Postcrete, also known as rapid-setting concrete or post-mix, is a convenient and efficient material specifically designed for setting fence posts, gate posts, and other vertical structures. Unlike traditional concrete, which can take several hours to set and days to cure, Postcrete is ready to use within minutes. However, handling and installing Postcrete requires careful attention to detail and adherence to safety guidelines to ensure a durable and secure installation. Below, we have outlined some comprehensive tips for installing Postcrete safely.

1. Preparation is Key

Before you even open that bag of Postcrete, preparation is essential for a successful installation.

Gather Necessary Tools and Materials

Ensure you have the following items ready:

  • Postcrete bags
  • Shovel or post hole digger
  • Level
  • Water supply (hose or bucket)
  • Protective gear (gloves, eye protection, and dust mask)
  • Measuring tape

Plan Your Post Locations

Mark out where each post will go. This step is crucial to ensure all posts are evenly spaced and aligned correctly. Use stakes and string lines to mark your guide points.

Dig the Holes Properly

For most standard fence posts, holes should be approximately three times the width of the post and half the height of the post above ground. For example, for a 100 mm post standing 1.8 m above ground, the hole should be 300 mm wide and 900 mm deep.

2. Handling Postcrete Safely

Postcrete can be hazardous if not handled correctly. Follow these safety guidelines to protect yourself.

Wear Protective Gear

Always wear gloves to protect your hands from the alkaline nature of cement, which can cause skin irritation. Eye protection is also a must to prevent dust from getting into your eyes. A dust mask can prevent inhalation of fine particles, which can be harmful to your respiratory system.

Open Bags Carefully

When opening the bag of Postcrete, do so carefully to avoid creating unnecessary dust. Cut the top of the bag with a utility knife and pour the content slowly.

3. Setting the Posts

Proper technique during the setting process is crucial for ensuring stability and durability.

Position the Post

Place the post in the centre of the hole and use a level to ensure it stands straight. It may help to have a second person hold the post steady while you proceed with the next steps.

Pour the Postcrete

Pour the dry Postcrete mix evenly around the post until it fills the hole up to ground level. Do not mix the Postcrete with water beforehand; it is designed to set when water is added directly to the dry mix in the hole.

Add Water

Pour clean water into the hole over the dry Postcrete mix. Typically, you will need about 2-3 litres of water for each bag of Postcrete, but always follow the manufacturer’s instructions on the bag for the exact amount. Ensure the water penetrates throughout the mix by pouring it evenly around the post.

Check Alignment and Adjust

Immediately after adding water, check the post’s alignment with your level. You have a brief window to make adjustments before the Postcrete sets. Ensure the post remains straight and firmly in place.

4. Curing and Final Touches

While Postcrete sets rapidly, allowing for immediate further work, it's essential to understand the curing process.

Allow Initial Setting

Postcrete typically begins to harden within 10 minutes. Avoid disturbing the post during this initial setting period. If you need to make any final adjustments, do so within the first few minutes after adding water.

Full Curing Time

Although Postcrete sets quickly, it requires time to achieve its full strength. Avoid applying full loads or stress to the posts for at least 24 hours to ensure the concrete has cured properly.

Fill and Tidy Up

Once the Postcrete has set, backfill any remaining space around the post with soil and tamp it down to level the ground. Clean up any excess material and tools used during the installation process.

5. Environmental and Safety Considerations

Lastly, be mindful of environmental and safety implications.

Dispose of Waste Responsibly

Do not dispose of excess Postcrete or wash tools in drains or natural water sources, as the cement residues can be harmful to aquatic life. Dispose of any waste material according to local regulations.

Store Leftover Material Properly

If you have leftover Postcrete, seal the bag tightly and store it in a dry place to prevent moisture from hardening the unused mix.


Installing Postcrete safely and effectively requires careful planning, proper handling of materials, and adherence to specific techniques. By following these top tips, you can ensure that your posts are securely installed, providing a stable and long-lasting structure. Remember, safety first, and take the necessary precautions to protect yourself and the environment throughout the process.

Ready to start your next project? Share your success stories and tips with us in the comments below!