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If your existing wood deck is looking tired but the idea of a full rebuild feels like overkill, it’s a fair question to ask whether you can simply install composite decking on top of what’s already there. The short answer is yes, this is generally possible, but it comes with an important condition that determines whether it’s the right move for your specific deck. At JPD Landscaping & Building Services, we’ve installed and overlaid decking across South East London for over 15 years. This guide explains exactly when installing composite over existing wood decking works well, what needs checking first, and a real example of how this approach can save both time and money compared with a full rebuild. Can You Overlay Composite Decking on Wood? Yes, composite decking can generally be installed over existing wood decking, as long as the existing structure is sound. The single most important thing to check before going ahead is the condition of the substructure and frame underneath, specifically looking for any rot or damage that could compromise the new decking above it. Condition Can You Overlay? Existing frame is solid, no rot or damage Yes, generally safe to overlay Frame has visible rot or damage No, repair or rebuild the substructure first Frame condition unknown or unchecked Get it inspected before proceeding Why the Substructure Check Matters Most Composite boards themselves are lightweight and durable, but they still rely entirely on the frame underneath for support. If you install new composite boards over a substructure that’s already rotting or weakened, you’re essentially building a nice looking deck on top of a failing foundation. The problem, invisible from above, will continue to worsen underneath your new boards, potentially leading to sagging or structural failure much sooner than the composite decking’s actual lifespan would suggest. This is why checking the substructure isn’t just one item on a checklist, it’s genuinely the deciding factor in whether overlaying is the right choice at all. A sound frame with slightly tired looking old boards on top is an excellent candidate for overlay. A frame with any sign of rot, softness, or damage needs to be addressed first, regardless of how the visible boards look. This is the same underlying principle covered in our guide on decking lifespan, where a weak substructure is consistently the biggest reason decks fail well before their expected years. What to Check Before Installing Composite Over Wood How the Overlay Process Actually Works Once a substructure has passed inspection, the overlay process itself is fairly straightforward, though it’s worth understanding the key stages so you know what to expect. First, the existing worn boards are removed, exposing the bare frame underneath for a proper close up inspection, since some rot or damage only becomes visible once the old decking is stripped back. Any minor repairs identified at this stage, such as replacing an individual damaged joist or adding extra noggins for support, are carried out before anything new goes down. The frame is then checked again for level and drainage, with any adjustments made to fixing points or joist packers where needed. Finally, the new composite boards are fitted directly onto the existing, confirmed sound frame, using fixings and spacing appropriate for the specific composite product being installed. This process is considerably quicker than a full rebuild, since the most time consuming parts of any decking project, digging footings, building a completely new frame, and disposing of a full structure’s worth of old material, are avoided entirely when the existing frame passes inspection. Advantages of Overlaying Composite Over a Full Rebuild The main reason customers choose to overlay composite onto existing wood, rather than opting for a complete rebuild, comes down to speed and disruption. Approach Speed Disruption Best When Overlay composite on existing frame Faster Lower Substructure is sound, boards just look tired Full rebuild Slower Higher Substructure has rot, damage, or design issues Limitations of Overlaying: What It Won’t Fix It’s worth being realistic about what an overlay can and can’t achieve. Overlaying addresses the appearance and surface performance of your decking, but it won’t correct underlying design issues with the original structure. If the existing frame has inadequate drainage slope built in, that same drainage limitation will remain after the overlay, since the frame itself hasn’t changed shape. Similarly, if the original substructure was built with joist spacing suited to a lighter softwood board rather than the composite product you’re installing, this needs to be specifically checked and potentially adjusted rather than assumed to be fine simply because the frame is structurally sound. An overlay is a genuine shortcut when the frame is right, but it isn’t a way to correct a poorly designed structure without addressing that design issue directly first. When You Should Rebuild Instead of Overlay Overlaying isn’t always the right call. If your inspection reveals rot, significant softness, or structural movement in the existing frame, it’s worth rebuilding the substructure properly rather than