Insulating Concrete Forms (ICFs) are stay-in-place formwork for energy-efficient, cast-in-place reinforced-concrete walls.
The forms are interlocking modular units that are dry-stacked (without mortar) and filled with concrete. The forms lock together somewhat like Lego bricks and serve to create a form for the structural walls of a building. Concrete is pumped into the cavity to form the structural element of the walls. Usually, reinforcing steel (rebar) is added before concrete placement to give the resulting walls flexural strength, similar to bridges and high-rise buildings made of concrete (see Reinforced concrete).
After the concrete has cured, or firmed up, the forms are left in place permanently for the following reasons:
The majority of forms are made of foam insulation, such as expanded polystyrene (EPS), and are either separate panels connected with plastic connectors or ties; or pre-formed interlocking blocks connected with plastic or steel connectors or ties. Most forms have vertically oriented furring strips built into the forms on 6”, 8”, or 12” centers which are used to secure interior and exterior finishes.
Different ICF systems also vary in the shape of the resulting concrete within the wall:
More success. (Romak and Associates uses insulating concrete forms for Knight's Landing project in Warton, MD)
Nov 01, 1997; While the Concrete Concepts Homes re a highly publicized ICF success story, there are numerous other examples all over the world....
Practical home building technology for today - and tomorrow.(Insulating Concrete Forms: A Better Way to Build a Better Home)
Dec 01, 1995; The ICF system that A. Lexis Homes used in the Concrete Concepts Home works like this: interlocking hollow blocks made of plastic...
The concrete house; building solid, safe and efficient with insulating concrete forms.(Brief Article)(Book Review)
Feb 01, 2008; 9781402736292 The concrete house; building solid, safe and efficient with insulating concrete forms. VanderWerf, Pieter A....