DIY How To Build Decking With Scaffold Boards

After months and months, I’m finally sharing our DIY Scaffold Board Decking. Yep, it’s been a while and I’ve had quite a few questions about when this post was coming – sorry, I’ve been such a bad blogger recently! We actually started building this at the end of summer last year (yikes!) and finished it up earlier in Spring this year. But then with travel and other commitments, it’s taken me quite a while to get this post properly written.

So as I say, I’ve had lots of questions about how we built our scaffold board decking, so I thought it was about time I wrote this DIY down!

As a quick reminder, here’s what we were dealing with pre-decking, this time last year.

#GardenGoals right? We had sloped paving slabs in front of the conservatory, then a large L-shaped area of concrete and a small section of soil in front of that – It was basically a mishmash of everything and anything. Needless to say, it didn’t look very appealing. The step into the kitchen (through the french doors) was also a little over 1ft high which our eldest dog was struggling to use. And on top of that, there’s a drain cover right beneath the door, which meant we couldn’t build a step there.

The step issue, in particular, is one of the main reasons decking appealed to me, as it meant we could easily raise the deck up to provide an almost seamless transition between the inside floor and outside floor. And not to mention, it would hide the unsightly drain cover too, but still, give us access in the future. I also quite like decking for its modern look and I also planned to use the space underneath the decking as storage too. You guys know I’m all about that storage space! It seemed like a win-win, so we went ahead with it.

Why Scaffold Boards?

So why scaffold boards over normal decking boards, you ask? Well, cost played the most important role here. With value decking boards costing upwards of £5 for a 2.4m length, my calculations led to me to believe we’d be spending considerable 3-figures on the amount we would need. Used scaffold boards are much cheaper priced per meter, and they’re much wider too which would mean we would need fewer boards. They’re also much thicker, which meant we could get away with using less wood within the frame. And less wood all round means less money. Plus, I really liked the look of them!

So if you’re interested in finding out how it’s all built and how much it cost, then here’s all in the info you need.

Step 1 – Prepare the Area

There are two main types of decking, one that sits straight onto the ground, the other is raised. Depending on how high you want your decking to be, and whether the ground is sloped or not, will usually depend on which route you take. The easier option is building it straight onto the ground, and for this, you would need to level the ground first.

We’re building ours as a mixture of both – slightly raised at the front, but sat onto the ground at the back (ever awkward here). This meant we needed to remove the sloping slabs near the conservatory and shift some sand/rubble beneath it so that the ground would be lowered enough, to provide a seamless step from the conservatory onto the decking, rather than a step-up.

Step 2 – Laying Landscaping Fabric

If you’re building decking on top of soil or cracked concrete where existing weeds grow (or may grow in the future), you’ll want to lay some heavy-duty landscaping fabric down over the top. If you miss this step, you’ll more than likely end up with weeds growing up in-between the gaps between boards in your decking. Weeds will take any tiny amount of light and start growth, so despite the fact you *think* light will be blocked out with decking alone, it may not be. We use this heavy-duty landscaping fabric which is much more durable to excessive wear and shouldn’t break up over time, unlike normal weed fabric.

This will completely block out light, but it’s still permeable for any rain or water to go through, so don’t worry it won’t end up like a swamp under there!

Step 3 – Creating the Frame 

It’s really important to always use treated timber when working with any wood outside. Standard softwood timber will rot and weather very badly in a very short space of time, where-as treated timber has been specially treated for outdoor wear. So despite Scaffold boards not usually being treated (we’ll get to that later!), we are using treated wood for the frame. All our wood has been purchased from Wickes, which is our go-to for most building supplies.

To create the frame you want to start by making the outer shape, usually a square or rectangle to suit the shape of your decking. Ours will actually be an L-shape decking, but we’re making it into two separate rectangles that join together. This just makes the whole thing a bit more manageable to move around.

For every piece of timber we cut, we also treated the cut ends with a wood treatment. Whilst the wood is already treated, any cuts you make won’t be, so to improve longevity and make sure those areas don’t rot, it’s best to treat them as you work. I simply dunk it into this wood treatment a few times, which I already had spare, and the wood will soak it right up. But any ‘End Grain Preservative’ will do.

We then used coach screws to secure the lengths of timber together, simply screwing through one piece of timber into the other, to create the rectangular outer frame. We always use a set-square when fixing screws to make sure the whole frame is square and isn’t going off at a wonky angle. Of course, if you’re not building a square (maybe a crazy hexagon?!) then you probably won’t need this.

Once the square/rectangle is built, you can then go in and add extra lengths of wood going either vertically or horizontally, depending on which way you want your scaffold boards to lay (they will always go the opposite way to the joists beneath).

Ideally, you should space them evenly apart, but in our case, we’ve had to work around a drain cover (so we can still access it in the future) which meant they weren’t quite that even. The more lengths of wood you use, the stronger the frame will be. We’ve gone for the bare minimum here to save on £££, however, scaffold boards are much thicker, so they need less support anyway. Normal decking boards would certainly need more than this.

