Interlocking Block Retaining Walls In Wollongong

Geogrid is a strong synthetic mesh laid horizontally between courses of block and extended back into the retained soil. It reinforces the soil mass so the wall and the ground work together to hold the slope, rather than the wall doing all the work alone. Taller segmental walls, and walls carrying a surcharge, generally need geogrid, and the engineered design sets the length and spacing of each layer. On the taller cut-and-fill walls common on steep Illawarra blocks, geogrid is often what makes a segmental wall viable.

No, we are not tied to any single brand. Systems such as Versaloc, Keystone and Allan Block are well-known examples, and there are others, but we choose the block to suit your site, wall height, look and budget rather than pushing one product. Different blocks suit different heights and finishes, so matching the right system to your job matters. We will show you suitable options when we measure up so you can pick the look you prefer.

Yes, they are one of the neatest ways to retain a slope. On the tiered, sloping blocks common through Figtree, Thirroul and the northern suburbs, segmental walls follow curves and steps cleanly and can be built as tiers to create usable, level ground. Each block sets back slightly to batter the wall into the slope for stability, and taller walls use geogrid to reinforce the soil. We assess the slope on-site and set the layout and engineering to suit.

Yes. Segmental walls drain better than some systems by nature, but they still need a proper drainage detail, because trapped water builds hydrostatic pressure and that is the number-one cause of wall failure. Behind every wall we lay an agi-drain, pack free-draining aggregate, wrap it in geofabric so soil fines cannot clog the drain, and add weep holes where they help. In the Illawarra's high-rainfall, escarpment-runoff climate, we never treat drainage as optional, whatever the block.

It depends on the height and load, like any wall. In NSW, walls over about a metre, or any wall carrying a surcharge such as a driveway, generally need an engineered design to AS4678 and often council approval or a CDC through a certifier. Taller segmental walls with geogrid are almost always engineered. We build to the engineered design and can arrange or advise on the engineer and certifier - the engineer designs the wall and the certifier approves it, and we construct to that.

Yes, curves and steps are exactly where segmental block shines. Because the blocks lock together and are usually mortarless, they follow curves, returns and stepped layouts far more easily than a straight sleeper wall, which is why landscapers favour them. That makes them ideal for terraced garden beds, tree surrounds and feature walls on Illawarra blocks. Even on a decorative wall we still build a sound base and proper drainage so the finished landscaping lasts.