Design Easy, Build Easy, and Easy Living

Insulating Concrete Formwork for Professional Builders

Going down the route of an insulated formwork construction method is a good idea.


Going down the route of an insulated formwork construction method is a good idea. It is fast and cost effective in most scenarios. And it can be built with less skilled labour.

So kick those brickies off your critical path and embrace the future of sensible construction.

However, with so many different systems in the market how do you choose which one suits your project? Read the 25 legitimate reasons why you should seriously consider Polarwall and we look forward to hearing from you.


25 Solid Reasons Why Polarwall Should Be Any ICF Builder’s System of Choice


1. Not A Block

Polarwall is made of planks of Insulation Board and WE ARE NOT A BLOCK !  This means that we do not have the male/ female connectors and the benefits of this are many.  

We believe that most experienced ICF builders will enjoy the peace of mind and the simplicity of building with Polarwall .

We are listing the differences between Polarwall and the block ICF systems so you can get an idea of how our differences will have a positive effect on your build and the structure that you present to your clients.

2. The Plank Advantage

We are not tied to using Expanded Polystyrene (EPS)and we are offering two other insulation choices in our formwork.

The first is Extruded Polystyrene (XPS) and this is the material of choice in our European business.  XPS is a more expensive material and offers superior mechanical strength, better moisture resistance and an improved thermal performance.  This is the material for those who want the best and are prepared to pay that bit more.

The third choice is a very expensive option where we use cellular glass insulation in the formwork. This board is made from recycled foamed glass and has the unique distinction of being the most fireproof insulation generally available today. 

Combinations of board types are possible so that for example. lets assume that you are building apartments you could choose a polystyrene generally for all parts of the structure but opt for cellular glass around the windows, which is where a fire usually escapes from the inside to the outside. Additionally you might opt to have cellular glass running as a band between storeys to provide the fire break that local code might require. 

3. The Uplift Issue

The trouble with flowing concrete is that it tries to lift and float light components.  Some block systems suffer from this and a continuous line of adhesive is the suggested remedy.  Trying to fix the mess from a lifted joint is time consuming and costly.  We are proud to state that in all the years that we have been pouring into Polarwall structures we have never seen or heard of one single incident of uplift of the formwork. The reasons for this are:

a) Our patented ties have the smallest cross section for the concrete to grab hold of.

b) Our patented rails have been designed with special barbs that are designed to lock into the insulation board and hold it where it is meant to be. 

4. Whalers and Soldiers

If you are familiar with traditional concrete formwork then you will understand that a necessary feature for keeping walls straight and vertical are horizontal whalers and vertical soldiers.   Soldiers in ICF are the props but no ICF has horizontal whaler members except one – Polarwall.  Our rails are assembled in “ladders” which are like beams laid on the flat with a stiffness and straightness that you wouldn’t expect from plastic.  This is the secret to why we can create the straightest walls of any ICF which means less time wasted later on in applying both internal and external finishes.

5. Any Floor, Any Roof

Being a plank system means that we can easily build with any type of floor – timber joist , pre-cast concrete,  cast in-situ. or cassettes. 

Our timber joist system is like no other as the wall plate becomes an integral part of the formwork.  Some builders have fastened the timber floor in place before the pour and then used it as their pouring platform rather than fork out for scaffolding.

Concrete floors can be any depth, be pre-cast or in-situ.  We even have a neat and simple way to deal with the camber on pre-cast floors. 

Similarly, we don’t know of any other ICF that can incorporate a shutter box to tie in those in-situ concrete floors so neatly,

6. Any R-Value

This is another advantage of using planks of insulation. We can get to whatever thermal performance you need simply by using the right type of insulation at the correct width. 

Our top performing specification is R35.

Check out our details and request our independently audited Psi value calculations to see some of the unique solutions we have for ensuring the Net Zero Design.

7. Concrete Core Sizes

 We have a wide range of core sizes available from 4″ to 12″ in 2″ increments. For above ground structures we advise the 6 inch core. The 8″ core is ideal for swimming pools and for shared dividing walls between residences in apartments, and though this size can be used in basements we would advise using the 10 inch or 12 inch.  The wider size allows for better concrete compaction when there are 2 layers of reinforcement. 

Ties can be joined together to make a very thick concrete core or an extra wide corbel detail.

8. Core width changing

Imagine a walkout basement built on a slope that is fully retaining on the rear wall partially retaining on the side walls and not retaining on the front wall.  The ideal engineering design might need a 300mm core on the rear, 250mm on the sides and 200mm (or 150mm) on the walk out wall. This isn’t an issue and there are no special components needed.  we just change the core width as we come round the corner.  And we can change the insulation thickness at the same time to if that is required.  In fact, the sloping side walls might also be stepped with core changes.

