How to lay porcelain pavers?

[PeterEllis49]

Laying Pavers    

I am developing a detailed plan for a garden in the restricted rear outdoor space at my daughter’s townhouse.  She wants a small paved area (about 1.8 m square) so she and friends can sit outside.  She wants charcoal porcelain pavers to match those in her balcony and entrance way.  Not yet sure of the size say 400mm square by 20mm thick.

I have viewed the Bunnings DIY Advice re how to prepare for and lay pavers.  I have also looked at a number of Bunnings Workshop Projects featuring pavers.  Most of these have varied in one or more details from each other and from the Bunnings DIY Advice.

I have decided to use the Bunnings DIY Advice as the basis of my planning.  However I have a few questions:

1             Base

In the Bunnings DIY Advice video a crushed rock base 100 to 150mm is recommended.  To minimize cost and the amount of excavation, and given the small area with minimum foot traffic,  can I with minimal risk reduce the base to maybe 50mm? 

And could I get away with manual compaction rather than hiring a plate compactor?

2             Paver “underlay”

One of the projects I viewed used Strol geotextile over the top of the base.  This is said on the Bunning’s site “to separate gravel or sand from intermixing with the clay layer.” 

Is this recommended?

3             Edge support

The video shows a relative high and thick timber box frame on the two sides of the area to be paved which do not butt up to a wall.  This frame seems to be a temporary and would be removed once the paving is completed. 

However the video did not mention how the base stone is retained to prevent the stone flowing out and potentially undermining the pavers.

What is your recommendation?

4             Gap grouting

The video emphasises keeping a relatively wide 5mm clear gap between the pavers for grout.  However the video did not provide detail on material, tools, and technique for applying the grout.

Is there a Bunning video or document which provides this detail?

[MitchellMc]

Hi @PeterEllis49,

It sounds like you've done thorough research and are well-prepared for your daughter’s paving project. Here’s my take on each of your questions, with some additional recommendations.

For the base, while reducing the crushed rock layer to 50mm and compacting manually may seem like a cost-effective and easier approach, it does come with risks. A thicker base, as recommended in the Bunnings DIY guide, provides better support and stability, especially for pavers that will see any foot traffic. Manually compacting a thinner layer may not provide the same level of compaction, and if the subsoil is prone to movement, this could lead to subsidence or uneven pavers over time. So, while you could go thinner, I’d recommend sticking with a 100mm base and renting a plate compactor for a more secure and long-lasting result.

Regarding the “underlay,” using a geotextile between the base and subsoil is a great idea, especially if there’s any clay in the ground. This fabric helps prevent the sand and gravel from mixing with the subsoil, which keeps the base stable. It’s particularly helpful in preventing the layers from shifting over time, so it’s worth including if the budget allows it. However, it's not entirely necessary.

For edge support, a strong frame is essential to keep the crushed rock and sand base in place. You’re correct that the video’s temporary timber frame isn’t necessarily for long-term support. A more permanent solution, like installing a small concrete edging along the edges or creating a permanent frame from sleepers, can help retain the base and prevent it from shifting. This added support will make sure your pavers stay stable and prevent the base material from migrating.

Finally, for grouting, a 5mm gap is ideal to allow grout to settle and keep the pavers securely in place. We have several options for grout materials, including sand-based grout for a permeable, flexible finish or epoxy grout for a more durable, water-resistant finish. Using a rubber grout float can help apply the grout evenly across the gaps. I’d recommend using a stiff-bristle brush to remove excess grout from the surface and gently clean the gaps afterwards. 

There is a bit of a discrepancy in that series where we don't talk about grouting the pavers. Typically, on a compacted base, where we bed the pavers on a mortar base, no grouting is done. We fill between the pavers with paving sand. This is because the pavers can still move, and the grout will crack. In the third part of the series, where they are sealing the pavers, it appears we've jumped to a section where the pavers are on a concrete base and in this scenario, you can grout as they have a solid, non-moving base. So, given this, if you are working over a compacted base, I'd recommend using sand and not grout.

Please let me know if you have any questions.

Mitchell