Removing old fence posts that have been set in concrete can be a difficult and time-consuming task. The concrete footing around the bottom of the post acts as an anchor, keeping it firmly in place. Trying to wiggle, pull, or lift a post straight out of concrete likely won’t work. You need the right tools and techniques to break apart the concrete so you can remove the post. This article will discuss several methods and tools that can be used to break up fence post concrete footings, making the removal process much easier.
Page Contents
Why Removing Fence Posts Set in Concrete is Difficult
There are a few reasons that removing fence posts concreted into the ground is so challenging:
- The concrete creates a very sturdy base that keeps the post from moving.
- The concrete footing is wider than the post itself, spreading out the holding power.
- The concrete may have been allowed to cure and harden completely before the post was inserted.
- Over time, dirt and debris can build up around the concrete, reinforcement it even more.
- Deteriorating wood posts can swell and wedge into the concrete as they rot.
With the concrete footing gripping the post so tightly, any lateral force applied to loosen the post is usually ineffective. The concrete needs to be broken up and demolished first.
Manual Tools for Breaking Concrete
One category of tools for breaking up fence post concrete is manual tools. These require swing and striking power from the user to smash and chip away at the concrete. Manual demolition tools have the advantages of being inexpensive, portable, and not needing any power source. The main downsides are that they require a lot of physical effort and time to use.
Some of the common hand tools used to break concrete footings are:
Sledgehammers
A heavy sledgehammer can be very effective for breaking up concrete. Use a 10-20 lb sledgehammer to strike the concrete block surrounding the post. Hit it from different angles to fracture the concrete. Focus on weak spots and cracks that develop. The key is delivering powerful blows consistently until the concrete splits apart. Wear safety goggles and heavy gloves when swinging a sledgehammer.
Jackhammers
Jackhammers with chisel or spade tips can demolish concrete much faster than a sledgehammer. Manual jackhammers require two hands to hold and control. Lift the hammer up and then use your body weight to drive the chisel down into the concrete. Keep repositioning the chisel to wedge cracks and holes open wider. Wear ear protection when using a jackhammer.
Pry Bars
Long steel pry bars are helpful after cracking the concrete with a sledgehammer or jackhammer first. Insert the pry bar into gaps and use leverage to widen cracks and split sections of concrete apart. Use a 5 to 8 foot bar for good leverage.
Post Pullers
Post pullers are manual tools specifically made for pulling up fence posts. They consist of long handles attached to a strong clamp or set of jaws that grip around the post. Downward force on the handles generates upward pulling force. Post pullers work best once the concrete has been broken up first.
Power Tools for Breaking Concrete
Power tools make demolishing concrete much faster and easier than manual tools. They utilize gas engines, pneumatic power, or electricity to drive high-impact tools that pulverize concrete easily. Here are some power tools well suited for breaking up fence post concrete:
Sledgehammers
Gas powered demolition hammers utilize pneumatic or hydraulic power to deliver hundreds or thousands of powerful blows per minute. This allows concrete to be broken quickly. Rotating chisel tips penetrate the concrete, while flat spade tips fracture the surface. Heavy-duty electric rotary hammers can also be used. Let the jackhammer do the hard work instead of swinging a manual sledgehammer yourself.
Rock/Bolt Splitters
Also known as post stake drivers, these tools use explosive charges or hydraulic force to split concrete footings. A steel wedge is driven into a pre-drilled hole in the concrete block. When the wedge is forced in under extreme pressure, it cracks the concrete evenly in a star pattern. This can break a footing into segments for easier removal.
Electric Breakers
Electric jackhammers, rotary hammers and demolition hammers share similarities with their pneumatic counterparts. They plug into an electric power source rather than relying on air compression. Electric breakers tend to be a bit less powerful but avoid the need for a bulky air compressor.