9. Curves and Angles

Sometimes a designer throws away his ruler and get his compasses out to create building with flowing curves.  with Polarwall this is not a problem.  We simply assemble our rails and boards vertically and create a smooth faceted curve.  Also, we can use our in-house software and our CNC cutters to create any curve you can imagine – and made exactly to the radius specified.  Sometimes architects want more flowing than a radius and design something “freehand” like an ogee curve.  This isnt a problem either.  In fact we can even do vertical curves – think pregnant woman !   See the picture at right.  We don’t know of any other system that would have attempted to tackle this particular feature.  We did this concrete pour on National TV working with an amateur builder.   

10. The Thermal Envelope

Polarwall can place any thickness of insulation board to both inner and outer faces which allows us to achieve ridiculous U-values.

Our window and door surround details can be built totally in insulation which means that we create the perfect thermal envelope around the concrete. 

Achieving Net Zero home standards in USA or PassivHaus standards in Europe is not an issue at all. 

11. Fast build

If you compare assembling Polarwall to assembling block ICF systems then on the face of it the block system appears quicker.  However, once you see the timber that most block systems require to strap together, make cuts and joints to meet modular dimensions and all the extra strapping then the scenario completely changes.  If you then add in the time taken to make good imperfectly poured walls then we would usually step well into the lead. This comparison is for site assembled forms but we have another weapon up our sleeve – large panelized construction and for more information on this go on to read the next section.

12. Fastest Build – Large Panels

For larger projects like apartment blocks a builder or developer should certainly consider pre-building the formwork in large panels.  

The panels for third and fourth floors are being built on site using simple jigs whilst the site crew are assembling bracing and pouring the second floor.  Now the construction schedule becomes non-linear and build speeds can get ridiculously fast.

See our case studies for a 95 apartment block near London. The largest panels on this job were full walls sized at 42 ft x 9 ft ! At left is a relatively small one being craned into position.

13. Special Basement Rating

Our UK company has been rated as the most effective ICF system for creating waterproof basements by Britains leading waterproofing manufacturers and designers.  They give us this rating because we are assessed as giving the most compacted concrete structure (which we are happy to vibrate) and because we use XPS in our formwork exclusively when building below grade.  Also our 10″ and 12″ crossties are seen as big positive in achieving waterproof concrete due to their having two waterbars (or puddle flanges built into each slimline crosstie.

14. A Fireproof ICF Solution

Our Polystyrene boards all have a fire retardant.  However, a fire retardant is NOT fireproof and even the highest dosed polystyrenes (like most foamed insulants) will melt away in high temperatures.

There are only two A1 rated fireproof insulants – mineral wool and cellular glass.  Mineral wool has no rigidity and accepts moisture so is completely useless in concrete formwork.  

Cellular glass (or foamed glass) is the perfect solution and Polarwall are about to build the first totally fire proof apartment block in Glasgow, Scotland, using this material to the outer face. 

We have previously incorporated cellular glass insulation to create the firebreaks between floors and have just added a detail in window soffit areas to stop the spread of flames from inside to outside, but this new fully fireproof ICF structure will be a World first in construction safety.

Obviously this is not a cheap solution.  

15. A Composite Material?

The XPS insulation we use has a special surface finish designed to bond to concrete.  When the concrete cures the permanent bond between the concrete and the insulation is huge.

At right is a photo showing a typical core sample taken form our walls.  Here you can see this 4 inch core of concrete is being held by the bond between the materials.  This simple sample always generates lots of interest at Trade Shows and demonstrates what happens inside the wall as the concrete cures.

16. Pool Building

Pool builders across Europe have been enjoying the simplicity of Polarwall pool construction for years.  They love that the nuslation can be removed on the inside (if required) and they enoy the savings from one concrete pump rental when they pour the pool walls and concrete raft all in one pour.  The one pour pool also removes the cold joint between the wall and the raft.

Add to that the simplicity of creating curved pool walls or building a deep and shallow end with Polarwall and you can see the attraction of this method.  

17. One Side Insulation or None

Sometimes it is required to have no insulation to one or more faces. Such uses might be for parking garages, commercial pools, or internal separating or buttressing walls. 

You can either build with cement fibre board as a permanent shutter to one, or both sides.  Or you can use a removable (and re-usable) ply shutter.  

Some builders have also oiled the boards and removed them fairly soon (inside 36 hours) of the pour and before the concrete bonds to the board. 

