Laying garden decking is like any other building project – it requires a good deal of planning.
This article serves as a general guide on how to lay decking. We’ll cover every aspect of installing a garden deck: the tools you’ll need; how to go about preparing the ground; best practices for frame assembly; and laying the deck boards.
We’ve written this how-to article in a way that’s easy to follow from your phone or when printed out. As we’re the UK’s leading supplier of composite decking, we’ve also included a bonus section with tips on how to install composite decking.
Skip to:
- Calculating your quantities
- What tools do you need to lay decking?
- Step 1: Preparing the ground for a deck
- Step 2: Frame assembly
- Step 3: Laying the deck boards
- Step 4: Decking base rails, spindles & handrails
- Bonus: How to lay composite decking
Calculating your quantities
Use our handy decking calculator to work out the exact quantities of materials you’ll need for your build. Simply enter the intended dimensions of your deck and the calculator does the rest, including generating the cost of materials.
You can choose for the calculator to recommend products automatically or, if you already have some of the required materials, you can manually select the specific products you need.
What tools do you need to lay decking?
You don’t need any specialist tools to lay timber decking, but there are a few tools that will make your life a lot easier.
- Tape measure
- String
- Spirit level
- Spade
- Landscape fabric & gravel
- Pencil
- Mitre / circular saw or regular handsaw
- Drill & drill bits
Step 1: Preparing the ground for a deck
Building on a solid foundation improves the stability and life expectancy of your decking. Some of our customers have built garden decks on existing patios, which requires next to no preparation, but most build over a lawn. Limiting the points where your frame is in contact with the earth extends its life expectancy, so building on a lawn requires you to prepare the ground.
1.1 Start by marking out the intended layout of your decking area with the string.
1.2 Using your spade, remove any turf and create a level area.
1.3 Lay some landscape fabric to prevent weed growth and then cover with a layer of gravel. This step is key. The gravel helps with drainage and creates a barrier between the ground and the frame. Concrete pads are the alternative option here.
Step 2: Frame assembly
Assembling the frame is a crucial step in the build. The frame supports the deck boards, ensuring a stable decking that doesn’t slope or move under weight.
2.1 Begin by laying out and then marking where you will join your decking joists.
2.2 After you’ve pre-drilled pilot holes, and have checked that the frame is level, join the decking joists with decking screws.
2.3 After fixing joist hangers to the outer part of the frame, you can begin adding internal decking joists. These should be spaced no more than 40cm apart.
2.4 To further support the internal joists, add noggins/struts at 120cm intervals. The top of the noggins should be level with the top of the joists.
Step 3: Laying the deck boards
Once you’re sure that your frame is level, you can move on to laying the deck boards.
3.1 Use a 2mm drill bit to pre-drill pilot holes before screwing the deck down. Pre-drilling helps to prevent the deck boards from splitting when you screw them to the joists. You can also countersink the pilot holes with a slightly larger drill bit to help the screws ‘sink’ nicely into the timber, ensuring a smooth finish with no screws sticking out above the deck.
3.2 Use a piece of off-cut timber as a spacer to ensure that you maintain uniform spaces between the boards. We recommend a space of between 5-8mm between deck boards.
3.3 If you’re adding steps or a ramp to your decking, consider adding anti-slip timber deck boards.
3.4 If you plan to add fascia boards to the edge of your decking, using 5-8mm packers below the decking ensures a uniform space along the length of the fascia and gives a clean finish.
Step 4: Decking base rails, spindles & handrails
You may want to add decking balustrades and handrails to your deck. These features can be used to enclose the area and improve the safety of your decked area. Handrails are suitable for residential or commercial decks, but are mainly used with raised decking and where there are steps or ramps.
We stock everything needed to add a balustrade and handrail to your decking area, including rail systems and various designs of posts and spindles. You’ll also find infill and cross-top panels that can be used to enclose your decking area and provide more privacy.
Bonus: How to lay composite decking
Composite decking offers a number of benefits, especially with the changeable weather conditions here in the UK. One benefit of going with composite decking is the relatively easy installation process.
We stock two types of composite decking; EZI Super Stable and the premier range from Millboard.
How to lay EZI composite decking
EZI composite decking uses a hidden fastening system with screws attaching from the side of the deck board to give a clean finish. The simplest way to install EZI Super Stable composite decking is to follow the fitting guide provided with a composite decking kit.
We can deliver composite decking kits with a subframe and all of the fixings included. Available in a choice of 5 contemporary colours and 2 anti-slip finishes, EZI composite deck boards can be cut to bespoke sizes with standard tools. Get in touch with any questions or to request a fitting guide.
How to lay Millboard composite decking
Millboard has produced excellent how-to videos and downloadable guides that cover the installation best practices and need-to-knows in detail.
You’ll also find tutorials on how to use Millboard’s proprietary installation tools, such as the DuoFix side-fixing tool.
Enjoy your decking
Now that you’ve done the hard work, it’s time to ‘dress your deck’. Furniture, plants and lighting can be combined to create a certain style and give your deck the perfect ambience for summer drinks and BBQs. For inspiration, check out our collection of ingenious decking ideas.
If you have any more questions around how to lay decking, whether you’re building with timber or fitting a composite deck, contact Estate Sawmills.
