Courtesy Rico Rock

Cast-concrete artificial rock provides an easy way to create a waterfeature that turns your client’s backyard pool into a backyard resort pool.

Today’s cast-concrete rock component systems look real because they are molded off actual rocks to provide the same shape, character and texture of the real thing, while holding up to the freeze-thaw temperatures in the northern U.S. and Canada.

For this product to truly transform a pool into a magical place, it must be stained and mortared in the most realistic and visually appealing manner possible.

Some installers may choose to purchase kits, in which the stones come from the manufacturer colored and ready to install.

For those who do their own coloring, here are several tips and tricks to ensure that you provide your clients with the most attractive rock water feature possible.

Staining and shading

Staining and shading the stone will be the most important step in creating the look you want.

Staining concrete is a true art form, but staining a cast-concrete waterfeature can be easier than getting natural stones to match and look good together. Cast concrete manufacturers provide kits to dye the concrete stone to mimic the surrounding natural hardscaping and deck treatments.

Be sure to select a blend of acrylic stains specially formulated to bond to cast concrete rocks. Some stains and paints are formulated to bond to porous surfaces but do not bond to a high-tech, virtually waterproof product like the fiber reinforced concrete (FRC) that is manufactured for pool waterfeatures.

The tools needed for this process include buckets, sprayers, water hose and sponge.

Here is a basic overview of the steps in coloring and shading the artifical rock: Damp the rocks; apply base color; sponge away any excess stain; damp rock again; add an antique stain; repeat the sponge-away process.

Getting Started

It is recommended that builders begin the staining process at the back of the hardscape feature and work toward the front. It takes a good eye and some patience to get the cast concrete to look like real stone. Testing small sections at the back of the waterfeature is always a good approach as hardscape designers master the art of staining concrete.

It takes several layers of staining, in fact, to achieve a truly natural look. Building these layers of stain happens both before and after the placement of each piece. The initial staining happens before placement of the stone. This can be done by the manufacturer or installer. The final staining then occurs after the waterfeature is complete.

When doing this step, it is important to make sure the waterfeatures blend seamlessly with the pool’s surrounding decks. Stain and shade the cast-concrete water features to match the surrounding natural rocks and pavers. Throughout the process, take time to stand back and look at the cast concrete in relation to the deck and any real stones that might be integrated into the greater landscape.

It’s a very visual process, and builders should plan for adjustment and modifications, as the process involves a bit of artistry.

Best Practices

Follow these best practices when staining cast-concrete rock waterfeatures for pools. This will further help ensure the best, more realistic-looking artificial rock:

1. Washing: Start the color staining process by first washing off the rocks. Be sure to remove anything from the surface that might interfere with the color bonding.

2. Moistening: It’s important that the acrylic stain be applied to a moist surface. This will help the stain apply properly. Builders should use very large sponges to moisten the cast-concrete rocks. Make sure the rock is not too wet or too dry before adding the acrylic stain. If the rocks are too dry, the color will absorb into the concrete too quickly, causing a very dark, deep color. Applying the stain to a damp surface, rather than a wet surface, allows it to blend with soft tones and hide overspray errors. After wetting, allow the stone to dry for a few minutes, depending on the outside temperature. Very hot and dry conditions may require frequent re-wetting.

3. Application techniques: Always apply the accent color first, before the antique coat. Accent colors are those such as rust, reddish brown and golden amber, which create a realistic base tone to the rocks. It’s very important to apply the stain color in a random fashion. You’ll be working with a spray bottle, and you must be careful not to overspray. If the accent colors are concentrated too heavily in one area, the color will start to look unnatural.

Once you apply the accent color to the damp surface, use a damp, clean sponge to either lighten heavily stained areas or blend in the color to create a tone that matches the surrounding color scheme. Sponging the excess also creates variations in tone.

While doing this, shake the bottle frequently to keep the stain fully blended throughout the application.

Always keep a bucket of clean water and a clean sponge handy to wash away excess finish or color.

4. Adding color: Once the rock has dried, the stain colors may appear to be lighter than when the surface was wet. If you’re not satisfied with the current color feel free to add more.

Many builders find that, once they have achieved their desired color, they can make the stone “pop” more with the addition of what we call an ‘antique’ finish, which gives rocks a weathered, natural look. This finish highlights the natural cracks and crevasses or areas of heavy texture in cast concrete rocks. To get nice, deep dark cracks you want to concentrate the finish in the cracks and sponge away everything else around it and definitely sponge away any dripping or it will leave those marks.

Since this color is a darker gray color, it is very important to have a clean damp sponge in hand in order to be able to sponge-off any excess antique color from the rock or it might compromise the accent color.


Creating attractive waterfeatures using cast-concrete artificial rock is not difficult. By using stains designed specifically for cast concrete and using the techniques mentioned above, getting a handle on the process isn’t as daunting as it might seem.

It’s important to remember that the process takes time and does require some patience and a little artistry. Builders will need to stand back and use their eyes to be sure the colors blend with each other and with the pool and backyard landscape.

Remember there are also options to use pre-colored artificial rocks to make the process less intimidating.