Draw up blueprints for your backstop so you know what materials you need to buy. If the field will be used for Little League, or by smaller children, it doesn't have to be as tall or wide as if it will be used by high schoolers or adults. The backstop should have three faces: a long one about 15 feet wide that will be perpendicular to the line created by the pitcher's mound and home plate. Two more on either side should be at least 10 feet wide, and should be angled toward the basepaths at approximately a 120-degree angle, or parallel to the foul lines. The height depends on the age of the intended users of the field: For small children, 10 feet will suffice, but 15 to 20 feet will be necessary for adults.
Mark the places where you want to place your fenceposts with scraps of dowel rod. Start at home plate and walk back at least 10 feet into foul territory. Be sure to leave enough room for the catcher and umpire.
Dig holes for the four fence posts. Make them at least three feet deep and twice the circumference of the steel pipe you will use. Place the posts in the holes one by one, pouring the cement in until it reaches the surface. Use the level to ensure that the posts are perpendicular to the ground. Repeat for the other three pipes. Be sure to follow the directions on the cement bag.
Once the cement is dry, affix the chain-link fence to one of the end fenceposts by wrapping it with 6-gauge metal wire. According to Frazier's Field Repair, 9-gauge wire will work, but 6-gauge wire will be more secure. Be sure to secure tightly to ensure the backstop will be able to block any high-speed balls hit into it. Use a ladder to fix the fencing anywhere that is too high for you to reach.
Finish the backstop by putting fencepost caps on the metal pipes and make sure all of the 6-gauge wire is wrapped over itself to reduce the risk of someone being hurt by a sharp edge.