St Margaret's College


The 100-year-old hall of residence at St Margaret's College, in Dunedin, had an original slate roof which was in extremely poor condition and was leaking.

Apart from the roof, this magnificent building in the University of Otago’s historic precinct, was in very good condition, so it needed a roof that would do justice to its style and grand-nature.

While falling into a poor condition, the roof had become a safety hazard for staff and students, as slate tiles were cracking and falling off the three-storey roof. Additionally, the underside of the slate tiles were stone with nothing underneath them, which led to condensation issues.

St Margaret’s College Deputy Master, Bruce Cowan, summarised the problem at hand perfectly: “We needed to replace the roof, which meant we faced the dilemma that a lot of old building owners face – to replace the roof with current materials while retaining the building’s historic look.”



R1 Rhs


Viking EcoStar roof tiles was the perfect system; hard-wearing roof tiles designed to emulate the look of slate. EcoStar would ensure the building received a roof that was in-keeping with the look of the rest of the building – while utilising modern materials.

Before the tiles could be installed, the EcoStar system would need to address the structure of the roof and ensure that the new roof wouldn’t experience condensation issues. As part of the EcoStar system, StrandSarking substrate was installed to brace and strengthen the entire building.

Viking’s Peel & Stick underlay was installed on top of the substrate, which worked with the StrandSarking substrate to ensure no moisture could enter.

Once this was done, Majestic Slate EcoStar roof tiles in a Midnight Grey colour were installed as the finishing, aesthetic touch of the system.

Being less than half the weight of traditional slate, the pressure on the building was more than halved. In fact, the EcoStar system weighed 20 tonnes less than the original slate roof – a dramatic weight loss.


The EcoStar system gave the St Margaret’s College hall of residence a new lease-on-life, while retaining all of its classical elements. The skill of the Viking Approved Applicator meant that the installation of the EcoStar system was top quality, and the roof would be safe, condensation-free, watertight and beautiful for at least the next 50 years, the length of the EcoStar product warranty.

Bruce Cowan was very pleased with the job, and felt very secure under the new EcoStar roof. “It is actually quite reassuring to have 20 tonnes less over your head,” Mr Cowan said.