There are three different types of configurations: 1). flat wall, 2). waffle-grid and 3). screen-grid. Flat wall systems yield a continuous thickness of concrete, like a conventional poured wall. Grid wall systems have a waffle pattern where the concrete is thicker at some points than others. Screen grid systems have widely spaced horizontal and vertical columns of concrete, which are completely encapsulated in foam. Whatever the differences among ICF brands, all major ICF systems are engineer-designed, code-accepted, and field-proven.