ICF – what is it?

ICF stands for Insulating Concrete Form. It is an energy efficient building method which creates insulated structural walls for residential and commercial buildings.

Imagine stacking giant, hollow, steel reinforced Lego blocks made from Expanded Polystyrene (EPS) to create the exterior walls of your house. Once you’ve finished joining them all together, then fill the cavity inside the Lego blocks with concrete and wait for it to solidify. You’ve just completed the building envelope of your project in one step! That’s basically the principle behind ICF. However, the reality is that this system of manufacturing walls has many advantages over traditional methods.

The EPS acts as a rigid thermal insulation that stays in place either side of the concrete core. ICF construction has become a great, energy efficiency solution for new builds. It is also useful in areas with natural disaster-resistant building codes. ICFs may be used with frost protected shallow foundations (FPSF) too.

The History of ICF

You might be forgiven for thinking that this innovative construction method is a fairly new invention. In fact, according to Wikipedia: “the ICF construction technique was first developed in Europe following World War II as an inexpensive and durable way to rebuild damaged structures. The first polystyrene ICF forms were developed in the late 1960s, following the expiration of the original 1940s patent, and the advent of modern foam plastics.”

Since the 1970s, ICF adoption as a construction method has steadily increased, although factors such as a lack of awareness, overly restrictive building codes, and manufacturers causing confusion by selling slightly different ICF designs have slowed its outreach.

In the developed world, ICF construction is now accepted as a reliable method of construction in most jurisdictions.

Why is it a good method?

There are a number of reasons:

Energy efficiency:

  • Air leaks are minimised, reducing heat loss and improving comfort.
  • Improved energy saving compared with uninsulated masonry as heat put into the building stays in the building longer.

Fire protection:

  • ICF walls can have a four- to six-hour fire resistance rating and negligible surface burning properties.


  • Up to ten times stronger than wooden framed structures.
  • The structural integrity of ICF provides better resistance to the forces of nature.
  • Rot-proof materials, even when wet.
  • Beneficial results when used in high seismic risk zones.

Indoor air quality:

  • Humidity levels are better regulated because they are generally constructed without a plastic sheet vapour barrier.
  • Less potential for mould
  • More comfortable interior whilst still maintaining a high thermal efficiency rating.

Sound absorption:

  • ICF walls have much lower rates of acoustic transmission.
  • Wall thickness, mass, component materials and air tightness all combine to provide better sound absorption.

Vermin and pests:

  • There are no gaps for insects, vermin and pests to exploit as an entrance into the property.
  • The entire structure provides a much more challenging barrier to insects and vermin.

How Monolith adds value

Whilst ICF is a great idea for the internal structural support of a building, it needs to be clad in an external product that looks attractive; adds thermal value if required; can add more fire retardancy if local building regulations or environmental factors dictate; and are fast to install and cost effective versus traditional methods.

This is where the entire Monolith range adds value to the exterior of your ICF project. They can all be adhered directly onto ICF substrates.

All of our products are designed to complement ICF projects, and are fast becoming the go-to range for forward-thinking planners, architects and self-builders.

BrickPlus: Pro

BrickPlus: Pro integrates a fire retardant mesh into twelve brick slips to create a panel, ideal for rapid installation. The benefits include:

  • Increasing application quantity whilst decreasing application time.
  • Very low porosity – 90% less absorption than clay brick, meaning the building sheds water much, much quicker.
  • Easier to work with, handle and apply.
  • Can be made to order in multiple colours, textures and finishes.
  • Higher strength per gram than a traditional brick slip.


StonePlus is a true alternative to traditional stone that is extremely lightweight. It has the same look and feel as stone, but is around 75% lighter whilst being equally as strong and weather resistant. Benefits include:

  • Lightweight stone alternative – two man jobs are easily converted to one.
  • Easy to handle, fit and manipulate, lessening Health & Safety concerns on-site.
  • Can be tailored specifically to the requirements of your project.
  • Almost endless designs are available in a wide variety of natural stone colours.

BrickPlus: Eco

BrickPlus: Eco is one of our most popular products for ICF buildings as it adds thermal value to a project. It consists of twelve of our BrickPlus: EcoSlip products which are bonded to lightweight, fire retardant, high grade EPS panels. This forms a system of interlocking devices that can dramatically increase the speed that a brick slip wall can be covered.

  • Easy to install.
  • Rapid fit – 75% quicker than traditional methods.
  • Thermally efficient.
  • Ecologically enhanced for your project.
  • If scaffolding is required on your project, it can be hired for a much shorter timeframe, with no loading platforms necessary – reducing your costs.

BrickPlus: EcoSlips

BrickPlus: EcoSlips is our range of thermally efficient brick slips. They are produced as individual slips on a 10mm lightweight, fire retardant, high grade EPS back panel. As with all our products, they can be made in a wide variety of colours, textures and finishes. They have very similar benefits to our BrickPlus: Eco product.

In conclusion, we feel that our entire range of products is ideally suited to ICF properties – large or small. Whatever you have in mind, contact us to see how we can add value to the exterior of your build.

Email us on orders@monolith.build or call 01745 535 855.