Porcelain Pavers on dry sand

[mattyjwolf]

Hi team, 

   

I'm about to lay Tuscan Path Porcelain Pavers 600x400 and have a question around the sub-base. 

We are on dry sand (coastal WA) and limestone. Very coarse and dry. We will be laying pavers on a bed of mortar.

I have viewed the Tuscan Path installation video where they lay the pavers on a bed of mortar, and the ground is roughly leveled. There is no road base or anything going in here. Just level the ground and apply mortar.

Also following @Adam_W 's path paving tutorial, it looks like there was no road base here either. (This tutorial uses paving sand rather than mortar since it's using standard pavers).

A lot of traditional paving seems to require massive amounts of road base under the paving sand.

I'm hoping that the dryness/coarseness of the sand here, and the large surface area of the pavers, means I won't have to dig up tons of sand and replace it with road base. (FYI, I have compacted along the area before; it does almost nothing. Zero sponge factor... the sand just sits).

Also, this path is 1m wide, wedged between the house slab and a limestone block council retainer.

I'm just chasing your thoughts around how to best prepare the site for these pavers.

Cheers!

Matt

[JacobZ]

Hi @mattyjwolf,

Thank you for your question about installing pavers on sand.

While the sand might be solidly compacted, my concern is that with heavy rain, it would be susceptible to erosion. 

In the examples you have linked to, the pavers are being laid over soil, whereas you have sand. 

Soil is a mixture of sand, clay, aggregate and organic matter, whereas sand is essentially just grains of quartz or silica.

Sand is more vulnerable to erosion than soil due to its loose structure and lack of binding agents like clay and organic matter. Sand is easily displaced by water, and its poor water retention leads to rapid runoff, increasing the risk of erosion. If you were to just put mortar over the sand, I'd be concerned that it would erode beneath the mortar which will eventually move because there are cavities beneath it.

Ultimately, the best thing to do is to add a layer of compacted road base before the mortar, but as you've said, this can mean a fair bit of digging.

You could reduce the amount of digging, by adding drainage gravel across the area and tamping it into the sand. If you can make the gravel, go between the sand, you may not even need to remove any sand. You'll have to use your judgement but if you can run a hose across the surface without sand washing away, then you should be fine.

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

Jacob