Postcrete & Post Mix – Everything You Need to Know

Postcrete and post mix are popular choices for securely installing fence posts, gate posts and other outdoor posts. Quick and easy to use, bagged postmix is designed to set rapidly when mixed with water, making it a convenient solution for fencing and landscaping projects.

Whether you're installing a single fence post or completing a larger fencing project, storing and using your postcrete correctly is important for achieving a strong and stable installation.

Can You Use Postcrete That Has Been Stored Outside?

Postcrete should be stored dry and protected from moisture. If a bag is exposed to rain, damp or humid conditions, moisture can cause the powder to harden and become lumpy inside the bag.

For best results, postmix should remain dry, loose and powdery before use. Damp or partially hardened material may not mix or set correctly and could affect the strength and stability of your fence post installation.

For storage, keep bags of postcrete in a dry, covered location and protect them from direct contact with damp ground.

How Many Bags of Postcrete Do You Need Per Fence Post?

As a general guide, you will typically need 1–2 bags of 20kg postcrete per fence post. The exact amount required depends on the size of the post, the diameter and depth of the hole, and the ground conditions.

• Standard fence posts: usually around 1 x 20kg bag
• Larger posts or deeper holes: often 2 x 20kg bags or more

Always check the product instructions and allow for the specific dimensions of your post and installation rather than relying solely on a general estimate.

Browse our range of fence posts to find the right post for your fencing project.

Do You Put Postcrete in First or Add Water First?

For many rapid-setting postmix products, the dry postcrete is placed around the correctly positioned post first, followed by water. The water is then absorbed into the dry mix, allowing it to begin setting quickly.

A typical 20kg bag may require approximately 2–3 litres of water, but you should always follow the manufacturer's instructions for the specific product you're using.

Because postcrete can begin setting quickly, make sure the fence post is correctly positioned, level and supported before the mix starts to harden.

Our 20kg postmix bags provide a quick and convenient solution for installing a variety of posts, including fence posts and gate posts.

Can You Put Soil on Top of Postcrete?

Yes. Once the postcrete has been installed correctly and has sufficiently hardened, soil can be placed over the top of the postcrete.

Adding soil around the finished installation can help the area blend into the surrounding garden and provides a suitable surface for grass, plants or turf where appropriate.

Always allow the postmix to achieve sufficient initial strength before disturbing the installation or adding additional material around the post.

Is Postcrete Cheaper Than Concrete?

The cost depends on the project and the products being compared. Generally, traditional concrete can be more economical for larger installations, while ready-to-use bagged postmix can offer greater convenience for smaller fencing projects.

Postcrete is specifically designed for quick and straightforward post installation. It is supplied as a pre-mixed dry product and requires only the specified amount of water, making it particularly convenient when installing fence or gate posts.

For smaller jobs, the faster installation process and ease of use can make 20kg postmix a practical alternative to mixing traditional concrete from separate materials.

Why Use Postcrete for Fence Posts?

• Quick and convenient to use
• Ideal for fence posts and gate posts
• Supplied as a ready-to-use dry mix
• Requires only water
• Sets rapidly when installed correctly
• Available in convenient 20kg bags
• Suitable for a wide range of fencing projects

Whether you're installing a garden fence, replacing individual posts or fitting new gate posts, postcrete provides a convenient way to create a strong and stable foundation for your posts.