How To Build A Wooden Fence
The first step in building a fence is to layout the area with spray paint and string lines. This will help you to get a visual of where the fence will be. Be sure during this process to observe elevation issues that may cause problems during your installation. Running the string lines at the finished height of the fence will help see the grade of the ground in relation to the finished fence.
Posts are commonly 4×4 or 6×6 and are 1/3 below grade to ensure a strong enough grab in the ground to avoid falling or leaning with age. The postholes can be approximated to the half of the fence height in depth. In areas where the ground freezes seasonally then you will need to know what the frost line is and set your posts a minimum of 6-12″ below this grade. This will help to ensure that your fence posts do not heave out of the ground when the ground freezes.
If freezing is a concern, or if you are in an area with a lot of ground water then you might want to dig the postholes 4-6″ lower than required and filling this extra space with gravel to aid with drainage from around the post.
The diameter of the hole should be around 4 inches wider than the post itself. This is to make sure that there is sufficient concrete on all sides of the post. The fence is only a strong as its weakest component and too little concrete will almost certainly cause early failure of the post, if not the whole fence section.
There are a few different options for how you can set fence posts in place however many of them can produce less than desirable results. The ideal method is to mix concrete as required, either in a wheelbarrow or from a concrete truck directly, and place into the post hole. You will want to use a pencil vibrator or another manual method of agitating the concrete to ensure that you have no air gaps around your posts. Use the minimal amount of water in the concrete that allows you to work with the concrete. Adding too much water will dramatically reduce the strength of the finished concrete.
It is for this reason that setting concrete posts by pouring in dry concrete mix and then running a hose into it is not required. This is a very common practice in the fencing industry however using this process does not allow you to control the amount of water in your concrete. You are strongly encouraged to use a high quality concrete and start with the corner posts.
When using concrete to set fence posts you will want to nail temporary supports in place to be sure that the post does not shift out of position during the curing period. Though the concrete will take a full 28 days to reach full strength, it should be sufficiently strong as to support the rest of the fence within 24 hours. In very cold weather you can wait an additional 24 hours before proceeding with the rest of the fence to make sure that the concrete has set properly on the posts.
Once the outside and corner posts have set then you can run a string line from the top and bottom of each post. This will allow you to build a grid template that you can follow as you put up the vertical fence boards. The rails are the horizontal boards that the vertical boards connect to. The rails are usually made from 2×4 lumber and are usually no more than 24 inches apart. You should try to use lumber that is as long as possible to eliminate joints in the rails. Any rail joints must fall on the back of a post and each side of the joint should be half way on the post to ensure maximum strength of the rail.
The process of putting up the fence boards will depend in which pattern you have chosen for your fence design. Whatever method you choose be sure to use spacers and levels to keep your fence square and plumb. Any small errors in the beginning will be very noticeable by the end of the project.