St Patrick's Cathedral Ponds
The Ponds within the St Patrick's Cathedral precinct are some 40 years old and were in serious need of refurbishment. There are 4 ponds located on the Albert St elevation of the Cardinal Knox Centre with offices directly below and a pond to the rear of the Cathedral known as the St Patrick's Presbytery Circular Pond. These ponds were constructed in the 1970's
The ponds were originally coated in an unknown Bitumen mastic and were subsequently coated over the years at various times with unknown liquid coatings. Much of the pond base was covered in Blisters and other deleterious materials. Over coating these materials was not a long term solution.
Our solution was to remove the old coatings back to a sound base. We found that the base was a bituminous mastic which was also suffering from serious contamination and over coating this was also not practical in this situation. We decided to go back to a sound concrete base onto which we could build the new membrane lining system.
The lining system consisted of a slurry coat using a high strength cement modified waterproofing slurry that provides very good adhesion to the concrete base and was able to be applied so as to smooth out bug holes and undulations in the surface. Lastly we applied several coats of a highly flexible cementitious waterproofing slurry. There were several expansion joints within the ponds and these were treated with a strong PVC modified joints system encapsulated within an epoxy adhesive mix.