Description
Wern-Wood Postmix 20kg is a ready-to-use rapid-set post concrete for setting timber fence posts, concrete posts, compatible metal posts and gate posts. It is the product customers often search for as Postcrete, post mix or rapid set post concrete.
Our current 20kg bag states a setting time of around 5-10 minutes. That makes it useful for fence repairs, new fence runs, garden gates, DuraPost installations and other suitable outdoor post-fixing jobs where you do not want to mix a separate batch of concrete.
20kg rapid-set Postmix for fence posts
- 20kg bag of ready-to-use rapid-set post concrete
- Suitable for timber, concrete and compatible metal fence posts
- Commonly used for garden fencing, gate posts, DuraPost and post repairs
- No separate concrete batch to mix
- Current bag states a setting time of around 5-10 minutes
- Available by the bag, so you can order for small repairs or full fence runs
Is this Postcrete?
Postcrete is a recognised Blue Circle/Tarmac product name, but many customers use the word to describe rapid-set post concrete generally. This listing is for Wern-Wood 20kg Postmix, our rapid-set post concrete for fixing fence posts and gate posts.
How much Postmix do I need?
For a standard 75mm or 100mm timber fence post, allow around 1.5-2 bags per post. For a complete fence run, we normally buy 2 bags per standard post and let the small differences between holes balance out.
Concrete fence posts often use around 2 x 20kg bags. Gate posts need a larger footing and usually more Postmix, especially on the hinge side.
See the full Postcrete / Postmix quantity guide for standard posts, concrete posts and gate posts.
How to use Postmix
Set the post in position and brace it before opening the bag. Add clean water to roughly one-third of the hole, pour the dry Postmix evenly around the post, then add a little more water only where needed until the material has absorbed it. Do not leave puddling water or obvious dry powder.
Rapid-set material gives very little correction time, so have your spirit level, supports and tools ready before you start. Always follow the instructions printed on the bag supplied.
For the step-by-step method, read How to Use Postcrete / Postmix for Fence Posts.
How long does Postmix take to set?
Our current bag states around 5-10 minutes, but setting and curing are not the same thing. The post may stand quickly, but the footing is still young. Keep supports in place for as long as practical and avoid unnecessary movement while the mix gains strength.
For rails and panels, we would normally give the post more time than the headline setting time where possible. If the job is carrying a gate or a lot of wind load, be more patient rather than loading the post immediately.
Postcrete vs concrete
For most normal fence-post jobs, we prefer rapid-set Postmix because it is quick, clean and convenient. Traditional concrete still makes sense when suitable concrete is already being mixed elsewhere on the job or you have enough left over from another project.
Read Postcrete vs Concrete for Fence Posts.
Complete the fence-post job
- Fence Posts
- Treated Softwood Gate Posts
- Fence Panels
- DuraPost Fencing
- Drive-In Fence Post Spikes
- Bolt-Down Fence Post Supports
- Fence Fixings & Postmix
Building a full featheredge fence? Use the Featheredge Fence Builder to work out the posts, rails, boards, gravel boards and Postmix for the run.