A leaning or rotten fence post does not always mean the whole fence needs replacing. In many cases, a concrete repair spur can be used to support the existing timber post and extend the life of the fence. This is especially useful when the post has failed at ground level but the fence panels, rails or upper section of the post are still in reasonable condition.

A concrete spur is a short, reinforced concrete support that is set into the ground beside a wooden fence post. It is bolted to the post above ground and fixed firmly into concrete below ground. Once installed correctly, it takes much of the strain away from the damaged section of timber and helps hold the fence upright.

This guide explains when a concrete spur is suitable, what tools and materials you need, how to install one safely, and what mistakes to avoid. It is written for practical domestic fence repairs where a timber post has weakened but the fence line can still be saved.

What is a concrete repair spur?

A concrete repair spur is a concrete support used to reinforce an existing wooden fence post. It is usually pre-drilled with holes so it can be bolted to the timber post. The lower part of the spur is set into the ground with post mix or concrete, while the upper part sits against the wooden post.

Concrete spurs are commonly used when timber fence posts have started to rot at ground level. This is the area where wooden posts often fail first because moisture, soil contact and changing weather conditions all affect the timber.

Rather than replacing the entire post, which may involve removing fence panels, rails, gravel boards and old concrete, a repair spur can provide a strong support with less disruption.

When is a concrete spur a good repair?

A concrete spur can be a good option when the fence post is weak at the base but still has enough solid timber above ground for secure bolting.

It may be suitable if:

The post has rotted at or just below ground level
The fence is leaning but has not collapsed completely
The fence panels are still usable
The upper section of the timber post is sound
The fence line only needs localised support
You want to avoid replacing the full post
Access is good enough to dig beside the post

A spur is often used as a practical repair where one or two posts have failed but the rest of the fence is still in decent condition.

When a concrete spur may not be enough

A repair spur is not suitable for every fencing problem. If the timber post is rotten along most of its height, there may not be enough solid wood to bolt into. If several posts are failing, the fence may be near the end of its life.

A concrete spur may not be the best option if:

The whole fence line is badly leaning
The post is rotten above the planned bolt points
The fence panels are badly damaged
The rail fixings are loose or rotten
The ground is unstable or waterlogged
The post has snapped too low to bolt securely
The fence is too exposed for a simple repair
A heavy garden gate is hanging from the damaged post

In these cases, replacing the post, or replacing the fence section, may be a better long-term solution.

Why timber posts fail at ground level

Wooden fence posts often fail where the post meets the ground. This is because the timber is exposed to moisture, soil, oxygen and changing temperatures at the same time. Even treated wooden fence posts can eventually weaken if conditions are difficult.

Common causes of post failure include:

Long-term ground moisture
Poor drainage around the post
Concrete shaped so water sits against the timber
Soil or mulch built up around the base
Storm pressure on fence panels
Heavy climbing plants on the fence
Posts that were too small for the fence height
Insufficient post depth
Old age and general weathering

A concrete repair spur helps because the new concrete support is not vulnerable to rot in the same way as timber.

Tools and materials needed

Before starting, gather everything you need. Stopping halfway through the job can be awkward, especially once the post has been moved or the hole has been dug.

You may need:

Concrete repair spur
Post mix or concrete
Bolts, nuts and washers
Drill and suitable wood drill bit
Masonry bit if adjusting concrete spur holes is required
Spanner or socket set
Post hole digger or spade
Digging bar for hard ground
Spirit level
String line if checking the fence run
Temporary braces or timber props
Tape measure
Bucket or watering can for water
Trowel
Gloves
Safety glasses
Dust mask if drilling concrete

Use fixings that are suitable for outdoor use. Bolts should be long enough to pass through the spur and timber post with washers and nuts fitted securely.

Choose the right concrete spur

Concrete spurs come in different sizes. The right size depends on the height of the fence, the size of the post and the amount of support needed.

A taller, heavier fence will usually need a stronger spur than a low decorative fence. The spur should also sit well against the existing post and provide enough above-ground height for secure fixing.

Check the hole positions before starting. The pre-drilled holes in the spur should line up with solid timber, not rotten or split sections of post.

