A backyard deck promises outdoor gatherings, amusement, cuisine, and contact with nature. Consider a detached deck as an alternative if the notion of constructing a full-scale attached deck seems daunting. A detached deck is a low deck that is not connected to the house’s side. This style of deck, as opposed to an attached deck, produces a warm atmosphere wherever it is located, be it by a water feature or in a garden.
Because unattached decks are often less than 30 inches in height, many municipalities do not require building permits or railings. Many households continue to build railings for safety. Consult your local building department regarding permit and code requirements.
Another advantage of a detached deck is that it does not interfere with the home’s exterior. Attached decks require the removal of a portion of the side in order to install a ledger board, whereas detached decks are self-supporting and do not need ledger boards. Instead of wet concrete and huge, deep footings, this deck’s base consists of precast concrete pier blocks. A detached deck may have a lower resale value than a full-scale attached deck, despite the fact that it is easier to install and less expensive to build.
What You’ll Need
Equipment/Tools
- Marking paint
- Tape measure
- Wood stakes
- Twine
- Post-hole digger
- Spade
- Wrench set
- Bubble level
- Electric miter saw
- Drill, with driver and drill bits
- Hammer
- Carpenter’s pencil
- Circular saw
Materials
- 9 Concrete pier blocks with metal brackets
- 3 12-foot long Pressure-treated 4-by-4 boards
- 9 0.8 cubic feet Bags of 7/8-inch drainage rocks
- 8-foot long Pressure-treated 2-by-8 boards or 2-by-6 boards for decking
- #9 by 1 1/2-inch External hex flange hex-head connector screws
- #8 by 2 1/2-inch Coarse thread polymer-coated exterior screws or hidden deck fastener system
- Oil-based wood preservative for cut ends
Instructions
Mark Out the Deck Area
- Choose an open, level location with firm, undisturbed soil at least 10 feet by 12 feet in size for your 8-by-12-foot deck.
- Mark the nine locations where the concrete pier blocks will rest using a tape measure.
- Mark three points in a straight line, with each point 4 feet apart on the centre.
- Create a similar line of three points 3 feet away and parallel to the original line.
- Create a third line parallel to the first two and three feet distant.
Determine the Depth of Holes
Determine the depths of the concrete pier block holes. Keep in mind that the average height of concrete pier blocks with attached metal brackets is 11 inches. If you require a few extra inches of height, another type of concrete pier block has a hole on top that will accommodate a 4-inch galvanized adjustable pier support bracket.
- Holes for Pier Blocks must be Dug.
- Remove all grass.
- At each designated location, using the post-hole digger and spade, drill a hole to the desired depth.
- Create holes that are approximately 1-1/2 times the width of the base of the pier block. Typically, the base diameter of pier blocks is 11 1/2 inches, so the diameter of your holes would be around 18 inches.
- Fill the area to the desired height with drainage rock.
Place the Pier Blocks
- Place the pier blocks in the indicated locations.
- Be sure to align pier blocks with attached brackets so that the open cradles of the brackets run in a straight line. With bracket piers that are adjustable, the brackets can spin 360 degrees.
Dry-Fit the Deck Beams
- Rest the three 4-by-4 boards in the brackets of each of the three sets of pier blocks.
- To ensure that they are properly seated, press down firmly.
Check Levelling and Adjust
- Check the deck beams’ levelness with the bubble or laser level.
- Perform this action from two neighboring sides.
- Any part that is excessively high or low must be corrected.
- For piers with attached brackets, you must remove the 4-by-4 board, the pier block, and either remove or add landscaping gravel to get the desired height.
- For piers with adjustable brackets, maintain the status quo. To raise or lower the bracket, rotate the bolt in a clockwise or counterclockwise direction.
Attach the Deck Beams
- Drill a pilot hole through the hole in the bracket to secure the 4-by-4 boards to it.
- Then, using the ratchet wrenches, tighten the flange hex-head connector screws into the flange.
Cut the Deck Boards
There is a wide range of joist spans for deck boards. Composite and PVC decking materials have small joist spans, ranging from 10 to 16 inches. Because the beams on this project are further apart, pressure-treated boards are required. Consult a structural engineer, a professional contractor, or your local building department if you have any questions.
Because the outer deck beams are 7 feet apart, you can use factory-cut 2-by-6 or 2-by-8 boards that are 8 feet long. On the two long sides, these will offer a 6-inch overhang. In addition to eliminating the need for cutting boards, the ends are also pressure-treated.
Attach the Deck Boards
- Attach the deck boards to the deck beams using deck screws or a concealed fastening technique.
- Use two screws per beam for deck screws, for a total of six screws per deck floorboard.
- Drive the deck screws directly through the floorboard face until the head is flush with the top of the board.
- Be cautious to remove any splinters that result from screwing into the board’s surface.
