How thick is an exposed aggregate overlay?

[ashleasmith]

We have a plain concrete alfresco, and would like to have this covered in exposed aggregate to match our driveway.

Generally how this is the layer that they’d put over this? And are they able to do the sides as well? Our backyard is sloped and I’m hoping to have the sides done so it looks like a step.

Thanks

 

[MitchellMc]

Hi @ashleasmith,

Exposed aggregate can refer to a few different types of coatings. Are you thinking of Pebblecrete, which consists of small, rounded pebbles (typically around 3mm in diameter) mixed with a resin? This type of finish can generally be applied in thicknesses of around 6–12mm, depending on the product and application method. With the right preparation, it can also be applied to vertical surfaces, such as the sides of your alfresco, to create a seamless step-like appearance.

Another type of exposed aggregate involves a cement-based mix with embedded aggregate, which is later ground back and polished. This type of finish often needs to be thicker than Pebblecrete, generally around 20–40mm, to ensure durability and proper adhesion.

Since these coatings require specialised application, it’s best to consult a professional installer who can assess your existing surface and recommend the best option for your space. 

Please let me know if you have any questions.

Mitchell