One of our customers used 3” x 6” x 8” StyroShapes™ Foam sheets to create a rock wall behind his 1000 gallon pond. The foam was specifically used to create realistic looking rocks within the wall.
Here is how he did it:“I actually poured the concrete walls from 80 lb bags of concrete hand mixed using forms we built to shape the project to hold it in place. After the walls had several days to cure I began the process of assembling the Styrofoam into shapes and patterns that looked closest to that of natural stones found anywhere in the environment.
To assemble them I cut each 3x3 block in half using a standard hand saw, and then cut them into various shapes and sizes. After all the shapes were prepared, I then mixed a thin layer of custom mortar and other additives into a "glue" like substance.
Once the mix was ready I spread it across the concrete walls. I then began sticking the blocks that were sized and shaped into various positions on the wall creating a "natural" look. After this process was complete, I waited a day for the concrete glue to cure. I then applied by hand a coat of this same concrete mixture over the tops of the concrete blocks. I envisioned what rocks looked like and began free hand carving the ripples, and other designs. Some of the rocks have images drawn on them such as fish bones, leaves, sticks etc to resemble fossilized rocks. I then waited several days for these to cure. Once cured, I applied using a stain pump sprayer several layers and colors of a reactive based concrete stain to reach the desired look of a weathered and aged rock.
After a few more days of curing the concrete was then sprayed with a few coats of concrete sealer. The pond was home to 20 koi fish and fancy gold fish which have since made it their home and reproduced resulting in a home to over 40 fish and counting!!”