Mark the desired fence line along your property using wooden stakes and string. Take into consideration the coverage or span of each fiberglass fence panel when marking spots for the fence posts. For instance, these panels are available in widths of 3 to 3 1/2 feet, thereby allowing overlap between adjacent panels. If you are using 36-inch fiberglass panels, set the posts 6 feet apart, so you install two adjacent panels between the posts.
Dig a hole at each post location that measures one-third of the finished post height, using a post hole digger. For instance, dig each hole 24 inches deep if you are using 8-foot posts, for a 6-foot-tall fence.
Prepare concrete in a wheelbarrow according to the instructions on its label. Set a post into a hole along the fence line, and plumb it using a level. Pour concrete into the hole until it is level with the ground. Repeat this process to install the remaining posts along the fence line.
Secure the 2-inch-by-4-inch framing boards horizontally between adjacent boards using galvanized screws. Attach one board to the tops of two posts, one near the middle and the third near the base. Drive two screws at each intersection using a screw gun.
Hold a fiberglass fence panel on the framing boards between two boards, with its corrugation valleys aligned vertically for drainage. Using a marker, form two marks on the panel where it intersects the top, middle and bottom framing boards before setting it aside.
Bore a pilot hole through each mark on the panel. Work carefully so you do not damage the surrounding fiberglass. Hold the panel back up against the framing boards.
Drive a galvanized screw into each hole through the panel and into the corresponding horizontal frame to secure it in place. Repeat the process to install the second identical panel flush against the side of the one you installed. Butt the edge of the panels so they are flush. Continue to install two panels between every pair of adjacent posts along the fence line.