After the fence posts have been set, the next step in building a fence is to install the stringers or rails. These are the horizontal boards that go between the posts and to which the fence boards or pickets are attached. Although there are many fence styles to choose from when constructing a fence, use three rails per section if you are building a 6-foot or higher fence. This middle rail helps keep the pickets from warping and increases the life and strength of the fence.
Hold a sample picket against one of the posts. Place a pencil mark on the post to indicate where the bottom of the pickets will be located. Typically, the pickets are positioned 2 inches above the ground to allow for drainage. Set the picket aside.
Measure down from the top of the post 8 inches using a tape measure and place a mark on the post. This is the location for the top stringer or rail. Measure up 8 inches from the mark that was placed on the post to indicate the bottom of the picket. This is the location for the bottom rail.
Measure the distance between the top and bottom rail location marks. Divide the distance by two to find the center point and place a mark on the post. This is the location for the center rail.
Cut the sample picket in two lengthwise. Hold it flat against the post with the top of the picket flush with the top of the post. Position it so you can see the top, bottom and center rail location marks. Make three corresponding marks on the picket. This creates a measuring stick and saves you the time of making measurements at each post.
Hold your measuring against each post and make three lines on each post to indicate the rail locations.
Attach three metal brackets to each post. Align the bottom of each bracket with the lines on the post. Center the bracket and secure it using 2-inch nails and a hammer. Repeat this for all the posts.
Hold up a 2-by-4 top rail to where it will be installed in the top brackets between two posts. Make a mark on the rail if it needs to be cut to size. Repeat this for the center and bottom rails. Make any necessary cuts and set the rails into the brackets. Secure each one with 2-inch nails. Repeat this process for all sections of the fence before installing the pickets.