Built with your fence

Retaining walls under fences

When your yard sits higher or lower than the neighbour's, the new fence needs something to sit on. We build sleeper retaining walls directly under the fence as part of the same job.

Request a Free Quote Call 0421 233 434

A level difference along a boundary is common on Sydney's sloping blocks and on newer estates where one lot has been cut and the next filled. Without a retaining wall the soil on the high side pushes against the fence and spills under it. We build a low sleeper wall on the boundary line and set the fence posts through it, so the fence sits straight and the soil stays put.

Our standard wall uses H4 treated pine sleepers – 2.4 m long, 200 mm high and 50 mm thick – on galvanised steel posts. For a maintenance-free option we also build with aluminium sleepers. Most under-fence walls are one to three sleepers high (200–600 mm).

Retaining walls above about 600 mm, or walls close to buildings, may need engineering and council approval and are outside what we build with a fence. We will tell you if your site needs a specialist.

Retaining walls we have built under fences

Colorbond fence with treated pine sleeper retaining wall directly under it

Colorbond fence above a treated pine sleeper retaining wall, Baulkham Hills

Colorbond fence with one row of timber sleepers

Colorbond fence with timber sleeper retaining wall

Timber sleeper retaining wall installation

Aluminium sleeper profile

Why the wall goes under the fence

Building the wall and fence as one structure on the boundary keeps both on the line, avoids a gap between wall and fence where soil and weeds collect, and means one set of posts. The fence posts run through the sleepers into concrete footings below the wall.

Pool fences and retaining walls

A retaining wall next to a pool barrier can change the effective barrier height and create a climbable surface. If your fence is part of a pool barrier, tell us – see the NSW pool fencing information centre for how ground levels affect compliance.

Common questions

Who pays for a retaining wall on a boundary?

Unlike a dividing fence, a retaining wall is not covered by the Dividing Fences Act. Responsibility usually rests with the owner whose land alteration created the level difference, or is agreed between neighbours. We quote it as a separate line so you can discuss it with your neighbour.

How high can you go?

Under-fence walls are typically up to three sleepers (600 mm). Higher walls need engineering and usually council approval and are outside what we build with a fence.

How long does treated pine last in the ground?

H4 treated pine is rated for in-ground use. The steel posts carry the load, and the sleepers can be replaced individually years down the track if ever needed. Aluminium sleepers are the maintenance-free alternative.

Ready for a free quote?

Send us your fence length, height and a couple of photos and Jye will come back to you with a preliminary price or arrange a free site inspection.

Enquire About This Design Call 0421 233 434

Licensed NSW fencer (Lic. 269038C) · ABN 76 612 245 594 · Servicing all of Sydney, 7 days

Call 0421 233 434 Request a Quote