ICF & Extending
What You Should Know About ICF
A guide by the Insulating Concrete Formwork Association
Will it be difficult to extend or remodel in the future?
When it comes to an insulated solid wall construction method like ICF, there are often questions about whether it will be difficult to add a home extension or remodel the building in the future. Most concerns stem around the difficulty in alterations to the inherent strength found in the concrete core of the wall.
However, with the right approach, extending or remodelling an ICF building should not be any more difficult when compared to traditional stick-frame construction. We explain what steps you should take before extending or remodelling your ICF building.
What Is ICF?
ICF is an on-site system of large blocks or formwork made from two layers of an insulating material. The UK’s most commonly available ICF systems are expanded polystyrene (EPS) or mineralised recycled wood chips mixed with cement known as woodcrete.
The system is quick and simple to build. You create the wall by stacking the blocks, which interlock via a raised edge and removes the need for an intermediate bedding material such as mortar. The walls are typically built in stages, usually to first-floor height at the first pass. Concrete is then poured into a central cavity in the blocks. Once set, the build continues until the desired full height is achieved. Unlike other formwork systems, with ICF the insulating blocks remain in place to create a strong and highly efficient building.
Planning Your ICF Home Extension
Before starting any home extension or remodelling work, it is advisable to consult with a structural engineer. They will evaluate the foundations, walls and roof of the building to determine how to attach and support the extension. They will also consider whether rebar will need adding to the new opening in the ICF structure.
What’s A Big Advantages Of Using ICF For Your Extension?
Whether you need to build above ground or increase structural strength by adding steel rebar for a basement, supporting wall or cantilever elements, ICF can cover it all. In fact, without the need for complicated structural solutions, some conditions such as corner windows and cantilevered openings are easier to design with ICF than traditional forms of construction.
Third-party certification confirms that ‘ICF systems are satisfactory for use in loadbearing and non-loadbearing walls as permanent formwork for in-situ dense aggregate concrete.’
How To Extend and Remodel An ICF Building
The main reason why ICF buildings are perceived to be difficult to remodel is down to the fact that it requires cutting through the solid concrete wall. This is potentially the biggest challenge when working with ICF but, with the right concrete cutting tools, it can be achieved easily.
The ICF blocks are then attached to your existing wall via the same methods used for extending with brick and blockwork.
Contact Us
Interested in building a home extension with ICF? Get in touch with our team today!