Choosing Insulated Concrete Foam (ICF) vendor

Hi MrChelsea, I don't usually participate on these forums but are doing so now, because people who answer questions about icf usually have had no or little experience with it.
I am 65 and am building my own icf house. We are living in it as we finish off.
We have no air-con con, are totally off grid services wise.
It remains at 18 to 28 degrees c all year round. Even with 5 days above 43c in a row this summer. We do have double glazed windows which face west, as a consequence we have to shade these windows in the late afternoon or our temp goes to 32c
Our internal walls are icf and it is so quite we have to yell out to each other (though that could be because we are getting older lol)
We are slab on waffle pods, with 200mm bondor roof 3 to 3.5 ceilings with 12v solar ceiling fans.
Oh and our pantry never gets over 20deg c and that is 2 x 4 Mrs.
And yes there are a few things I would change but not much.
In my opinion if you don't build out of icf or is your crazy.
Brick anything don't go there, think about it your in Aussie, why would you put a big heat sink around your house?

Have you seen Durisol Nexcem? I initially was considering Zego ICF build, but then found out about Durisol and never looked back since then.

http://durisol.com.au/
https://nexcembuild.com/

It is also ICF, but so much better and much more ecological alternative to poly-ICFs as it is made from the real pine wood.

Truly incredible material properties (by the way, USSR has built its "Molodyozhnaya" station in Antarctica out of solid Durisol blocks):

https://nexcembuild.com/wp-content/uplo ... erties.pdf

Main advantage that Durisol house is "breathable", while foams are barely breathable (as they are not vapour permeable and hygroscopic), and also some of them Australian supplied forms still contain cancerogenic HBCD in them, which is used in EPS as fire retarder (and this is why they were banned in Europe and US and is currently being phased out, https://chemicalwatch.com/16534/end-in- ... rdant-hbcd). The rule of the thumb, if you consider a foam house, strongly consider a mechanical ventilation system for your house.

Durisol provides superb indoor air quality which has been proven by the best academic researchers in this field:

https://nexcembuild.com/indoor-air-quality/

Also, Durisol itself is a "wood concrete", made out of pine, smells like a pine, meaning you can you can nail your pictures, etc. directly into it. In fact, you feel like you are living in a wooden house.

With regard to insulation, poly ICFs do not have much of internal thermal mass as the core is heavily insulated from both inside and outside, while Durisol material is not only an insulator itself, but also carries a decent amount of thermal mass itself, which, when working together with concrete core and insulated from outside (with Rockwool in 250 mm block), significantly multiplies your thermal conductivity properties.

Not even closely comparable to brick veneer with that regard, which also has a strong thermal bridging effect, meaning that real life values can be up to 2x lower from the calculated ones.

More on Durisol thermal performance properties here:

https://nexcembuild.com/Webdocs/Durisol ... rmance.pdf

As for acoustics, you use Durisol 250 mm insulated blocks on your external walls with their recommended renders, you can achieve STCs of up to 65, your only problem will be the choosing right windows to match (but ask Werner from Durisol, they also distribute triple glazed Internorm windows from Europe, with the best acoustics and thermal properties you can get on both Australian as well as global markets). I have seen those in action, e.g. I was literally standing behind a huge 2.4 m x 5.6 m stacker door built into Durisol 250 mm wall and shouting as much as I can and the person standing inside approx. 3 meter from the door couldn't here even a glimpse of the sound.


By the way, if you use 150 mm Durisol walls blocks for your internal walls, you will be getting STC of 52+ (vs STC 38 in a studded insulated wall) including all the insulation and breathability/moisture handling properties - you will barely see any moisture in your bathrooms, etc.

Well insulated brick veneer house will be delivering STC of around 55 through external walls, as far as I remember.

In fact, they use Durisol walls for noise cancelling in tunnels and between railroads and residential areas.

There are few dozens of Durisol houses in Australia already, the distributor can also help you with the designs, engineering and advice through all the stages of your build as they are promoting a "fully composite system" helping you out to design a house from your slab to your roof to perform in the high end range both thermally and acoustically. A really customised approach, feels like being in "best houses" club. You can also visit Durisol houses and talk to their owners. When it gets to BASIX, Durisol house with Internorm windows is generally rated at least 9 stars.

By far, they are building/helping to build the best houses you can build in Australia. And from the costs, it is only about 20% add on when comparable to traditional brick veneer with single glazing, etc. and mainly due to the increasing cost of concrete.

If interested, leave me PM and I will connect you directly with Werner who runs the Durisol distribution in Australia, extremely knowledgable gentlemen with old style German engineering background.

There will be several Durisol builds starting in Sydney this year (including my own house in the Upper North Shore), by the way, so you can always visit and talk to the owners, builders, etc.

Hope it helps.

Thank you Alexp79. I'll direct PM you.

Mr ChelseaFC.
Sorry to take so long to reply, I am not a social media type of person, just an old buggy.
Our roof is 200mm thick solarspan that also forms our ceiling, and provides the ceiling insulation all in one go. I wanted the 300mm but they could not provide fixing screws at the time long enough. As solar span will spam 6 metres and we have a 3deg pitch no timber structural requirements. The building inspector wanted to inspect the structure before placing the roof, I think to inspect the trusses, which was very funny as when they got here there were only the outside walls and totally open to the sky and we are cyclone rated.

We used the 200mm block on both outside and inside walls, space did not matter to us we live on a farm and our design mentioned that we really only have two internal walls. Strength was our requirement as it is VERY windy here.

The cost of the blocks was 40 dollars per square metre plus get. I think the cost of the block is high considering what it is. But it is very comparable wit any other type of structure when you consider that there is no need for any other insulation, it is very easy to get an air tight envelope. Plus plus plus

Yes it is polystyrene, but it is 100 percent reyclable as is concrete and this type of structure will stay the distance as far as time goes.
You do not have to use it on internal walls, but the zego 100mm for such is great.
It is quick two people can build an average 3 Beaderbox in 2 weeks to before roof goes on, plus of course your finishing.

As far as your embedded concrete heat sink is concerned as it is encased in insulation it maintains a reasonable constant temp, as I said we are totally off grid, no air con, just 12v fans and no heating, just my woman. But the 3mtr plus ceilings certianlly help to keep it cool

What would I change? Well I got carried away with curved walls etc, so keep it simple for speed and no head aches.
I put in earth cooling tubes to the pantry, they work well, but I should have put them in for the main body of the house.
We are in SA so there was little BS ready building restrictions of what you can and can't do licence wise, but I did employ a building inspector to sign off on various stages purely to keep everyone happy.

But once again the so called experts called for things that were just not required with polystyrene, as an example the engineer we employed, well known but not used to styrene techniques called for expansion joints around the structure, as you would for brick or concrete, but as the the concrete is tottaly insulated, there is no expansion.
The tile supply, we did our own tiling easy, insisted that we have expansion joints but that is not a problem until you get over 12mtr runs, that's a big room and it is not a styrene problem but a tile problem and I feel that as the temp and humidity are reasonably stable it would not be a prob anyway, my call and choice.
If I knew how to provide my contact details without making them public, Elizabeth would be more than happy to help.
Sorry for the long post

Thank you for your reply. Much appreciated