When it comes to securing fence posts or similar structures in the ground, Postcrete is a go-to choice for both professionals and DIY enthusiasts alike. Its ease of use, coupled with its strong and durable setting properties, makes it an efficient alternative to traditional concrete mixes. However, one of the most common questions that arise is: "How long does Postcrete take to set?" In this blog post, we'll explore not only the answer to this question but also provide you with all the necessary information to ensure successful application and optimal results.

Understanding Postcrete

Before we get into the specifics of setting times, it's important to understand what Postcrete is. Postcrete is a pre-mixed, quick-setting concrete designed explicitly for securing posts in the ground. It requires no mixing; you merely need to add water to activate the chemical reaction that causes it to set.

Setting Times

The general claim by most Postcrete manufacturers is that it sets hard within 5-10 minutes after water addition, and you can expect it to bear the weight of a fence post in about 20 minutes to an hour. This quick setting time makes it incredibly convenient, especially when compared to traditional concrete mixes that can take upwards of 24-48 hours to set to a point where they're load-bearing.

However, several factors can influence the actual setting time of Postcrete:

1. Temperature

The ambient temperature plays a significant role in the setting time of Postcrete. In warmer conditions, you can expect it to set quicker, sometimes even in less than 5 minutes. Conversely, in colder weather, the setting time can be prolonged, and it might take closer to 10 minutes or slightly longer for it to firm up.

2. Water Quantity

Following the manufacturer's instructions for the amount of water used is crucial. Adding too much water can delay the setting time and weaken the final result, while too little water might cause an incomplete reaction, affecting the structural integrity.

3. Humidity and Wind Conditions

High humidity and windy conditions can affect the setting time and final strength of Postcrete. Wind can cause quicker evaporation of the water, speeding up the setting process but potentially leading to a weaker bond if not monitored.

Application Tips for Best Results

To ensure you get the best results from your Postcrete application, consider the following tips:

  • Prepare the Hole: Ensure the hole for your post is clean of debris and is damp before application. It helps the Postcrete to bond better.
  • Measure the Water: Always use the correct amount of water as specified by the product instructions. This is usually printed on the packaging.
  • Stabilise the Post: Make sure the post is level and properly supported before adding the Postcrete. Once it starts setting, it'll be difficult to make adjustments.
  • Pour Evenly: Distribute the Postcrete evenly around the post, following it immediately with the measured amount of water.
  • Monitor the Weather: If working in extreme temperatures, take precautions—consider shading the work area in direct sun or delaying the project if temperatures are near freezing.


Postcrete offers a convenient and reliable solution for setting posts, with a rapid setting time of approximately 5-10 minutes under ideal conditions. Remember, however, that external factors such as temperature, water volume, and even weather conditions can affect this timeframe. By following the manufacturer's guidelines and considering the tips provided in this guide, you can ensure a successful and durable installation that meets your project's needs.

Whether you're a seasoned DIYer or taking on a fence project for the first time, understanding how long Postcrete takes to set, alongside the factors that influence it, puts you in a better position to plan and execute your task efficiently.