Nu Flow relines at Wits University
Wits University, Braamfontien, Johannesburg.
The FNB Building at Wits University, which accommodates the School of Accountancy and shared teaching venues, was built in 1936 for the Empire Exhibition, providing exhibition space for the government of South Africa for many years.
The building has a mixture of 45 PVC and steel roof drain pipes varying in length and size from 150mm to 200mm in diameter. They run from the roof, through the lecture room and faculty ceiling spaces through multiple walls and finally into box gutters, feeding downpipes to the ground.
Since the 1980’s the building has grown with several additions and was in need of a major upgrade to equip it for the academic needs of the coming decades. The pipes were made from sheet metal and were screwed together to the box gutters and joined to sections of PVC pipe with screws. These points were leaking into the building causing damage, and in some sections the sheet metal was coming apart. These points were leaking into the building causing damage, and in some sections the sheet metal was coming apart.
Replacing the pipes was a completely unviable option as the roof slab and walls would need to be cut open in multiple places to access the failing pipes. The only two options were to reroute, which is very time consuming or reline which was completed in less than a month.
The pipes were cleaned of any buildup and debris and returned to original diameter by using the Pneumatic Micro-Cutter prior to lining. With existing access points inside the building, technicians installed the epoxy-saturated liner and gained secondary access from the box gutter side of the building to properly position the liner. Once in place, the bladder was inflated and the epoxy-saturated liner was left to adhere to pipe walls, creating a new pipe within the existing system. This process saved Wits not only time and money, but saved them from destruction to existing infrastructure and disruption for the students in class.