Talk to us to discuss the various options here.

18. Shutter Box

When you have a cast in-situ concrete floor it is necessary to tie the wall reinforcement into the floor reinforcement. 

On some high rise projects the builder has opted for using a shutter box, for safety and neatness. These are ideal for using with Polarwall.

All the L bars are out of the way to the site operatives and removes lots of the risk for injury from the rebar.   

19. Formwork Blow-Outs

This is a topic that no-one wants to discuss because we all know that no ICF system ever bursts!

All formwork systems can hold concrete and all can burst – even our super strong one.  However, lets have a look at how to fix that burst in a way that is so simple and neat that bursts will hold no fear and is totally stress free.

On the photos at left one of the builders operatives put in some rail without ties. This should never happen because rails are snapped to the ties with the Snapper and each course should be checked before the next course goes on. But we are all human and mistakes happen.

Here, we simply let the concrete out, gave it a quick clean with a wet cloth, and added some ties to make it strong again.  Then we cut a new board down its length at around 45 degrees.  Then we simply insert the two halves back into the H-rail above and below the opening. Then we use a couple of pieces of scrap ply or timber to support the cut in the board and we simply screw this ply strapping pieces into the H-rails.  Afterwards, when the concrete has cured the ply can be removed. Apart from the concrete stains below the burst and the  horizontal cut line along the board, there is no evidence that a burst ever happened, and the wall is still straight and true.

20. Low Volume & Low Waste

Everything is flat packed so the Polarwall system doesn’t take up the same room on site that others do.  This also means reduced shipping costs for you and general ease of handling. 

And because we can use up all offcuts of rails and ties right down to about 4 inches long the total waste on site should be almost nothing.

The ladders of H-rail and U-rail do have to be assembled but for that we have the Snapper – see next section.

21. The Snapper

The Snapper is a simple jig that we make sure is on every site.

The Snapper clicks all the ties onto the rails at the proper centres. It takes about 20 seconds to lay it out and pull the lever so the day’s production can be snapped up by one person in no time at all.

Its a simple matter to adjust the Snapper to take the range of crossties that make up the Polarwall system.

22. Straightest Walls

We occasionally see ICF projects posted on Social Media boasting about how quick this was built.  But “Basement Built in 4 days” is not much use if the walls are out of square and the finishing is going to take days longer on the inside and outside. 

Our approach to corners and our rigid ladders (acting as whalers) can give perfectly straight and aligned walls for those with only a basic building knowledge.

The secret to a straight wall is very simple.  You keep your corners vertical and plumb and it is very difficult not to have a straight wall.  However if your corners are not kept plumb then it is virtually impossible.   Here is another area where Polarwall comes into its own.  Our specially moulded rigid corners when combines with our corner bracing make keeping the corners plumb a very simple task. 

We hold that it is better to pay a little extra attention to the corners and get things right because no one wants to deal with crooked walls once that concrete has set.

23. Fewer is Better – A True Story

It was an International Construction Show at the Excel Centre in London, and Polarwall was one of several ICF systems exhibiting there.

Late in the day, a young man from a well-known European ICF system came onto our stand and introduced himself and pleasantries were exchanged before he stuck his chest out and smugly announced,

“We believe that we have the most complete ICF system in the world!”

“Oh really? Why is that?” I asked politely.
“Because we have 239 separate moulded components.  And with that amount of components we can build practically anything.”
I smiled and said “I bet you can”
He looked questioningly at our sample wall and followed this up with, ” And how many components do you have?”

I said “Good question, but I have never counted them.  Lets see… we have three moulded corner types,  two different rails, four sizes of cross tie, and the insulation boards. So I suppose that we have 10”

He looked a bit confused, before I gave him the coup de grace…
“But with those 10 components, we can build absolutely anything!”

It was “Game Over” and he wandered off

24. Level Set Out ?

We have seen that some systems require that their forms are built off a surface that is level to within a quarter of an inch. 

Obviously it is easier building off level but we don’t worry too much about such perfection as our walls can be height adjusted at any time.  

The photo to the left probably gives a better indication of what we mean by not being flat.  This is a swimming pool being built in a large leisure centre and this pool has a deep end.

25. And Finally It’s Training

We work collaboratively with architects engineers and builders to try and build the best structures possible.  To that end, we are always available to discuss methods, details and related products, and to help you understand the possibilities of our products we offer free online training to anyone who asks.  This online training is not a new thing for us and we have been offering this service for over 13 years. 

We have never charged for training.  We always attend a builder’s first concrete pour and treat this as the most important element of our training.