Once those timbers have been attached in the same way, you can then add some cross timbers. Again, this is all just for additional support and to make it as secure as possible against the whole frame twisting or moving in any way.

To affix both rectangular frames together (remember I said we’re building an L-shape made up of two rectangular parts?) we simply adjoined them side by side with several screws to hold in place.

How We Added Under-Decking Storage
Ok, so I mentioned we planned on having some storage space underneath our decking at the beginning – specifically, we wanted space to store our large ladders. Since we don’t have a shed or garage, we’ve had them just hanging around the garden for the last 3 years, which is kind-of unsightly and not to mention, not so great for home-security either.

So the way we’ve done this is by having a ‘break’ in the frame of the decking, as it were, in which we can slot the ladders into. Kinda hard to explain, but just like this.

This gappy section in the middle which is missing cross-timbers is where we plan on laying the ladders down. We’ll then have a clever open/closing door at the front of the decking in order for them to slide in and out, so it means we don’t have to go lifting up every single scaffold board every time we want to use them (which won’t be very often anyway, but y’know!). Here’s an example of how they will fit in..

Of course, you could adapt this idea for a much smaller area and use it to store garden chairs, garden tools, other random bits and bobs too – which I kind of wish we’d added a separate space to do too.

It’s worth remembering though, that this big void with no cross-timbers is more likely to twist and move until the scaffold boards have been laid on top, so we did have to be extra careful until it was finished. We’re confident the whole thing has been built strong enough though to not need cross-timbers here and luckily since scaffold boards are so thick and strong on their own – we can get away with fewer cross-timbers anyway. Again – another good reason for picking scaffold boards!

Step 4 – Levelling the Frame

We actually simultaneously merged this step into the one above, but writing that as one giant step felt a bit too much. So I’ve separated it just for the purpose of being easier to read/understand, but you’ll actually need to do this as the frame is being built.

Building the frame is one thing, but getting it level is another. If you’re building the frame straight onto the ground, then you can simply level the ground out, add gravel or compacted rubble underneath and build away. If it’s a raised deck and you’re building on top of soil, you will need to use wooden pillars submerged into the ground and concreted in place (think like a fence post!), which you can then fix the frame onto. If you’re not sure what I mean or want to see how that’s done, I recommend checking out this video.

Or, if you’re building on top of concrete (like us) then you can use concrete padstones to simply ‘prop’ the frame up. You can buy these and then mortar them onto the concrete beneath, but because we’re on a budget, we’re improvising with very thick paving slabs, which we’re re-using from the floor in front of the conservatory.

The way we’ve done this is to simply stack the paving slabs up and sit the decking frame onto it. Our concrete ground is on a slight slope, so at the back (near the conservatory) we’ve been able to just rest the frame onto the floor, and then we’ve slowly propped it up more and more towards the front of the decking.

Of course, it takes a lot of going back and forth to get it right and it is a bit fiddly, but we got there in the end. We’ve made sure to provide as much support to every joist and timber as possible, so there are no large areas without any paving slab support underneath. It’s extra important to particularly support the corners of the frame and where the Timbers have been joined together.

In some areas, we’ve propped just one paving slab underneath the frame, in other areas two or three were required. And if there was still a few mm wriggle room, then we’ve added several plastic levelling shims wedged in-between the paving slabs to sort this out. In an ideal world, we would have mortared the slabs into place, but since we’re on a reaaaaallly tight budget, we decided to save our ££ and risk it for a biscuit. You want to make sure it’s solid though, there should be no wobble or movement what-so-ever – we’re fairly confident ours won’t be budging any time soon!

We’re one year in having finished this project now and we’ve have had no problems so far! And as I mentioned, we’ve provided a lot of support under the frame all over. The more support, the longer your decking will last and the fewer problems you will have.

Step 5 – Sourcing Scaffold Boards

One of the most asked questions I get about this decking is, ‘where did you get your scaffold boards from?!”. Well, luckily you can find them online on most secondhand sites, and I found mine via Facebook Marketplace.

When scaffold boards are used for scaffolding purposes, they actually come with a relatively short lifespan. Any kind of defect will void their use and they’ll be swapped out for new ones. The UK is keen on health and safety, so this makes perfect sense, but it also means there are a lot of old unused expired scaffold boards out there which can no longer be used. These secondhand boards are therefore relatively cheap to buy since they can’t be used for scaffolding and they make the perfect budget-friendly option for decking.

So ours were just £7 for one individual 13ft board. We bought a total of 20 and due to their crazy long nature, we had to take a saw to cut them all down to be able to fit into our car. Yep, we’re crazy people. It took two trips and embarrassingly, we had to cut them down in a public car park. The things you do to save money eh?!

Obviously, these are used boards, which means they do come with a used look. Some are slightly split at the end, some have saw marks in them, some even had tea stained rings, one even had a lovely splash of red paint on it. Personally, I love it! But it might not be for everyone.

