Heavy Duty U-Shape Post Support Base Bracket – Concrete-In Anchor

This heavy-duty U-shape post support base bracket is a concrete-in (wet-set) post anchor, made to be embedded directly into fresh concrete rather than bolted onto an existing slab or paving. A ribbed steel spike below the U-shaped socket keys firmly into the setting concrete as it cures, locking the bracket permanently in place, while the U-shaped jaw above grips your timber post and holds it clear of the ground, away from standing water, splashback and direct soil contact, the conditions that cause fence and decking posts to rot from the base up.

The bracket is manufactured from 4mm-gauge (0.16in) S235 structural steel, giving it the load-bearing strength needed for a permanent structural post fixing rather than a light decorative one. It's available in four finishes, so you can match the corrosion protection and the look to your project: galvanised silver, a bright zinc coating for long-lasting rust protection; galvanised gold, a zinc coating with a warmer, golden-toned passivation layer for enhanced corrosion resistance; and powder-coated black or powder-coated anthracite, tough decorative paint finishes suited to more contemporary fencing and garden structures. All four finishes are intended for permanent outdoor use, so the choice comes down to appearance as much as durability.

Key Features

• Concrete-in (wet-set) fixing: a ribbed steel spike keys into fresh concrete for a permanent, structural anchor rather than a surface-mounted base plate
• U-shaped jaw holds the post clear of the ground, reducing the risk of base rot from standing water and soil contact
• Four finishes to choose from: galvanised silver, galvanised gold, powder-coated black and powder-coated anthracite, all rated for permanent outdoor use
• Heavy 4mm-gauge (0.16in) S235 structural steel construction for high load-bearing strength
• Nine post-socket sizes from 61mm (2.4in) to 161mm (6.3in), covering common timber post sections (availability varies by finish; see specification table)
• Pre-drilled through both sides of the U-jaw, ready to take M10 bolts or 10mm-diameter (0.39in) coach screws with no on-site drilling required
• Equally suited to new-build post installations and to repairing or reinforcing an existing post that has started to rot at its base

Specification

Available sizes & finishes

Key specifications

• Material: S235 structural steel
• Steel gauge: 4mm (0.16in)
• Fixing: M10 bolts or 10mm-diameter (0.39in) coach screws through the pre-drilled U-jaw; concrete-in spike base
• Unit weight: from 0.876kg (1.93lb) for the smallest size
• Overall length (bracket + concrete-in spike): 324mm (12.76in)
• U-jaw socket height: 124mm (4.88in)
• U-jaw flange depth: 60mm (2.36in)
• Finishes: galvanised silver, galvanised gold, powder-coated black, powder-coated anthracite

Typical Applications

This bracket suits any timber post that needs a permanent, ventilated fixing set into concrete: fence posts and fence panel posts, decking sub-frames and support posts, pergola and gazebo uprights, and verandah or carport posts. Because it's a wet-set (concrete-in) fixing rather than a surface-bolted plate, it's particularly well suited to new post foundations, where the bracket is positioned and held square in the wet concrete as it's poured, giving a single permanent connection between post and footing without a separate base plate or fixings into already-cured concrete.

It's equally useful for post repairs: where an existing fence, pergola, decking or carport post has begun to rot or split at ground level, the affected section can be cut away and the post reset into a new concrete footing using this bracket, restoring a solid, ventilated fixing without rebuilding the whole run of fencing or the structure above.

• Fence posts and fence panel posts set in new or replacement concrete footings
• Decking sub-frames, joist ends and support posts requiring a raised, ventilated base
• Pergola and gazebo uprights
• Verandah and carport support posts
• Repairing an existing post that has rotted or split at its base, by cutting back to sound timber and resetting into a new footing

Installation Guidance

Set the bracket into the concrete footing while the concrete is still wet and workable, checking that it sits vertical and square to the post line before the concrete begins to go off; the ribbed spike keys into the concrete as it cures, so the bracket's final position is fixed once the footing has set. Leave the concrete to cure fully before loading the post.

When fitting the post, leave a gap of roughly 1cm (0.4in) between the underside of the post and the base of the bracket's socket (a timber offcut or a purpose-made shim works well as a spacer), so air can circulate freely around the end grain. This keeps the post ventilated and helps prevent the trapped moisture and rot that can occur when timber sits flush against metal or concrete. Fix the post through the pre-drilled holes in the U-jaw using M10 bolts or 10mm-diameter (0.39in) coach screws.

Order before 2pm Mon–Fri for same-day dispatch from our UK warehouse.