeguard four empty churches in villages taken over for military training operations in 1942. The Stanford Training Area is accessible to contractors for a few days each year, during the lambing period. The most basic and essential repairs are undertaken. We joined S&L Restoration on the roof of St Mary in West Toffs, with its Pugin chancel.
Here we had the task of cutting strips of code 7 lead to form support clips for the base of a sacrificial valley flashing, preventing roof leakages in the infrequently accessed church is vital. Edges were scraped from clips to promote a clean bond during the hot works. The contractor easily demonstrated how to cut a clip, holding the cutter with one hand and gently pulling the lead strip with the other. We mostly reverted to the force of two hands on the snips!
Ruth organised a demonstration and a chance to core weld on some left over lead. Oxygen and acetylene gasses were combined and ignited to create the welding flame, the right blue colour indicated the required temperature. We lowered the flame onto the lead joint until the weld pooled, then rapidly flicked the flame to the side. We continued to melt the adjacent spot until this spot pooled and lead dripped across to combine with the previous melt. All the time carefully ensuring the flame didn’t burn through the lead below. It was all in the wrist and the timing.
Another week we spent a day with CEL Ltd near Peterborough where we watched the process of sand casting lead. We discussed the health and safety issues of working with lead, the fortnightly blood tests for poisoning and the time off required if lead levels in the bloodwork is too high. CEL had separate changing and shower facilities to ensure working overalls were cleaned onsite, not contaminating the family washing machine. Sinks were highly decorated with the required hand-washing techniques and special abrasive hand soaps.
Discussion also focused on the problems of theft and trusting large suppliers to provide authenticity. CEL began as a single lead worker, evolving to become a main and roofing contractor with the skills to remove and recast existing lead in addition to supplying it. Lead is valued due to its versatility, durability and ability to be recast and recycled constantly. Created using three methods, milled lead, machine cast and sand cast, the lead casters at CEL spend 45 minutes preparing the sand bed before sand casting.
Meanwhile lead is heated to 400 degrees and recycled lead is added to the furnace. Pure lead ingots can be added to ensure the correct chemical mix, preventing a pour that is too brittle. With the sand bed ready, the slag is removed from the lead, which floats due to lead’s density.
Video of the process:
Pouring the lead onto the prepared table takes a matter of seconds. The speed of the pour can control the thickness or code of sheet, along with a skim.
Sand casting allows CEL to provide the required size of sheet to reduce waste, measured cut and rolled after the casting. The cut sizes are weighed to ensure the correct thickness and ensure quality. CEL supply to Clare College, Sandhurst and the Cathedral of Notre-Dame at Reims to name a few.
In addition to learning about the sand casting, we were also able to cast lead roses and discuss more decorative works. Lead is a versatile metal used in windows and statues such as the urns we noted in our first week’s visit to Hampton Court Palace.
With the two visits fresh in our minds we could really appreciate the discussion on the re-leading of the dome at Brompton Cemetery with MRDA Architects and contractors Bolt and Heeks. Here, previous details were being improved with better drip and expansion details to add longevity to the repairs.
Lead was also used to offer drip details in timber frame repairs at projects visited throughout Shropshire with Treasures & Sons contractors, such as the 1640’s decorative gatehouse at Stokesay Castle, protecting impressive carvings.
These detailing issues were explored further in the recent SPAB Repair of Old Buildings Course, covering roofing in general and highlighting the issues of expansion and snow loads potentially allowing water ingress to lapped joints if poorly detailed.
With such a valuable, ancient and versatile material, we hope that thefts do not deter its use or lead to irreplaceable losses or damage to buildings like the Inglesham Church and its paintings. A donation page for the repair of Inglesham Church has been set up by the Churches Conservation Trust.