December 03, 2021
Floating decks are wooden decks built on the ground that are not attached to any structure, including your house. They are also known as freestanding decks and are easier to build than attached decks. As long as they are no more than 30 inches above the adjacent ground, then a building permit is not required.
Building a floating deck is relatively simple. It does not require a foundation and can be set directly on the ground. Or it can be set on a bed of gravel. It also does not require the installation of railings or steps.
If you choose wood as the material for your floating deck. Then you are better off building the overtime on concrete blocks. This will keep the wood deck away from the moisture in the ground, which will keep it dry and facilitate longer use. Or you can choose wood-plastic composite decking as the material of the floating deck. Which has good waterproof and moisture-proof performance. It can adapt to a more complex environment.
Floating decks usually do not require a building permit. However, check this with your local building department. Before beginning your project to avoid unnecessary hassles. Some areas may have special building regulations. Wo it is necessary to get permission from your local government before starting an outdoor project.
Clear the ground for the installation of the deck, removing grass and other debris as needed. Rake the ground to make it level and tamp it down with a hand tamping tool. If needed, lay landscape fabric over the soil and add a layer of gravel to prevent weeds from growing under the deck.
Arrange the four concrete blocks in a rectangle so that they are 12 feet apart along the long side of the rectangle. And 10 feet apart along the short side, measured from the center of the concrete block.
Place a wooden block between each pair of corner blocks so that they are evenly spaced. If desired, add one or more blocks to the center of the rectangle. This can make the deck feel more stable but is not necessary to support the interior joists.
Use a 6-foot level or a standard (4-foot or 2-foot) level and a 12-foot straight board to ensure that all blocks are level with each other. Add or remove gravel under the blocks as needed to level the blocks.
Clear a flat lawn to build the deck frame. If necessary, you can also build the deck on top of the concrete block. Cut 10 pressure-treated 2×8 boards to 117-inch lengths with a circular saw or power miter saw; these are the standard joists. Or you can just use the composite joists that come with wood-plastic composite decking. Which is a much simpler and time-saving way to install a deck.
Measure two 12-foot 2×8 boards. If they are more than 12 feet, trim them to exactly 144 inches. lumber is usually a fraction of an inch longer than the nominal size; in this case, it’s 12 feet. These long joists are the end joists. Place two end joists at the ends of two standard joists to form a 120-inch by 144-inch rectangle.
Drill pilot holes and secure these two joists with three 3 1/2-inch deck screws at each corner using a drill bit. Measure from the inside of one corner of the frame and make a pair of marks every 16 inches along with one of the 12-foot-long joists. Mark the other end of the joist in the same way.
Add two more standard joists to the frame so that each end is located between a pair of layout lines, making sure the tops of the joists are flush. Drill pilot holes and secure the end joists and standard joists with three 3 1/2″ screws at each end.
Place the deck frame on the concrete block so that the frame section rests on the center of the concrete block. Measure between the diagonal lines. Push the frame away from the diagonals as needed to make it square. The frame is square when the diagonal measurements are equal.
Verify that the deck frame is level and in solid contact with each concrete block. If necessary, add or remove soil or gravel under the frame to adjust its height.
Install the remaining six standard joists according to the layout lines. Remember to make the standard joists flush with the top of the end joists. This will ensure that the decking boards will lay flat.
Measure all 12-foot lengths of decking deck and trim as necessary so they are each 144 inches. Place one decking board along one long edge of the decking frame so that it is flush with the outside surface of the end joists. Alternatively, you can place the first and last boards on the joists. So that they overhang by about 1 inch to get a full look. Just be aware that you won’t have the same overhang on either side of the frame.
Drill a pair of pilot holes for each standard joist, one hole into the end joist and one hole into the standard joist. Position the holes slightly off-center so they don’t interfere with the screws in the frame. Secure the deck boards to the joists with 2-inch deck screws (for 1-inch-thick lumber) or 2 1/2-inch screws (for 1 1/2-inch-thick lumber).
Install the next decking board on each standard joist with two screws, spacing the two decking boards approximately 1/8 inch apart. Install the remaining decking boards using the same technique, spacing them evenly.
Pressure-treated lumber is the least expensive option for floating decks. For a modest upgrade, you can choose Southern Yellow Pine (SYP) as a decking material. Which typically has fewer knots and looks better than standard pressure-treated decking. Moving up the ladder is cedar, followed by redwood. These materials are chosen just for their looks. They are not as rot-resistant as treated lumber. There are also many people who choose composite decking. It is made from recycled plastic and wood pulp has good environmental resilience and does not require a protective finish.