History: The Four Courts was constructed between 1776 and 1796. During the 1922 civil war the building was occupied by anti-treaty forces. The Outer Dome and Inner Dome above the Entrance Rotunda suffered extensive damage as a result of a major fire caused by shelling. The original timber roof and much of the interior were destroyed. An extensive restoration programme was carried out under the direction of T.J. Byrne, Principal Architect at the Office of Public Works and completed in 1932. These work included construction of a reinforced concrete dome to replace the destroyed timber outer dome of the original Gandon building and a steel frame to support the ceiling of the Entrance Hall and the floor above. The restoration also included the replacement of all 24 external columns to the dome with new Portland stone columns The Carved Capitals which sat on these columns and supported the roof above were retained however, rotated to present the less weathered faces and repaired with mortar repairs where necessary. As part of the works in the 1920’s a new continuous steel support angle was installed externally around the circumference of the building but this corroded and was repaired in the 1940’s. It was also moved inwards to provide more weathering and a new concrete cover added. Background: In 2011, a section of one of the capitals fell onto the roof of the Four Courts below which necessitated the installation of catch netting to mitigate the immediate risk pending the development of a programme of works to fully remediate the dangers emerging. Some limited scaffolding was put in place at a number of selected points to allow the necessary access for specialists to urgently examine and report on the cause, location and extent of the structural issues but it became evident that the full extent of works could only be established by erecting a full scaffold. This commenced in Jan 2015. Project Scope The initial scope included: - Scaffolding - Repair of the damaged Capital - Examination of the support role of the steel support angle above the capitals and its removal/ repair/replacement. - Repairs to gutter at the base of the Dome and provision of safe maintenance access system. - Examination of the concrete dome which is now over 90 years old and preventative passive cathodic protection of part of the reinforcement of the concrete dome. Once the scaffold was in place detailed stone by stone analysis began. Meanwhile the specialist cathodic protection system to the steel reinforcement of the concrete dome was installed. Examination of the underside concrete surface found traces of the original sky blue decoration but also found that the reinforcing steel mesh required protection. This involved the application of a new protective coating to the dome along with specialist plaster repairs and replacing the original decoration to this upper dome. The supporting structure of the lower dome which is formed by steel trusses with a central opening allowing a view of the outer dome above and its plasterwork, again on steel supports were all meticulously checked to ensure it could take the weight of the stone sections required for an initial replacement of two capitals. Following detailed temporary works design to ensure that the capitals could be relieved of their loadbearing role without any movement of the overall structures the intricately carved Portland Stone replacement capitals were carefully hoisted from the floor of the entrance Rotunda and out onto the scaffold. Attached photographs show damaged capital and new replacement. The steel angle is clearly visible above each. The condition of the removed section of old capitals raised further concerns about how the load from the dome is being transferred though each capital and has led to further structural investigation which is still ongoing to ensure the future long term integrity and safety of the of the remaining capitals while retaining original historic fabric. While this analysis was ongoing additional maintenance and repair work such as the removal of decayed asphalt weathering details and replacement with lead thereby allowing more of the original stonework to be again revealed. Earlier this year progress was affected by Covid 19 restrictions but currently stone indent repairs to the entablature are underway. Remaining works In removing the capitals which required immediate replacement it became evident that the capitals were not only damaged at the edges but that the load bearing core was also damaged. The proposed work now being detailed will involve replacement of a greater number of Capitals than originally envisaged with each Capital assessment in itself a separate exercise involving extensive alteration to scaffolding to provide support during each phase. The steel angle above the capitals will then be replaced or repaired. Works are expected to be complete early in 2022 but this is subject to the extent of replacement capitals required and the related limited level of availability of the highly specialist skills required of specialist stone carving. The advice and related studies on repair mortars and structural analysis by the Graduate School of Professional Engineering Studies in TCD should also be acknowledged. Funding: Costs in the five years to end 2019 amount to over €4m with scaffolding costs accounting for nearly 1/3 of this sum. Op ?ii; Inn-up..- 2 '4 7%