What is insulated concrete formwork?

What is insulated concrete formwork?

Insulating Concrete Formwork (ICF) is a type of formwork for reinforced concrete that is typically manufactured from polystyrene or polyurethane foam which acts as a permanent insulation system for walls, roofs, and floors. ICF consists of twin-walled expanded foam panels that are locked together to create the permanent formwork that is used to contain the ready-mixed concrete. ICF’s rise in popularity can be attributed to its high performance and environmentally friendly nature, along with being a robust, cost-effective method of constructing a variety of structures, from residential houses and basements to multi-story commercial buildings.

History of ICF

The ICF technique was originally introduced after WW2 in Europe, where many buildings were destroyed or damaged and needed to be repaired in an affordable but effective way. Since then, building codes around the world have been updated to put more emphasis on energy efficient and natural disaster resistant building materials, particularly for low rise commercial and residential construction. After witnessing a steady rise in the 1970’s, the ICF technique has now become very popular due to it being a durable, low cost, and energy efficient construction method for both residential and commercial buildings.

A better alternative to traditional buildings

ICF has many advantages over traditional building materials. ICF walls contain a solid concrete mass core with permanent insulation on both sides. The ICF technique can be used on walls, floors, and roofs, and have an R-17 plus rating. Since the exterior of the walls contain foam blocks, interior and exterior finishes can be easily attached, and wiring and plumbing can be done without the need to cut into the concrete core. Despite this, any major wall penetration such as pipes running through the walls need to be considered before the concrete is poured between the layers of formwork.

Not only is ICF flooring stronger and more durable than traditional materials, but it is also much lighter than traditional concrete flooring. In addition to this, ICF flooring can be constructed independently or designed to create a continuous reinforced structure with the buildings walls. In terms of fire resistance, the foam used in ICF is typically treated with flame retardant chemicals which means that it doesn’t burn and add fuel to the fire, but rather self-extinguishes. When compared with traditional building materials such as wood, masonry, and concrete, ICF provides a continuous insulation system and sound barrier, along with a backing for drywall on the interior, and lap siding, brick, or stucco on the exterior.

What are the costs associated with using ICF?

When compared with traditional wood framing units, ICF costs roughly $3 – $5 more per square foot. Despite this, the cost savings achieved through the insulating materials will more than offset the increased initial outlay throughout the life-cycle of the product. In fact, many contractors are choosing to use ICF as a building material so they can qualify for energy credit and other ratings like LEED.

Additional advantages of using ICF

Additional advantages of using ICF as a building material include:

  • When compared with wood framing, ICF reduces infiltration by 50%
  • There are no mould or mildew issues when using ICF material. No vapour barriers are required given that the insulated blocks act as natural moisture barriers
  • ICF walls receive between a R-17 and R-26 rating as opposed to an R-9 rating generally seen in wood framing
  • ICF creates a sound barrier, and has double the sound resistance of wood framing
  • Labour costs are greatly reduced and only semi-skilled labour is required to build ICF materials
  • ICF materials can be used in buildings and walls that are more than 40 feet tall
  • No rodents or insects will be attracted to the insulated forms simply because there is no food value to them

Looking towards the future

Instead of using traditional materials, contractors are now looking to build structures using energy efficient and environmentally friendly materials. Not only does ICF materials provide an easy means of achieving high standards of structural, energy, fire, and acoustic performance, but these structures can be built much faster, using semi-skilled tradesman, at much lower costs than traditional materials.

If you’re interested in using ICF materials for your next project, reach out to the formwork specialists at Uni-Span by phoning 1300 882 825.

Categories: Home Improvement

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