How deep to dig fence posts

At Jacksons Fencing one of the common questions we get asked  is 'how deep should I install a fence post into the ground?'. The depth of the hole is dependent on a number of factors including the height and type of the fence as well as the width of the fence post.


How deep should I dig fence posts

To begin, we suggest digging the post hole so it is approximately three times wider than the fence post. For example, if you have a 3 inch wide post that you need to sit over 1.83m (6ft) in height above the ground, we recommend the hole size should be: 23cm [width] (9”) x 30cm [depth] (12”). This rule of thumb that can be followed for all size posts (e.g. a 6ft high fence would require a hole depth of at least 600mm or 2ft).

Fence post hole

Safety first

We strongly recommend before you start digging your fence post hole that you either check for any mains electrics or contact your utility company to mark any underground cables or hazards. Doing this also allows for you to reassess the fence line, layout and any positioning issues to make sure everything is exactly where you require it.

 Timber or concrete posts

If using timber posts it is important to note that they must be set in either concrete or Postcrete on top of a minimum of 2 inch ballast/gravel. This is to allow drainage to take place between the post and the concrete. For the best results we recommend using rapid drying Postcrete. Always try to angle of Postcrete slightly so it can shed water away. 

For additional advice about the positives and negatives for both concrete and wooden fence posts, giving you a fair evaluation of each type see our blog covering the topic.

Tools required
  • Rabbit hole digger
  • Hand shovel
  • Hammer
  • Garden stakes
  • Measuring tape
  • Level
  • Concrete / postcrete

Top tip

If you are planning on doing DIY we highly recommend a post hole digger or a rabbit hole digger which  is essentially a single shovel that been designed to dig circular holes. The unique design enables the user to dig straight down to the ideal depth and keep the hole relatively narrow in diameter compared to a conventional shovel.

Why not use a local Jacksons Approved Installer to undertake the job for you?

This blog is designed to help you with installing a fence post. We have official timber fence posts instructions that you can view by clicking the link below.

Timber Fence Post Instructions