Check the existing fence before repair

Before installing a concrete spur, inspect the fence carefully. A spur will support a failing post, but it will not repair rotten panels, broken rails or weak fixings.

Check:

Whether the post is sound above ground
Whether the panels are still secure
Whether rails have pulled away
Whether gravel boards are damaged
Whether nearby posts are also weak
Whether the fence is leaning along the whole run
Whether a gate is putting extra strain on the post

If the surrounding fence is in poor condition, a single spur may only be a temporary fix.

Check for underground services

Always think about underground services before digging. Gardens can contain electrical cables, drainage pipes, water pipes, gas pipes, irrigation lines and lighting cables.

Look for clues such as inspection covers, outside taps, sockets, lights, drainage channels and previous landscaping. If you are unsure, use proper detection methods or seek professional advice.

Do not dig blindly beside a house, garage, shed, patio, garden room or outdoor power supply.

Make the fence safe before starting

If the fence is leaning heavily, brace it before you start. This helps stop panels moving while you dig and keeps the post in a safer position.

You can use temporary timber props fixed or wedged carefully to hold the fence upright. Do not rely on the damaged post to support the fence while the ground around it is being disturbed.

Keep children and pets away from the work area. Open holes, loose panels and heavy concrete spurs can all create hazards.

Clear the area around the post

Remove anything that blocks access to the post. This may include weeds, soil, stones, old fixings, garden furniture, pots or loose debris.

If plants are growing tightly around the fence, cut them back carefully. Climbing plants can add weight to a weak fence, so remove or reduce them before the repair if they are contributing to the lean.

Clear enough space to dig beside the post and position the concrete spur properly.

Work out which side to fit the spur

The spur is usually fitted on the side of the post where it can provide the best support and where there is enough room to dig. It should sit tight against the timber post.

Consider:

Which side gives better access
Where the fence is leaning
Where panels or rails are fixed
Whether a neighbour’s land is involved
Whether the spur will obstruct paths or planting
Where the bolts can pass through safely

If the fence is on a boundary, make sure you are working on land where you have permission. Do not place a spur on a neighbour’s side without agreement.

Dig the hole for the concrete spur

Dig a hole beside the post wide enough for the spur and surrounding concrete. The hole needs to be deep enough to hold the spur securely.

As a general principle, a substantial part of the spur should be below ground so the repair has strength. The exact depth depends on the spur size, fence height, soil conditions and the repair needed.

Keep the hole close enough to the post for the spur to sit flush against it. Remove loose soil from the bottom and sides of the hole.

If you hit old concrete around the original timber post, you may need to dig beside or partially around it. Avoid undermining the existing post so much that the fence becomes unstable.

Position the spur

Place the concrete spur into the hole and hold it tight against the timber post. Use a spirit level to check that the spur is vertical.

Also check the fence line. If the fence was leaning, gently bring it back into position before fixing the spur. Do not force old panels or rails so hard that they split.

Temporary bracing can help hold the post and spur in place while you drill and bolt them together.

Align the bolt holes

Most concrete repair spurs are pre-drilled. Use these holes as guides and mark the timber post where bolts will pass through.

The bolts should go through solid timber. If the timber is soft, rotten or split where the bolt will sit, the repair may not hold properly.

Ideally, use at least two bolts to secure the spur to the post. This helps prevent twisting and spreads the load.

Drill the timber post

Drill through the wooden post at the marked positions. Keep the drill level so the bolts pass through cleanly.

Use a bit suitable for the bolt size. The hole should allow the bolt to pass through without excessive movement.

Wear eye protection when drilling. If the post is old, check for hidden nails, screws or fixings before drilling.

Bolt the spur to the post

Push the bolts through the concrete spur and timber post, then fit washers and nuts. Tighten them with a spanner or socket.

The connection should be firm, but do not overtighten so much that you crush damaged timber or crack anything around the hole. If the timber is too soft to hold a bolt securely, the post may need replacing rather than spurring.

Once bolted, check the spur and post again with the spirit level. Make adjustments before concreting.

Use post mix or concrete

Once the spur is positioned and bolted, fill the hole with post mix or concrete according to the product instructions.

Post mix is often used for fence repairs because it is quick and convenient. Traditional concrete may also be used, depending on preference and site conditions.

