First phase of Four Courts dome repairs completed, says OPW

Scaffolding and mesh on the Four Courts dome has begun to be taken down by the Office of Public Works (OPW) as the first phase of repair works on the historic building concludes.

The OPW completed the enabling, investigative and entablature renovations to the dome at the end of July.

The scaffold that facilitated this phase of works will be dismantled over the court’s recess period of August and September, to minimise disturbance to the courts service, it says.

A further final phase of repair works is required to the decorative stone capitals which support the dome.

The investigative findings will be reviewed and works are anticipated to be tendered in early 2022 and commence on-site in autumn next year.

In 2011, a section of one of the capitals fell onto the roof of the Four Courts below, forcing the OPW to install a catch net while a full programme of remediate works were developed.

Limited scaffolding was placed 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.

However, according to the OPW, it became evident that the full extent of works could only be established by erecting a full scaffold.

This began in January 2015.

Initial works included the installation of scaffolding, the repair of the damaged capital, an examination of the steel support angle above the capitals, the renovation of the gutter at the base of the dome, and a full examination of the 90-year old dome.

Once the scaffold was in place, detailed stone-by-stone analysis began and the concrete dome was reinforced.

According to the OPW, “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 (the ceiling to the Round Hall) 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,” it said.

While this analysis was ongoing, additional maintenance and repair work was carried out such as the removal of decayed asphalt weathering details and replacement with lead, thereby allowing more of the original stonework to be again revealed.

The OPW says that during the removal of the stone capitals, it “became evident” that the load-bearing core was also damaged.

“The next phase of works now being detailed will involve the replacement of a greater number of capitals than originally envisaged, with each capital assessment in itself a separate exercise in removal, inspection and either repair or replacement depending on the structural viability of the stone core,” says the OPW.

The steel angle above the capitals will also need to be replaced or repaired.

It is anticipated that this phase of works will be tendered in early 2022 and commence on-site in autumn 2022.

The costs for the works to the end of this year are anticipated to amount to € 5.8m with scaffolding costs accounting for nearly one third of this sum.