A fence post spike is driven into the ground and suits soft or grassy surfaces where digging is impractical. A bolt-down post support, sometimes called a post shoe, fixes flat to a hard surface such as concrete or paving using anchor bolts. The post then slots into the shoe and is clamped in place. Bolt-downs are also useful because they keep the base of the timber post raised off the surface, which reduces the risk of rot at the bottom of the post.
Metal Fence Post Supports: Spikes, Bolt-Downs & Repair Spurs
Fence post supports are the hardware that keeps posts firmly anchored, whether going into soft lawn, hard concrete, or existing ground where a rotted post needs replacing. MacBlair stocks a range of galvanised metal supports to suit the most common installation scenarios, so there's no need to dig deep holes or pour large volumes of Postcrete for every job.
The range covers three main types:
- Drive-in spike supports — driven directly into soft ground using a post driver, no digging required. Available to fit standard 75mm and 100mm square posts.
- Bolt-down post supports — fixed to an existing hard surface such as concrete, tarmac, or decking posts bases. The post sits in a metal shoe that bolts flat to the surface, keeping timber clear of moisture.
- Repair spurs — used when an existing post has rotted at the base but the surrounding concrete is intact. The damaged section is cut away, and the spur is driven alongside to clamp a replacement post in position.
All supports in the range are galvanised steel, which resists corrosion through prolonged ground contact and wet weather. Keeping timber off or out of the ground also extends post life considerably, reducing the need for frequent replacement. Used alongside fence posts and fence panels, these supports suit garden boundaries, gate installations, and any project where speed of installation matters.
Spike supports are sized to suit both 75mm x 75mm and 100mm x 100mm posts, so check the post dimensions before ordering. For longer panel runs, combining drive-in spikes with intermediate fence rail will give a more rigid overall structure. MacBlair offers fast delivery across Northern Ireland, or click and collect from the local branch.
Fence Post Suports FAQ's
Spikes work best in firm but penetrable ground such as lawns or compacted soil. In very stony or rocky ground, driving a spike is difficult and risks bending or distorting the socket. In those conditions, it is better to drill a pilot hole using a post hole borer, or to use a bolt-down support on any existing hard surface nearby. If the ground is too stony to spike or dig, setting the post in Postcrete is usually the most reliable option.
The size you need depends on the cross-section of your fence post. Standard sizes are 75mm x 75mm (3 inch x 3 inch) for lighter panel fences, and 100mm x 100mm (4 inch x 4 inch) for heavier panels or gate posts. Check the post dimensions before ordering a support, as a loose fit in the socket will compromise stability. Most spikes are also available in different depths, with longer spikes giving better holding power in softer ground.
Yes, this is exactly what repair spurs are made for. When a timber post has rotted at ground level but the panel and surrounding concrete are otherwise sound, the damaged section is cut off cleanly just above the rot. A metal repair spur is then driven into the ground alongside the remaining stump or existing concrete, and a new post length is bolted into the spur. It is a much faster fix than removing the original post and concrete entirely, and it avoids disturbing panels on either side.
Fence post supports work with any fencing that uses standard square timber posts, including overlap and featherboard panel fences, close-board fencing, and garden gate posts. They are not generally suited to concrete posts, which need to be set directly into the ground or in concrete. For decorative or lightweight trellis structures, smaller spike supports can also be used, though check the post size matches the support socket. Bolt-down supports are also commonly used for pergola and decking posts where fixing to an existing hard surface is needed.