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Erecting a post in concrete

Step 1 - Dig the hole

Use a posthole digger, or a small bladed spade to dig the hole for the post. Don't dig the hole too wide but ensure 25% of the post is below ground level to give sufficient strength.

Step 2 - Put the post in the hole

Check the post is straight by using a spirit level. Stabilise the straight post by wedging broken bricks against the side of the post and the side of the hole.

Step 3 - Fill the hole with water

Calculate the size of the hole (one 25kg bag of Cemix Fastcrete can be used if the length of the post below ground is 0.3mts and the height above ground is 0.9mts). Pour three to four litres of water in the hole per 25kg bag of Cemix Fastcrete. Compensate for any ground drainage that might soak up water. If the soil you are erecting the post in is particularly sandy, line the hole with plastic. 

Step 4 - Fill the hole with concrete

Pour Cemix Fastcrete into the hole around the post. Ensure the concrete gets wet progressively as you pour. Do not empty the bag quickly as this will lead to dry patches. If any drying on the top persists, sprinkle with water. Rod the concrete if need be to release entrapped air.

After a minimum of 15 minutes the hole can be topped up with earth.
NB: For structural projects use SUPERSTRENGTH FASTCRETE 30MPA.
To protect untreated timber posts apply CEMIX Bituproof Plus to the section of post which will be buried into the lime mixture with a paint brush.

Posts can be erected using steel brackets. These are concreted in the hole with the post bolted to a stirrup above ground level. If you wish to use this method we recommend CEMIX Multicrete or CEMIX Maxcrete High Strength Concrete35 for additional strength.