Traditional Approach
The standard method for building tiered concrete slabs requires establishing a well-compacted, sloped base. Several factors work against successful preparation and maintenance of the inclined grade: finding stable fill materials, dealing with unsuitable weather conditions, installing and bracing the forming system, placing structural reinforcing, and providing accessibility for construction workers.
Alternate Approach
Another method involves forming and placing concrete one tier at a time. After placing the lower row, subsequent rows bear upon six inches of the previous row. Once the edge forms are stripped, fill is brought in and compacted to the top level of the adjoining concrete. This redundant, labor-intensive technique produces an assembly of disconnected slabs that risk shifting and settling over time.
Innovation
An early advancement in the industry was the development of pre-assembled gang forms fabricated for specific project needs. While these heavy, crane-handled forms can significantly reduce labor costs, the concept only works when there is enough reuse to justify the cost of building and transporting them.
Improvements
For nearly two decades, contractors have used EPS Geofoam as a lightweight replacement for compacted fill. This proven material provides a substantial base that is capped with concrete to produce tiered slabs. This method has been widely adopted in the construction of movie theaters and cinemas.
System Approach
2007 ushered in the newest and most versatile method for constructing tiered concrete slabs. Riser Solutions® easily adapts to the needs of smaller or unusual projects, yet it is equally effective on larger, more demanding jobs. Tiered concrete slabs designed with radius riser faces can be built with the same confidence as those with straight riser faces.
Previous construction methods provided either structural concrete over marginal fill or non-structural concrete over engineered fill. Riser Solutions® is a hybrid system that offers rapid, accurate installation of structural concrete over EPS (expanded polystyrene) — a lightweight, engineered fill. Whether used for stepped concrete slabs, large stairways, or frost-protected entry stoops, the design and installation of tiered structural concrete slabs is reaching new potential.