Yes. A sewer or toilet waste pipe can change direction by 90 degrees, but it should use an approved fitting suitable for its position, not a tight, sharp elbow. The exact arrangement must comply with the current drainage requirements adopted in NSW.
What does the 135-degree description mean?
The phrase “135-degree rule” is not a safe standalone design rule. In fitting terminology, a 135-degree bend commonly creates a 45-degree change from a straight run. It does not turn the drain through 135 degrees. Any claim about cumulative changes in direction or access-point spacing must be checked against the current standard and the actual layout.
Which fitting should be used?
A long-sweep 90-degree drainage bend is generally preferred because its wider radius helps wastewater, toilet paper and solids move through the turn. It also allows drain-cleaning equipment to pass more readily than a compact elbow.
Depending on the pipe layout, suitable options may include:
- a long-sweep 90-degree bend
- two 45-degree drainage bends forming a gradual 90-degree change.
A sharp elbow can create a catch point and increase blockage risk, particularly where solids pass through it. However, whether an existing bend is unsuitable cannot be determined from its angle alone; its orientation, fitting type and cleaning access also matter.
A licensed plumber should confirm the fitting and installation against the Plumbing Code of Australia, AS/NZS 3500.2 and the requirements currently adopted in NSW.
Do not cut into or alter sanitary drainage yourself. This can involve sewage exposure, concealed services and regulated plumbing work. If a bend requires assessment or alteration, contact our licensed Sydney sewer-plumbing team for a compliant solution.