covering the problem up with new boards on top. Installing composite over a compromised frame doesn’t fix the underlying issue, it just delays when the problem becomes visible again, often at a point where more of the deck needs replacing than if it had been addressed properly from the start. A full rebuild is also generally the better route if you’re planning significant design changes alongside the material upgrade, such as adding steps, altering the deck’s footprint, or changing its height, since these changes typically require frame modifications beyond what a straightforward overlay covers. If your garden also has slope or level change issues feeding into the decking area, it’s worth looking at this alongside anyretaining wall work that might be needed as part of a wider rebuild, rather than trying to overlay around an unresolved groundwork problem. Cost Considerations: Overlay vs Full Rebuild While exact pricing depends on garden size and the specific composite product chosen, it’s useful to understand where the cost savings in an overlay typically come from. A full

If you’re planning a decking project, board width is one of those details that seems minor at first glance but actually affects both the look of your finished deck and how well it performs over time. Different materials come in different standard widths, and the width you choose can influence stability, cost, and even how likely your boards are to warp or cup as they age. At JPD Landscaping & Building Services, we’ve installed softwood, hardwood, and composite decking across South East London for over 15 years. This guide breaks down the standard widths for each material, explains why width matters more than most people expect, and covers when narrower boards make more sense than wider ones. Standard Deck Board Widths Deck board widths vary depending on the material. Softwood and composite boards are typically wider, usually between 140mm and 150mm, while hardwood boards like Balau tend to be narrower, usually between 90mm and 120mm. Decking Material Standard Board Width Softwood 140mm to 150mm Hardwood (e.g. Balau) 90mm to 120mm Composite 140mm to 150mm The main reason for this difference comes down to stability. Narrower hardwood boards are less prone to warping and cupping over time compared with wider boards of the same material. Softwood Deck Board Width Softwood decking boards typically come in widths between 140mm and 150mm. This wider format works well for softwood because the timber is generally lighter and more flexible, meaning wider boards don’t experience the same stability issues that can affect wider hardwood boards over time. Wider softwood boards also mean fewer boards are needed to cover a given area, which can slightly reduce the number of joints and overall installation time. If you’re still deciding on softwood as a material more generally, our full decking cost guide covers pricing across the full range of widths and grades typically available. Hardwood Deck Board Width Hardwood decking boards, such as Balau, are typically narrower, usually between 90mm and 120mm. This is a deliberate choice rather than just a supply convention. Hardwood is denser and naturally more prone to movement as it expands and contracts with temperature and moisture changes. Narrower boards move less overall, which significantly reduces the risk of warping or cupping compared with a wider hardwood board experiencing the same conditions. This is one of the key reasons why hardwood boards are generally sold narrower than softwood or composite, even though the material itself is often considered more durable overall. If you’re weighing up Balau specifically against other timber species, our guide on the best wood for UK decking goes into more detail on why it’s such a popular choice for UK gardens. Composite Deck Board Width Composite decking boards typically match softwood in width, usually falling between 140mm and 150mm. Because composite boards are manufactured rather than cut from natural timber, they don’t experience the same warping and cupping risks that come with real wood, meaning manufacturers can produce them in a wider format without the same stability concerns that apply to hardwood. Some composite manufacturers also offer wider premium boards, sometimes up to 200mm or more, aimed at a bolder, more contemporary look with fewer visible joint lines. Since composite doesn’t carry the same movement risk as timber, choosing a wider board is largely a style decision rather than a stability trade-off, which isn’t the case with hardwood. Why Does Board Width Matter? Board width isn’t just a cosmetic choice. In our experience, the single biggest reason it matters is stability. This is exactly why you’ll often see hardwood sold in narrower widths than softwood or composite, even though hardwood is generally considered the more premium, durable material overall. The Science Behind Timber Movement and Board Width It helps to understand exactly why width and warping are so closely linked in natural timber. Wood is a hygroscopic material, meaning it constantly absorbs and releases moisture from the surrounding air, expanding slightly as it takes on moisture and contracting as it dries out. This movement isn’t uniform across a board though, since