There are many variations on the design of ICFs however the basic principle behind them is the same. An insulative material is used to form a hollow core block usually there are two leaves of expanded polystyrene insualtion connected by means of a metal or plastic tie.

Moulded castellation on the top and bottom of the block allows each block to interlock firmly with the row above and below, the bonds are staggered at each course.

The blocks are marked at 50mm increments which simplifies cutting and speeds up the construction process.

To stabilise the walls during construction metal frames called trestles are bolted to the slab or floor and temporarily fixed to the walls to ensure they remain straight and plumb.

When the walls are complete ready mixed concrete is poured into the walls by means of a concrete boom pump.

Once cured the concrete core forms the loadbearing part of the structure which is typically four times stronger then a standard cavity wall.

There are many benefits to this method of construction including:

• Superior airtightness
• Minimal cold bridging
• Thermal mass heat retension
• High levels of insulation, U Values from 0.27 to 0.075 W/m2K
• Quick and easy to install
• Can be used in all situations above and below ground
• Infinatly adaptable giving complete fredom of design
• Excellent sound Insulation properties
• Can be erected in all weathers

Typically only four component parts are needed to construct a simple building design.

1. Straight wall blocks
2. Corner blocks 90? and 135? available
3. End stops to close off window and door openings
4. Lintel formers to close off door and window heads

By reducing the number of component parts needed to build the walls, waste is drastically reduced and installation is quicker and easier.

ICFs are extremely strong allowing up to 4 meters of vertical wall to be poured in a single day. Typically the walls are completed and poured floor by floor but most single story building such as bungalows can be poured in one day.

Most walls above ground need no additional reinforcement except in lintels over door and window openings where normally a single 20mm high yield bar is sufficient, larger openings over 2m may require more reinforcement.

Concrete is extremely versatile, it can be moulded into any shape; the strength can easily be increased and steel reinforcement added to cope with larger stresses or loads for uses underground and to form large openings.

The concrete used for the wall construction is standard unless site conditions require a stronger mix. C25 pump mix with 10mm aggregate at a slump of 80mm-120mm is the preferred specification.

The ICFs are a poor conductor of heat/cold energy. Heat energy is trapped within the concrete core of the building creating a thermal mass which retains heat and remains relatively constant fluctuating slightly with the change of seasons. The insulating characteristics of an ICF building are non-discriminatory allowing the building to be cool and remain cool in summer and warm in winter.

ICFs are available in a range of thicknesses achieving U-values from 0.30 to 0.117 W/m2K.

It cost the same amount in labour and for concrete to install a 0.30W/m2K block as it does to install a 0.117W/m2K block.

Typical U-Values

Values quoted are based on the Logix wall system; prices are subject to change without notice.

Depending on the choice of wall block the running costs of a building constructed from ICFs can be 50-80% lower than a conventional build.

The energy efficiency of a building is now about more then just high levels of insulation.

Getting a building air tight is just as important as getting enough insulation in it. A building with vast quantities of insulation will not perform as well as it might on paper if it is built badly with cracks voids and gaps which allow heat to escape and cold air to penetrate.

By ensuring a building is airtight you can significantly reduce:

• Draughts
• Heat loss
• External sound levels
• Energy consumption
• Running costs

ICFs are ideal when it comes to maintaining air tightness. Because concrete is poured into the walls a floor at a time a solid monolithic structure is created with minimal day joints. As a result the number of joints between materials and air gaps is drastically reduced.

Where non ICF buildings are concerned the level of air-tightness is directly linked to quality of work and quality of work is largely dependent on time and budget. If the building schedule and budget allows the air tightness of brick and block or timber framed buildings may be improved but it is guaranteed with ICFs at no additional costs.

Using ICFs in place of a cavity block, three experienced operators can complete the walls of an average sized, bungalow in just five days, with roof construction able to commence the following day

Along with supplying our various products, we provide practical advice and offer full product support during your build, we will do as much or as little as you require of us.

We will train you or your builder in all aspects of the ICF installation; with as little as 1 days basic training a competent self builder will be able to start construction.

We realise that some customers are looking for sustainable alternatives to EPS based products. Which is why we have enhanced our product range with an eco friendly alternative to polystyrene ICFs.

Trusted internationally for over 50 years, Durisol is a proprietary material that’s recycled, renewable, and energy efficient. At 30% cheaper than traditional brick and block masonry construction, Durisol is proof that green building can be cost effective building.

• U values of 0.19 as standard
• U values of 0.15 easily achievable down to 0.1
• Suitable for internal, external walls and basements
• No block laying skills required
• Estimated cost savings of 30% over traditional building solutions

Durisol blocks are made from 80% recycled wood which replaces the polystyrene insulation. They have all the benefits inherent with other ICFs and boast sustainable credentials making them an ideal system for meeting the high standards of the code for sustainable homes.

Durisol can be dry stacked without mortar up to 26 storeys high. What’s more it won’t rot or burn, they are suitable for internal, external walls and basements, above or below ground.