FAQs
Welcome to our ICF Design FAQ page! Here, we’ve compiled answers to the most common questions about Insulated Concrete Forms and our design services. Whether you’re new to ICFs or looking for specific details, we hope this resource helps you understand the benefits and process of building with this innovative, energy-efficient material.
About ICF:
Insulated Concrete Formwork is a modern construction system which combines hollow EPS blocks that are filled with concrete to form a solid wall. Strip footings or slab foundations are installed and then the hollow forms are built into a wall on the foundation. They are laid with staggered vertical joints and are held in place by scaffolding or a propping system whilst they are filled with high strength pumped concrete made with 10mm aggregate. Find out more.
Yes. The forms become part of the wall and the EPS from which they are made provides valuable insulation.
The concrete core is solid concrete that has very high strength and rarely cracks because the shutters are never removed as with traditional concrete. Therefore it cures very slowly under ideal conditions so that it eventually becomes twice as hard as shuttered concrete where the shutter is removed within a day or so – as shown in this graph.
Ties (or webs in the US) are used to hold the EPS together. This is an interesting topic because the internal ties are one of the primary elements that differentiate ICF systems. Some manufacturers use the same polystyrene to make the ties (Beco Wallform and Econekt) as the wall elements. This makes the forms much cheaper to make but has the drawback that they do not provide solid concrete sections that comply with the Codes of Practice and hence are very limited in terms of what they can be used for by the Structural Engineer. Most of the other manufacturers use polypropylene ties, spaced at either 150mm or 200mm (6″ or 8″ in US speak). The closer the tie spacings are, the more rigid the forms are. Polysteel uniquely uses galvanised steel ties, spaced 150mm apart and is consequently the most rigid form available. And the steel wire ties bond with the concrete making the Polysteel forms more water-resistant and ideal for the construction of basements. Explore the different ICF Suppliers in the UK, here.
Experience has shown that the life of very good quality concrete is virtually infinite if the surface is protected from moisture and salts as is the surface of ICF walls. The better quality ICF forms use Neopor EPS manufactured by BASF and the forecast life is 75 years (click here for more information).
In truth, the biggest potential problem with ICF is that it is not easy to demolish, however all the constituents are recyclable. It is highly likely that most ICF houses currently being built with last several times as long as modern timber frame or cavity wall ones will.
The Council of Mortgage Lenders issued a letter to the ICFA on the 13th September 2012 confirming the following statement:
FEBRUARY 2010
The Valuation Panel of the Council of Mortgage Lenders confirmed that ICF (Insulating Concrete Formwork) construction is acceptable for mortgage purposes as a standard form of construction, subject to provision of valid product certification and monitoring of ICF System providers by the ICFA (Insulating Concrete Formwork Association) of the UK. The lending decision is always at the discretion of the mortgage lender advancing the funds.
If you have planning permission for your project, we will provide a proposal to develop your architectural drawings into building regulation drawings using the ICF system that you have chosen.
If you are currently working with an architect on your project, we can work with them to advise them on all the ICF elements of the build.
We can also act as your Structural Engineer should your project require these services.
Find out more about our different design services.
We can collaborate with your architect on the design and planning of your project and advise them on how to maximise the benefits of using ICF.
ICF will take you a long way to achieving a home with Passivhaus insulation standards. However, to be frank, any level of insulation that is higher than the 0.18 w/m2K current requirement of the UK building regs will not provide any discernible benefits.
ICF can be used for practically any type of building. Some projects will require specialist advice on the best course of action. We will advise you if your project is complex and requires particular attention in certain aspects of the build.
Find out more about the different types of projects that can be built using ICF.
It depends on the ICF system you choose. Some suppliers have specialist installers that are required to use their products whereas others do not require you to use workers from their list of recommended installers.
Find out more about the different ICF Suppliers in the UK and compare the differences between them.
There are a number of ICF suppliers in the UK. We will only recommend using members of the ICFA as they are required to uphold valid certification as part of their membership. This is a critical element to consider when selecting your supplier as this could negatively impact your mortgage if they did not have a recognised certificate.
Find out more about the different ICF Suppliers in the UK and compare the differences between them.
We can change any plans to ICF.
Find out more about our different design services.
Yes. If built correctly, ICF is not susceptible to the same issues as timber frame and cavity wall homes. ICF walls have no cold bridges like cavity walls and are not susceptible to damp like timber frame. ICF walls are waterproof, dampproof, soundproof, fire resistant and pestproof.
Explore the differences from ICF Construction to Timber Frame and Cavity Wall Construction.
Our Services:
Build smarter: stay up to date with the latest industry news & icf insights
Subscribe to our newsletter for exclusive Insulated Concrete Formwork construction insights, key industry developments and updates on the constantly evolving landscape of house building in the UK.