Follow the instructions carefully. Do not guess water quantities if the product gives specific guidance. Too much water can weaken the mix, while too little may prevent it setting properly.

Shape the concrete finish

After filling the hole, shape the surface so water sheds away from the timber post and spur. Avoid leaving a dip that collects water around the post base.

A sloped finish helps reduce standing water, which is one of the reasons timber posts fail in the first place.

Keep checking the spur has not moved while the mix is being added. Make any adjustments before it begins to set.

Allow the concrete to cure

Post mix may firm up quickly, but the repair should still be treated carefully while it cures. Follow the manufacturer’s instructions before removing braces or putting strain on the fence.

Avoid pushing, shaking or loading the fence too soon. If the post supports a gate, allow enough curing time before using the gate normally.

Bad weather, cold conditions and very wet ground can affect setting and curing. Check product instructions for suitable conditions.

Check the fence after installation

Once the concrete has set, check the repair carefully.

Look at:

Whether the post is upright
Whether the spur is firmly fixed
Whether the bolts are tight
Whether panels or rails are secure
Whether the concrete has set properly
Whether the fence line looks straight
Whether any extra repairs are needed nearby

If other posts are starting to move, plan further repairs before the next storm exposes the weakness.

Can you install a concrete spur without removing fence panels?

In many cases, yes. One of the advantages of a concrete repair spur is that it can often be installed without dismantling the whole fence. This makes it useful for repairing an otherwise sound fence line.

However, if panels are loose, heavy or making the post difficult to straighten, it may be safer to remove or temporarily support them.

Do not work under unstable panels without support.

Can a concrete spur fix a snapped post?

A concrete spur can sometimes support a post that has snapped at ground level, provided there is enough sound timber above ground to bolt into. If the post has split badly or is rotten above the bolt points, the repair may not be strong enough.

If the post is completely unstable, replacing the post may be the better option.

Can a concrete spur support a gate post?

It depends on the gate and the damage. Gates place more strain on posts than fixed fence panels because they move and hang from hinges. A small or badly damaged gate post may not be suitable for repair with a spur.

For a light garden gate, a spur may help if the post is otherwise sound. For a heavy side gate, wide gate or frequently used gate, replacing the gate post may be safer and more reliable.

Concrete spur or new fence post?

A concrete spur is often quicker and less disruptive than replacing a post, but it is not always the best option.

Choose a concrete spur when:

The post is mainly damaged at ground level
The upper timber is still strong
The fence panels are in reasonable condition
You want a practical repair without full dismantling
Only one or two posts have failed

Replace the post when:

The post is rotten along its full height
The fence is very old and failing throughout
The panel fixings have pulled away
A heavy gate is involved
The fence needs a cleaner appearance
The original post was too small or poorly installed

A spur is a repair. A replacement post is a rebuild. The right choice depends on the condition of the whole fence.

Concrete spur or concrete fence post?

A concrete repair spur is used with an existing timber post. A concrete fence post replaces the timber post entirely and usually supports panels directly.

If you are repairing one failed timber post, a spur may be enough. If you are replacing a whole fence line and want a more durable system, concrete fence posts may be a better long-term choice.

Concrete posts are often used with fence panels and concrete gravel boards for a durable, low-maintenance boundary. Repair spurs are more often used to extend the life of existing wooden fencing.

Will a concrete spur look obvious?

A concrete spur will be visible on the side of the post where it is installed. Some homeowners do not mind this because it is practical and often placed on the less visible side of the fence.

If appearance is a priority, think carefully about which side it is fitted. A new timber post may look cleaner, but it may also involve more work.

In many gardens, a concrete spur is a sensible compromise between cost, durability and disruption.

Maintaining a fence after fitting a spur

Once a spur is installed, continue maintaining the rest of the fence. The repaired post may now be stronger, but panels, rails, gravel boards and nearby posts still need checking.

Maintenance tasks include:

Checking bolts after strong winds
Keeping soil and mulch away from timber posts
Clearing leaves from gravel boards
Trimming heavy climbers
Retreating timber where needed
Checking panels for movement
Inspecting nearby posts for rot
Repairing loose fixings promptly

A concrete spur can extend the life of a fence, but it does not remove the need for basic maintenance.

