ICF Suppliers

When considering which ICF system to chose for your UK project, selecting a supplier that is a member of the Insulated Concrete Formwork Association (ICFA) offers a crucial layer of assurance.

ICFA membership signifies that the ICF supplier’s products have undergone a rigorous vetting process and comply with recognised quality assurance schemes, such as those provided by the BBA or KIWA. This commitment to independent certification ensures you are investing in a proven, high-quality product that meets UK industry standards and is always essential for securing mortgage finance.

Selecting an ICF Supplier.

You are choosing a building system, not insulation. The form size, the joints, the connection system between blocks and the method of bracing are of fundamental importance.

The choice should not be determined by the overall U-Value. Each system listed can achieve higher insulation levels by adding EPS inside or outside the wall. The flexibility that this provides will be even more important when the Home Energy Model replaces SAP in the summer of 2025.

uk-icf-suppliers-insulated-concrete-formwork

When choosing between ICF Suppliers, consider the main factors that will impact the build in terms of simplicity, reliability and flexibility.

Buyers should bear in mind that products from across the Atlantic like Nudura forms which are “unfolded” are not as easy to use as the European products that are rigid and less likely to “burst” when the concrete is being pumped into them.

UK ICF Suppliers List

ICFA Membership

There are currently 11 different Insulated Concrete Formwork suppliers in the UK who are active members of the ICFA. Established in 1992, the ICFA is a trusted association aiming to promote the use of ICF in the UK. The leading supplier is nudura icf, who manufacture their forms in North America and ship themn to the UK in continers.

The price of materials is obviously important but the real cost lies in the total construction cost, which includes installation time and labour. Some key factors to consider when evaluating the overall cost-effectiveness of different ICF forms are:

Dimensions: metric or imperial?
Size & Installation: do they require specialist installers?
Joints: how do they connect together?
Rigidity: what are the concrete blowout risks?

How can I plan my ICF project?

To make your project the most budget friendly and effective you should use an optimal approach to planning with ICF for the maximum efficiency and minimal cost.

Appoint an architect or ICF Design to prepare the Concept Design.
Apply for Planning Permission OR Permitted Development.
Choose between ICF, Cavity Wall or Timber Frame & identify project schedule and budget.
Pick your preferred ICF Supplier.
Apply for Building Regulation Approval with Full Plan submission OR Giving Building Notice.
Appoint ICF Design to prepare Construction Drawings

What are the differences between ICF Suppliers?

Whilst UK ICF suppliers offer similar products, key differences in their systems can significantly affect your project’s timeline, accuracy, and budget.

These differentiating elements encompass the dimensional units of the blocks (imperial or metric), the scale and installation mechanism of the forms, the inter-form connecting systems, and the inherent rigidity of the constructed wall.

As the metric system is universal in the UK, there is no doubt using forms with metric dimensions is a lot easier and reduces potential errors.

This is particularly true with respect to levels where it is important to keep window and door sills and heads at the top of an ICF course to avoid extra cutting of the forms and reduce the risk of concrete leaks.

The primary difference between ICF Suppliers in the UK is the size of the forms. The longest form is the standard Nudura block measuring 2438mm x 457mm x 286mm and equal to 1.1m2 of wall. The highest is the Polysteel form measuring 1200mm x 600mm and equal to 0.72m2 of wall. The smallest is the Beco Wallform block that is equal to 0.28m2 iof wall.

Size is an important consideration as the larger the form is, the faster the installation. For instance, a standard concrete pour height of 2.4m requires 6 courses of Nudura insulated concrete forms and 4 courses of Polysteel forms.

Concreting problems can be reduced by choosing forms with the best and lowest number of joints. The joint frequency can be compared by using the joint length / area ratio for each type of form. Polysteel is lowest with a ratio of 5.0 and Nudura is next with 5.1. The highest is Becco Wallform at 10.7.

Polysteel have deep tongue and groove joints on the horizontal and vertical joints whereas Nudura insulated concrete forms just have the castellation joints on the horizontal surfaces. The majority of ICF forms have various sizes and design of castellation of joints on the horizontal but not on the vertical joints.

The Polysteel forms are provided with steel spring clips that hold the vertical joints together at the top and bottom of the form. Nudura insulated concrete forms require reinforcement to hold the forms together during concreting. Some forms such as Polysteel do not need reinforcement unless it is required for structural purposes.

The standard Nudura ICF forms have polypropylene ties and are flat packed to save storage space during transport. The forms have hinges and need to be unfolded before they are installed by trained installers of Nudura products.

Polysteel, Beco, Amvic and Altherm forms are prefabricated and cannot be flatpacked. This might increase the transport cost slightly but reduces installation time and substantially increases rigidity of the wall.

Polysteel ICF blocks are extremely rigid because of the x48 pieces of 3mm steel wires that connect the two leaves of the form together. As you woiuld expect galvanised, fabricated steel webs are a lot more expensive to make than injection moulded polypropylene webs but they do provide the most rigid form available in the UK.

