A DIY Garden Deck Installation - Step By Step Guide

Last week I shared a little photo story showing the progress of our DIY garden deck installation – from concrete prison yard to relaxing oasis in six short weeks.

Today I’d like to share some DIY deck-building tips with you all, for the benefit of those of you who are considering attempting this project yourselves! Seriously, it’s not that difficult. You should totally do it.


Factor in the hardware cost (I also gave the same advice for working out a kitchen installation budget). You will need literally hundreds of special outdoor/weather-proof screws. Plus those L-shaped metal thingies for fastening the pieces of the supporting framework together. We ended up spending around £200 just on hardware.

Before you order your decking planks, think about the design. Clearly, the most efficient method is to take plank A, and lay it from left to right. Measure how much is left, and cut plank B to fit. Take the off-cut from plank B, and lay it as row two, from left to right. And so on. This will naturally create a staggered effect.

However, we wanted to create a symmetrical effect, and this made things a little tricky for us.

OK, I should probably fess up here and say that I wanted to create a symmetrical effect. Andre wasn’t bothered. What can I say – as my legendary Grandpa said confidingly to Andre the first time I introduced them to one another: “She’s really fussy, you know”. He’s right. I am. Symmetrical it was. So although deck was 6m x 6m, we had to order more than 36m of decking planks in order to create the right design. Don't worry, we used every one of the off-cuts to make a path at a later stage.

You can see the symmetrical effect in this photo – see how the edges of the planks are all neatly lined up. That is no accident, I can assure you:

So in summary, before you order your wood – find out exactly how long and how wide the planks are. Then measure your space. Then spend an hour or two with paper, pencil, and a calculator, working out your design. 

Figure out exactly how many planks you will need, and order that number from your supplier. Don't just go to your supplier with the square metre measurements, as there is no chance that they will factor an attractive design in when they work out how much you need.

Oh, and also work out how much wood you need for your base as well.


You will need an electric drill/screwdriver. Don’t even think about attempting this without power tools.
You will also need a workmate (portable work bench), a saw, a counter-sink drill bit, sandpaper, a set square, a tape measure, a spirit level, a wooden hammer, an outdoor extension cable, little plastic wedges, a calculator, plenty of chocolate (to get your through the headache-inducing afore-mentioned design process) and many, many pencils (as they will mysteriously disappear).

Here is our Tool Tree - it actually worked rather well to keep track of some key items:

Here's the workmate and saw, plus some rather stern concentration:

And here's me proudly blowing on my saw as if it were a smoking six-shooter:

No, really, that's what I'm pretending to do. I'm also wearing about six layers on account of the cold. Just in case you were wondering. And yes, that's Enrique making his move on the off-cut. Man, that dog loves to pick up pieces of wood and carry them around.


We bought a pile of decking planks, and a pile of 2 x 4 inch lengths of wood for the base. Both were pressure-treated, and so were suitable for outdoor use. All our wood came from Atlantic Timber.

Installing the base

I never thought I’d be grateful to whichever previous owners of our Nest decided it would be a really great look to throw a load of concrete slabs on the ground at the back of the house. But when it came to building our deck, it meant that we had a perfect, sturdy base:

Well, not perfect – the concrete slabs were totally wonky. We did initially try to level them out – but decided it would be a lot easier to just trim down the wood pieces that made up the supporting base as required. So some of the wooden pieces stayed as they were, some were trimmed down to a few cm, and some we had to raise by stuffing other pieces of wood underneath them. For every piece, we used a spirit level to ensure it was the correct height:

We also had to ensure that we would have a piece of the base below the sections where we knew (from the design) that the screws would be placed.

Oh, and we had to angle it very slightly so the deck would slope away from the house:

In fact, you won’t be surprised to hear that it was laying the base that took the time – I’d say five weeks out of the six. Some of us were rather tired by the end of the process:

Laying the planks

This part was sooooo easy. We completed it over a single weekend. Cut plank to fit as required. Drill preparatory hole through plank into base. Swap drill bit to counter-sink drill bit. Create little hollow for screw head to sit in. Swap drill bit to screwdriver. Screw screw through hole. Check level with spirit level, and unscrew/tighten slightly as required.

Once you have more than one plank in place, you’ll need to control the distance between the planks. Because our planks were so swollen from all the rain, we only left a 5mm gap (knowing the planks would shrink to the desired 8-10mm gap). We used plastic wedges and upper arm strength to respectively increase/decrease the gap to the desired width. 

The only tricky part was cutting the planks to fit around the trees that would grow up through the side of the deck – we managed this by making paper templates, and tracing onto the planks:

Yep, that's Enrique gnawing on the tree. Classic. Oh, and you can also see the cable that we laid below the deck as we went along in preparation for the garden lighting, which we installed a few months later.

Staining the wood

Use good quality decking oil. After all your hard work, don’t spoil it by splashing some nasty wood stain around. We used Ronseal decking oil in Natural Oak:

You can see some photos of the finished product here.

As a bonus, here's how the garden looks overall now:

Wow, that was a long post. If you’d made it through to the end, congratulations! You now have everything you need to go away and build a deck of your own. Oh, unless you don’t have a concrete base already. In which case you’ll need to ask Google for another base installation method.

Right, time for me to sign off, and start cooking Pasta Inventi. This is a pasta dish that I invented myself one glorious evening when all we had in the house was a tin of chopped tomatoes, a couple of slices of bacon, a clove of garlic, some tired basil, and a little linguine. There you go, I basically gave away the recipe. You have to kind of shrug your shoulders and put on a dramatic Italian accent to really make the most of it – Paaaastaaah Inveeeeentiii!

OK I really hope some of you just said that out loud :-)

Oh, and Happy Thanksgiving to all you lovely US folk!