Do Fence Post Spikes Work?

When it comes to erecting a fence quickly and with minimal effort, fence post spikes are often marketed as a convenient alternative to digging holes and using concrete. But do they really work? Let’s break it down.

What Are Fence Post Spikes and How Are They Used?

Fence post spikes, also known as ground spikes or metal post anchors, are metal supports designed to hold timber or metal fence posts in place. They usually consist of a pointed metal spike that drives into the ground, with a hollow square or round section on top where the post sits.

Installation is straightforward:

1. The spike is hammered or driven into the ground at the desired location.
2. The fence post is then inserted into the spike and secured, usually with screws or bolts.

The main selling point is speed: no digging, no concrete, and minimal disruption to your garden or lawn.

An example of a fence post spike before it is forced into the ground.

Where Fence Post Spikes Commonly Fail

While fence post spikes can work in the right conditions, they have some common weaknesses:

• Soft or sandy soil – The spike can loosen over time as the soil shifts.
• Heavy or tall fences – Large or wind-prone fences put extra leverage on the spike, causing tilting or wobbling.
• Frost heave – In colder climates, the ground expands and contracts during freezing, which can push the spike out of alignment.
• Rot at the base – Timber posts sitting in spikes may not get water contact, but if water collects in the spike, timber can rot over time.

In short, spikes work best for lightweight fences in stable, well-draining soil. Anything more substantial requires more robust support.

How to Stop Fence Post Spikes Failing

If you do opt for spikes, there are ways to increase their longevity:

1. Choose the right spike – Heavy-duty spikes are available for larger posts or windier locations.
2. Use gravel for drainage – Pouring a little gravel around the spike can help prevent water from pooling.
3. Check alignment regularly – Small shifts can be corrected before the fence becomes wobbly.
4. Consider post sleeves – Some spikes come with sleeves that help keep the timber off the base and reduce rot.
5. Use spikes with adjustable bolts – Some spikes have bolts or clamps that can be tightened around the post, securing it more firmly and reducing wobble.

Even with these precautions, spikes are generally less secure than posts set in concrete.

Pros and Cons of Fence Post Spikes

Pros:

• Quick and easy installation
• Minimal digging required
• Less mess and disruption
• Easily removable if you want a temporary fence

Cons:

• Less stable than concrete-set posts
• Can loosen over time, especially in soft or shifting soil
• Not suitable for heavy, tall, or wind-exposed fences
• Timber may rot if water collects in the spike

Is It Better to Just Dig Holes and Use Concrete?

For most permanent fencing, digging holes and setting posts in concrete remains the most reliable method. Concrete provides a solid, long-lasting foundation that resists wind, frost heave, and soil movement.

It’s also crucial to use well-treated timber posts with long guarantees, ideally 25 years or more. High-quality posts are less likely to rot or warp over time, ensuring your fence remains straight and stable for decades.

While fence post spikes are tempting for a quick solution, they are best suited for:

• Temporary or lightweight fences
• Garden screens or small enclosures
• Situations where digging is difficult

For fences you want to last decades, traditional post holes with concrete and high-quality posts are worth the extra effort.