Blue Circle Postcrete 20kg Ready-to-Use Post Fix

In-Depth Look

Blue Circle Postcrete has simplified one of the most common garden maintenance tasks in the UK. Setting fence posts used to involve bags of cement, ballast, a wheelbarrow, and a good deal of physical effort. Postcrete reduces the process to pouring a dry powder and adding water.

How It Works

The process is remarkably simple. Dig the post hole to the recommended depth (typically 600mm for a 1.8m fence post), position the post and check it is vertical, pour the dry Postcrete around the base to within 50mm of ground level, and then slowly add approximately 3 litres of water. The compound reacts with the water and begins to set almost immediately, reaching a firm, load-bearing state within 10 minutes. There is no mixing, no wheelbarrow, and no mess.

Practical Considerations

A 20kg bag will set between 4 and 6 posts depending on the diameter of the hole. For a standard fence run with posts at 1.8-metre centres, one bag comfortably handles a reasonable number of posts. The product works in wet conditions — in fact, rain during or shortly after application does not compromise the set. For very large gate posts or posts bearing significant weight, it is worth using additional product to ensure a solid footing.

Verdict

Blue Circle Postcrete is one of those products that makes you wonder how you ever managed without it. The cost premium over traditional concrete is easily justified by the time and effort saved, especially on domestic fencing projects where mixing concrete on-site is disproportionately laborious. For professional fencers and DIY homeowners alike, it has become an essential product.

How It Compares

Against traditional bagged cement and ballast mixed on site, Postcrete costs more per post but saves substantial time and physical effort — for a handful of fence posts, the difference in labour alone usually justifies the extra cost, while for a very large run of posts on a budget-conscious job, mixing your own concrete can still work out cheaper if time isn’t the constraint. Against other rapid-set post-fix products from rival cement brands, the practical differences are minor — most work on the same pour-and-add-water principle with similar 10-15 minute set times, so price and bag availability at the local merchant often decide the choice. One genuine consideration when comparing to mixed concrete: Postcrete’s rapid set means less working time to adjust the post’s position once water is added, so getting the post level and aligned before adding water matters more than it does with slower-setting mixed concrete.

Common Questions

How deep should the post hole be? As a general rule, bury around a third of the total post length, so a 1.8m fence post typically needs a hole around 600mm deep. Deeper holes give a more stable post, particularly for taller fence panels or gate posts that take more sideways load.

Can Postcrete be used in wet or rainy weather? Yes, this is one of its genuine advantages over traditional concrete — the setting reaction isn’t disrupted by rain during or shortly after application, which makes it a reliable choice for fencing jobs that can’t wait for a dry weather window.

Is Postcrete strong enough for a gate post that will take regular use? Postcrete is generally suitable for standard garden gate posts, but for gates that will see frequent, heavy use, using extra product per post and ensuring good hole depth improves long-term stability. For genuinely large or heavy gates, a larger volume of standard mixed concrete may give a more substantial footing.