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Contact Info

Arklow, County Wicklow

Info@classicconservation.ie

(+353) 83 026 9045

Chapel Royal Pinnacles

The main body of repair works to the Chapel royal focused on the pinnacles along south side of the roof. Given the pinnacles height above ground and close proximity to the centre of the city, the pinnacles had been subject to adverse weather conditions as well as exposure to a high degree of
pollution. Following inspection, it was found that that all seven pinnacles on the South side of the roof had suffered a significant levels of water damage, causing the ferrous metal located inside to expand and
swell. This resulted in the stonework moving and the pinnacles becoming loose as they were displaced from their bedding.

A decision was taken to commence conservation works. The repair works would involve the careful dismantling of all seven pinnacles on the south of the roof, dismantling from pinnacle finial right down to the lower course at parapet level. The ferrous metal which had swollen due to water damage was to be removed. Once the pinnacles had been dismantled to the parapet level, they were to be rebuilt using NHL lime and sand, with all original ferrous metal pins and timber dowels
being replaced with new 316 L stainless steel components.

The first step in the conservation works was to identify the jointing and coursing in the stonework of each pinnacle in preparation for dismantling. A detailed sketch was produced with each stone being labelled and numbered for reference. Once the jointing and coursing had been identified, the next step was to open the joints by removing the old mortar. This was done using hammers and chisels or, in the case of cement, a small grinder. The upmost care was taken to ensure no damage was caused to the original stonework during this process. A hammer and chisel were then used to remove any remaining redundant mortar which was still attached to the stone. Once the stone was removed, it was carefully lifted and marked to correlate to the detailed sketch produced. The stone was then removed and transported to the loading bay for safe storage. This process continued until the pinnacle was dismantled down to the parapet level. In some cases, the lower stones of the pinnacles contained damaged ferrous metal cramps holding them together. The damaged ferrous metal was carefully removed using hand tools. Given our experience with carrying out similar dismantling/rebuilding works to pinnacles, additional care and caution was taken during the removal of the ferrous metal cramps as there is a high risk of the stone cracking while they are being extracted.

 

 

Once the pinnacles were dismantled, marked, and stored, the rebuilding process could commence. The first step in the process is to mix out the mortar, which was produced using sand mixed with NHL lime and water. Once the mortar was mixed, it is hoisted up to the loading bay, where it was used to rebuild the Pinnacles. Starting with the bottom stone and correlating back to the original drawing , a layer of mortar was spread onto the stone bed. The stone was then strapped and carefully hoisted into position using the block and tackle. As the work progressed, new slots were chased into the stone to receive the new steel cramps where needed, ensuring that the Pinnacle was securely held in place. This process was repeated until the entire Pinnacle was rebuilt leaving the joints recessed back to be repointed at a later stage. Each rebuilt pinnacle was covered in hessian to protect and assist the lime mortar in setting efficiently.

 

 

 

Stone graft/indent repairs were used to repair and restore damaged or deteriorated stone surfaces via the insertion of new stone material into the existing stone to strengthen and stabilize it as well as return the original features which had worn away over the years. Salvaged ardbraccan stone to match the original was obtained from the OPW yard to carry out the repairs. After the grafting process is complete, the repair was finished by tooling and shaping the new stone material to match the existing stone using hand tools to match the surface and feel of the new stone
to the old. On the completing of the graft/indent repairs, the carbon deposit clusters that had adhered to the pinnacles in various locations were then cleaned and removed. This was achieved using a hammer and chisel to delicately removed the hardened carbon deposit while ensuring that the original stone is not damaged or defaced. While being time consuming, this process is the safest and best way to protect and conserve the original stone.

 

 

 

The final stage of the restoration works was to repoint the joint of the rebuilt pinnacles. the mortar was kept moist by misting it with water to ensure that it did not crack or dry out too quickly. The work was then covered with hessian to protect it from the presence of frost disrupting the curing process and weakening the integrity of the lime mortar. Upon completion of all works, the site area and surrounding pavements were cleaned and washed to bring the surrounds back to its original state in preparation for handover to the client.