SELF-BUILD ESSENTIALS
What is ICF?
Insulating concrete formwork (ICF) can offer extenders and self-builders a quick build and an efficient home, but what’s involved in this build method?
CLAIRE LLOYD Is a renovator and editor of Homebuilding & Renovating.
THE SUPERSTRUCTURE EXPLAINED
ICF is an on-site method of construction and tends to be used to build the walls only. As the name suggests, there are two main ingredients: the formwork and concrete. The formwork is built up in stages and is typically made of polystyrene, providing a mould into which ready-mixed concrete is then poured using a concrete pump. Crucially, the formwork is held in place and aligned with a bracing system prior to the pour. Bracing systems differ from supplier to supplier but often double up as a working platform, and in doing so, remove the need for scaffolding at this stage. Once cured, the concrete provides a strong, solid core; the formwork is left in place, providing a continuous, insulating layer on both sides.