How Do You Drive a 4” Post into the Ground with a Petrol Post Driver?

The Easy Petrol Post Driver is a highly versatile post knocker tool that’s perfect for those jobs that the tractor isn’t quite suitable for. Built to allow you to knock in posts in almost any inaccessible location, such as the very edge of fields, around trees and in corners, on steep banks and across uneven ground, adding one to your arsenal is worth it. It’s even suitable for driving in 4-inch posts.

If you want to drive a 4” post into the ground, follow our steps for an efficient and safe installation of your fence posts.

Before you start, you’ll need:

• Your Petrol Post Driver
• The correct Petrol Post Driver adapter for your 4” post – the 107mm round adapter for round posts, or the 107mm square adapter for non-round posts.
• Safety gear such as gloves, eye protection, ear protection and sturdy boots.
• A measuring tape and marker to position the post.
• A spirit level to ensure straight placement.
• You might also need either a Pointed Pilot Bar, Pilot Core Tool, or Earth Auger if you have got especially tricky ground conditions.

How to Drive a 4-inch Post into the Ground with a Petrol Post Driver

Prepare the post and ground

• Identify and mark where the post will be driven into the ground.
• If the ground you’re working on is quite hard, you can still get a post in the ground with a little pre-preparation. Using a pointed pilot bar, create a pre-hole. This doesn’t need to be wide, but needs to be as deep as you want your post to go. This hole will give your fencepost a route to follow through the soil, and also move any stones out of the way. These few preparation steps will help you to ensure you’re driving your post in vertically.
• If the ground is very hard (e.g. baked hard clay in the summer) a Pilot Core Tool will create a wider hole and also remove some of the soil. Or, if you already have an Earth Auger, this will do the same job, and you will need to use a 2” auger bit for a 4” fence post.
• Ensure it fits comfortably inside the adapter. The adapter size needs to be a snug fit for the post size you’re working with. We recommend that it’s no more than 5-10mm larger than your post. For non-round posts, i.e. squared and T-shaped posts, the outer corners also need to be within this tolerance.
• It can also help to set out your stakes in a line, marking out where you want your whole fence line to go. Using a line wire will also allow you to get the fence line straight.

Set up the Petrol Post Driver

• Check the fuel level and inspect the machine for any damage before use.

• Use an adapter that matches the post size and ensure a snug fit.
• Follow the manufacturer’s instructions to start the post driver. This video also gives some handy tips: