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Insulated Concrete Formwork

Polysteel is a UK based ICF manufacturer that uniquely uses steel ties to produce ICF blocks called Polybloks.

Our in-house engineering expertise offer specialised ICF Design and Training services to ensure the success of any project.

Delivered in 2 or 3 days

Made in Newport, Wales

Premium Quality Forms

Used in UK since 2008

Polysteel is not just another ICF supplier. We will become part of your project team and will always be on hand to guide the site management team and help them overcome every problem that arises.

Send us your Architects drawings and we will provide a preliminary ICF wall layout, precast beam layouts for the ground floor by Litecast with Gdeck insulation and quotations for the following:

The Polyblok (ICF) Walls
The Ground Floor Precast Beams
Gdeck Insulation at Ground Floor Level

All this data will provide you with the essential information required for budgeting and project planning.

And after you have placed the order for your Polybloks we will undertake the Detailed Design that will provide every detail that you need for the successful construction of your Polyblok project.

Polybloks are provided with a BBA (British Board of Agrément) certificate that ensures all buildings incorporating our ICF blocks will be accepted by the NHBC (National House Building Council) and similar building insurance schemes.

Polybloks are also certified for use in basement retaining walls. If you are planning a basement this is fundamentally important. Not all ICF blocks are certified for this type of use.

Building Inspectors may also require to see the certificate before allowing their use.

Polybloks are made in the UK with steel ties and ferrule strips – not plastic and this makes them very suitable for newcomers to ICF.

The rigidity of the Polybloks, made with steel ties firmly anchored inside the EPS, facilitates easy and accurate, installation of every Polyblok wall.


Our design drawings will show how to prop the walls using vertical bracing timbers to ensure that movement does not occur during concreting
The steel ferrule strips inside the EPS leaves provides a quick, reliable way to fix the vertical bracing timbers and external or internal finishes.
The steel ties allow Polybloks to be fixed together with steel clips that holds each block rigidly against its neighbour and ensures that the wall will not “blow” when being filled with concrete.

Polysteel provides free training for all Clients that are new to ICF construction.

The steel wire ties ensure that the one third of a ton of concrete in every square metre of a 150mm Polyblok280 wall is maintained at the internal room temperature. Plastic ties do not provide this advantage and are fa more susceptible to damage from an internal fire.

When the external temperature drops or rises it can take 10-12 hours for the concrete walls to reach the same temperature without any energy input. This means that houses built in Polybloks remain much warmer in winter and much cooler in summer.

When Polyblok walls are based on footings buried deep into the earth this adds to the warming and cooling effects as the concrete is heated from below in winter and cooled from below in summer.

This effect is enhanced if the walls are reinforced as the vertical steel bars carry the heat very effectively.

Why choose ICF?

Polysteel’s unique ICF system is superior to traditional construction methods like Timber Frame or Cavity Walls.


polysteel icf-apartment-construction

1978: American Polysteel is founded.

1980s: Modern ICF blocks are introduced.

2008: Polysteel (UK) is born.

In 2022, Polysteel (UK) was taken over by new management. The new Polysteel Team is led by a Chartered Civil and Structural Engineer with two decades of experience in ICF Design and Construction.



The new Team at Polysteel have been using ICF forms to build swimming pools and pool halls for 20 years and have always called them “Polybloks” and will carry on with this tradition.

The Team are undertaking research into the future development of Polybloks to meet the needs of its customers – so please watch this space!

Polysteel provides Clients with an integrated Design Service that provides Structural Layouts based on the Clients Architectural Plans.



Polysteel’s sister company Bluepools is a specialist Pool Design Engineering company that has been using ICF for decades.

Bluepools has helped Builders, without any ICF experience, construct over 100 complex swimming pools and pool halls for their delighted Clients.

This success is based on the Structural drawings produced by a team that really understands how to use ICF and will now provide the same service to Polysteel Clients.

ICF Construction

If you are looking to use ICF on your next project but need more detailed information before you start, give us a call.