frequently asked questions

Are the pebbles in exposed aggregate only in the top layer of the mix?

No, the aggregates chosen in each particular concrete mix are responsible for the colors and textures which result in the final product. This means that, unlike the traditional blue/grey screenings used in “normal” grey concrete, a wide variety of options are now available. These aggregates (or stones, screenings or pebbles as you may refer to them) are throughout the entire batch of concrete.

Once laid and troweled, the concrete sprays a chemical on the surface of the concrete which slows down the “going off” or setting of the top few millimeters of the mix. Allowing several hours for the chemical process to take place, the concrete then pressure washes back the surface of the newly laid concrete to “expose” the aggregate in the mix. This is how the natural beauty of the various aggregates is revealed in an exposed aggregate design mix. Once sealed, the colors and textures are further enhanced.

How will I know the sample I choose will match my exterior designs at home?

All customers are welcome and encouraged to bring along a spare tile or brick from existing landscaping to gauge the compatibility of design mixes when choosing a sample to suit your needs.

For concreters, builders and landscapers, the on-site displays at Cranbourne Pre-Mix can streamline the selection and quoting process by refering your customer to directly view and choose a mix on site here. Looking forward to seeing you here!

Can anyone lay exposed aggregate concrete?

Whilst many concreters may claim to be confident to “have a go” at laying exposed aggregate, we recommend that you choose a concreter who is experienced at this technique. Exposed aggregate can be a technique which is sensitive to many factors such as the correct use of the retardant chemical and proficient “washing back” technique.

We are more than happy to recommend a concreter whom we know is experienced and professional in the laying of exposed aggregate concrete. Please feel free to contact Angelo or one of his team to refer you to one or more concreters who can provide you with a quote.

How do I know how much concrete to order?

Concrete is ordered in cubic metres. If a concreter is doing your job, he will be able to measure up and estimate an accurate quantity of concrete to be ordered. If working on a small job at home, we can help you out with quantities required if provided with accurate metric measurements.

Is my concrete going to look exactly like the samples displayed?

Whilst taking great care to constantly maintain ratios of aggregates in each sample mix, we can not guarantee that you job will be exactly the same. Obviously, the aggregates may fall in different places and patterns and, if oxides are added, they may appear more “garish” when first laid but will mature to a softer hue over time. Whilst viewing samples on this website, a better appreciation of the finished product can be found in viewing our many in ground displays at 219 South Gippsland Highway, Cranbourne or by viewing your concreter’s previous job sites.

NB: All aggregates are a naturally mined resource and may vary in composition. Natural oxidation of minerals in aggregates can sometimes result in concrete rust stains for which Cranbourne Pre-Mix cannot be held responsible.