Common mistakes when installing concrete spurs

A concrete spur repair can fail if it is rushed or fitted poorly.

Common mistakes include:

Fitting a spur to timber that is too rotten to hold bolts
Digging the hole too shallow
Not checking for underground services
Not bracing a leaning fence before work
Setting the spur out of plumb
Using bolts that are too short or too weak
Forgetting washers
Not tightening the fixings properly
Using too much water in post mix
Leaving concrete shaped so water pools around the post
Putting strain on the repair before it has cured
Ignoring other failing posts nearby

The repair should be treated as a structural job, not just a quick patch.

Safety tips

Concrete spurs are heavy and awkward to handle. Work carefully and get help if needed.

Basic safety advice includes:

Wear gloves when handling concrete and timber
Use eye protection when drilling
Wear a dust mask if drilling concrete
Check for underground services before digging
Brace unstable fencing before working on it
Keep children and pets away from open holes
Lift heavy spurs safely
Do not work in high winds if the fence is unstable
Dispose of old concrete and rotten timber safely

If the fence is leaning dangerously or close to a public path, neighbour’s property or road, professional repair may be safer.

Concrete spur installation checklist

Use this checklist before and during the repair:

Check the timber post is sound enough above ground
Inspect nearby panels and posts
Choose the correct size concrete spur
Check the bolt holes line up with solid timber
Confirm where underground services may be
Clear the area around the post
Brace the fence if it is leaning
Dig a suitable hole beside the post
Position the spur flush against the timber
Check it is vertical with a spirit level
Drill the post accurately
Fit bolts, washers and nuts securely
Add post mix or concrete as instructed
Shape the top so water runs away
Allow curing time before loading the fence
Check bolts and alignment after the repair

Frequently asked questions

What is a concrete spur used for?

A concrete spur is used to support a damaged or rotten wooden fence post. It is set into the ground beside the post and bolted to the timber above ground.

Can I fit a concrete spur myself?

Yes, many capable DIYers can fit a concrete spur if the fence is safe to work on and the post is suitable for repair. Heavy spurs, unstable fences or difficult ground may require professional help.

How deep should a concrete spur be set?

The depth depends on the size of the spur, fence height and ground conditions. The spur must be set deep enough to provide strong support, with a substantial section below ground.

Can a concrete spur repair a rotten fence post?

It can repair a post that is mainly rotten at ground level, provided there is enough sound timber above ground to bolt into. If the whole post is rotten, replacement is usually better.

Do I need to remove the old fence post?

Usually no. A repair spur is designed to support the existing post without removing it. However, if the post is too badly damaged, removal and replacement may be needed.

Can a concrete spur be used with fence panels?

Yes. Concrete spurs are commonly used to repair timber posts that support fence panels. The panels should be checked to make sure they are still secure and in good condition.

What bolts should I use for a concrete spur?

Use bolts of the correct length and diameter for the pre-drilled holes in the spur and the thickness of the timber post. Outdoor-suitable bolts with washers are recommended.

Should I use post mix or concrete?

Either may be suitable. Post mix is convenient for many domestic fence repairs, while concrete may be preferred in some situations. Follow the product instructions carefully.

Can I use a concrete spur on a gate post?

Sometimes, but gate posts take more strain than ordinary fence posts. A light gate may be repairable with a spur if the timber is sound. A heavy or frequently used gate may need a new post.

How long does a concrete spur repair last?

A well-installed concrete spur can extend the life of a fence for many years, but the result depends on the condition of the original post, the rest of the fence, the ground and the quality of installation.

Final thoughts

Installing a concrete spur is a practical way to repair a weakened wooden fence post without replacing the whole fence. It is especially useful when the post has rotted at ground level but the upper timber and fence panels are still sound.

The key to a good repair is careful preparation. Check that the post can take the bolts, brace the fence if needed, dig a suitable hole, keep the spur upright and use the correct fixings. The concrete should be shaped to shed water away from the post, and the repair should be allowed to cure before the fence is put under strain.

A concrete repair spur will not fix a fence that is failing everywhere, but it can be an effective, long-lasting solution for localised post damage. Installed properly, it can restore strength to the fence and delay the need for a full replacement.