How to Make Concrete for Fence Posts, Bases & Garden Projects

Learn how to make concrete for fence posts, concrete bases, and garden projects. Our step-by-step guide explains the best mix ratios, materials, and practical tips for strong, long-lasting results.

Cement vs Concrete — What’s the Difference?

Before you start mixing, it’s important to understand the difference between cement and concrete:

• Cement is the fine powder that acts as the binder.

• Concrete is the full mix — a combination of cement, sand, aggregate (gravel), and water.

So when you say “making cement,” you’re usually talking about making concrete — the hard-setting material used for fence posts, Shed bases, paths, and driveways.

What You’ll Need

To make concrete at home, you only need a few ingredients and tools:

General Purpose Cement | 25kg Bags

20mm Ballast | 25kg Mini Bags

Sharp Sand | 25kg Mini Bags

20mm Shingle | 25kg Mini Bags

Materials:

• Cement 

• Sharp sand & 20mm shingle Mixed

• Alternatively all in ballast

• Clean water

Tools:

• Wheelbarrow or mixing tray

• Shovel

• Measuring bucket

• Gloves and safety glasses

Optional but useful:

• Cement mixer (for larger jobs)

• Trowel and spirit level

The Correct Mix Ratio

The ratio depends on what you’re building.

Tip: For quick jobs like setting fence posts, Postcrete is faster and easier — it’s a pre-mixed version that just needs water.

Step-by-Step: How to Make Concrete

Step 1: Measure the Ingredients

Use a consistent container (like a bucket) for easy measuring.
For example, for a small batch using the 1:2:4 mix:

• 1 bucket cement

• 2 buckets sharp sand

• 4 buckets gravel

Step 2: Combine Dry Ingredients

Pour all the dry materials into a wheelbarrow or mixer.
Mix thoroughly until the colour is even — this ensures the cement is evenly distributed.

Step 3: Add Water Gradually

Add water slowly while mixing until the concrete is workable but not sloppy.
You’re aiming for a texture like thick porridge — wet enough to bind, dry enough to hold shape when piled.

A good starting point is about ½ bucket of water per 25kg of cement, but adjust based on weather and materials.

Step 4: Mix Until Uniform

If mixing by hand, keep turning the mix over until every part looks consistent — no dry patches or puddles.
If using a cement mixer, run it for 3–5 minutes per batch.

Step 5: Use Immediately

Concrete begins to set within 1–2 hours, so always mix small batches that you can use straight away.

Tips for the Perfect Mix

• Always use clean water — dirty water can weaken the mix.

• Don’t overwater — too much water reduces strength.

• In hot weather, dampen the base before pouring to stop rapid drying.

• Compact the mix well around fence posts or in formwork to eliminate air pockets.

• Smooth the surface with a trowel for a clean finish.

Curing: Let It Set Properly

Concrete reaches its full strength over time.

• Allow 24 hours before light use.

• Avoid heavy loads for at least 7 days.

• For best strength, keep it damp for 48–72 hours after pouring — you can cover it with plastic or sprinkle with water occasionally.

This prevents cracking and ensures maximum durability.

When to Use Postcrete Instead

For quick domestic fencing jobs, Postcrete (also known as Post Mix) saves time.
It’s pre-blended and sets in around 10 minutes — ideal if you’re setting wooden or concrete posts without needing to mix manually.

Use 1–2 bags per post, following the guide in our related article:
👉 How Much Postcrete Do You Need Per Fence Post?

Common Mistakes to Avoid

• Mixing too wet: makes concrete weak and crumbly.

• Adding extra cement: won’t always make it stronger — it can cause cracking.

• Pouring on dry ground: it sucks out water too quickly, causing poor bonding.

• Not compacting properly: leaves voids that lead to instability.

Clarke Fencing Ltd – Supplying fencing, timber, and landscaping materials across Suffolk and East Anglia since 1984.

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Jason Clarke

Ask them a question by emailing [email protected]

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