I've always wondered why no company is using polyurethane for ICF forms.   I found a company that does it and wanted to get opinions from the ICF gurus here.  I understand polyurethane is a better insulator and is stronger than eps foam.  This is a post/beam construction probably uses less concrete than typical ICF forms.

What do you think about the advantages/disadvantages of this system?

www.insulock.com

Looks interesting...however, flat ICF's seem to have an advantage in engineering simplicity. Most, if not all, of the prescriptive guide for ICF construction addresses flat ICF's. It would appear that most post and beam designs require civil engineering. In addition, the installation would appear to be pour sensitive. This design appears to be less forgiving in concrete installation.

Good points to consider. Not sure how much civil engineer would cost for that or the difficulty of pouring/vibrating those columns w/ rebar in them. Wonder why nobody is using polyurethane for regular ICF blocks?

There are a couple more I found.

www.thermoblock.com and www.emegabuild.com too.

No Guru here but...

Attachments/webing is not standard, read closely
Post and beam-> not for me
High R-value is obtain in two ways, 1) post and beam means less concrete=> more foam. 2) Higher R for this foam, but not so much.

As an alternitive, High R-values can be obtained by using Quad-loc(sp?) Or attaching additional foam to a common block.

Patrick T

It's sad that all three of those companies are out of business now, some 13 years later.

It's also a bummer because I've been looking for higher performance ICF blocks that don't use cheap Type II EPS. It's a shame that we don't see blocks with higher R-value materials, like XPS, Kingspan's Kooltherm (R = 8 per inch), or the better types of EPS – the types with higher compression strengths and R-values. XPS also has higher compression strengths than EPS, and it would be nice to have something tougher and sturdier than standard Type II EPS. Polyurethane looks interesting, though I never see it anywhere and I don't fully understand how it fits in with the rest.

Although XPS does offer a slightly higher R-value per inch than EPS (R5 vs R4 approx) I would be concerned with offgassing of XPS products when used as the insulation on a home's intereior. Remember these are both polystyrene insulation products (ie, polystyrene bead is the base product), but they differ in that the blowing agent used when manufacturer XPS is encapsulated within the product thereby yielding the higher R-value. This can passively escape during the products life - intuitively, this would suggest that with enough offgassing you would be left with essentially an EPS foam with the associated R-value. XPS also seems to be considerably more expensive (in our area at least). Paying 50%+ more per inch for something that only offers 25% more insulation is not a great investment (ignoring rules of diminishing marginal returns with insulation) - and it gets even worse over the years as R-value shifts to closer to the R4 value that you could have purchased initially for less costs.

Just me 2 cents (and worth every penny!)

Correct as XPS offgasses it degrades to similar R-value as EPS.

The XPS R-value drop is more confusing than I thought, because some of the manufacturers are quoting the long-term R-value these days, not the initial. So Owens Corning is saying R5 per inch as the lasting value on their boards. Somehow it looks like XPS still beats EPS. The other wrinkle is that denser EPS actually delivers R-values like 4.2 or even 4.5. These are the higher compressive strength types. So if denser types of EPS can exceed R4, this implies that XPS should be able to deliver similar values even after years of offgassing, since XPS too has higher compressive strength than Type II EPS. On the value equation, one other variable would be wall thickness. If you can get better insulation for the same thickness, that can be a big win, especially if it makes a difference in downstream purchases like bucks and other tweaks needed for unusually thick walls. ICF blocks don't have very good R-values by default, if we're talking say five inches of cheap Type II EPS. To get excellent R-values, we need thicker blocks or better material. An ICF block using Kingspan's Kooltherm phenolic foam would be outstanding. At this point in history, we really ought to be further along than Type II EPS. The science and technology is there for much better performance.

ICCF blocks use a screen grid and they have EPSCrete instead of straight EPS foam. The EPS foam in the EPSCrete is recycled, not a big deal but nice.

Looking at the combination of less concrete used and recycled foam, ICCF seems like the most environmentally friendly choice initially and it's certainly good long term but it might be possible for a more insulated block to pass it up over time depending on the climate it is installed in.

The current ICF prescriptive guides cover screen grid construction the same as flat core ICFs so engineering is equal now.

Any way, higher R value materials don't really matter except for potentially making walls thinner. "Cheap EPS" has some advantages to it so unless you need your wall 1-2" thinner, you can avoid the downsides of XPS and Polyiso and save a little money.

Rather than looking at the individual pieces of a wall, it is better to look at the finished result of the options that you would consider.

In my comparison, ICCF with stucco did well compared to stick built with continuous external foam and steel siding with the benefit of being extremely resistant to fire, insects, rodents, solar radiation, car crashes, hurricanes and tornados. Typical EPS foam ICF pretty much lost on the zonts and zuckles, I don't want to deal with that.

Couple of thoughts:
-reducing thickness of XPS ICFs simply to achieve the same R-value and result in a reduced wall thickness may not be practically possible, as you still need an appropriate thickness to hold while placing concrete (this performance would be more a function of the flexural strength than the compressive strength of the given material - I haven't compared EPS vs XPS, but if someone has the time feel free to elaborate/correct me on this)
-I assume long-term R-value would be tested on a molded panel that is not cut - would off-gassing be increased once forms are cut as needed on a jobsite (ie, cutting opens the panels for increase offgassing and therefore reducing R-value over time)?