How to pave over concrete and cubby house base?

Question

Hi all, I’m after some advice 😊

I have a concreted outdoor area (photos attached). At the moment there is a shed on it, which will be removed this weekend, and I’m planning to install a large wooden cubby house in that space.

Initially, I was planning to build a simple sleeper frame base over the concrete for the cubby. However, I’m now considering paving the whole area instead, as it would look much nicer than the current concrete.

The concrete wraps around the house, but the section along the side of the house is quite uneven, which is where I’m unsure how to proceed.

I’d really appreciate some advice on the following:

* Do you think it’s realistic to DIY lay pavers over the entire concrete area, even with the uneven sections?
* If so, would a sand base alone be enough over concrete, or would I need something like a levelling compound first?
* The area where the cubby will go and the section leading to it are fairly even — would it make sense to just pave those areas and leave the uneven side for now?
* Alternatively, would you recommend leaving paving to the professionals and sticking with a timber sleeper base for the cubby?

I am happy to put in the work but we are beginners and want to make sure we are not taking on something that's likely to fail long term.

Photo 1: Main slab where cubby will be installed

Photo 2: Connection area between slab and side path

Photo 3: Uneven section I’m most concerned about

Some more picture where I tried to capture the uneveness

JacobZ · Answer

Hi @GiuliaExpat,

For consistencies sake, I'd suggest using timber sleepers for the edge restraint along the green line and then rip cut a sleeper, so it is a consistent height with the ones in the soil and attach it to the concrete using galvanised

https://www.bunnings.com.au/products/building-hardware/fasteners-fixings/wall-floor-anchors/screw-bolts?srsltid=AfmBOopuEiRMc9ih9DhtWJ_qyPSwYf4147mFAHJl89C8wlJnUjWIlSEm

every 600mm or so along the sleeper. If you did plan to continue the paving at a later date, you could then simply remove the screws and sleeper then continue the paving.

In doing this, I would also suggest you add some small drainage holes at the base of the sleepers to allow for any water that finds its way underneath the pavers to drain.

This will give you a clean, consistent edge restraint around the full perimeter of your pavers.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

GiuliaExpat · Answer

Hi @JacobZ ,

Thank you for your reply,this is really helpful. It sounds like a mortar bed might be the best option for my situation. I’ve done a bit of reading and watched a few videos, and it actually looks like something I could potentially tackle as a DIY project.

Your point about edge restraints is also really valuable.

I’ll be honest—the idea of paving the entire area feels a bit daunting at this stage. I’m thinking of starting with just the section where the shed currently sits. It’s flat, relatively small, and has minimal imperfections, so it feels like a good place to learn. If that goes well, I could then extend the paving to the rest of the concrete area later.

My question is about the edge where the new pavers would meet the existing concrete (the red-marked side). What would be the best way to finish that edge neatly? Would I need some kind of edge restraint fixed to the concrete, or is there another method you’d recommend?

For context, the green-marked side will have edge restraint into the soil, and the other sides are already contained by a sleeper garden bed and a rock retaining wall.

Any advice would be greatly appreciated, thank you again!

JacobZ · Answer

Hi @GiuliaExpat,

Welcome to the Bunnings Workshop community, it is wonderful to have you with us.

Yes, it is definitely possible to pave over an existing concrete slab and your area looks like a prime candidate. The key thing to understand though is that the success of the job comes down to the preparation and the method you choose, particularly when working over concrete rather than a traditional soil base.

In traditional paving, you would put down a compacted base before applying your pavers, however in your situation, you already have a firm, stable base in the form of your concrete. The main issue you have to overcome is the unevenness and the potential for the pavers to shift over time.

My first suggestion is to add edge restraints, which are what stop your pavers from spreading or shifting outward over time. Without them, even a well laid area can slowly move and lose its shape. In this case, timber sleepers can act as your edge restraint. They should be dug into the soil so they end flush with the top of your pavers, and fixed in place with sleeper stakes, posts or pegs. This gives your paving a solid boundary and is the first step before laying anything else. I'd also suggest these sleepers are set back from the edge of the concrete by around 50-100mm and drainage gravel is added to allow for water to drain. This drainage gravel can then be compacted and paved over.

While sand might seem like the easiest option, it is not the most reliable when laying over concrete. Unlike laying on soil, the sand cannot be properly compacted into a stable base, so it essentially just sits on the slab. Over time, this can lead to movement, minor sinking, or pavers becoming uneven, especially with foot traffic or moisture getting underneath.

For a more durable and long-lasting result, a mortar bed used alongside your edge restraints is a much better approach. Mortar provides a solid, bonded base that won’t shift or wash away, and it allows you to properly correct any small imperfections in the slab as you lay the pavers. This means your finished surface stays level and stable for years, rather than potentially needing adjustments down the track.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob