Insulated Concrete Formwork Building Systems

Viking House

Yes! but Polysterene is one of the least dense insulation materials there is, so if you turn off the heat on a cold day the house will get cold quite quickly. Polysterene is made up of closed bubbles that won't leave heated air into the insulation so it can't leave the heat back out when the heat is turned off.
People talk about the thermal mass of concrete, concrete leaves off its heat in about 3 hours.

If you bring a concrete block into your heated living room for three days you will still get a cold arse when you sit on the block on the third day.
Its what they call cold material in Scandinavia and the feeling of cold you get when you stand close to a concrete wall even though the temperature is the same near the wall as the middle of the room.

In order to put some density into ICF to reduce dramatic heatloss and to avoid fungus and mould problems I would consider lining the inside of the house with 50mm softboard and then Plasterboard or Fermacell.

kadman

It is possible to order varying densities and thicknesses of some ICF manufacturers polystyrene products, as there are double panel systems , and single panel systems available. Whereby the double panel wall effectively acts as both a polystyrene formwork with a core fill of concrete, and a structural render on the 2 cores of polystyrene. And the single panel polystyrene being coated on the 2 faces, internal and external, with a structural render. Thes single panel can be manufacured as thick as 330 mm polystyrene, with 35 mm structural render. Double panel 100mm polystyrene, 150+ core fill, 10mm polystyrene.

kadman

Do-more

Is there much benefit in using aerated concrete to fill the ICF's?

Come to think of it, is there anyone pumping aerated concrete in this country?

Viking House

ardara1 wrote:

Main advantage in ICF is the airtightness achieved - nothing much different when it comes to U-values - same results, thermal and airtightness can be achieved using traditional methods - if built properly.

When has the traditional method ever been done properly? Irish blocks are made with a tolerance of +- 1mm so any 2 blocks in a pallet can have a 2mm difference between them. Thermal Looping occurs when there is 1mm between the insulation and the block reducing the effect of the insulation by 33% on average!

Have you ever seen an Airtightness test result for a traditional Irish built house?

ardara1

Viking House wrote:

When has the traditional method ever been done properly? Irish blocks are made with a tolerance of +- 1mm so any 2 blocks in a pallet can have a 2mm difference between them. Thermal Looping occurs when there is 1mm between the insulation and the block reducing the effect of the insulation by 33% on average!

Have you ever seen an Airtightness test result for a traditional Irish built house?

I've carried out 4 over this pas 2 months - on houses where the builder had not been notified as to what the test was about - we averaged 6 - just about twice as good as the standards asked for under Part L. (All house were were wet finished internally) We've also tested Timber frame and had results of 5 (And 12 - bad one!)

I'm confident that wth a bit more care on site air permeability can achieve below 5 (or 0.25 achr) quite easily)

Do-more

Do-more wrote:

Is there much benefit in using aerated concrete to fill the ICF's?

The only benefit I can think of is a marginally better U value of the completed structure.
May be OK for non-loadbearing parts of the structure, But you would need to use ordinary concrete over lintels etc, probably more trouble than it's worth.