When choosing an Insulated Concrete Formwork (ICF) system, availability is a critical factor. If you’re just a few forms short to finish a build and the supplier’s stock is tied up in overseas shipments, your project will grind to a halt.

What’s more, some suppliers offer competitive pricing only on full lorry or container loads. This means you could end up over-ordering and essentially becoming a stockholder until your next project. Remember, stockholding is a costly overhead, so factor this into your decision when selecting an ICF supplier.

What about the insulation?

To accurately assess the thermal performance of different ICFs, always ensure you’re making a like-for-like comparison of their insulation. A key benchmark for walls in the UK, post-June 2022 Building Regulations, is a notional U-value which generally necessitates around 150mm of EPS insulation.

The better quality ICF forms are made from grey coloured Neopor (manufactured by BASF) with a density of 24 kg /m3 that provides a U value of 0.030 W/mK

So if the leaves of a form amount to 130mm wide, then about 25mm of extra EPS will be required to meet the 0.18 W/m²K. This can be added as External Wall Insulation (EWI) or as insulated plasterboard with 25mm of insulation.

Increasing the insulation in this manner is far more cost effective and won’t slow down the installation rate. Remember, the only real risk with ICF is problems during concreting so it’s important to keep this element simple.

UK ICF SUPPLIERS

Principle Characteristics of Standard Forms

This information was compiled from supplier certifications (like BBA and KIWA). For the most current details, you should always verify directly with the suppliers, as updates occur regularly.

UK ICF Suppliers
EU ICF Suppliers
North American ICF Suppliers

SUPPLIER	Beco Wallform	Polysteel
Made In	UK	UK
Availability	3 days from stock	3 days from stock
Certification	BBA	BBA
Standard Form Size (Length x Height x Width)	1125 x 250 x 313 = 0.28 m2	1200 x 600 x 280 = 0.72 m2
Standard Concrete Core (mm)	140	150
Basic U-Value (W/m2K)	0.18	0.23
Reinforcement Required in all walls	NO	NO
Certified for basement use in BBA	NO	YES
Web & Anchor Plate Material	EPS without no anchor plates	Galvanised Steel
Distance between Webs	187mm	150mm
NOTES	In standard forms the webs are made from EPS reducing fire resistance. Special forms with metal ties are provided for 1 hour fire resistance. The manufacturing process is a lot cheaper and simpler when the webs are made from polystyrene but the big disadvantage is that there are no anchor plates provided in the forms.	American Polysteel was the 1st ICF manufacturer established in the US in 1978. Polysteel (UK) Ltd was established in 2008. The galvanised steel wire webs and steel anchor plates, spaced 150mm apart, result in a very rigid form that is suitable for the heavy duty formwork required for basement construction.

SUPPLIER	Altherm	Amvic	Econekt	Bewi (formally Jackon)	Thermohouse
Made In	Ireland	Ireland	Poland	Norway	Ireland
Availability	10 days from stock	10 days from stock	?	Several Weeks	?
Certification	BBA	BBA	Passivhaus (does not provide UK Reg. compliance)	BBA	BBA
Standard Form Size (Length x Height x Width)	1200 x 400 x 300 = 0.48 m2	1200 x 400 x 280 = 0.48 m2	1219 x 406 x 298 = 0.495 m2	1200 x 300 x 250 = 0.36 m2	1200 x 250 x 250 = 0.3 m2
Standard Concrete Core (mm)	150	150	150	150	150
Basic U-Value (W/m2K)	0.21	0.23	0.28	0.28	0.195
Reinforcement Required in all walls	YES	NO	YES	YES	YES (in 12mm bars)
Certified for basement use in BBA	NO	YES	NO	NO	YES
Web & Anchor Plate Material	Polypropylene	Polypropylene	Polypropylene	Polypropylene	Galvanised Steel
Distance between Webs	200mm	200mm	200mm	150mm	150 mm
NOTES	Established in Dublin, Ireland in 1917.	Originally established in the US in 1997.	UK agents with stock shipped into the UK.	Minimum order of x1 lorry load.	Established in Ireland in 2006. Has UK Agent that ships to the UK.

SUPPLIER	Build Homes Better	Integraspec	Nudura
Made In	Canada	US	US
Availability	-?	-?	1+ month (depends on UK supplier)
Certification	BBA (suspended)	KIWA	BBA
Standard Form Size (Length x Height x Width)	1219 x 406 x 298 =0.495 m2	1220 x 311 x 65 =0.379 m2	2438 x 457 x 286 = 1.114 m2
Standard Concrete Core (mm)	159	140	152
Basic U-Value (W/m2K)	0.21	0.23	0.23
Reinforcement Required in all walls	NO	YES	YES
Certified for basement use in BBA	BBA Suspended	NO	NO
Web & Anchor Plate Material	Polypropylene	Polypropylene	Polypropylene
Distance between Webs	200mm	200mm	200mm
NOTES	Details taken from Logix Canadian website.	UK agents with stock shipped into the UK.	UK suppliers split into regions (South West, South East, Wales, etc.)