In 2018, Raging River Waterpark in Bismarck, ND was trying to determine whether or not to refurbish or to rebuild their 60 foot long by 10 foot high decade old waterfall that spills over into the Lazy River on the north side of the Park. The decade old decorative concrete rock waterfall, composed of a carved concrete sprayed onto burlap held up by a hollow rebar steel substructure, had corroded overtime. Although this is a common concrete construction practice, the intense aquatic environment began to infiltrate the feature and cause the steel to rust. This weakened the interior steel structure which started to buckle under the weight of the concrete surface. Repairs to the facade became more difficult, requiring more time and materials.
The waterfall was rebuilt using a combination of ICF (Insulated concrete forms) and EPS Foam (Expanded Polystyrene) to provide the structural integrity and to fill the major voids. Once in place, the EPS foam was covered with rebar, fiberglass lathe and shot with a regular mortar mix for the rough base coat and a fine mortar mix for the sculpted finish coat. The sculpted feature was then sealed to provide an added layer of protection to the elements and stained to create a natural rock look.
