You will work very hard raising your chickens, and you cannot afford to have them escaping your property, getting stolen or eaten by predators. A chicken fence must enclose the entire boundary where you will be keeping your birds to prevent such losses; it must not only prevent escape of your chickens but it must also be built in such a way as to prevent predators from gaining access to your birds by digging a hole under it.
Measure your fence boundary with a tape measure, in a straight line, along all four sides. Press a wooden stake into the ground every twelve feet to mark the locations where you will be installing your metal fence posts.
Run a chalk line, or mark off with spray paint, a straight line all the way around your fence perimeter two feet out away from the wooden stakes. The area between the stakes and the outer line is where you will be digging your predator barrier trench.
Use a shovel to dig the trench around your perimeter between the stakes and the line you marked off in Step 2. Dig the trench two feet deep to accommodate a two-foot length of chicken wire.
Remove one wooden stake at a time and, using a sledge-hammer, drive the metal posts into the ground at each stake location. Drive the bottom two feet of post into the ground, leaving six feet visible above ground.
Use 1/16 inch wire to secure one end of your chicken wire to an end post. Begin by wrapping a 3 inch piece of the wire around the top of the metal post and the chicken wire and bring the ends of the small piece of wire together. Use a pair of pliers to twist the wire so the chicken wire is pulled firmly against the top of the post. Install additional pieces of wire around the post, moving down toward the bottom and using one piece of the wire per four inches of metal post. Install one final piece at ground level where the post enters the soil.
Unroll the chicken wire until the entire perimeter is enclosed by the fence, pulling it tightly against all of the posts and wiring the fence to every post in identical fashion, just as you did with the first post in Step 5. When you are securing the other end of the chicken wire to the last post, use only two or three pieces of the 1/16 inch wire and twist loosely so it may be taken off, allowing the fence between the last two posts to act as a door should you need to enter the area. You will need to trim the two-foot section of wire off the bottom of this section, using a pair of wire cutters, as it won't be buried. Remove only a three-foot-wide section to minimise the chances of predators finding this "weak point" in your fence.
Curve the bottom two feet of chicken wire outward into the trench so it forms an "L" shape. In so doing, you are creating a buried barrier to predators who may attempt to dig holes under your fence for access to an easy meal (your chickens). Fill in the trench with your shovel and pack tightly.
If you desire to go through added planning and expense, you may desire to construct a sturdy wooden door to incorporate into your chicken wire fence, even though such additional expense is unnecessary and would lend itself only toward aesthetics rather than functionality.
Consult with your utility and phone companies before digging so they may help you locate any buried cables which may exist at the location on which you will be building your fence.