How to Lay Decking


Deciding to install your own decking can seem like a daunting task which is why we at Building Supplies Online have put together this guide to help you on your way. Laying your garden decking can actually be achieved quickly and efficiently if you follow certain basic guidelines.

So with our simple to follow guide we will show you how to construct your decking and base, treat your timber decking, construct a raised deck and install posts, fix the decking board inplace, create steps and a balustrade and even create a stringer and affix steps.

Installing timber decking is a very economical way of creating an outdoor seating area or terrace. Timber decking can be designed to fit almost any space in and around your garden area, and depending on your desired look you can choose to have your decking at ground level or for a more extravagant look opt for a raised decking platform. Before your start your Timber Decking project it is important to first check with your local authority to establish if there are any building controls of planning permission required for the location or type of Decking your would like to install.

Treating your timber decking

It is important to ensure that the timber decking you purchase has been correctly weatherproofed and pressure treated. Please also remember that If you have had to cut the timber decking you will need to use timber decking wood preserver to treat the cut ends.

There are generally three types of different decking styles

  • Ground Level Decking
  • Raised Level Decking
  • Multi Level Decking

If you are planning to build your Decking on a sloping ground the you can incorporate the features from the raised deck and ground level deck.

Types Of Decking Explained

Ground Level Decking

This type of decking is constructed close to the ground level and the timber decking bearers are used to support the decking boards that will be laid directly onto paving slabs. When installing ground level decking it is important to make sure that the decking joists rest directly onto a suitable foundation making sure that these fully support for a Ground Level Decking. A good example of a suitable foundation would be 50mm thick paving slab or building block which should be placed onto a bedding made of either lean mix concrete, sand/cement or just. The next step is to fix your decking timbers of the same size between your timber decking joists which will help to prevent them from twisting. These are known as ‘noggins’ and are staggered to allow them to be nailed into position through the timber joist and into the end of the noggin.

Raised Decking

A raised deck is supported above ground level with the use of timber decking legs. By creating a decking ramp, steps or stairs you will be able to provide access to the raised level of your decking. Decking supports will need to be installed for a raised deck and this is acheived by digging a hole in the location of your decking and concreting the support inplace taking into consideration the height of the decking your require. The recommended depth usually required should be between 300mm and 750mm however this will depend on the height required above ground. When installing the decking supports please remember not to place any concrete directly under the post as this will create a pocket that will collect water.

Multi-Level Decking

As it suggests, Multi Level Decking is designed to give several levels to your timber decking project either to create a uniquely looking Timber Deck area or, as is often the case, to suit the varying conditions and slopes of the garden.

Constructing the decking

Use 75mm x 50mm (3in x 2in) timber decking joists to build a timber frame that will form the perimeter of your decking area. The timber joists need to be fixed together with 75mm countersunk decking screws as these are suitable for outdoor use. If your Timber Decking Joists need to be fixed to a wall you can do this by using 100mm masonry bolts.

Make sure that the decking joists are completely level and that they come together at right angles at the corners. If you are installing a square or rectangular decking then make sure to measure the diagonals so that it is perfectly square.

Cut and install more timber decking joists inside the frame at 400mm intervals and once complete you are ready to start installing the first decking board which should be placed on the edge of the frame that is furthest from your house and screwed into the frame with a screw in each corner.

Position your next decking board, making sure to leave an expansion gap of 5 mm between the previous board and then continue to lay the rest of your decking boards the same way, leaving the expansion gap the same 5mm between each board.

The final decking board will probably require cutting and scribing to fit against the wall and remember, as mentioned at the beginning of this guide to treat any sawn edges with wood preserver.

Finally to complete the look of your Timber Decking and to conceal the framework, fascia boards should be screwed to the outside of the frame.

Laying Deck Boards – Top Tips

Use two fixing screws each where decking board crosses the joist joist. Only use galvanised decking screws to install decking joists and planks as these will not rust. To avoid having to pre-drill timber decking boards, with the exception of adjacent decking board ends, use proprietary deck screws.

Make sure you leave at least 5 or 6mm gap between each timber decking board to allow for swelling, shrinkage and drainage.

Tools Needed

  • Tape measure
  • String line
  • Spirit level
  • Scissors
  • Power drill
  • Panel saw or jigsaw
  • Spade or shovel

Materials Needed

Posted By Building Supplies Online, 21st Nov 2018