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How to Lay Garden Decking

Garden decking is a perfect way of extending the outdoor living space. It provides a seamless link between the home and garden. Whether you like having a barbeque, get vitamin D in the sun or want to make your outdoor space contemporary and complement your pool or hot tub, decking is an answer.

Straightforward garden decking is a relatively easy structure to built, and the construction process does not take a lot of time. It can be installed on non-uniform terrains.

In this guide, you will find out step by step how to build a new garden decking.

Before you start

Make sure you plan your deck. It helps to consider any primary purpose before you build your garden deck. Planning will prevent any headaches once you start your new deck construction. At this stage, you must consider the size, access, location and shape of your new project.

What you will need

  • decking boards

  • exterior wood screws

  • weed membrane

  • joists (pressure impregnated timber)

  • concrete slabs (optional-depending on the type of deck construction)

  • tape measure

  • square

  • pencil

  • spirit level

  • hammer

  • jigsaw/handsaw

  • drill driver

Laying Garden Decking in steps

Step 1 - Preparing a garden site and building the outer frame.

Once your planning stage is complete, you have all the tools and materials it is now the time to prepare the ground to prevent any issues in the future. Create the framework, cut the timber to the desired length and join by using exterior wood screws. Within the frame, clear away weeds and rocks to rebalance the surface. You can use a weed killer spray to prevent any unwanted weed growth. Measure and cut out the weed membrane so that it covers the entire area.

Raise the frame by screwing cut to the desired height, four blocks of tanalised timber at each corner. They need to be flush at the top. These legs will be taking all the weight of your garden decking.

If your deck is going to be sitting on grass or soil, do not forget to place blocks or slabs underneath edge leg. It helps to spread the load and creates a stable base.

With your spirit level, check the frame is level and adjust accordingly.

Step 2 - Fixing joists

Joists are responsible for supporting deck boards. The recommended spacing between them depends on whether you intend to position your boards. For horizontal boards, the centre spacing is usually 40 cm, and 30 cm for diagonal.

On a small deck, you can get away with three joists (one in the middle and the others at the centre-point between the edge of the frame and the centre joist). Mark the spacing with a pencil.

Cut the joists to the required length. Tap the joists in with a hammer. Then attach to the outer frame using screws from the outside of the frame.

Step 3 - Support joits

Cut some additional legs to support the joints. Space them approximately at 1m intervals.

Step 4 - Fitting decking boards

Please note that if you have chosen wooden decking boards, you should allow them to dry out & acclimatise for around one week before fitting. Following this simple tip will allow your wooden boards to reduce moisture content & shrink down to their standard size.

To start with, measure across the top of the frame and cut the boards to length. Some people choose to overlap the deck frame & then cut the boards to the desired length once they are in place. It is up to you.

Position the first board flush with the outside edge of the frame. Use a sharp countersink to mark the location of each joist on the board. Pre-drilling the holes prevents cracks and splits in the decking materials. Incorporate small gaps (approximately 3-5mm for non-acclimatised boards and 7-10 mm for acclimatised) for expansion during wetter periods. Here spacers come handy ( off-cuts of wood/ plastic or spare screws). You do not want any objects falling through your decking boards!

Once the boards are positioned on the frame, you can start fixing them in place.

Step 5 - Prepare Facing

Measure the length of the outer sides of your frame and cut the decking boards to suit. Countersink the facing and screw to the frame. Make sure the edging is flush with the top.

Step 6 - Adding finishing touches

If there is a significant drop from the surface of your newly-laid garden decking to the ground, it is worth considering to fit balustrading or steps. It will help to ensure your new project is safe and conforms to UK building regulations. The frame for the steps (aka "stringer") can be made separate to your deck and attached afterwards. If you want to complement the aesthetics of your decking, a pergola is a great addition.

Yes, that's it! Six simple steps, describing how to build a new garden decking. Hopefully, we have managed to give the confidence to crack on with your new garden decking.

However, you are not a keen DIY-er and after reading the guide above still think that installing garden decking is a complicated process, please get in touch with us. We are happy to help and provide a free no-obligation quote for your project.

Thank you for reading.


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