Block and Masonry Retaining Walls in Gosford and across the Central Coast

What block and masonry retaining wall work in Gosford and across the Central Coast actually involves

A brick or masonry retaining wall crossing a sewer main needs a reinforced concrete foundation designed so no load from the wall transfers to the main, a bridging slab foundation. As with any material, keep at least 1.5 m clearance to the centre of a sewer manhole or lamphole, and do not build within 3 m of a Council water main without approval. These lines are from Council's June 2014 guide, written for the former Gosford City Council.

Built for fill, near a boundary

Where a masonry wall retains fill, it cannot sit within 1 m of a side or rear boundary unless it is within 1.5 m of an external wall of the house.

Height and approval

A masonry wall is exempt only to 600 mm and 1 m from each boundary. Over that it needs engineer certification or a development application to Council. The main page has the full exempt list and the drainage page covers the clearances around mains in one place.

Ask Council for the sewer main's depth and location before the formwork goes in: a bridging slab is designed to a position, not a guess.

Block and Masonry Retaining Walls in Gosford and across the Central Coast — common questions

What does a masonry wall need where it crosses a sewer main?

A reinforced concrete foundation designed so no load from the wall is transferred to the main, known as a bridging slab foundation.

How close can a retaining wall be to a manhole?

Council's guide asks for a minimum clearance of 1.5 m to the centre of a sewer manhole or lamphole.

Is there a limit near a water main?

No earthworks or improvements are permitted within 3 m of a water main without Council's approval, and that includes retaining walls.