Exposed Aggregate is a concrete finishing method that leaves the pebbles (i.e., Aggregate) exposed on its surface. The end product will look as if the concrete was poured, topped by a bag of tiny pebbles that were then flattened and allowed to cure within the concrete.
There are multiple ways to achieve this finish, and the methods range from applying a surface retarder to brushing the concrete to using a pressure washer to expose the pebbles in the concrete. Depending on the amount of work you wish to do and whether you want to use chemicals will determine which method you will use. Let’s look at each method.
Washing and Brushing
Washing and brushing is the most straightforward approach to an exposed aggregate finish on concrete. It is the oldest method and one of the most labor-intensive. Timing is vital in this process. There is an optimal time at which the concrete needs to be sprayed with a water-hose and brushed. It is recommended to only use this process for smaller areas. A deck brush and a high-pressure water hose are the best approach for this type of method.
Using a Surface retarder is the most common method of exposing the Aggregate. It is a chemical that prolongs the drying time of concrete so that the top layer can be washed off without you having to rush. In most instances, the retarder will extend the setting process to around 24 hours, so you will have plenty of time to Expose the Aggregate. Using Surface retarders removes the top layer of cement to mimic the way that sand looks.
One other method to get the exposed aggregate look is by hand seeding pebbles, polished stones, shells, or even glass directly into the Aggregate. This is one of the messier methods to achieve an exposed look.
Since hand seeding occurs after the concrete has been poured, one can change the coverage density based on the client’s preference. A more comprehensive selection of stones and pebbles also provides more customization options. This allows for some artistic refinement in the final result.
Exposed Aggregate is a classic look to set off any landscaping project. One can achieve an exposed look anywhere that concrete is poured, so its versatility is endless. The Exposed Aggregate can embellish any surface that concrete can be poured from walkways to staircases and even to walls and benches.
Along with its timeless beauty, exposed Aggregate will require very little, if any, maintenance. Concrete itself is a very durable material, and even though the Aggregate is exposed, the material will retain all of its robust features. Exposed Aggregate may prove to be more desirable after ten years as the top layer of most concrete pours tend to chip and crack after years of abuse. Exposed aggravate is a timeless look that is well suited for any project in or around the house. Its low level of maintenance makes it the perfect option for any future projects.