Heavy Duty Adjustable Bolt Down Fence Post Support Bracket

Heavy-duty adjustable bolt-down post support bracket for anchoring timber fence, decking, pergola, veranda and awning posts to a concrete or masonry base. The bracket is built around a central M24 threaded rod, so once the base plate has been bolted down, the finished height of the post can still be fine-tuned by up to 250mm (9.84in), no digging, no wet concrete, and no need to set the post directly into the ground.

It works as a simple two-plate jack. A lower plate bolts down flat to a concrete or masonry base; an upper plate, raised and lowered by turning the nut on the central M24 threaded rod, carries the timber post itself. Because the post is fixed to a plate rather than dropped into a socket, it doesn't need to be cut or machined to length before fitting; the finished height is simply set on site once the post is in position, which is particularly useful where a slab, patio or paved area isn't perfectly level. The whole bracket is manufactured from zinc-plated S235 structural steel for reliable general-purpose corrosion resistance outdoors, and is designed for vertical structural loads, in line with the European Technical Assessment (ETA) requirements that apply to this type of construction connector.

The bracket is offered in three post fitting widths: 80mm (3.15in), 100mm (3.94in) and 130mm (5.12in), so it can be matched to the actual cross-section of the timber being used, from a standard fence post up to a heavier pergola or veranda upright. Height adjustment, plate thickness and the M24 fitting are held constant across all three sizes, so the same fixing method and tools apply whichever size is chosen.

Key Features

• Central M24 threaded rod gives up to 250mm (9.84in) of height adjustment, even after the base plate has already been bolted down
• Two-plate jack design: a lower plate anchors to the concrete or masonry base, an upper plate carries and adjusts the post
• No cutting or machining of the post required before fitting; finished height is set on site to suit an uneven or sloping base
• Manufactured from zinc-plated S235 structural steel for reliable general-purpose corrosion resistance outdoors
• M24 hex nut (class 10) included, finished in the same zinc-plated coating as the rest of the bracket
• Designed for vertical structural loads, in line with European Technical Assessment (ETA) requirements for this type of connector
• Available in three post fitting widths: 80mm (3.15in), 100mm (3.94in) and 130mm (5.12in), each with four pre-drilled corner holes top and bottom
• Consistent 4.0mm (0.157in) plate thickness across the range for a rigid, low-flex base

Specification

The height-adjustment rod is an M24 threaded bar secured with a matching M24 hex nut (class 10), both finished in the same zinc-plated coating as the rest of the bracket, confirmed via manufacturer technical drawings for all three sizes.

Typical Applications

This bracket is designed for above-ground timber post bases carrying vertical structural loads. Its adjustable height and bolt-down fixing suit a range of garden and outdoor timber projects. Typical uses include:

• Fence post installation onto a concrete strip footing, pad or existing slab, without needing to set the post directly into wet concrete
• Decking frame construction, anchoring perimeter and intermediate support posts to a solid base before building up the frame around them
• Pergola, veranda and awning post bases, where a bolted, above-ground fixing keeps the foot of the post clear of standing water at ground level
• General garden and outdoor timber construction on paved, patio or slabbed areas that aren't perfectly level, using the M24 adjustment to bring each post to a consistent finished height

Installation Guidance

1. Choose the bracket size that matches the cross-section of the post being fitted: 80mm (3.15in), 100mm (3.94in) or 130mm (5.12in).
2. Bolt the lower plate down to the concrete or masonry footing through its four pre-drilled corner holes (12mm diameter on the 80mm size), using suitable M10/M12 bolts or concrete anchors (not included).
3. Turn the nut on the central M24 threaded rod to raise or lower the upper plate to the finished height required; up to 250mm (9.84in) of travel is available.
4. Fix the timber post to the upper plate through its own four corner holes, using suitable coach screws or bolts (not included).

Whether it's a single replacement post foot, a full run of fence posts, or the support posts for a new deck, pergola or veranda frame, this bracket gives an above-ground, fully adjustable fixing, so the post stays accessible for final levelling and plumbing right up until it's fixed in place, without ever needing to be set into wet concrete.

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