James BeattieHow to lay a recycled concrete path

When it comes to landscaping, costs can often quickly spiral out of control. By the time hard landscape elements like paving, retaining walls and fencing are built, figures can run into the thousands well before the first plant goes in the ground. I’ve had a lacklustre front yard for almost three years now, and despite previous attempt to spruce it up a bit, one thing continued to stymie my efforts – a distinct lack of time.

Our rubbish front garden

Our lacklustre front garden

Working as a researcher for ABC’s Gardening Australia is a great job, but seeing and writing about some the country’s most beautiful gardens leaves you precious little time to make your own garden shine! I’ve been on holiday from work for the last week and half and it’s the first large block of time I’ve had off work for several years, so I’ve been busy building the front garden I’ve always wanted. To save money I’ve been reusing old concrete paths as crazy paving, and the front garden is now starting to take shape.

The inspiration to reuse the smashed up concrete came from numerous sources. Catherine’s gorgeous recycled concrete terracing was one, and after pulling up half of the concrete pathway earlier this year, the sheer amount of it I had left over was another. The solution hit me one day about a month ago, and since the idea took shape in my head I’ve been champing at the bit to get stuck into it. Here is how I built a cheap and (hopefully) beautiful flexible paving system out of old concrete.

Line of pathThe first step is obviously to remove the existing pathway – to make this process easier, lever up sections of the concrete, wedge something under it then tap it with a sledgehammer. When you’re breaking it up be mindful that you want to relay the pieces later, so try to keep the broken sections quite large, but also small enough that you can lift them easily. Pile the pieces into roughly large, medium and small sizes. If you’re a stickler for neatness, also pile up squarish and triangular pieces separately as well (this will make finding the ‘right piece’ when you’re laying them much less fraught). After I pulled up my concrete, low and behold there was a double course of red brick beneath the entire pathway that had to come up too!

Dug out& string lineThe next step is to lay out a rough line for the path you want and begin digging. Unfortunately there’s no easy way to do this by hand – it’s sweaty, dirty and slow, just how gardeners like it! For a basic flexible paving system, you want at least 10cm of crushed road base (I used 15cm), then at least 5cm of sand to set your pavers into, so excavate to accommodate these layers. When you begin to dig out your pathways, set up a level string line at the hight of your completed pathway and stick to it.

The next steps involve yet more shovelling – this time lay down your road base, wet it lightly and use a whacker to compact it evenly, being sure to check and recheck your levels. On top of your compacted base, lay your paving sand and screed it as in this video. Now you’re ready to pave!

Pathway DetailBefore laying crazy paving it’s a good idea to spend the previous few weeks playing Tetris – lots and lots of Tetris. There’s no by-the-book way to lay crazy paving, and the only advice I would give is to not be too choosy with your pieces. I suspect many an apprentice pavior has been sent mad with frustration when laying odd-shaped stone. The way I overcame this was to lay the concrete with big joints, giving me more room to move and larger margin of error (and a much calmer attitude throughout). Tighter joints will give a more professional-looking finish but unless you’ve had experience doing it I would recommend aiming for a more rustic approach.

Getting the concrete to go down evenly is essential – you want a slight fall if you’re laying near the house so the rain runs away. Every piece you lay needs to be checked with a spirit level, both the piece on its own and against your string line. If the pieces aren’t level the end result will be rubbish and potentially hazardous to walk on. Check and recheck your levels, and then check them again with each piece you lay. Use a rubber mallet to tap the concrete into position and anchor them into the sand so they don’t move.

Completed PathwayWhen you’ve laid down your concrete pavers it’s time to fill the joints with something. I used rock dust, known as crusher dust if you’re from Queensland, which compacts hard after being wet down but also drains freely. I would recommend a similarly small aggregate be used, as anything larger runs the risk of wobbly pavers. After sweeping the rock dust into the joints, wet it down and use a thin bit of wood to compact it, then top it up and repeat. It took me three applications of rock dust to fill the joints completely, the end result being rock-solid pavers that don’t give when walked on.

The whole process from beginning to end took me a week and a half, and although feeling like an 80 year old with rickety hips every night at bedtime, building the front garden thus far has been a satisfying. Over the coming weeks I’ll be levelling out the beds and choosing dry perennials to fill them, so stay tuned for more garden action!

Until next time, happy gardening.

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James Beattie

About James Beattie

James is a horticulturist working in the Melbourne area. His work in the industry has included landscape planting design, hard landscaping, bushland management, garden consulting as well as extensive experience in the horticultural media. He worked for four years as one of the horticultural guns for hire behind the scenes at ABC TV's Gardening Australia program and has been a semi-regular guest on Melbourne's 3CR Gardening Show (855 AM). You can follow his whimsical garden musings at Horticologist

8 thoughts on “How to lay a recycled concrete path

    • Thanks, Helen. It’s a satisfying process to see it completed. After all the heavy labour I’m itching for the fun to begin – planting up! But there’s a camping trip to Wilson’s Prom before that happens. It’s a hard life.

  1. Looks gorgeous. Presumably there will be a run after (broken) concrete in your part of the world soon. And for breaking it up: I often fancy it should be possible to use those people who would otherwise waste their energy in gyms or on racing bikes etc. But then you have to supervise them and it becomes doubtful whether one really saves time.

  2. Love your work with re-cycled concrete. Years ago I constructed a large terrace (9m x 5m) off our back deck using variously sized flat(ish) slabs of basalt. It has sunk in places (laid just on sand as I wanted to plant between the slabs with mondo grass). As it was done in stages, the whole lot needs re-arranging and levelling. If you have another spare week or so James…..? Or any suggestions as to how to go about it? I was going to make copies of the slabs (already in place) using cardboard, number them, and then do trial layouts elsewhere in the back yard and go about it that way. Whaddya think? And do you reckon I can get away with just tamping down the sand, after lifting the slabs, and re-laying them – with out future settling becoming a problem again?

    • Hi Lloyd,

      The cardboard templates are a good idea if you want to keep the same pattern once you relay the stone, but take lots of photos of the path as it is now for a back up as well. Relaying existing odd-snapped paving is always pretty quick – the ‘right piece’ drama is already sorted.

      For the pavers not to move in the long run you really need to lay them on a solid, well-compacted base, such as road base, with sand on top. Sand alone will move and you’ll be back where you started before too long. Do it right, do it once, as they say. It’s hard yakka but it’s worth it. It’s been three years and my path hasn’t budged at all.

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