Whether you’re installing closeboard, trellis panels, post and rail systems or standard lap fence panels, all require sturdy fence posts for a long life. The following guide describes how to install wooden fence posts and includes tips and guidance on how to make sure they stay solid and looking good for years to come.
Tools for installing fence posts
- Rammer / post driver
- Spade / trenching shovel
- Claw hammer
- Post level
- Tape measure
- String line
- Marker pegs
- Hardwood / pressure treat fence posts
- Weak concrete mix
- Preservative for cut timbers
- • Measure out the area to ascertain how many fence posts are required. Once you have marked out the area use markers for the corner posts first and then mark out every 1.5m – 1.8m (five or six feet) for each fence post, depending on your chosen fencing style.
- Carefully measure out where you want the fence to go and decide where the ends will be, where the corner posts will be placed then mark this area out with the pegs pushed into the ground.
- The first fence post and the last fence posts should be installed first to establish the fence line, which can then be used as sighting posts. However, if you are building a particularly long fence you might want to break it down into smaller sections. This also isn’t strictly necessary with fences that turn corners and in which case, careful measurement and marking is required to follow the pre-determined line, for example a property boundary.
- • Dig a hole for the first vertical post, keeping it as tight as possible to the size of the post being used. A trenching shovel is useful for this purpose, as it has a narrow blade designed allowing the digging of smaller holes. Keeping the post hole as small as possible also makes refilling and ramming the earth around the post quicker and easier.
Alternative methods of installing fence posts are with a mechanical auger, which act like giant corkscrews to drill and lift out soil leaving a round hole. These can be basic manual versions that take two people to use or are available with motors to make the process easier. For very large projects with very long fence runs, auger attachments for diggers can be used. Once marked, holes can be very quickly and easily drilled ready to accept fence posts. Other options include ramming tools (hollow metal tubes with handles) to drive posts directly into the earth or again, attachments are available for diggers on large projects.
If using the hole digging method, the following method applies to installing fence posts. Place the fence post in the hole taking care to ensure that enough of the post is above ground to suit the style and size of your fence. If your fence is going to have morticed posts you need to ensure that the mortice holes are facing along the fence line. However, if the fence is going to have nailed or screwed on rails, the narrowest side of the post will need to face along the line of the fence. Place the excavated soil back into the hole a small amount at a time ensuring that it is rammed in well ensuring that the post is completely level. For particularly soft ground, a weak concrete mix or fast setting post concrete should be used and packed around the post in order to prevent the posts from moving. If a wet concrete mix is to be used, bracing timbers hammered into the ground surrounding the post may need to be used and left in place until the concrete has set.
- • Carry out the same process as above to install your last fence post or if on a bend, curve or corner, the next post required to establish a suitable straight line. If you are going to mortice in your fence posts, posts shouldn’t be made completely set firm until you have fitted the rails in order to allow the rails to be added.
- • If using fence or trellis panels, these can be used as spacers to ensure the posts are in the exact right place. These can be clamped or temporarily screwed in place while the posts are being erected using bracing timbers screwed to the posts to keep them perfectly vertical.
- • Check that each post is perfectly vertical (plumb) as you work using a post level, double checking before ramming or packing the post into place.
- • Tie a string line to the first and the last fence post in the run and then ensure that it’s pulled taut, around 750mm above the ground. Once in place, the line can be used to mark out the post centers along the section (the distance will be determined by the style and size of fencing that you’re going to install). Make a small hole in the ground with a shovel to mark the post centers. It’s advisable to only dig out a few holes at a time to reduce any possible errors along the fences length.
- • When digging out the holes to the correct size and depth move the string line out of the way and then replace it afterwards. Once you have placed the second post in the dug out hole sight across to the first post and the last post to ensure that your new post is at the correct height. If mortices are going to be used, the rails will need to be loosely fitted into the mortice until the fence post is in its final position. Continue to check that each post is plumb as you install them and once at their correct height they can be backfilled and rammed with earth or concrete.
- • Once you have completed your post installation, you can install and fix the chosen style of fence.
- • Any cut ends of timber should be treated with preservative to ensure a longer life and prevent rot.
- • When installing a wooden fence post, it is advisable to use fence posts that have rounded or triangular tops as this prevents wear and tear from the rain. If you use a flat top post the rain can seep into the wood post more easily causing the post to rot.
- • The most time consuming and labour intensive part of installing wooden fence posts is digging the hole so that it is large enough to bury at least one third of the posts total length. This means that if you want to put up a five foot tall fence, you will need to buy fence posts that are at least 8 foot in length.
- • As wooden fence posts have to bear a lot of weight they need to be installed correctly to prevent them from getting uprooted in the wind or from leaning to one side.
If you think that a project of this scale may be become your level of skill or confidence, TimberClick are able to recommend good quality tradesmen to carry out any work that you might be unable to do yourself. Please just ask and we will put you in touch with them.