The Problem
The Four Courts, Ireland’s main courts building, was built between 1776 and 1796 making parts of the structure well over 200 years old. A proportion of the original timber dome and drum below suffered extensive damage during the civil war in 1922. Subsequently, in the 1920s, the dome was replaced in reinforced concrete (believed to have been the first such dome constructed in Europe at the time). This iconic building was starting to show its age with the early onset of reinforcement corrosion and the continued deterioration of the stonework.

The Solution
McFarland Associated Ltd (MAL) were commissioned by the Office of Public Works (OPW) in April 2015 to undertake a Condition Survey and Structural Analysis of the dome and provide recommendations for repair works that would last 100 years. MAL designed a series of scaffolding systems which allowed full access to the inside face of the upper dome as well as to the inside face of the lower dome and to the soffit of the reinforced concrete slab over. MAL undertook a suite of non-destructive testing to the concrete dome to determine the nature, source, extent and significance of any deterioration as well as a series of structural health monitoring (SHM) techniques to determine its current structural performance. A full Finite Element Analysis (FEA) model of the structure was created. This gave a holistic view of the nature of deterioration within the building. The use of a cutting-edge, magnetic field, remote, crack monitoring system provided continued insight into the movement of various structural cracks as repair works were undertaken. Various intrusive structural breakouts and inspections were undertaken around the stone work to determine its structural composition and condition. Detailed propping designs were also undertaken to allow for the removal and replacement of a number of ornate external capitols.

The Result
The Four Courts is arguably the most recognisable and iconic building in Dublin, if not Ireland. Its reinforced concrete upper dome, thought to be the oldest in Europe has performed well for many years, but reinforcement corrosion has recently been initiated. We believe our repair recommendations have highlighted how modern techniques can be used sensitively to preserve, conserve, restore and strengthen these historic structures providing significant extensions to their serviceable life. In addition, modern and innovative monitoring techniques can be employed to ensure that works are undertaken without causing any additional damage.