How to build a timber deck


Decking continues to be a popular option to help transform any outdoor space. Whether you want to add new areas to your garden or revitalise an old paved area, a timber deck is a perfect cost-effective solution.

Building a timber deck is a reasonably straightforward DIY job which tends to be a quicker and more affordable option than investing in patio materials.

Step 1 – Prepare your decking area.

You will need to prepare a level, weed free area for the deck. If the spot you have decided on is on lawn or uneven ground dig out any soil or vegetation to a depth of at least 50mm, then cover with weed membrane and add a 50mm layer of gravel to help aid drainage. Once you have decided on your perfect spot, mark out your area with pegs and string (these can be found in our retail shop). Check your marked area is square by using a builder’s square to check the corners.

Step 2 – Building a decking frame.

First you will need to create a framework out of decking joist either 100mm x 50mm or 150mm x 50mm size timbers. Cut the joists to the required length, then join using joist hangers and decking screws.

Now internal joists can be added to the inside of the frame to provide support to the deck surface. These will run at 90 degrees to your decking boards. Starting at the centre measure 600mm intervals along the outside joists, cut the internal joists to size and join using joist hangers and decking screws.

Lastly to further strengthen your decking frame noggins should be added at 90 degrees to the internal joists. Mark out 1200mm spaces on the internal joists and cut your noggins from a piece of joist timber. These marks should be staggered on each internal joist to make the noggins easier to fit. Lay the noggins out between the internal joists and attach with decking screws.

Step 3 – Fixing the decking boards

Before you begin laying your deck, cut the boards to the length required. Then you can position your first decking board at the edge of the frame. However, remember to add a slight overhang if you intend to add fascia boards along the sides. Drill two pilot holes at each end of the boards over the centre of each joist, then fix the deck boards to the joist using decking screws. Repeat this until you have covered the whole surface of the deck, its important to note that wooden decking boards will naturally expand and contract, so its essential to leave a space of 5-8mm between boards. Finally, fix the fascia boards along the outer edges of the frame using additional decking boards.

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