CASE STUDY: NATIONAL UNIVERSITY OF IRELAND GALWAY - patch repair to colonnade ceilings

This contract was for the patch repair to the West Colonnade ceilings and The Aula Maxima bay window to the Quadrangle building at NUIG.

Our brief on this project was to repair the damaged plaster to the walls on the upper and lower bay windows in the Aula Maxima hall which had been damaged by water ingression and also in the Colonnade ceilings. The repair work had to match the existing render which was a smooth finish with an ashlar effect scribed into it.

Firstly we had to carefully remove the damaged render some of which was a cement based material. Great care had to be taken in this phase of the work so as not to damage any salvageable elements of the existing render. The render itself was up to 40mm in depth on the Aula Maxima walls and as itwas a working building, great care had to be taken in the housekeeping element of this process to prevent dust spreading through the building. We removed most of the render using hand held tools.

Internally on the Aula Maxima bay walls the substrate was brick and we had to build this out to 40mm depth to match existing render. Due to the time constraints on the project we opted for an hydraulic lime mortar as the there where several backing coats and this mortar has a faster setting time than a lime putty mortar which would have been more sympathetic to the existing render. We used a pre cast rolled arris where the existing detail had to be removed.

The Colonnade ceilings had been damaged by failure in the roofing elements. The lathe and plaster ceiling, mostly on the outer sections had failed completely and had to be totally removed where as the inner sections where still sound, again great care had to be taken in removing this and props had to be put in place to protect the sound parts of the ceiling. After we removed the damaged sections of ceiling, the joists and framework to carry the new ceilings had to be replaced. We replaced the original lathe and applied a three coat render to achieve the desired finish to match the existing.

Also on the Colonnade the render above the arched windows had begun to delaminate from the substrate. To preserve this render we incorporated a grouting technique which is injecting lime based slurry to bond the mortar back to the substrate.