ICF is stay-in-place formwork (what makes the shape, or form) for concrete buildings.

Traditionally concrete buildings are made by making shapes with timber and then filling these shapes with steel and concrete. Another way is to use concrete blocks. Timber formwork is expensive and time-consuming. Concrete blocks require block layers and they not as strong as a solid concrete wall. And concrete is cold.

ICF changes all that. ICF’s are recyclable polystyrene sheets which are assembled with plastic connectors and make the shape of blocks. These blocks are them assembled a bit like children’s blocks. As they are assembled, steel is placed inside them. They are then filled with concrete. This gives a solid concrete reinforced structure. The blocks then stay in place and become the insulation giving and insulation (R) rating of more than 3.7 which is almost twice what is required by NZ law.

After that the external and internal linings are fixed to the plastic battens of the block, giving you a beautiful modern structure.

External cladding can be anything the designer wants. Cladding is fixed directly to the formwork. Another popular method is external plastering. 

ICF is used extensively worldwide and many videos can be seen showing construction with it.

ICF stands for Insulated Concrete formwork. We work with ICF and sell it.

The benefits of ICF construction over traditional construction methods are many-fold.

1. Increased Strength: Steel-reinforced concrete for strength.
2. Moisture-Resistant: The indoor climate of your ARKFORM ECO-Block home is protected by the air and water vapour barrier qualities of the ARKFORM ECO-Block ICF system.
3. Airtight: An ARKFORM ECO-Block wall assembly stops air filtration into the structure. It provides greater control of interior air quality, eliminating drafts and cold spots.
4. Fire-rated Assembly: Concrete structures are far more likely to remain standing through fire than are buildings made of other materials. Concrete doesn’t break down until it’s exposed to thousands of degrees Fahrenheit – far hotter than a typical house fire.
5. Soundproof: Walls constructed with ARKFORM ECO-Block forms dramatically reduce noise pollution.The result is a super-quiet environment – a 150mm wall assembly has tested at STC 51, exceeding the requirements for apartment demising walls.
6. Cost: The cost to build your ARKFORM ECO-Block home will be comparable to that of other energy-efficient structures, but with many additional benefits. Building with ICF is faster. It’s likely that building with ICF will save you thousands of dollars in man-hours.
7. Heating and Cooling: The minute you move into your ARKFORM ECO-Block home, you begin saving money. That’s because ECO-Block walls are airtight and have an R-3.78 minimum insulation value.
8. Insurance Rates: Because most of an ARKFORM ECO-Block home is concrete, the insurance industry considers it masonry construction, ultimately resulting in lower insurance costs. This is recognized in the USA but not here in New Zealand yet.
9. Resale Value: All the features integrated into an ARKFORM ECO-Block home will add value when it comes time to sell. Many appraisers consider energy efficiency when determining a home’s value.