the outer face exposed to sun and rain dries and wets at a different rate than the underside sitting closer to the substructure. On a wider board, this uneven moisture exchange across the width creates more pronounced internal stress, which is what causes the board to cup or bow over time. A narrower board experiences the same uneven exposure, but because there’s simply less material width for the stress to act across, the resulting movement is far less visible and far less likely to develop into a noticeable structural issue. Comparing Board Widths Across Materials Factor Softwood (140 to 150mm) Hardwood (90 to 120mm) Composite (140 to 150mm) Stability over time Good Very good, narrower reduces movement Very good, manufactured, doesn’t warp Visual style Modern, fewer joints Traditional, more joint lines Modern, fewer joints Boards needed per m² Fewer More Fewer Risk of warping or cupping Moderate Low, due to narrower width Very low Does Board Width Affect Cost? Board width does have a small knock on effect on cost, mainly through the number of boards required to cover a given area. Wider boards, like softwood or composite at 140mm to 150mm, cover more area per board, meaning fewer boards and slightly less installation time for a given deck size. Narrower hardwood boards, at 90mm to 120mm, require more boards to cover the same area, which can add a small amount to both material count and installation time, though this is a minor factor compared with the material cost difference itself. This is worth factoring into your board quantity planning if you’re calculating your own order, since the standard coverage per board figure used in most decking calculators assumes a specific width, and swapping between a narrow hardwood board and a wider softwood or composite board will noticeably change your total board count for the same deck area. Board Width and Visual Style Beyond stability, width has a genuine impact on how a finished deck looks. Wider boards create

Choosing the right wood for your deck matters more in the UK than in many other climates. Between the constant rain, damp winters, and unpredictable temperature swings, some timber species simply hold up better than others over the years. Get the choice right, and your deck can last decades with minimal fuss. Get it wrong, and you could be repairing or replacing boards within a handful of years. At JPD Landscaping & Building Services, we’ve installed decking across South East London for over 15 years, working extensively with both softwood and hardwood species. This guide breaks down the best wood options for UK decking, why one hardwood species stands out above the rest, and how to choose based on your own budget and priorities. Best Wood for UK Decking For most UK gardens, Balau is the best overall choice for decking wood. It combines strong natural weather resistance, a long lifespan without heavy maintenance, and noticeably better value than premium hardwoods like Ipe, making it a smart middle ground option for homeowners who want durability without the highest possible price tag. Wood Type Best For Typical Lifespan Balau (hardwood) Best all round choice for UK weather and value 25 to 30+ years Pressure treated redwood or pine (softwood) Budget friendly projects 15 to 20 years Ipe (premium hardwood) Maximum longevity, higher budget 25 to 30+ years Why Balau Is the Best Wood for UK Decking Balau is a dense tropical hardwood that has become one of the most popular decking choices for UK gardens, and for good reason. It combines three things that matter most in a wet, temperature varying climate like ours. In our experience, these three factors together are exactly why Balau tends to be the recommendation we come back to most often for customers who want a genuinely long lasting deck without paying top tier premium hardwood prices. What Is Balau, Exactly? Balau, sometimes labelled Bangkirai depending on the supplier, is a hardwood species native to South East Asia, prized in construction and decking for its density, natural oil content, and tight grain structure. That natural oil content is part of what gives Balau its strong resistance to moisture and rot without needing chemical treatment, unlike softer, more porous softwood species that rely entirely on applied stains and sealants for protection. Freshly installed Balau typically has a warm, reddish brown tone, which gradually weathers to a soft silvery grey if left untreated, similar to other hardwoods. This weathering process doesn’t affect the wood’s structural integrity, and many homeowners find the aged grey tone just as attractive as the original colour, which is part of why Balau needs so little ongoing maintenance compared with softwood. Best Softwood Option: Pressure-Treated Redwood or Pine If budget is the primary concern, pressure treated redwood or pine remains the best softwood option for UK decking. It’s significantly cheaper than any hardwood option upfront, and when properly maintained with yearly staining or sealing, it typically lasts 15 to 20 years. The trade off is ongoing maintenance. Softwood needs that yearly treatment to protect against the UK’s wet climate, and skipping it can shorten its lifespan considerably. For homeowners happy to commit to that yearly upkeep, pressure