5 Steps to Install Composite Wood Deck
– Step 1: Define your composite decking project
– Step 2.0: Install the joists on a concrete slab
– Step 2.1: Install the joists on a natural floor
– Step 3: Install the first row of deck boards
– Step 4: Install the next row of boards
– Step 5: Finish the composite deck by installing the edge boards
As soon as the warm weather arrives, the deck becomes a real additional living space. As a link between the house and the garden, it is a pleasant place to relax and have lunch or rest. Composite wood has many advantages: it is light, easy to install, and durable over time, without requiring maintenance. You can install the composite deck on a concrete slab or a natural ground. Follow these detailed explanations to learn how to install a composite deck.
1. Define your composite decking project
Choose the location of the deck
– Choose a location near the house for convenience.
– If your deck is not attached to the house, make sure it is accessible through Japanese steps or graveled paths.
– Orient your deck to the south or west to get maximum sunlight.
Good to know: avoid a north-facing orientation to avoid having a damp, cold, and dark terrace.
– A terrace facing the wind is not very pleasant, but it is possible to remedy this problem by planting a hedge or wooden fences.
Determine the size of your deck
Think about how you will use your deck to determine its size.
– For a family dining area with a table and chairs, 10 to 15 m² is sufficient.
– For a relaxation and reception area, plan for at least 30 m².
Draw a plan for your deck
– Choose the shape of your terrace, L-shaped, rectangular or rounded, according to your tastes but also the configuration of the garden.
– Draw a plan on paper, noting all dimensions.
Good to know: make a view of the garden to visualize your project better.
Determine the type of deck support
You can install a composite wood deck on natural soil or a concrete slab.
– If you already have a concrete deck, use it as a base.
– If your substrate is natural soil, follow the recommendations for installing a deck on natural soil.
2.0 Install the joists on a concrete slab
With a concrete slab, the joists are fixed directly on it.
Place the 2 joists perpendicular to the house
– Place 2 joists of the same size perpendicular to the wall of the house.
– Insert an expansion block between the joists and the wall.
– Make sure that they are square.
Attach the 2 joists
– Drill a pilot hole at both ends of the joists, then every 70 cm or so.
– Countersink the screw heads using a larger drill bit.
Good to know: do this operation carefully so that the screw heads do not protrude from the wood.
– Drill the slab through the joists with a concrete drill bit.
– Then, insert knockout dowels into each hole to secure the joists.
Place and fasten the intermediate joists
– Place the intermediate joists every 30 to 40 cm.
– Check that they are horizontal and square.
– Attach the joists as before.
2.1 Install the joists on a natural floor
Before installing the joists, prepare your natural floor to obtain a horizontal deck at the desired height.
Prepare the ground
– Mark out the decking area.
– Place a geotextile film on the ground, covering the entire surface.
– Place a bed of sand on the film.
– Pack it down over the entire surface with a roller.
– Place concrete slabs at each corner, then distribute them evenly. They will serve to stabilize the joists.
Good to know: you can replace the concrete slabs with adjustable blocks. To fix the joists to the blocks, refer to the instructions provided.
– Check the level of the whole by placing a mason’s rule on the slabs and a spirit level on it. If necessary, adjust the level by adding sand.
Install the joists
– Assemble a frame of joists around the deck by screwing them together, edge to edge.
– Double the 2 sides by laying 2 joists, one against the other, on the sides where you will lay the first and last row of boards.
– Check the squareness of the frame by measuring the diagonals. They must be identical.
Good to know: with a string, take the length of the first diagonal. Then check that the second diagonal is the same length.
– Install the intermediate joists inside the frame, approximately every 30 to 35 cm.
3. Install the first row of deck boards
Place the first board on the joist
– Place the first decking board in perfect alignment with the joist.
– Insert a shim between the wall and the joist to allow for expansion.
– Then screw the board into the joist. – Drill pilot holes and countersink the screw heads.
Insert fasteners and continue the installation
– Insert the fastening clips into the board’s groove, centering them on each joist.
– Screw the clips lightly (without locking them) into the joists.
– If necessary, complete the installation with another board up to the end of the deck.
Caution: the board joints must be in the middle of a joist.
4. Install the following rows of boards
– Place a board in the second row along the first row.
Note: If the side of the deck is against a wall, insert a shim between the wall and the board.
– Insert the clips into the board’s groove and snap them into place.
– Continue installing the second row in the same way, making sure to position the board joints in the middle of a joist.
Good to know: if you want to install the boards with staggered joints, mark the distance needed to reach the middle of the joist and cut the panel to the correct size.
– Once the line is installed, adjust the alignment of the boards by tapping on the end of the line and the side with a mallet.
– Then screw the clips completely onto the joists.
– Install the other lines in the same manner.
5. Finish the composite deck by installing the edge boards
– Measure the height of the deck, then subtract several centimeters to allow for rainwater drainage and air circulation.
– Transfer this measurement to the width of the boards and cut them to remove the grooved side. This will give you a clean edge with no grooves.
Good to know: if several sides of the deck are to be covered, cut the end of the boards at a 45° angle using a miter box to ensure a perfect finish to the corners.
– Screw the edge boards into the joists.
Your deck is finished, and you can enjoy it as soon as the first rays of sunshine arrive!
Materials needed to install a composite deck