Description
Redwood Treated Post 150mm x 150mm x 2.4 m – Heavy Duty Timber Fencing
Overview
Standard 75mm or 100mm posts are perfectly fine for everyday, low-exposure fence panels. However, when your design introduces massive lateral forces—such as hanging heavy side gates, anchoring high-exposure corner runs, or retaining soil tiers—standard posts will slowly yield, warp, or snap under the pressure. Our 150mm x 150mm Redwood Square Post provides the ultimate heavy-duty structural upgrade.
As shown in the product profile, this post features a beautifully uniform, square-cut configuration milled from premium European Redwood (Pinus sylvestris). Because the raw timber undergoes an intense hydraulic vacuum treatment process, the advanced anti-rot copper triazole solution is driven deep into the heartwood matrix. This creates a highly uniform, protective chemical jacket that completely shields the critical ground-line junction—the high-oxygen moisture zone where subterranean wood is most vulnerable to rotting out.
Key Features
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Premium Boundary Structural Anchor: Provides a substantial visual and structural statement, anchoring heavy-duty bespoke closeboard frameworks effortlessly.
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Significantly Limits Timber Checking: The high-density fiber structure of slow-grown redwood shrinks and expands uniformly, significantly minimizing the large, deep splits common in low-grade whitewoods.
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Multi-Application Utility: An incredibly versatile structural component, ideal for supporting garden pergolas, timber carports, heavy deck corners, and low retaining wall systems.
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Natural Landscape Aesthetics: The subtle pale-green preservative tint fades smoothly over time under UV exposure into a warm honey-brown, before settling into a silver-grey weathered look. It readily accepts all exterior wood stains or paints.
Technical Specifications
| Attribute | Specification |
| Product Type | Heavy-Duty Square Structural Timber Post |
| Timber Species | Premium European Redwood (Pinus sylvestris) |
| Dimensions | 150mm x 150mm (Nominal 6″ x 6″) |
| Length | 2.4 Metres (Nominal 8 feet) |
| Weight Class | Heavy Structural (Approx. 25-30kg per post depending on seasonal moisture retention) |
| Treatment Grade | UC4 (User Class 4) – Formulated and Tested for Permanent Ground Contact |
| Preservative Base | Eco-Friendly Tanalith-E (Or equivalent copper-triazole formulation) |
| Compatibility | Heavy-Duty Hook-and-Band Hinges, Structural Framing Connectors, Postcrete |
Trade Installation & Ground Anchoring Advice
Pro Tip: Sinking a 150mm square structural post requires a substantial foundation footprint to properly anchor its weight capacity and resist wind leverage.
The Professional Method: For a standard installation, dig a hole measuring at least 350mm to 400mm wide by a minimum depth of 600mm to 750mm deep. Drop a 2-inch layer of gravel or drainage ballast at the bottom of the hole to allow moisture to drain cleanly away from the base-cut end-grain. Position and brace the post completely plumb. Fill the void using 2 to 3 bags of rapid-setting Blue Circle Postcrete, layering it with water according to instructions. Use a trowel to taper the top of the concrete wet mix into a smooth, downward-facing dome above ground level, forcing rainwater to shed completely away from the timber base.





David West Beale (verified owner) –