treated softwood is a genuinely sensible, budget conscious choice. If you’re weighing softwood against Balau on cost specifically, our detailed decking cost guide breaks down real project pricing for both options side by side. Full Wood Comparison for UK Decking Factor Balau Pressure-Treated Softwood Ipe Upfront cost Mid range Lowest Highest Weather resistance Strong Moderate Very strong Maintenance required Low High (yearly treatment) Low Typical lifespan 25 to 30+ years 15 to 20 years 25 to 30+ years Best for Most UK gardens seeking durability and value Budget conscious projects Maximum longevity, higher budget Ipe is worth mentioning as the true premium option, offering excellent durability similar to Balau, but at a noticeably higher price point. For most homeowners, Balau delivers very similar long term performance without the extra cost, which is why it tends to be our default recommendation. Other Timber Species Worth Knowing About While Balau, pressure treated softwood, and Ipe cover the vast majority of decking projects we complete, a few other species come up occasionally and are worth a brief mention. For the overwhelming majority of UK garden projects, the decision really does come down to the three options covered in detail above, with Balau sitting as the strongest all round choice. What Makes a Good Decking Wood for UK Weather? When we’re advising customers on wood choice, a few specific factors matter more in the UK than they might in drier climates. How Wood Choice Affects Long-Term Maintenance Choosing the right wood doesn’t just affect how long your deck lasts, it directly shapes the ongoing workload you’re signing up for. Softwood demands a genuine yearly commitment to staining or sealing, and skipping even one season can allow moisture to penetrate the grain, accelerating greying, splitting, and warping well ahead of schedule. Balau and Ipe, by contrast, need little more than an occasional wash with mild soap and water to stay in good condition, since their natural density and oil content do most of the protective work that a softwood stain would otherwise need to provide artificially. This is a major reason why many customers who’ve previously owned a softwood deck switch to a hardwood species on their next project, having grown tired of the yearly maintenance routine. How Wood Choice Affects Installation The timber you choose can also have a small but real impact on the installation process itself. Hardwoods like Balau and Ipe are considerably denser than softwood, which means they typically require pre drilling before screwing to avoid splitting the board, along with more robust cutting tools capable of handling the density without excessive blade wear. Softwood is generally quicker and easier to cut and fix, which can make it a marginally faster material to install, though the difference in installation time across a full project is usually fairly

If you’re considering composite decking, particularly for a UK garden that sees plenty of rain, it’s a fair question to ask before you commit. The honest answer is yes, composite decking can get noticeably slippery when wet, especially cheaper boards with a smooth finish. That said, it’s worth understanding the full picture, including how it actually compares to timber, before ruling composite out. At JPD Landscaping & Building Services, we’ve installed composite, softwood, and hardwood decking across South East London for over 15 years. This guide explains exactly when and why composite decking gets slippery, how it stacks up against timber in wet weather, and the simple choices that reduce the risk significantly. Is Composite Decking Slippery When Wet? Yes, composite decking can become slippery when wet, particularly cheaper boards with a smooth surface finish. However, in our experience, timber decking is actually noticeably worse than composite when wet, since rain soaked wood grain tends to become slicker and less predictable underfoot than a properly textured composite board. Decking Type Slip Risk When Wet Cheap or smooth composite Higher Textured or grooved composite Lower Softwood Higher than textured composite Hardwood Higher than textured composite, varies by finish The key factor isn’t really composite versus timber as a blanket comparison. It comes down to the specific board finish, and whether it’s been chosen and maintained with grip in mind. Why Does Composite Decking Get Slippery When Wet? Composite decking is made from a mix of wood fibres and recycled plastic, often finished with a smooth protective capping layer. This capping layer is great for resisting moisture damage and fading, but on cheaper boards, a smooth, flat surface finish offers very little texture for water to disperse through, which is what causes the slippery feeling underfoot in wet conditions. It’s worth understanding what’s actually happening at a surface level here too. Water forms a thin film across any flat, non porous surface, and without texture to channel that film away or break it up, the contact point between a shoe sole and the board becomes far more frictionless. This is essentially the same principle behind why smooth bathroom tiles feel more dangerous when wet than a textured stone floor, and it applies just as directly to