Also known as: disconnector trap · boundary shaft
A boundary trap sits at the lowest point of a property's sanitary drainage, usually near the front boundary. The permanent water seal inside the U-bend blocks odours and gases from the sewer main while still letting wastewater flow through.
In boundary-trap areas (common in older parts of Brisbane), every property must have one. Because it is the lowest and busiest point of the drain, it is also one of the most common places for blockages to form.
Prevents sewer gases from the public main entering a property's private drainage system.
Below ground near the front property boundary, usually with a riser and access cap at surface level.
A CCTV drain inspection is the standard way to confirm whether this is what's happening in your pipes: the camera shows the condition on screen, a locator pinpoints the exact position and depth, and you get a recorded report before any repair decisions are made.
A CCTV drain inspection shows exactly what's happening inside your pipes — no guesswork.