Floating docks can costs thousands of dollars. A cheaper option is to make your dock at home using materials found at a lumber yard or big box retailer. A floating dock can be constructed in a day or two and will last for years. Making the floating dock form recycled plastic barrels is especially cost effective, and upkeep is cheap because individual barrels can be swapped out as needed. Building a small dock will also keep costs down. An eight-by-eight-foot square only requires four barrels.
Mark the four-by-four post at eight-inch intervals using the measuring tape. Cut the post at the marked spots with the circular saw.
Align the four two-by-eight-inch boards in a square and stand the four-by-four-inch post sections in the corners to create the dock frame. Connect the four-by-four-inch boards to the two-by-eight boards using a screwdriver and screws.
Screw the two-and-a-half-inch deck screws through the corners of the frame and attach the posts to the boards. Repeat this twice on each corner and screw in all four corners.
Measure the width of the barrels. Put the two-by-four inch support beams horizontally across the width of the frame and spread them out a distance equal to the width of the barrels. Attach the support beams to the frame using galvanized screws every foot. Attach the L brackets wherever the two-by-four-inch beams meet the two-by-eight inch boards by using two screws per bracket and attaching one side of the "L" to the two-by-four inch beam and the other to the two-by-eight beam.
Apply the caulking to the barrel seal around the lid after making sure the barrels are shut tightly.
Flip the dock over so the frame and cross beams are sitting on the posts and the top of the structure is up. Place the deck boards perpendicular to the cross beams. Screw the boards into the beams using two screws on each beam.
Flip the dock back over to attach the barrels. The barrels must fit tightly under the dock in the four corners of the structure. String the rope over the barrel and around the beams to secure each barrel. If the barrels fit loosely, apply a shim between the barrel and the corner. Turn the dock back over and place it with the barrels down in the water. Secure the floating dock to an attached dock using rope strung through the barrels.