decking. Composite vs Timber: Which Is More Slippery When Wet? This is where composite decking often gets an unfair reputation. In our direct experience installing and maintaining both material types, timber decking is generally more slippery than composite when wet, not less. Rain soaked timber, particularly softwood, tends to develop a slick surface as water sits on top of the wood grain, especially once the boards have started to grey or the original finish has worn down. Composite, even at its worst with a cheap smooth board, still tends to offer a more predictable, consistent surface underfoot than wet, ageing timber. Factor Composite Decking Timber Decking Surface consistency when wet Predictable, depends on board finish Less predictable, worsens with age Algae or moss growth Slower to build up Faster to build up, especially untreated Grip when new Good, if textured finish chosen Good initially, decreases as finish wears Grip after several years Stays fairly consistent Often decreases noticeably If you’re weighing up composite against timber more broadly, our guides on composite decking costs and decking lifespan by material are useful companion reads, since grip is only one part of the wider comparison between these decking types. Understanding Slip Ratings and What They Actually Mean Many composite decking manufacturers now publish a slip resistance or pendulum test rating for their boards, often expressed as a coefficient of friction or a simple wet and dry grip classification. While these ratings are a useful starting point for comparing products, it’s worth knowing they’re typically measured under controlled laboratory conditions, which don’t always reflect exactly how a board performs once it’s been outdoors for a few years and exposed to weathering, algae, or general wear. As a practical rule, boards marketed specifically for wet weather or high traffic use, rather than a generic residential range, tend to have been tested and designed with genuine grip performance in mind, rather than grip being an afterthought behind appearance and colour options. How to Reduce Slip Risk on Composite Decking The good news is that slip risk on composite decking is largely avoidable with the right choices upfront and a bit of ongoing care. In our experience, choosing the right textured board upfront solves the vast majority of slip concerns before they even become an issue, making it a far more effective fix than trying to correct a smooth, slippery deck after installation. Where Slip Risk Tends to Be Highest in a Garden Not every part of a deck carries the same level of risk, and it’s worth being aware of where problems are most likely to develop. Shaded areas beneath overhanging trees, pergolas, or the shadow line of the house itself tend to stay damp for longer after rain, giving algae and grime more opportunity to establish. North facing sections of a garden, which receive less direct sunlight throughout the year, follow a similar pattern. Areas near water features, hot tubs, or outdoor kitchens also see more frequent splashing and standing water, independent of rainfall, which can accelerate both algae growth and general surface wear. Steps and transition points between different deck levels are worth particular attention too, since these are naturally higher risk areas regardless of decking material, simply due to the change in level and the tendency for water to run toward and pool at the base of each step. Additional Grip Solutions Beyond Board Choice For gardens where extra grip is a priority, whether due to young children, elderly family members, or a particularly exposed, shaded garden layout, a few additional measures can help beyond board selection alone. Case Study: Fixing a Slip Issue With Textured Composite Boards We were called out to a garden in South East London where the homeowner had a smooth finish composite deck

Building your own deck is a genuinely achievable weekend project for a lot of gardens, particularly if you’re working with a simple, ground level design. With the right tools, the correct materials, and a bit of patience, most confident DIYers can put together a solid, good looking deck without needing to bring in a professional. At JPD Landscaping & Building Services, we’ve installed decking across South East London for over 15 years, and we’ve also seen plenty of DIY builds up close, both the ones that turned out great and the ones that ran into trouble. This guide walks you through exactly how to build a ground level deck yourself, step by step, along with the mistakes that trip up most first time builders and when it’s worth calling in a professional instead. Can You Build Your Own Deck? Yes, building your own ground level deck is realistic for most homeowners with basic DIY experience. For a beginner, expect the project to take around 3 to 4 days, including groundwork, frame building, and laying the boards. The most common mistake that causes problems later isn’t the build itself, it’s using the wrong type of screws, which can lead to boards lifting, loosening, or rotting prematurely. Project Detail What to Expect Deck type suited to DIY Ground level, low height, minimal foundation Time required (beginner) 3 to 4 days Most common mistake Wrong screw type, causing lifting or