As fosroc celebrates 50 years in reland we look back at key project case studies from recent years.

Fosroc provided the solution to the concrete repaair of Irish Water/AQL’s 40-year-old sedimentation tanks at Obserstown WWTP, Co Kildare. The specification covered all concrete repairs, the overall coating of Renderoc ST05 throughout including the top section and the launder channel with Nitocote EN901 for full chemical protection.

Following further inspection, it was discovered that a significant amount of surface area with exposed aggregate required multiple layer applications of the repair mortars with Renderoc HB45 for the deeper areas and Renderoc ST05 for surface repairs. There were also a large number of blowholes that were predominantly filled with the Renderoc ST05. Once all compromised areas were repaired and fully coated, a final 2mm layer of Renderoc ST05 was applied. The top metre of the internal tank wall and the launder channel received two coats of Nitocote EN901 each at 300 microns in thickness. All existing joint sealants were removed, joint surfaces repaired and resealed with Nitoseal MS600.


The sedimentation tanks are back in service and will be protected for many years against the mechanical action of the sewage being treated and the aggressive gases which build up inside these refurbished, enclosed tanks. The work was carried out by the competent and recommended concrete repair and coatings contractor AQL, supported by technical advice from Fosroc throughout the whole refurbishment. The project was finished well ahead of schedule which allowed the steel and mechanical contractors an early handover for subsequent works.



Denise Maguire   Editor of Irish Construction Industry Magazine & Plan Magazine