Guide to Exposed Aggregate: Procedure, Pros and Cons

When you want to change the look of your outdoor area, it is worth considering exposed aggregate. The combination of various stones, shells, colored glass, and seashells can create a magnificent display and striking surfaces. For almost 100 years, this technique has been changing the look of paved concrete.

Exposed aggregate uses a specialized technique to remove the thin top layer to uncover the aggregate under. The exposed layer comprises different stones like sand, gravel, quartz, or crushed glass. In this post, we will discuss the procedure of making exposed aggregate, its pros, and its cons.

Procedure to Make Exposed Aggregate

The first step of making the exposed aggregate is preparing the concrete base. Once the concrete floor hardens, various methods are used for exposing the surface, some of which are— brushing and brooming, using surface retardants, and abrasive blasting.

The different procedures to prepare the concrete base are:

• Standard Method: In this method, cement, sand, crushed stone, and water is mixed. The mixture is poured over the boxed area and allowed to settle for an hour and hardened. After one hour, the surface is vigorously swept with a broom or brush to expose a layer of gravel. The thickness of the concrete mix should be such that the gravel does not sink in the combination.
• Topping Method: This method is basically used to renovate the existing concrete, which is still in good condition but has become slippery. A thin layer of concrete, approximately 1 inch thick, is poured over the surface; this brings the thicker stones along the surface. This reduces the slipperiness of the surface.
• Seeding Method: The concrete mix is prepared and laid down in a box frame. Stones or gravel are densely sprinkled on the concrete by hand. On application, the mixture is allowed to settle for one hour before it is cleaned using a broom to further expose the layer of the gravel.
• Polishing Method: This method is used primarily for decorative purposes; the concrete prepared by this method is used indoors. In this method, instead of exposing the aggregate special equipment is used to thoroughly grind the surface post which coat sealers are used to polish the surface. The result is a smooth, shiny surface.

Pros and Cons of Exposed Aggregate

Pros

Using exposed aggregate comes with many benefits most significant benefit is the aesthetic value it adds to the landscape. It provides a range of possibilities with a combination of aggregate materials to match the property’s exteriors. It is cost-effective and is easy to carry out the entire project from start to finish.

The second advantage is that exposed aggregate has a long life and will easily last for four decades with little or no maintenance. The concrete can withstand extreme weather conditions like rain, sun, and snowfall. The exposed aggregate concrete is skid-resistant, making it safer in the rainy season.

Cons

There are some disadvantages of working with exposed aggregate, especially if you are doing a DIY project; there could be a learning curve. A previous experience of working with concrete is a must. Various materials can be used, but some materials may be prone to damages, especially decorative stones that tend to crack.

The aggregate chosen for the driveway should be carefully selected. Some stones may not withstand traffic and may get dislodged, creating gaps in the concrete that is difficult to repair. Washing of the concrete is not required frequently, but it is difficult to do so due to the uneven texture when needed.

Conclusion

Exposed aggregate is an extremely durable, inexpensive, and aesthetically appealing option to decorate your landscape and pavements. However, it may not be easy to install especially for someone who is working with concrete for the first time and may require professional help. The more decorative aggregates can be used to beautify pillars and walls as well.