rot When to hire a pro instead Sloped or uneven gardens needing groundwork What You’ll Need Before You Start Before you begin, it’s worth gathering everything upfront so you’re not stopping halfway through the project to make a supply run. If you haven’t already worked out your board quantities, it’s worth doing that calculation before you buy anything, since getting the number wrong at this stage is one of the easiest ways to delay a DIY build partway through. Step-by-Step: How to Build a DIY Ground-Level Deck Step 1: Plan and Measure Your Space Start by measuring the exact area where your deck will go, and mark it out clearly using string lines and pegs. Double check your measurements against your decking board calculations before ordering materials, so you’re not left short partway through the build. Take a moment at this stage to also think about the finished board direction relative to your deck’s shape, since this decision affects both material efficiency and the overall look of the finished surface. Step 2: Clear and Level the Ground Remove any turf, plants, or debris from the marked area, then level the ground as best you can. For a ground level deck, the base doesn’t need to be perfectly flat, but any major dips or slopes should be addressed before moving forward. This is also the stage where you’ll notice if your garden is more uneven than expected. Step 3: Lay a Weed Membrane and Gravel Base Roll out a weed membrane across the cleared area to stop weeds growing up through the deck over time. On top of this, add a layer of gravel or hardcore, which helps with drainage and gives the frame a stable base to sit on. This step is easy to rush, but it plays a big part in how well the deck drains over its lifetime, so it’s worth taking the time to get an even, compacted layer across the whole area. Step 4: Build the Frame Construct your frame using pressure treated joists, spaced evenly according to your decking board manufacturer’s recommendations. For a ground level deck, the frame typically sits on deck blocks or paving slabs rather than dug foundation posts, keeping the whole structure simple and low to the ground. Getting joist spacing right at this stage matters more than most first time builders expect, since incorrect spacing is one of the leading causes of a deck feeling bouncy or developing sag well before the boards themselves would naturally wear out. Step 5: Check Everything Is Level Before laying a single board, use a spirit level to check the entire frame is even in all directions. This step matters more than people expect. A frame that’s slightly off level at this stage will show up clearly once boards are laid on top. It’s worth checking multiple points across the frame rather than just the edges, since a frame can appear level at the corners while still having a slight dip or high point somewhere in the middle. Step 6: Lay the Decking Boards Starting from one edge, lay your decking boards across the frame, leaving a small gap, typically around 3mm, between each board for drainage and natural expansion. Fix each board using decking specific screws, not general purpose screws, driving them straight and flush with the board surface. Working methodically from one side to the other, checking your gap spacing every few boards, helps keep the finished surface looking consistent rather than gradually drifting out of alignment. Step 7: Cut and Fit Edge Boards Once you reach the far edge, you’ll likely need to cut the final row of boards to fit. Measure carefully before cutting, and double check your gap allowance so the final board sits neatly against the border. It’s generally worth cutting these edge pieces slightly oversized first and trimming down gradually, rather than cutting to the exact measurement in one go, since this gives you room to correct for any small errors without wasting a full board. Step 8: Finish the Edges Add fascia boards or trim around the visible edges of the deck for a clean, finished look, and to help protect the exposed ends of the frame and boards underneath. This finishing touch also helps disguise the substructure and gives the whole deck a more professional, complete appearance once the project is finished. The Most Common DIY Mistake: Using the Wrong Screws Of everything that can go wrong on a DIY deck build, using the wrong type of screw is the mistake we see cause the most problems

A wood deck can look brand new for years, or it can start greying, growing algae, and feeling slippery within a single season. The difference usually isn’t the wood itself, it’s how regularly and how correctly the deck gets washed. Getting this simple task right is one of the easiest ways to protect your investment and avoid costly repairs down the line. At JPD Landscaping & Building Services, we’ve installed and maintained wood decking across South East London for over 15 years. This guide walks through exactly how to wash a wood deck properly, how often to do it, the mistakes that cause the most damage, and a real example of how consistent washing keeps a deck looking good for years. How to Wash a Wood Deck To wash a wood deck safely, sweep away loose debris first, then clean the surface using warm water and a mild soap or detergent, working with the grain using a soft bristled