Typical spacing is right around 8 feet between each post however different circumstances may call for different measurements and it is not uncommon to have spacing between posts reach up to 10 feet.
So, how far apart should fence posts be? The standard spacing for fence posts is 8 to 25 feet apart, depending on the type of fence. A standard wood fence would require posts 8 feet apart, while a high-tensile wire could span 25 feet.
Post lengths for fences start at 8 or 10 feet for a 6-foot-tall fence. They are commonly four-by-fours, which measure approximately 3 1/2 by 3 1/2 inches, or six-by-sixes, at around 5 1/2 by 5 1/2 inches.
Also, before you start to dig, be sure to call your local utilities to come mark any underground wires or pipes. The general rule of thumb when setting a post is that the depth of the post's hole needs to be one-third to one-half of the actual above-ground height of the post.
Wooden Fence Post Spacing
The ideal spacing for wooden fence posts is 5 to 8 feet apart. If you're installing premade fence panels, the distance between fence posts should match the panel width. Standard intervals include 6 and 8 feet.
The American Standards for Testing Materials (ASTM) suggests always setting fence posts in cement. One of the most important reasons your fence posts should be set in concrete is to keep them plumb and level over time.
It doesn't matter if it is a do-it-yourself (DIY) project or a professional installation, wood fence or vinyl fence, your fence posts should be set in concrete. Without a properly set concrete footer, your fence posts will begin to sag until they eventually fail.
Most fence posts require anywhere from one to 10 bags of concrete. Actual concrete amounts vary depending on post hole diameter and depth. Account for frost lines and gravel when doing calculations.
In most applications, a wooden fence should be mounted at least two inches off the ground. Your posts and rot boards (if you want to mount them) should be the only fence components that come into contact with the ground.
The space needed between your boards depends if your boards are kiln-dried or green. For kiln-dried wood, leave about 1/16th of an inch, and for green wood go snug, but not overly tight.
First, the fence itself is likely to be weaker if it's not built on level ground. Second, an uneven fence is more likely to fall over, which could cause serious injury to anyone who happens to be nearby.
One general rule of thumb is to have a horizontal rail for every 24 inches in height. For a six-foot-high fence, this means three rails. While a middle rail may not be a structural necessity, it will help keep fence boards in place and may limit warping and twisting.
For most wood fences, the standard spacing is eight feet. When you're building a fence, proper spacing of the posts is crucial. If you set them too far apart, the rails will sag, and the wind will make short work of your fence.
For reference, a 40-pound bag of concrete typically yields about 0.3 cubic feet, a 50-pound bag yields 0.37 cubic feet, a 60-pound bag yields 0.45 cubic feet, and an 80-pound bag yields 0.6 feet. This means that in the example above, each post would require about eight 50-pound bags.
Adding a 6" gravel base under each post and finishing the concrete base so that it slopes away from the posts are popular methods for protecting posts against rot from moisture contact.
With concrete holding the moisture against the wood, wood has no chance and will eventually lose the battle. Now you don't have to lose all hope because it's for certain that the concrete around the post will crack, therefore making it easy to pull out when it starts to rot. Even worse, the concrete cracks early.
While expanding foam can secure posts for lightweight fences such as vinyl or wire mesh, it's better to go with concrete for structural posts, such as posts for porches, decks, or large and heavy gates. Expanding foam is not as strong as concrete when supporting load-bearing posts.
DO Employ a Base Gravel Layer. If a fence post fails without any sign of a pest infestation, it's likely that the failure was caused by moisture that rotted the wood over time. To help slow such deterioration, add pea gravel or crushed stone to the bottom of the posthole.
This method is stronger than using dirt, but not as strong as using cement. Sand: Filling the hole with sand will help to support the fence post. Like gravel, this method is stronger than using dirt, but not as strong as using cement.
For example, if your vertical short fence will be 100 lineal feet long and your boards are 6 inches wide with no gaps, this means that you'll need two boards per foot = 200 boards. Examine the length of each plank in relation to the height of your fence.
Fence Panels in Windy Areas
Also, fence posts are designed to support fence panels 2ft shorter than themselves. For example, an 8ft fence post is used with a 6ft fence panel. If you decide to increase your existing fence's height, you might need to consider replacing the posts too.
The 2 ft Rule
Lawsons experts recommend you should dig a hole which has a depth of 2 ft (24 in / 600mm) to ensure you have a stable timber or concrete fence post.