Our Rapid Set Postmix is supplied in 20kg bags, and the supplied guidance recommends allowing around two bags per post for initial quantity planning. The actual amount depends on the size of the hole and the particular installation.
For initial planning, the supplied guidance for our Rapid Set Postmix recommends allowing around two 20kg bags per post. That is a useful starting point, but it should not be treated as a fixed quantity for every fence post.
The amount of postmix actually required depends on the volume of the hole after the post has been positioned. Post dimensions, hole diameter, hole depth and ground conditions can all change the amount of space that needs filling. A larger hole around a substantial gate post can therefore require more material than a smaller installation.
Rapid Set Postmix is a pre-blended post-setting product activated with clean water. The supplied guidance states an initial setting time of approximately five to ten minutes, so the post should already be positioned, aligned and checked for plumb before water is added. On a longer fence run, have any temporary support ready before starting each post so alignment can be maintained while the mix takes hold.
It can be used for suitable timber, metal and concrete posts. For a larger project, use our post mix calculator to estimate the quantity from the job rather than simply multiplying every post by an assumed universal bag count. Other post-setting products can be found under cement products.