brush. Rinse thoroughly and allow the deck to fully dry before applying any stain or sealant. We recommend washing your deck once a season, four times a year, to stay ahead of dirt, algae, and mould buildup before it takes hold. Step What to Do 1. Clear debris Sweep away leaves, dirt, and loose material 2. Wet the deck Soak the surface with water before cleaning 3. Apply cleaning solution Warm water with mild soap or detergent 4. Scrub with the grain Use a soft bristled brush, never a wire brush 5. Rinse thoroughly Remove all soap residue completely 6. Let it dry fully Wait at least 24 to 48 hours before sealing or staining Step-by-Step: How to Wash a Wood Deck Properly Step 1: Clear the Deck of Debris Before any water touches the deck, sweep away leaves, dirt, and any loose debris sitting on the surface or trapped between boards. This prevents you from just pushing dirt around, and it stops organic material from staining the wood once it gets wet. Pay particular attention to the narrow gaps between boards, since this is where leaf litter and grit tend to accumulate unnoticed and can trap moisture against the wood over time. Step 2: Wet the Surface Give the entire deck a good soak with clean water before applying any cleaning solution. This helps loosen surface dirt and stops your cleaning solution from being absorbed too quickly into dry wood, which can leave patchy results. A garden hose on a wide spray setting is usually enough for this step, there’s no need for high pressure at this stage. Step 3: Apply a Mild Cleaning Solution For routine cleaning, warm water mixed with a mild soap or detergent is all you need. There’s no need for harsh chemicals for a standard seasonal wash, they’re generally reserved for tougher jobs like removing algae or old stain buildup. Apply the solution evenly across the deck’s surface using a mop, soft brush, or garden sprayer. If you’re dealing with a specific problem area rather than a routine clean, a dedicated decking cleaner formulated for algae or mould can be more effective than a general soap solution, though it’s still worth testing on a small, unobtrusive area first to check it doesn’t affect the wood’s colour. Step 4: Scrub With the Grain This step matters more than most people realise. Always scrub in the direction of the wood grain using a soft bristled brush. A stiff wire brush might feel like it’s working faster, but it actually damages the wood fibres, roughing up the surface and making it more likely to trap dirt and hold moisture in future washes. Scrubbing against the grain, even with a soft brush, can also lift and roughen wood fibres over time, so it’s worth taking the extra moment to work in the same direction as the board’s natural grain pattern rather than in random or circular motions. Step 5: Rinse Thoroughly Once you’ve scrubbed the full deck, rinse it completely with clean water to remove all traces of soap or cleaning solution. Leftover residue can attract dirt faster and interfere with any stain or sealant you apply afterward. Pay close attention to gaps between boards and any corners or edges where suds can collect and take longer to rinse away fully. Step 6: Let the Deck Dry Completely Give your deck at least 24 to 48 hours to dry fully before walking on it heavily or applying any stain or sealant. Sealing over damp wood traps moisture underneath the surface, which can lead to peeling, bubbling, or mould growth later. Drying time can extend beyond 48 hours in cooler, damper weather, so it’s worth checking that boards feel genuinely dry to the touch, not just dry on the surface, before moving on to any staining or sealing work. How Often Should You Wash a Wood Deck? We recommend washing your deck once a season, four times a year, rather than waiting until it visibly looks dirty. Regular seasonal washing keeps algae, mould, and dirt from building up to the point where they start affecting the wood itself, rather than just sitting on the surface. Season Why It Matters Spring Removes winter grime, checks for damage after cold or wet months Summer Clears pollen, dust, and prevents dirt buildup during high use Autumn Clears fallen leaves and organic debris before they trap moisture Winter Reduces algae risk during the wettest, coldest months Sticking to this seasonal rhythm makes each individual wash quicker and easier, since you’re never dealing with months of built up grime in one go. Gardens with more shade or overhanging trees may benefit from an extra wash between these seasonal points, since damp, shaded areas are more prone to algae and slower drying than open, sunnier sections of decking. Should You Pressure Wash a Wood Deck? Pressure washing is safe for wood decking, as long as it’s done correctly. Used properly, with the right pressure setting and nozzle distance, a pressure washer can clean a deck