Cut-Off Saws
Concrete cutting saws with diamond abrasive blades can cut through concrete like a knife through butter. They slice concrete footings open to free fence posts easily. This does generate a lot of localized dust when cutting. Respirators, dust control and eye protection are a must.
Chemical Concrete Breaking Methods
In addition to traditional demolition tools, there are some chemical techniques that can help break the grip of concrete on fence posts:
Removing Soil Around Footing
Some of concrete’s holding strength comes from soil pushing against the outside of the footing. Carefully digging out 6″ to 12″ of soil surrounding the concrete will reduce external pressure. With less confining pressure, it’s easier for concrete to crack when struck.
Hydraulic Fluid
Non-flammable hydraulic fluid poured around the post concrete can soften the concrete and concrete-to-post interface. After letting it soak for a day, the concrete loses some of its tensile strength. Hitting it with a sledgehammer then becomes more effective.
Sodium Silicate
Also known by the brand name “Rod Buster”, this is a liquid that penetrates and dissolves concrete when applied. It takes several days to work, but makes the concrete more brittle. Pressure washing can also erode concrete.
Rust Expansion
Applying water or rust accelerator liquids to steel fence posts over several days can speed up rust formation. As the steel rusts, it swells and expands. This expansion places outward pressure on the surrounding concrete, causing it to crack and weaken its grip.
Techniques for Breaking Concrete Footings
In addition to using the proper tools, utilizing effective techniques is also important for successfully demolishing fence post concrete:
Isolate Footing from Post
The best approach is to focus on breaking the concrete apart into smaller segments first, before trying to pull up the post. This reduces the amount of concrete holding the post. Create a narrow air gap all around the post within the footing.
Strike Concrete at Post Level
Focus your demolition tool strikes on the concrete at ground level, nearest where it grips the wooden post. Fracturing it here helps separate the post from footing. Trying to break higher areas of concrete first is less productive.
Work in Sections
Break the concrete into smaller sections by isolating areas with control cuts from a saw or chisel. Take each section out one-by-one by hammering and prying until reaching the post.
Use Wedges to Loosen
After cracking and weakening concrete, drive stone or steel wedges into gaps around post to spread sections apart. This expands fractures.
Remove Post before Last Concrete
The easiest time to pull up a post is after most of the concrete has been cleared but a small amount remains. Removing it with concrete still fully encasing the bottom is much harder.
Comparing Methods for Breaking Concrete Fence Post Footings
Each method and tool has pros and cons for breaking up fence post concrete footings:
| Method | Pros | Cons |
|---|---|---|
| Sledgehammer |
|
|
| Jackhammer |
|
|
| Rock/Bolt Splitter |
|
|
| Cut-Off Saw |
|
|
Safety Precautions
Breaking up concrete fence post footings involves demolishing a very sturdy material. Follow these important safety precautions:
- Wear eye protection to guard against debris chunks.
- Use heavy work gloves when handling tools.
- Wear ear plugs or muffs when using loud power equipment.
- Prevent scattering debris – cordon off a safe workspace.
- Wet dry concrete before breaking to reduce dust.
- Follow all manufacturer safety procedures for power tools.
- Keep fingers clear of pinch points and moving parts.
- Avoid contact with concrete closer than 6 inches to post.
- Have a first aid kit available in case of minor injuries.
- Work carefully to avoid muscle strains from overexertion.
Staying safe is the most important consideration when tackling demolition projects. Don’t take unnecessary risks just to speed up the work.
Conclusion
Removing old fence posts set deeply into concrete can seem like an impossible task without the right approach. Using proper demolition tools coupled with smart techniques breaks up concrete footings safely and efficiently. Sledgehammers, jackhammers, rock splitters, and cut-off saws all have advantages in different situations. Focus on fracturing concrete starting closest to post, and remove it in manageable sections. With persistence and the correct methods, even the sturdiest concrete will eventually break apart. Just be sure to take steps to protect yourself. A difficult fence post removal project will quickly turn into a success.