Located within a metre of a magnificent oak tree and in the middle of the sandstone paved courtyard thoroughfare there is a sewer manhole that services a large number of washrooms and student facilities.
The firm that provided maintenance services for the site regularly had to unblock the sewer which was filling with roots, and the man hole was in danger of future collapse due to massive root intrusion.
Perma-Liner Victoria, which is certified by Heritage Australia as an approved Heritage Site Contractor, was called in by the maintenance firm to fix the problem.
Safe site management was paramount, with thousands of students moving around the site, as was ensuring no damage was caused to surrounding structures or trees.
Initial high pressure water jetting and manual root clearing was undertaken around the top sides, walls and benches.
Then gaps, holes and areas where mortar had been eaten away were filled with a water stopping compound called FIX 10 S, a proprietary product from Perma-Liner that seals holes within 30 seconds and take the pressure of a 90 m head of water.
Two coats of Perma-Poxy, another proprietary product from Perma-Liner, were then applied. Perma-Poxy is a two part epoxy that completely seals a surface with a H2S resistant coating. The surface dries to a smooth, almost glazed type surface, that does not allow fats or sewer to stick to it.
Perma-Poxy can be applied by spray, trowel, brush or roller. Due to the small working space and the requirement to keep noise to a minimum within the University grounds, it was decided to enter the man hole and apply it manually. Perma-Liner Victoria is accredited by the CCF and has all necessary CSE tickets and compliances.
The job was successfully completed with both the client and University happy with the end result – and twelve months later the manhole surface looks the same as the day Perma-Liner left the site.