Rock Works & Waterfalls To hear all KerberKasts, click here Hear what Rock Work is all about. Jeff Kerber Pool Plastering is proud to offer the finest rock work in the industry. We are using the latest technology to add affordable rock waterfalls that look realistic and are completely customizable to match your vision. Our rock work is made to last, unlike other products constructed from foam and fiberglass. Ask our Pool Consultant about this exciting option to add a water feature to your backyard.