The UK Restoration Team has been conducting extensive restoration work throughout Burnley Town Hall since January 2019. Phase 1 Roofing work was completed at the End of April, which involved a complete re-roofing of the North West Elevations, along with repairs to stone work, guttering and lead details.
Phase 2 of the Roofing repairs is on going, which will see the front elevation of the building completely re-slated with new Welsh Blue Slates. Structural repairs are also being made to the roof, as well as stone repairs and reconstruction of the stone balustrades.
One of the biggest aspects of the project is the restoration of the Clock Tower, which was constructed over 120 years ago. Many of the original Features were still in place and had extensive deteriorated, requiring immediate attention.
6 levels of scaffolding were erected around the clock tower providing our team safe access to all elements of the structure. The scaffolding was then tented to prevent any water ingress during the works.
Grouting & Pointing
The clock tower had previously been pointed with a cement based mortar which had failed, causing stone deterioration and water ingress through the stonework. Our team of stone masons removed any remaining cement based mortar and flushed all the joints with clean water. The stone work was then grouted using a free flowing lime Mortar. Clay is used to close the joints of the stonework, allowing the mortar to flow into the gaps. Once the clock tower was fully grouted, our team then applied a lime based pointing to the exterior. Lime based mortars are porous and allow moisture to escape easily though the joints as apposed to through the stone.
Our Stone masons also replaced the cramps holding the stone around the clock faces. The original iron cramps had started to corrode causing hydraulic jacking. This is where the iron expands and puts pressure on the surrounding stone, often resulting in cracking or corrosion. Stainless steel cramps replaced the old ones, which were then embedded with molten lead. Combination of stainless steel and lead allows the metal to expand and contract without causing damage to the surrounding stone work.
Internal Repairs
Due to the water ingress issues on the clock tower, our team had to make some major repairs to the internal structure of the clock tower dome. The bases of the main support beams & steel brackets holding them had become rotten and posed a serious malfunction if not replaced. The internal stone work was also saturated and stone erosion had occurred. Our team started by repairing the stone work to create a solid base for the support beams to be remounted. The rotten sections of timber were cut out and new stainless steel brackets fabricated and install.
Lancashire clock makers were contracted to service the clock mechanism and bells. They also made repairs to the clock face and repainted the hands. Throughout the restoration of the clock tower the bells were disconnected to ensure a safe working environment.
Copper Cladding
The clock tower dome was originally clad in lead when it was constructed in 1888, but was replaced with copper in the late 50’s. A thorough survey of the copper revealed micro cracking, failed joints, pitting and accelerated corrosion in certain areas and the decision was made to completely replace the copper cladding. The old copper was removed and some minor timber repairs were made to the substructure, before the new copper was installed. We used a pre-patinated copper to match the colour of the old cladding. New internal gutters were also fitted to remove water from the base of the copper dome.
Oak Lantern
At the highest point of the clock tower above the copper dome was an ornate lantern. The lantern was the original structure, fabricated from various timbers including oak. The main legs of the structure were in relatively good condition considering their age, however all other elements of the lantern were rotten. The Lantern was removed from the clock tower and returned to our joinery workshop, where it was replicated in a combination of new air dried oak & kiln dried oak. Our joinery team made some adjustments to the design and construction of the new lantern to ensure longevity of the structure.
Once the lantern had been fabricated , it was returned to the Town Hall and hoisted into place on top of the newly clad copper dome. The oak timber was prepped and painted using linseed oil based products. These protect the timber from the elements but still allow it to breath, increasing the longevity further. The 2 small domes located at the top of the lantern have been clad in ornate lead details for aesthetics, but also to provide weather proofing and stop any water ingress to the internal structure of the lantern.
A new lighting protection system has also been installed on the clock tower, which will extend across the whole of the building.
The Clock Tower restoration has taken approximately 16 weeks and has now been signed off as completed. The scaffold structure is set to be dismantled over the coming weeks, revealing the the newly renovated Clock Tower. Scaffolding has already been erected on each side of the clock tower to facilitate phase 2 re roofing and stone repairs.
