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.
- Decking boards, softwood, hardwood, or composite depending on your budget and preference
- Joists for the frame or substructure
- Decking screws, specifically designed for outdoor decking use, not general purpose screws
- Weed membrane to lay beneath the deck
- Gravel or hardcore for the base layer
- A spirit level, tape measure, and string line
- A drill or driver, saw, and safety equipment such as gloves and goggles
- Post supports or deck blocks, if not building directly on soil
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 down the line. General purpose screws aren’t designed to handle constant outdoor exposure to moisture, and they can corrode, work loose, or fail to hold boards securely over time.
- Use: Decking specific screws, designed with coatings that resist rust and corrosion from outdoor moisture exposure.
- Avoid: Standard general purpose screws, which often corrode and loosen within a year or two of outdoor exposure.
The right screws cost a little more, but they’re a small expense compared with the cost and hassle of boards lifting or loosening just a season or two after you’ve finished building.
Choosing the Right Fixings and Fittings
Beyond screw type, a few other fixing choices affect how well your deck holds up over time. Stainless steel or coated decking screws are generally worth the extra cost over basic zinc plated options, particularly in a wet climate. If you’re using composite boards, it’s worth checking whether the manufacturer recommends a hidden fixing clip system rather than surface screws, since some composite products are specifically designed for this and can affect the finished appearance significantly.
Joist hangers and brackets, where used, should also be galvanised or otherwise treated for outdoor use, since untreated metal fixings can rust and weaken well before the timber frame itself shows any signs of wear.
Tools Worth Investing In Before You Start
While the core tool list is fairly minimal, a few additional items can make a genuine difference to how smoothly a DIY build goes. A decking specific spacer tool helps maintain a consistent gap between boards far more reliably than eyeballing it with an offcut of wood. A good quality circular saw with a sharp, clean blade will give straighter, cleaner cuts than an older or blunted blade, particularly on hardwood or composite material. A right angle drill attachment can also be genuinely useful for driving screws into tight corners or edge boards where a standard drill doesn’t have enough clearance.
Other Common DIY Deck Mistakes to Avoid
- Not levelling the ground properly first. Skipping this step can lead to an uneven frame that’s difficult to correct once boards are already laid.
- Skipping the weed membrane or gravel base. This affects long term drainage and can lead to weeds growing up through the deck within a season.
- Inconsistent board gaps. Uneven spacing between boards looks messy and can affect drainage across the deck surface.
- Rushing the levelling checks. Small levelling errors early in the build tend to get magnified by the time the boards go down.
- Underestimating board quantities. Running short partway through a build is one of the most frustrating and avoidable DIY mistakes, and it’s worth calculating your board count carefully before ordering.
- Ignoring drainage slope. Even a slight, deliberate slope built into the frame helps water run off rather than pool, which matters just as much on a DIY build as a professionally installed one.
When You Should Hire a Professional Instead
A simple, ground level deck on relatively flat ground is a genuinely reasonable DIY project. However, there’s one situation where we’d strongly recommend calling in a professional rather than tackling it yourself.
Sloped or uneven gardens needing groundwork are where most DIY builds run into serious trouble. Levelling a sloped garden properly often requires retaining structures, significant excavation, or engineered foundations, work that goes well beyond typical DIY tools and experience. Getting this wrong doesn’t just affect appearance, it can lead to drainage problems, an unstable frame, or a deck that sags and shifts within a year or two. If your garden falls into this category, it’s worth looking into retaining wall solutions as part of the wider groundwork plan, since managing the level change properly is often the deciding factor in how long the finished deck actually lasts.
If your garden is reasonably flat, DIY is a solid option. If it’s sloped or uneven, it’s worth getting a professional assessment before starting, even if you plan to handle the rest of the build yourself.
DIY vs Professional Installation: A Realistic Comparison
It’s worth being honest about the trade offs between building a deck yourself and having it professionally installed. A DIY build generally costs less in labour, since you’re only paying for materials, but it demands a genuine time investment across several days, along with a reasonable level of confidence with basic tools and measurements.
A professional installation costs more overall but comes with the benefit of experience across ground conditions, correct joist spacing and fixing choices, and typically some form of workmanship guarantee that a DIY build won’t have. For straightforward, flat gardens with a simple design, DIY remains a genuinely sensible option for confident homeowners. For anything involving a slope, unusual garden shape, multiple levels, or a larger overall footprint, professional installation tends to be the more reliable route to a deck that lasts its full expected lifespan.
Example: A Typical DIY Ground-Level Deck Project
To put the process into context, here’s what a fairly typical DIY ground level deck build looks like for a small to medium garden.
| Detail | Specification |
| Garden type | Flat, ground level garden |
| Deck size | Around 12m² |
| Materials used | Softwood boards, treated joists, decking specific screws |
| Time taken | 4 days (beginner pace) |
| Key success factor | Correct screws used throughout, proper weed membrane and gravel base laid first |
Builds like this tend to go smoothly when the ground is reasonably flat and the builder takes the time to level the frame properly before laying boards. Problems tend to appear later, sometimes six months to a year in, when the wrong screws were used and boards start to loosen or show early signs of rust staining around the fixing points.
Maintaining Your Deck After the Build
Once your deck is finished, the work isn’t quite over. Softwood decking in particular needs yearly staining or sealing to protect it from the weather, and regular seasonal washing helps prevent algae, mould, and dirt building up on the surface. Taking the time to build good maintenance habits from the very start makes a real difference to how long a DIY deck ultimately lasts compared with one that’s built well but then left unmaintained.
Frequently Asked Questions
Can I build my own deck without hiring a professional?
Yes, for a simple, ground level deck on relatively flat ground, DIY is a realistic option for most homeowners with basic tools and some patience.
How long does it take to build a DIY deck?
For a beginner building a ground level deck, expect the project to take around 3 to 4 days, including groundwork, frame building, and laying the boards.
What’s the most common mistake in DIY deck building?
Using the wrong type of screws is the most common issue we see. General purpose screws corrode and loosen with outdoor exposure, unlike decking specific screws designed for that purpose.
Do I need planning permission for a DIY deck?
Most low, ground level decks under 30cm in height and covering less than 50 percent of your garden don’t need planning permission in the UK, but it’s worth checking with your local council if you’re unsure.
When should I hire a professional instead of building my own deck?
If your garden is sloped or uneven and needs significant groundwork, it’s worth hiring a professional, since this type of work often requires equipment and experience beyond typical DIY tools.
What tools do I need to build a deck myself?
You’ll need a drill or driver, saw, spirit level, tape measure, string line, plus decking boards, joists, decking specific screws, weed membrane, and gravel for the base.
Is DIY decking actually cheaper than hiring a professional?
It’s usually cheaper in labour costs, since you’re only paying for materials, but it requires a genuine time commitment and carries more risk of costly mistakes if the groundwork or fixings aren’t done correctly.
How do I know if my garden is flat enough for a DIY deck?
As a general guide, minor unevenness that can be corrected with standard levelling is fine for DIY, but any noticeable slope, retaining requirement, or significant excavation is a sign it’s worth getting a professional assessment first.
Get a Free Quote for Your Decking Project
Get a Free Quote.If your garden isn’t quite flat enough for a straightforward DIY build, or you’d simply rather leave it to the professionals,JPD Landscaping & Building Services offers free quotes across South East London.
