Retaining Walls Direct supplies concrete sleepers, galvanised steel posts, and drainage kits direct to Brisbane and Greater South East Queensland — crane truck delivery to your site across Brisbane City, Ipswich, Logan, Redlands, Moreton Bay, the Gold Coast, and the Sunshine Coast. No depot markups, no middlemen — direct-to-site pricing with freight calculated to your postcode before you pay.
Our sleepers are manufactured by QPro at Brendale QLD — a Queensland manufacturer — which means shorter freight distances, consistent local supply, and products designed specifically for Queensland site conditions. See the full Brisbane retaining walls overview or read the complete Brisbane retaining wall guide for soil data, post selection and council approval by suburb.
Brisbane materials estimator
Enter your wall details to get a materials estimate and grade recommendation for your Brisbane suburb. Takes 30 seconds.
Estimate for budgeting only. Does not include waste, cuts, or stepping on sloped sites. Grade recommendation is indicative — confirm with a structural engineer for walls over 1 m, walls near boundaries, or walls carrying surcharge loads. Sleeper sizes are post-centre spacings; physical sleepers are ~10–15mm shorter.
Brisbane's geology varies significantly by suburb, elevation, and proximity to waterways. Getting the soil classification right before you order is the most important step in specification — and it's where most retaining wall failures in Brisbane begin.
For suburb-specific soil data, post selection and council approval thresholds, see the complete Brisbane retaining wall guide.
40MPa sleepers suit low decorative walls under 600mm on well-drained sandy soils with no reactive clay and no surcharge load. In Greater Brisbane, this applies to a small number of coastal Redlands and Bayside sites. If soil type is uncertain, default to 50MPa — the cost difference per sleeper is minimal and the long-term performance difference on Brisbane's reactive clays is significant.
50MPa is the standard specification for the vast majority of Brisbane retaining wall projects. Brisbane's subtropical climate delivers intense summer rainfall — often 100–200mm in a single storm event — which saturates reactive clay soils and generates hydrostatic pressure that 40MPa concrete is not designed to resist over decades of wet-dry cycling.
Use 50MPa for:
60MPa sleepers are specified for commercial retaining structures, walls carrying heavy vehicle or crane surcharge, and walls over 1.5m where a structural engineer has specified the higher grade. Available through our 60MPa premium sleeper range. Contact our team for current pricing and lead times.
Every concrete sleeper wall needs correctly sized galvanised steel posts set in concrete footings. On Brisbane's reactive clay soils, undersized posts are among the most common causes of wall lean after wet seasons. See the steel post sizing guide for the full embedment table by soil class and wall height.
| Post series | Wall height | Brisbane application | Min. embedment |
|---|---|---|---|
| 100 Series H-beam | Up to 600 mm | Sandy Redlands / Bayside coastal sites only — stable, well-drained, garden loading | 600 mm |
| 150 Series H-beam | 600 mm – 1.0 m | Standard Brisbane residential — most inner, north and south suburbs | 700–900 mm |
| 200 Series H-beam | Over 1.0 m, or any Woogaroo clay site | Western Brisbane, Ipswich, flood-prone areas, engineer-specified | 1.0–1.2 m+ |
All posts are hot-dip galvanised to AS/NZS 4680. Use C-channel PFC posts for wall ends, corners and returns. Browse the full steel post range.
Brisbane's wet season delivers intense rainfall events — often 100–200mm in a single storm — that saturate reactive clay soils and build hydrostatic pressure behind retaining walls rapidly. Absent or blocked drainage is the leading cause of retaining wall failure in Queensland. Every Brisbane retaining wall must include:
Read the complete Brisbane retaining wall drainage guide for installation sequence and the specific drainage specification for flood-prone sites. Browse drainage kits and ag pipe.
In Queensland, retaining wall approvals are governed by the Building Act 1975 (QLD) and the Queensland Development Code:
Key contacts: Brisbane City Council · QBCC · Moreton Bay Regional Council · Logan City Council · Redland City Council
Full detail: QLD retaining wall regulations guide.
We deliver by crane truck to all Brisbane suburbs and Greater SEQ — from our QPro depot at Brendale (north Brisbane) and Beenleigh and Acacia Ridge depots for south Brisbane and Logan. Shorter depot distances mean faster delivery and lower freight for Brisbane orders than interstate suppliers.
Most Brisbane metro orders are delivered within 2–3 business days from the QPro Brendale depot. Freight is quoted to your postcode at checkout before payment is processed. Request a delivery quote or call 1800 880 124.
Brisbane's Woogaroo Subgroup clays in the western suburbs and Ipswich are among the most reactive soils in South East Queensland. After Brisbane's heavy summer rain events, these soils absorb water rapidly, expand significantly, and generate lateral pressure on retaining walls. 50MPa provides the bending resistance and compressive strength needed to handle this pressure through decades of wet-dry cycling. 40MPa is adequate only on sandy coastal soils in the Redlands and Bayside for walls under 600mm. See the Brisbane complete guide for suburb-by-suburb specification.
Walls under 1.0m are generally exempt from building approval in Brisbane. Walls over 1.0m require building approval and engineering certification from a QBCC-registered certifier. Walls in flood overlay zones and walls within 1.5m of a boundary may have additional requirements. Always check Brisbane City Plan 2014 for your property and confirm with your council before starting. Full detail in the QLD regulations guide.
On Brisbane's reactive clay soils, posts must penetrate through the reactive clay layer into competent subsoil. As a guide: 600–700mm minimum for walls up to 600mm; 800–900mm for walls up to 1.0m; 1.0–1.2m for taller walls. On flood-prone alluvial sites, deeper embedment is required — confirm with a structural engineer before ordering. See the steel post sizing guide for the full embedment table.
Yes — when correctly specified and drained. 50MPa concrete sleepers are designed to handle the lateral pressure generated by saturated clay soils after heavy rainfall. The critical factor is drainage: a wall without proper ag pipe and aggregate drainage will fail on Brisbane's reactive clays regardless of sleeper grade. Install 100mm ag pipe, 300–400mm of clean 20mm aggregate, and geotextile fabric — and your wall will outlast the house.
Never backfill with native clay directly against the sleepers or within the drainage zone. Use 20mm clean crushed rock (not crusher dust) behind the wall face to a minimum 300mm width, with geotextile fabric separating the aggregate from the retained clay. On Woogaroo clay sites, increase the drainage zone to 400mm. See the backfill guide for the full Brisbane specification.
Our sleepers are manufactured by QPro at Brendale — a Queensland manufacturer. Compared to suppliers shipping from interstate, you get shorter freight distances, faster delivery, and products batch-certified for Queensland site conditions. We deliver by crane truck direct to your site across all Brisbane suburbs and Greater SEQ, with freight quoted before you pay.
Yes. Trade and bulk pricing is available for landscapers, builders and civil contractors across QLD. Open a trade account for trade rates, volume pricing and priority dispatch from the Brendale depot.
For walls over 1.0m, near property boundaries, in flood overlay zones, or subject to surcharge loads, always engage a structural engineer and confirm QBCC and council approval requirements before ordering materials or commencing construction. All materials comply with AS 4678-2002 Earth Retaining Structures.
