Interlocking blocks vs core-filled Besser
Interlocking (segmental) blocks stack without mortar and suit curves and garden walls. Core-filled Besser walls are reinforced with steel and concrete-filled cores, and are used where a wall needs more strength, such as beside a pool or under a patio.
Good for curves and tight spaces
Blocks are smaller and lighter than sandstone or sleeper panels, so they suit courtyards and backyards where an excavator can’t easily reach, and designs that wrap around garden beds or steps.
Built to last
- ✓Compacted road-base footing or a concrete footing, depending on the wall
- ✓Drainage aggregate and ag-pipe behind the wall
- ✓Steel reinforcement and core-fill for structural Besser walls
- ✓Engineering for walls over the exempt height or supporting a structure
Drainage and approvals
Every retaining wall needs a way for water to escape: slotted 100 mm ag-pipe in a geofabric sock, bedded in washed 20 mm aggregate, relieves water pressure behind the wall. Walls over the NSW exempt height (generally 600 mm, and at least 1 m from a boundary), or walls supporting a structure, need structural engineering and CDC/DA approval. More on retaining walls in Wollondilly.
Frequently Asked Questions
Can a block wall be used next to a pool?+
Yes, core-filled Besser walls are often used around pools, but pool walls may be supporting loads and usually need engineering. Your builder can tell you what’s required.
Do block walls need council approval?+
Walls up to 600 mm high and at least 1 m from a boundary are generally exempt development in NSW. Higher walls, or walls supporting structures, need engineering and CDC/DA approval.
How Wollondilly Wall Co works
Wollondilly Wall Co is a local lead-matching service connecting Wollondilly property owners with independent, licensed structural landscapers and retaining wall contractors. When you call or send a request, we pass your details to a local builder who contacts you to arrange a site measure and quote. The builder you’re matched with is responsible for the work, its pricing and any warranties.