The concept of installing fences or posts seems relatively simple – stick posts in the ground deep enough so they stand on their own.
Easier said than done as there are a number of methods (granted, some are better than others) to accomplish this:
Dig a hole by hand (or auger if you have one) and tamp the hand-set post. For dense soil, posts can be directly installed (only if the soil is really dense and has good drainage). The hole should ideally be about 1/3 of the total length of the post. The diameter should hug the fence post size.Pros: Requires no heavy machinery and little equipment; inexpensive; and more likely to be decay resistant. Cons: Time consuming; labor intensive; and less stable.
Consider using gravel if the soil has poor drainage. Follow the same procedure as setting a post directly in soil by hand except the size of the hole must be made larger to accommodate the gravel. For a standard 4x4 post, dig roughly 8 inches across. Tamp down pea-sized gravel or crushed rock into the hole. Continue to tamp every 4 inches. Steady the post into the hole and continue to fill with gravel and tamp on the surface around the post.Pros: Requires no heavy machinery and little equipment; inexpensive method that can repurpose materials from other jobs. Cons: Time consuming; labor intensive; less stable; and requires another set of hands to stabilize the post while pouring the fill.
Alternatively, fill the hole with concrete if you are working with soft or sandy soil. Be aware that concrete increases the risk of trapping moisture in the post and subsequently the risk of premature rotting. Because the posts in concrete require a surrounding gap of 12 inches, a post hole digger or clamshell digger is recommended. This allows for more uniform sized holes – holes that should be consistent throughout and not cone shaped. Fill then tamp the hole with a base a gravel/crushed stone. Use stakes to keep the post in place during the pouring process and scrape the concrete up against the post in a cone shape.Pros: A stable and long-term option if done correctly; inexpensive if you already have the materials on hand. Cons: Reduces the lifespan of the post because of the likelihood of the concrete to trap water between the post; requires materials/knowledge of cement.
Also known as a “side hammer,” a hollow steel tube with handles encases a heavy steel weight. Fitting over a post, the driver works like a sledgehammer with a larger striking surface – the momentum of the lifting and falling weight drives the post down.Pros: A manual method that is relatively inexpensive; control the depth of the post in the ground (i.e. smaller hits would mean less drive into the ground). Cons: Physically taxing; high risk for injury if used incorrectly; posts widths are limited by the size of the driver; and difficult to use on stony ground which often causes damage to the post.
Post driver attachments are the most efficient method because it requires no prior prep work, such as digging holes. The hydraulics drive a wide range of materials and size posts into any soil condition.
However, it is important to remember that there are two main kinds of post drivers...
A free fall system utilizes the force of a falling weight without the aid of springs, a hydraulic cylinder, or return line. It is important to remember that drop hammers are frequently used to break and demolish concrete, which means there's no mercy for fragile wood posts. Not to mention, more moving parts drastically increases the risk for injury.Pros: A drop hammer is powerful and can drive almost all posts with ease. Cons: There is no way to control the power of the drop hammer; fractures and damage to the post head is common and inevitable when working with a drop hammer system on tough terrain; expensive when considering it is a single-purpose attachment; requires a skid steer.
Works the same way as a drop hammer style post driver except that it has more control over the weight. A game changer from Eterra and arguably the best post driver attachment on the market, this popular post driver attachment is 670 lbs of solid high alloy strength steel. Measuring in at a height of 52” and a width of 45”, its 8-inch coned styled driver head cuts down on the number of additional parts unlike a drop hammer style attachment. In just 10 seconds, it can drive a 6” diameter post 3 ft into the ground — a demonstration of its speed and effectiveness. A breaker style post driver has been tested on posts as small as 4” with the same results: no splitting, cracking, or post head damage. The BPD-750 is called the “breaker style” because it doubles as a concrete breaker with the purchase of a 5 foot spike. Not only will it shatter rocks, but it can also be used to create pilot holes for your posts.
Pros: Powerful without being damaging; cost effective as a multipurpose tool; and fast.
Cons: The upfront cost is more expensive than other options; requires a skid steer.