If you don’t like the used look, you can also buy new boards for more money and you can also buy new-but-defected boards, which are still not suitable for scaffolding purposes but cost a little less than new ones. If you’re struggling to find anything online near you, I would perhaps try reaching out to scaffolding companies to see if they have any expired stock they’re willing to sell on.

Step 6 – Treating Scaffold Boards

Whilst scaffold boards are indeed used externally for scaffolding, they’re not always actually treated for external use. In fact, they’re usually made from a very inexpensive whitewood which won’t last the test of time outdoors. Unless you’re certain they’re treated (and yes, you can buy treated scaffold boards!), in order to use them outside long-term, you will need to treat them. And if you don’t and they’re not treated, well don’t expect them to hold up for nearly as long as decking would.

So, in order to treat the scaffold boards, I used a Wood Treatment. Specifically, the same No-Nonsense one from Screwfix, which I used on all the cut ends too. It’s not too expensive considering you get 5L worth and we’ve used it on other external wood in the past, which has so far held up really well.

The treatment is a clear liquid which doesn’t seem too dis-similar from water, except for the ponging smell that is. I applied it with a brush to all four sides of the scaffold boards, making sure to wear a suitable mask (don’t breathe in those fumes!) and I did a minimum of 2 coats, with the top of the board having 3. You should be able to see water repellency working after you’ve finished. I actually needed two tins to do the whole of our decking, which worked out more than I had planned (eurgh!) so worth bearing in mind when you do your costings.

Step 7 – Laying and Fitting the Scaffold Planks

Several hours of wood-treating later, the boards were ready to lay. I had already planned the exact length of cuts we would need and how many of them we would need so that when we crazily cut the boards in the car park, we would be prepared to have as minimal wastage as possible. Ever forward-thinking!

To fit them, we simply used long decking screws and screwed them down into every joist/timber available. We had to make some tricky cuts around the wall/gutter etc, which we used a jigsaw for, but other than that it was relatively straightforward and they went down within a matter of minutes.

Step 8 – Applying a Finishing Decking Oil

Finally, for extra protection, I then added a finishing oil to the top of the boards as well. Not only will this provide extra protection, but it will also provide visual protection – which means I’ll be able to see when it needs a top-up of oil. I used Cuprinol’s Total Deck, which I had already had a tin of, although I did have to buy extra as well. Although it was fairly priced, it turned out fairly orange. Can’t say I love it visually, but it has so far done a good job of treating the boards.

A few people have asked whether I sanded boards as well – and the answer is no, I didn’t. I was worried that if I did sand the boards, they would have become very slippy in the wet and frosty months, which I really didn’t want. These boards weren’t too rough anyway and we’ve certainly had no problems with splinters (and yes I do walk on it bare-footed!) so I personally wouldn’t bother, unless you think it needs it.

Step 9 – Adding a Hinged Door

You’re probably wondering how I’m going to access the ladders beneath the decking? Well, I’m adding a hinged door on the front, which will lift up and allow me to slide the ladders in and out. To do this, I simply added flush hinges and drilled a small hole into the board to act as a handle. Nothing more, nothing less. It simple and it works.

Step 10 – Finishing Touches

To finish off, I’ve added a little flower bed in front of the decking, with a little step in-line with the french doors. The step is again made from scaffold boards and I’ve set it on top of gravel so that it’s not in direct contact with the wet ground.

I think the flower bed provides a softer transition between the decking and the grass and I’ve re-used some old Victorian edging tiles and some black bricks to do this. They’re simply just wedged neatly into the ground, which is how I originally found them when we moved in. And then I’ve planted some French Lavender for a bit of colour.

I’ve also added a built-in Belfast sink, which is fully functioning with all the waste plumbing hidden beneath the decking. We plan on using this to wash the dogs, clean stuff we don’t want to clean in the kitchen sink (you know what I mean!) and even perhaps provide a little ‘potting area’. I might do a separate post on this, but I definitely recommend if your garden is a working-style kinda garden.

Step 11 – Enjoy!

And that’s it, you can now enjoy your lovely new scaffold decking. You will need to visually check for any signs of wear that suggest you need to reapply the treatment in order to keep it all in good condition and free from degrading – But generally speaking, this is standard for most outdoor wood anyway. Here’s a finished look at how it all turned out!

So that’s it! I know no-one likes a bragger, but it looks good right?! I’m personally really pleased we went for scaffold boards. I love the rustic finish and my bank account is also thanking me for it. Well kinda, it was still fairly pricey – but maybe I’m just a tad unrealistic with my hopes?

What do you think of our scaffold decking? Is it a material you would use in your garden?!

Total Costs:

(rounded to the nearest pound)

New Tools Purchased:
None

Materials Used:
Scaffold Boards (20 total) – £140
Treated Timber for Frame (15 total) – £104
Landscaping Fabric – £20
Coach Screws – £7
Decking Screws – £12
Wood Treatment x2 – £50
Decking Oil – £30
Hinges – £2
Plastic Shims – Free from previous jobs
Paving Slabs for levelling – Free, Re-used from the garden

Total: £365
(our decking is approx 15m squared to put this figure into perspective if you’re looking to do similar!)

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