Knowing how to lay decking can be a significant life skill to have. You can gain an understanding of how it can work in your space, how to maintain it over time, and many other benefits.
A well built decking area can completely overhaul the usability and appeal of any garden or landscape. But only if it is done correctly.
At The Builders Supply Company, we work with tradespeople and homeowners across the UK, helping them source the building materials they need for projects like decking. We know a thing or two when it comes to using the right materials, and getting it installed, all of which we will cover in this guide.
Preparing For Your Decking
Take the time to assess your space. Is the ground level, sloped, or already paved? Does the area get a lot of sun, or will you need to account for tree cover or drainage?
Always mark out your planned decking area using stakes and builder’s line, then clear the ground of turf, plants, and debris.
If you’re building decking on soil, you will likely need weed control fabric followed by a gravel layer for stability.
Concrete pads or footings may be necessary for added support, especially for larger or raised structures.
Check the ground is level, or adjust with a compacted sub-base where needed.
Choosing Your Decking
You have the choice between timber decking, or composite decking, both of which are great in their own ways and should be chosen depending on your circumstances.
Timber decking offers a natural look and is often easier to cut and shape for custom layouts. It does require regular upkeep to prevent rot or discolouration, but it remains a popular choice for most gardens.
Composite decking is made from a mix of wood fibres and plastic. It's designed to resist moisture, staining, and fading, making it a more low-maintenance option. Composite is better for those who want a modern finish with minimal ongoing care.
You then just need to find a finish that suits you and the correct sizing/amount.
How Much Does Decking Cost?
The cost of decking comes down to project size, materials, and installation. On average, you can expect prices as the following:
Softwood timber decking is typically the most affordable option. It’s good for smaller or more budget conscious builds. Expect to pay around £90 per m² for small decks (up to 15m²), dropping to £70 per m² for larger areas (30–60m²), with total project costs ranging between £1,350 and £4,200.
Hardwood decking is a much more durable and premium finish. Prices typically range from £130 per m² for small decks to £110 per m² for larger decks, meaning a total cost between £1,950 and £6,600.
Then you have costs like joists, screws, weed membrane, fixings and your landscaping supplies.
How Much Is Composite Decking?
Composite decking is fairly similar to softwood and hardwood pricing, but it can be more economical in the long term due to its low maintenance. It usually costs £110 per m² for smaller areas, reducing to £90 per m² for larger spaces, with project totals from £1,650 to £5,400.
How to Build A Deck Foundation/Frame
A foundation/frame forms the structural base for your decking and needs to be solid and level.
Use treated timber or composite joists to build a perimeter frame. For timber, treat all cut ends with end-grain preservative. Inner joists should be spaced according to the type of boards you’re laying, typically 400mm apart for composite, or slightly closer for timber.
Secure the joists with coach screws or angle brackets. If you’re raising the frame off the ground, ensure posts are concreted into place at regular intervals.
Check regularly with a spirit level as you go; small inaccuracies at this stage will affect the whole deck.
How to Lay Timber and Composite Decking Boards
Start by laying your first board flush with the frame, perpendicular to the joists. Keep a gap of 5–8mm between timber boards (or follow manufacturer guidelines for composite). This is for expansion and drainage.
Timber boards are usually fixed with two screws per joist. Pre-drill holes to avoid splitting. For composite boards, T-clips or hidden fasteners are generally used, which also help maintain uniform spacing.
Stagger board joins and maintain consistency for a cleaner finish. Take your time - laying boards is where the finished quality of your deck really shows.
How to Clean Decking
Timber decking should be swept regularly and washed with warm, soapy water to remove dirt and algae.
Annual treatment with decking oil or wood stain is recommended to protect the wood and maintain its appearance.
Composite decking is easier to maintain. A standard hose down and occasional scrub with a soft brush is usually enough. Avoid harsh chemicals or pressure washers - these can damage the surface or strip finishes. A specialist composite cleaner can be used for stubborn stains.
Keeping your decking clean not only keeps it looking great but also prevents it from becoming slippery in wet conditions.
Moving Forward With Your Decking
Building your own deck is a rewarding project that adds a lot of value to your outdoor space and skillset. It could be a small timber platform or a full-scale composite decking. With plenty of preparation, the right materials, and proper installation, you can achieve exactly what you’re looking for.
The Builders Supply Company can help with all the material sourcing like boards, spindles, newel posts, handrails, sleepers and more. We have it all.