Getting your decking board calculation right before you order is one of the most important steps in planning a garden project. Order too few, and you’ll end up with a delayed job waiting on a second delivery. Order too many, and you’re paying for materials you’ll never use. Get the layout direction wrong, and you can end up needing far more boards than expected due to extra cuts and waste. At JPD Landscaping & Building Services, we’ve calculated and ordered decking boards for gardens across South East London for over 15 years. This guide walks through exactly how we work out board quantities, including a simple formula you can use yourself, a real worked example, and the most common mistake that trips up DIY calculations. How to Calculate Decking Boards The number of decking boards you need depends on three things: the total area of your deck, the size of the boards you’re using, and the gap left between them for drainage and expansion. As a general guide, most standard decking boards are 150mm wide and 4800mm long, with a 3mm gap left between each board. Using standard sizing, one board covers roughly 0.73 square metres of deck space once the gap is accounted for. To work out roughly how many boards you need, divide your total deck area by 0.73, then add 10 percent extra to cover cuts, waste, and mistakes. Deck Area Boards Needed (Before Waste) Boards to Order (With 10% Waste) 10m² 14 16 15m² 21 24 20m² 28 31 25m² 35 39 30m² 41 46 These figures are a strong starting point for budgeting and ordering, though your exact numbers may shift slightly depending on the layout direction and how much cutting your specific garden shape requires. The Formula: How to Calculate Decking Boards Yourself If you want to work out the number yourself, here’s the simple process we use on every project. Step 1: Measure your deck area. Multiply the length and width of your deck in metres to get the total area in square metres. For example, a 4 metre by 4 metre deck gives you 16 square metres. Step 2: Work out the coverage per board. Using a standard 150mm wide board with a 3mm gap, each board effectively covers 153mm of width. Multiply this by the board length (4800mm, or 4.8 metres) to get the coverage area per board: 4.8m × 0.153m = 0.7344 square metres per board Step 3: Divide your total area by the coverage per board. Total deck area divided by 0.7344 gives you the number of boards needed before waste. Step 4: Add 10 percent for waste and cuts. Multiply your board count by 1.1 to account for offcuts, mistakes, and boards used at awkward edges or corners. This formula gives you a reliable estimate for straightforward, rectangular decks. More complex shapes, with curves, steps, or multiple levels, will need a bit more allowance, which we’ll cover further down. Worked Example: Calculating Boards for a 16m² Deck Let’s put the formula into practice using a 4 metre by 4 metre deck, which comes to 16 square metres, a common size for a medium garden. Step Calculation Result Deck area 4m × 4m 16m² Coverage per board 4.8m × 0.153m 0.7344m² Boards needed (before waste) 16 ÷ 0.7344 21.79, round up to 22 Boards to order (with 10% waste) 22 × 1.1 24.2, round up to 25 So for a 16 square metre deck using standard 150mm by 4800mm boards, you’d want to order around 25 boards to comfortably cover the area, account for cuts, and avoid running short partway through the job. What Affects How Many Boards You Actually Need The formula above gives you a solid baseline, but a few real world factors can shift the final number. The Most Common Mistake: Wrong Board Direction In our experience, the biggest cause of over ordering, or running short, isn’t a maths error. It’s laying boards in the wrong direction relative to the deck’s shape and dimensions. Boards are most efficient when they run the length of your longest dimension, minimising the number of joins needed. When boards are laid the other way, running across the shorter dimension instead, you often end up needing more boards overall, along with significantly more offcuts and joins, simply because the board length doesn’t match up as cleanly with the space. Getting this decision right before ordering can make a noticeable difference to both your final board count and your overall project cost. Why Board Direction Matters More Than Most People Expect It’s worth explaining why this happens, since it isn’t always obvious at first glance. Every time a board doesn’t reach the full length of a run, it needs to be cut and joined with another piece. Each of these joins uses up material that could otherwise have covered new area, and depending on the layout, that join often needs to land over a supporting joist for a solid fixing point, which limits exactly where it can go. When boards run the wrong way relative to the deck’s dimensions, you end up with far more of these joins across the whole structure, each one consuming extra material and adding installation time. On a small deck this might only mean a few extra boards, but on a larger or more irregular garden, the difference can add up to a genuinely significant chunk of your total material cost. Calculating Boards for Non-Rectangular or Complex Decks Not every garden is a simple rectangle, and the calculation above needs a bit of adjustment for more complex layouts. Steps and Additional Features: Calculating Separately Steps, built in seating, and raised sections all need their own board calculation, separate from the main deck area, since they’re rarely a simple continuation of the main surface. As a rough guide, each standard step typically uses one to two full boards for the tread itself, depending on step width, plus additional material for the riser if it’s also being finished