When purchasing your fence post make sure it is a third longer than the height of your fence panels and your gravel board (if you have one). Also measure the width and depth, as there are two sizes 100mm x 100mm and 75mm x 75mm.
Start by detaching the fence panels from the damaged post. If these are nailed in you can use your hammer or a nail bar to pry them loose. However, this method could damage your panels if not done carefully. Should you wish to retain your existing panels you can use a hacksaw blade to cut the nails, then hammer them flat for safety.
Always remembering to wear gloves and adequate protective clothing whilst doing so. If you have a gravel board, this might be screwed in, if so simply unscrew the supports and pull it away. Should the gravel board be nailed in, repeat the process you used for removing the panel.
Once the panels have been moved aside, you can begin digging out the damaged post. Use your builder’s spade to dig around the existing post and its concrete plug. Then rock the post side to side until it is free enough to pull out.
After removing the damaged post use your tape measure and check the depth of your hole. Often the cause for a listing fence is a fence post dug too shallow into the ground. The depth of your hole should be determined by the height of your post above ground divided by three. So for example if you are erecting a 6’ (180cm) fence then divide 6’ (180cm) x 3 giving you 2 (60cm), 2’ (60cm) is the depth the hole should be.
Should you need to dig a deeper hole a post hole digger is a great tool for making light work of this task.
Before putting in the new post you need to lay down two plum lines in order to ensure your new post is set to the correct height and in line with the rest of your fence. To set the first line in place fix a piece of string close to the ground and to the front of your posts, stretching across the gap where your new post will go.
This line will mark the inside boundary of your fence and will keep everything in line. The second line is fixed across the top of your posts and will give you the guide needed to set your new post to the same height as the rest.
With these guides sorted put the new post in place. Check with the top line that your height is correct. If it’s not at the same height as the other posts you will need to dig or fill your hole as needed until the post sits at the same height. Next using the second plum line check the post is correctly aligned, remembering to use your spirit level or post level to ensure the post is standing up straight in the centre of the hole.
Once you are happy with the new posts positioning you will need to attach three supports to it, so that it will stand upright without your assistance. Using three lengths of timber angled outwards towards the ground.
Use the spirit level or post level to check the post is vertical and upright, the wooden props will help keep the post upright while the Postcrete is poured into the hole.
Before you pour the Postcrete in lay a length of timber across the tops of two consecutive posts and use your spirit level toneed to dig or fill your hole accordingly.
Before using the Postcrete we recommend you use a mask, goggles and a pair of gloves. The size of your hole will determine how many bags of Postcrete to use so check the manufacturers instructions.
Half fill the hole with water, then top up with the Postcrete until you’re almost at soil level. Postcrete comes ready to use and there is no mixing required plus it dries quicker than concrete. While the mix is still wet, use your spirit level to check the post is still vertical.
Just before the Postcrete has fully set use a trowel to shape the Postcrete into a slight mound, sloping away from the base of the post. This will help stop water collecting at the bottom of the post and help avoid the bottom of the post rotting.
Once the Postcrete has set (look on the packaging as different manufacturers may vary), you can nail your panels back to the posts, or you can use a bracket and screw method. These are exterior grade. If you position them 20cm from the top, 20cm from the bottom and one in the centre, you’ll have a secure panel.
Before lifting the panel back into place, a couple of off cuts of gravel board are perfect spacers to lift it off the ground to the right height. Hold the panel in position against the first post and screw the panel into place.
And finally it’s time to fit the gravel board onto the bottom of the panel, using two off cuts of exterior grade two by one.
It’s worth finishing the job by putting post caps on the top of your post. They look good and help prolong the life of the post.
If the rest of your posts don’t have the Postcrete or concrete sloping away from the post you can cover the cement plug with earth, forming it into a mound around the base of the post. This will aid in natural water/rain drainage, taking moisture away from the post and helping to prevent rot.
For more information on how to put up a garden fence you can refer to DIY guides in the ‘help and advice section’