Nullifire was engaged by Bellmont Facade Engineering to perform rectification work on a heritage-listed building in Sydney.

Located in the Sydney CBD, the building that housed the Department of Education offices in NSW had several issues arising out of ongoing water penetration through the concrete slab roof. Bellmont Facade Engineering, the appointed engineers, commissioned Nullifire in late 2004 for the rectification work through a tender process.

During the tendering process it was determined that the 1500-square-metre roof was protected by a combination of Nuralite (a sheet membrane containing bonded asbestos) and a rubber sheet membrane over the top. However, this system had failed in a number of places, causing cracks in the concrete slab, which led to water ingression.

Removing the existing waterproofing membrane was a complicated process, given the presence of asbestos. Safe working procedures had to be adopted to protect the workers executing the project as well as the staff inside the building. Extensive hazard analysis was undertaken with the building manager to ensure that health and safety interests were protected at all times.

According to the company's Occupational Health, Safety and Environmental Officer, Mr Hamish Anderson, Nullifire inherently understood the risks posed by asbestos to health; therefore, all the staff working on the site undertook extensive training in safe work procedures, and asbestos removal and containment.

Work commenced on the rectification project, beginning with the safe removal, bagging and disposal of Nuralite as per legislative guidelines. Drummy concrete on the slab was removed and falls corrected to ensure correct drainage. Following these preparatory works, Nullifire’s experienced applicators installed a torch-on membrane system over the entire roof.

Nullifire additionally performed remedial works to the parapet walls using a protective membrane, which would prevent the ingress of water. Pressure strips were also used in several areas to completely seal the membrane.

With the works completed, the client awarded Nullifire another contract based on their professionalism and quality of work.