How to Install Wood Fence Rails

A wood fence can provide security and privacy, keep pets or livestock in or out, or simply enhance the appearance of your property. It is also a project that you can do alone or with others. Your wood fence will be sturdy once the rails have been properly installed. After your fence posts have set for 24 hours, you are ready to begin work on your wood fence rails.

Install Wood Fence Rails
  1. Decide how many rails you need and the type of rail you want. If you are building a post and rail fence, use split rails, small logs or 1-by-8 inch boards. For picket fences, 2-by-3 inch or 2-by-4 inch stringers are best. Two rails should be used for fences that are 3 feet high or shorter. For taller fences, three rails are most often used.

  2. Decide how high you want the bottom rail, measure this distance, and mark it on the post with a pencil. Have someone hold one end of the rail at the mark. Position the other end against the next post. Using a level, make sure the rail is horizontal, mark the position of the rail on the post. Decide where the top rail should be and mark this spot by measuring up from the bottom mark. Repeat for a third rail, if necessary.

  3. Choose a style of mounting joint. Rails can be attached to fence posts using a lap, mortise or slot joint.

    A lap joint is the easiest to use. The rail simply overlaps the post. When building a picket or stockade type fence, the lap joint is best. If your posts were set correctly, your rails should be either the length, or twice the length, of the distance from one post to the next. Position the rail at the correct height, covering half the width of the post. Either nail or screw the rail to the post. Continue in this fashion, making sure the rails are level as you go.

    The rustic look of the post and rail fence are enhanced by the use of the mortise joint. To create a mortise, measure the size hole you need for the rail or board to fit into and draw this on the post at the mark you created previously. Drill holes along the outline of the mortise. Chisel out the wood to create a smooth mortise of the proper depth.

    A variation of the mortise joint is the slotted joint. Mark the post as above. Drill holes all the way through the post along the outline of the slot. Use a wood rasp or chisel to smooth the sides.

  4. Install the rails. If you set your posts at exactly the length of your rails and you are using a mortise joint, you will need to saw a little off the end of each rail to make it fit. Insert one end of a rail into a mortise. Bend the rail so that the other end will fit into the mortise on the next post.

    Repeat until all the rails are installed.


  • Make sure your fence line is on your property.
  • Before digging, always contact the utilities companies.
  • Contact your city or county for any needed permits.