Concrete Finishes: Three Techniques for Exposing Decorative Aggregate

There are numerous finished to consider selecting for your new concrete surface. One of the most popular and beneficial choices is exposed aggregate. The likability can be attributed to the unique aesthetic appeal, durability and the non-slip gripping texture. Typically, an exposed aggregate surface is created by mixing the standard concrete with special aggregate materials such as rock salt, slate and even natural rock. As the concrete cures, the upper layer of the surface is removed so that the pertinent aggregates are exposed, instead of remaining beneath. If you have decided to install this type of concrete in your home, here are the primary techniques to consider for exposing the aggregate.

Scrubbing and Washing

The simplest and least expensive method to expose the aggregate on your concrete surface is scrubbing and brushing. As implied, you will need water to wet the material and a broom for the scrubbing task. Ideally, you will only need to scrub away the top layer, and your aggregate material will be revealed. The main consideration for this technique is timing. If you wait too long, the surface will over-cure, making it difficult to efficiently expose the aggregate. On the other hand, if you scrub the concrete too early, the aggregate will not be fully settled and might be dislodged. Therefore, you should test the surface for readiness by scrubbing lightly with a stiff brush on an inconspicuous area before proceeding.

Utilising Chemical Retarders

As mentioned above, timing is critical if you would like to expose the aggregate by scrubbing and washing. This can be a major disadvantage if you are dealing with a large surface area, such as a long driveway. In simple terms, you will not be able to scrub the entire area with a broom before the concrete sets completely. If this is your case, consider using a chemical surface retarder. This is a special product designed to delay the curing process, and it is applied after pouring and finishing the concrete surface. This will increase the length of time within which you can expose the concrete using a pressure washing machine or even by scrubbing.

Abrasive Blasting

Abrasive blasting is an ideal method for aggregate exposure because there are no time limits. Simply speaking, you can choose this technique for concrete surfaces that have already set. In general, this process uses sand or metal shot propelled at high speeds to eliminate the mortar. This method should be used with care because it can easily fracture the new surface.