Every home should feel like a castle. That place of refuge where you can shut the door and feel safe. But, just how safe are the materials your home is built with? Since Grenfell, the combustibility of materials used during construction has been widely discussed. We look at how the materials in an insulated concrete formwork wall can provide fire safety for homeowners.
ICF Fire Resistance
Building with insulated concrete formwork is a simple process with only a handful of materials. It is this simplicity of build which aids the safety on an ICF building and creates its own natural fire suppression system. The wall is formed with large blocks made from an insulated material. In the UK this is either expanded polystyrene (EPS) or woodcrete. Once the blocks are in place concrete is poured into a central cavity. Once cured the blocks remain in place to create an inherently strong structure.
One big advantage of a having solid core in an ICF wall is that the concrete will not burn. It can also withstand extremely high temperatures and when affected by fire it will not emit any toxic fumes. As a material concrete has been given the highest fire resistance classification under EN 13501-1:2007-A1:2009, which specifies fire rating for construction products and building materials. Concrete is classified as Class A1 which means it is non-combustible.
Concrete also has a slow rate of heat transfer which ensures the structural integrity of the building remains. This means, depending on the floor and roof specification, an ICF wall will act as an almost impenetrable shell that contains a fire and prevents it from spreading internally or externally.
The ICF formwork has also been designed to ensure maximum safety. EPS forms are treated with a flame-retardant additive. The mineralisation process during the manufacture of Woodcrete blocks makes them burn resistant. In the event of a fire the solid concrete core will contain the fire within the room and prevents it spreading internally or externally. The fire resistance of the forms can be further enhanced depending on external finish.
Most ICF walls offer a fire protection rating of up to 4-hours.
