Tools required :- Spade / shovel, spot board, bucket, wood saw, lump hammer, post / 600mm spirit level and tape measure.
Safety tip :- Wear gloves when mixing mortar and concrete as cement can irritate and burn skin.
Concrete posts need to be bedded in the ground and set in place using concrete. As a rough guide I would recommend having 25% of the post below ground level to provide good stability and strength. As an example I would use an 8ft post for a 6ft high fence or a 4ft post for a 3ft high fence.
Once you have dug out the hole for the post to the required depth, have some bricks or wooden stakes readily available for when you site the post in position. The 6ft and 8ft posts are very heavy and having some assistance, just from the safety point of view wouldn’t be a bad idea. Site the post in position and stand it level, you can use a spirit level on the sides of the post to get your vertical levels set, having a post level ( fig 1 ) makes the task easier to carry out.
When you are satisfied with the siting of the post have your assistant wedge the bottom of the post in the hole using the bricks or wooden stakes ( fig 2 ). Double check your levels and then back-fill the hole with concrete, I normally make a mix of 1 part cement, 2 parts sand and 2 parts stone ( aggregate ).