Insulating Concrete Formwork (ICF) is a construction system which uses insulating blocks as the formwork for in-situ concrete. The insulating blocks lock together like Lego bricks with tongue and groove connections and stay in place as a permanent interior and exterior substrate for structural members. Fresh concrete is normally pumped into the forms built up the required high as a complete wall. Once the concrete wall is set, it becomes high strength concrete frame structure with the formwork remains in place as thermal insulation. ICF blocks are formed of sheets of insulating materials normally Expanded Polystyrene (EPS) tied together with plastic or steel ties or integral web of the same insulation. EPS is a magnificent material for building due to its excellent energy efficiency, light weight feature, durability and low maintenance costs.
ICF blocks are normally manufactured in typical shapes. The blocks will need to be cut to the right size to comply with the architectural plans and then be placed next to each other. Although not all the blocks need cutting, several blocks need to be cut first before laying on the correct place. It normally happens near wall corners and around the openings such as windows and doors. In addition to the more required labour work for cutting, the manual cuttings may remove the tongue and groove connections and cause weak joints between the blocks. Such weak joints may result in concrete leakage or even block breakage in concrete pumping especially when the blocks are installed by less experienced labours. The normal block joints can also cause the same leakage and breakage problem but in lesser extent. Tailored Blocks are made in such a way that their installation becomes easier and faster with the minimum risk of concrete leakage or block breakage.