Water is backing up in my Prahran flat. Is the problem in my unit?
Often it is not. In a subdivided terrace or a small apartment block, the lowest fixture on a shared line is where backed-up wastewater surfaces first, even when the obstruction is somewhere else entirely — a flat above, or a shared section beyond the building. Clearing your own traps will not resolve a shared-line problem. A camera inspection finds the real location, which also tells your owners corporation whether it is common property work.