Lead theft: a heavy toll on heritage

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.

Aoife Murphy, cutting out Code 7 Lead Clips, St Mary’s West Tofts.png

Aoife Murphy, cutting out Code 7 Lead Clips, St Mary’s West Tofts

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!

Scholar produced Lead Clips to secure the base of the flashing.jpg

Scholar produced Lead Clips to secure the base of the flashing

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.

Videos of the processes:

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:

Smooth sand bed ready for casting.jpg

Smooth sand bed ready for casting

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.

Videos of the processes:

Lead quickly cooling once cast onto its sand bed.jpg

Lead quickly cooling once cast onto its sand bed

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.

Videos of the processes:

Rolled lead sheets ready for distribution.jpg

Rolled lead sheets ready for distribution

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.

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Scholars’ lead cast roses

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.

Repairs to the Dome at  Brompton Cemetery.jpg

Repairs to the Dome at Brompton Cemetery

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.

Protective Lead drip detail inserted at Stokesay Castle.jpg

Protective Lead drip detail inserted at Stokesay Castle

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.

SPAB Repair of old buildings course, Architect Peter Pace’s Lecture on Roofs.jpg

SPAB Repair of old buildings course, architect Peter Pace’s lecture on roofs

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.


Keeping it in the family

By Charlie Wellingham

A key element of conserving historic buildings is the specification and application of suitable traditional materials. The SPAB believes passionately in supporting traditional craftsmen and sustaining their skills through the encouragement of apprentice schemes to ensure that they are passed down through the generations. As such, an important part of the Scholarship programme is time set aside for visiting forges, brickworks, quarries, masons’ yards, and numerous other types of factories and manufacturers – and viewing the processes and crafts first hand. Many of these companies pride themselves on their production of materials in the exact same way as they would have been executed originally, and as such the premises of these industrial processes have remained unchanged for decades. Due to the nature of passing on traditional skills, several of them have also been run by the same family for several generations. It has been a real privilege to see some of the UK’s oldest surviving manufacturers and family companies as a part of the SPAB Lethaby Scholarship.

Whitechapel Bell Foundry (WBF) was established in east London in 1570 and has endured generations of ownership by just 4 families until the present day. It remains one of just 2 bell foundries casting new bells within the UK. It has been in continuous operation since the 16th century, and is cited in the Guinness Book of Records as Britain’s oldest manufacturing company. The current foundry buildings date back to 1670, when much of London was being rebuilt following the Great Fire. In the intervening years the foundry has produced the United States Liberty Bell (in 1752) and Big Ben (in 1858), as well as surviving the legacy of Whitechapel’s most notorious resident, Jack the Ripper (in 1888).

We were met for the day by Alan Hughes, the managing director and 5th generation of the Hughes family (who have lead the foundry since 1904), who explained the complexities of manufacturing bells – including the exact sizing and shaping of the bell’s profile in order to create the correct 5 note harmonic when struck. Alan explained how WBF has amended its techniques over the centuries as the fashion and technology of bell ringing has developed; including the evolution of bell wheels (from striking hammers), ‘Simpson Tuning’ (harmonics within a single bell), peel ringing (timed ringing across numerous bells), and steel bell frames (from the earlier oak and iroko).

Norman & Underwood (N&U) Ltd began as a glazing and plumbing contractor in Leicester in 1825, set up as a partnership between Henry Thomas Norman and his nephew John Underwood. From these modest beginnings the company has grown over 190 years into a large-scale glazing and cladding manufacturer with particular expertise in building conservation – lead by the production and installation of sand cast lead sheeting in the traditional technique. Throughout this time N&U has been commissioned to produce glazing for such prestigious projects as St Pancras Station (1866), and sand cast lead for Westminster Abbey (1953) and the dome of St Paul’s Cathedral (1955).

We were shown around the 20th century factory by Dr Jon Castleman, managing director and 7th generation descendent of Henry Thomas Norman. Jon explained that although sand-casting lead is more costly and time consuming, it produces a stronger and more reliable product than the contemporary ‘rolling’ technique. The ‘puddling’ of the lead allows for a more complex interlocking structure within the sheet, rather than a stretched directional structure which develops weaknesses more readily. N&U are also able to remove the failing lead from a church roof, melt it down and re-cast it into new sheets.

N&U sketch

N&U photo

Sadly there is not enough space in this blog to describe all of the amazing heritage manufacturers we have visited and who have generously given their time to explain their crafts to us. Thanks also to Ridgeway Forge, Shaws of Darwen, Holywell Glass and Bulmer’s Brick & Tile and the many others I haven’t mentioned. It has been an incredible privilege to see these historic operations continuing – unchanged since before many of the buildings we conserve were even originally built. As architects we hope to continue to contribute to an industry that supports the legacies of these fascinating institutions.

We would also like to thank Dr Jon Castleman of Norman & Underwood once again for the generosity of his sponsorship of the Scholarship and Fellowship – supplying and insuring the much loved spabmobile for use by Scholars and Fellows throughout the 9 month tour. Thanks Jon!Car