hello from Melbourne Australia I am new to this forum as we are in the process designing a modern energy efficient house on a down slope. The information I have been reading in the forums is extremely useful as we are probably going to utilise ICF blocks or panels for cost, ease of construction and the obvious insulating effects of living in a climate which reaches over 43 (109F) degrees in the shade in summer, and be bitterly cold in winter. We are building a 2-level solar house with hydronic underfloor heating, double glazing, water recycling systems and photovoltaic electricity generation. We also will be incorporating a swimming pool which I will build from ICF Blocks - because of the slope, it will be an above ground pool with decking to the house. One problem I need to address is shrinkage (drying) of the polystyrene due to heat over time. What experience or advice can members offer about shrinkage and other hurdles we will face? Thanks

I'm jeolous. I love Australia although my experience is limited to about ten days.

Regarding ICF shrinkage: Although it's unusually cold today (and for the past week) we have our share of heat here in Texas with an occasional week or two with highs that do not drop below 100 F. (about 38 C).

The only measureable or perceivable shrinkage i've encounted occurs when a manufacturer ships product that has not been properly cured. Do your homework when you select a block manufacturer and make sure they cure their product prior to shipment. What this means in the case of NUDURA ICF is they place product on a very slow moving mechanism that moves over a period of days through a high temp room (FIFO - First in First out) --- when it comes out on the other side -- dimensions are checked to ensure the product is within a very small tolerance and then the product is packaged and shipped. I don't know this for a fact but believe you will be unlikely to find this problem with the major ICFs.

If for some reason you must use a manufacturer that does not cure their material you might find that after the concrete is in place it may not make much difference anyway ;)

We have been distributing and building with AMVIC for 5 years now and they are very consistent shrinkage is not an issue as I am sure most ICFs are consisent or they would be out of business.
You may have the issue of sourcing ICFs in Australia. Find out what brands are available and who is building with them and for how long. You may find out you could become a distributor down under. Good Luck

Thanks for the info which is reassuring.

My only experience with polystyrene is that I used to own a beanbag chair company and those polystyrene beans dried out and shrunk over time. Also my father had many years in the frozen foods industry, so had seen polystyrene insulated panels also shrink over time.

I have found some Australian ICF polystyrene block suppliers:

ZEGO (Australia's largest?)
QUADLOCK USA - has an Australian agent
Ecoblocks South Australia
Formcraft
Insulbrick (Danish Constructions)

If anyone has any dealings or recommendations, that would be appreciated!
Thanks
Dan