The other system is the accelerated building technology panels. Steel framing encapsulated w/ EPS, which still gives room on the interior for trades and add extra spray foam to seal it up.

AKA   ACTech, panels are NOT EPS they are that nasty PU, they are only 3" thick, require stitch screws in and out , rely on a heavy red-iron sub-structure

Ok, please read this detailed report from ORNL. And, please note that the comparisons are to a 2x4 stick framed structure not SIPS.

Thermal Mass - Energy Savings Potential in Residential Buildings

Enjoy.

Posted By Quantum on 11/07/2007 6:48 PM
ICFs are a good product but some of these arguments of ICFs versus SIPs aren't very realistic.  There's this tendency to pit this as a steel versus OSB versus concrete material argument and they all have their places in different environments.  ICF is certainly stronger than an OSB SIP but I'm not convinced its stronger than a steel SIP, especially if you do a truss roof.  The whole thermal mass idea goes away when you realize you have insulated yourself from the thermal mass.  The idea that only ICFs are sealed therefore you double the R-value and compare it to SIPS as though SIPS are not a tight structure is another one.

I don't think you understand how concrete works in terms of strength.  Concrete has almost no strength in tension (only compression).  Besides the strength of our roadways is based on the consolidated soils beneath the concrete.  The concrete distributes the load to the subbase below that supports the traffic.  If it depended on the concrete alone the road would crumble as it does when the subbase is not done properly.  Even concrete bridges derive their strength from the steel reinforcement.  Reinforced concrete in fact depends on the concrete cracking for the steel to provide the strength for which it was designed.  The concrete always cracks.  The only exception is prestressed concrete which of course does not include ICFs.

I had a chance to see the the metal SIP duplex Donaldson is putting up this morning.  I was really impressed with how the system is put together.  I think it would be overly optimistic to think the smae thing could be done with ICFs in twice the time.

Donaldson, to each his own. No one ever said concrete should not be reinforced. In fact ICF can be reinforced to three seismic strengths: C, D1, & D2. To my knowledge SIP can only be built to Seismic C under the IBC. An ICF structure can (and has) been built up to 9 stories. It is solid rock, after all. And it has the strength for concrete inter-floor decks and a rooftop concrete patio.

As to the completely enclosed envelope, apparently most builders where you are, are doing it wrong. Over the walls should be steel trusses, with cementicious sheathing and fiber-cement shingles or tiles. Then in the rafters on the underside of the sheathing should be sprayed expanding foam, preferably soy-based ('insoylation'), all the way down to the walls. This adds rigidity to the roof, glues it to the walls, and seals the attic as conditioned space. Airtight. Same can be done with SIPs.

coddave, WRT fire, I want non-combustible. Period. No, we cannot buy concrete furniture or steel toys, but we do the best we can, don't we? A non-combustible structure should be the goal, and in the event of fire a structurally-sound building should remain, and the ability to -replace- damaged foam is vital. These are not the case with SIP.

slanzen, true, thermal mass shines best when outside temps make wide swings during the day. When the weather is continually cold, it will eventially permeate halfway through the concrete and start absorbing heat from inside, albeit very slowly. Even so, check this out:

LINK

cmkavala, interesting study. For example:

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Some foam plastic insulation materials use blowing agents that have a high resistance to heat flow causing the insulation to have an abnormally high R-Value at the time of manufacture. It is now known that these blowing agents diffuse from the cellular structure of the foam until a level of equilibrium is reach many years after it is manufactured. As the high R-Value gases diffuse out of the cellular structure, the ability of the insulation to prevent thermal flow is reduced, losing up to 30 percent of its original insulating ability. EPS foam does not use these types of blowing agents, therefore, its insulation performance remains stable over its entire life.

"If you compare EPS side-by-side with some foam plastic insulation materials right after they are manufactured, the other materials may have a higher R-Value," said de Campos. "But EPS is stable and does not experience any thermal drift and does not lose R-Value over its life. In the long run, the thermal performance of EPS insulation is constant, and when all cost and performance factors are considered, it typically provides the greatest insulating value available."
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Meaning, when SIP isocyanurate insulation is first blown it tests high insulative value, but then as it offgasses (formaldehyde), the insulative value constantly declines. And the study makes clear that ICF's EPS does not do this, and maintains its insulative value over the lifetime of the home.

PanelCrafters, that Oak Ridge study proves the benefit of the thermal inertia of concrete, even -with- the inside insulation of ICF:

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A 20% difference was noticed between the ICF house and the conventional wood-framed house’s energy consumption. In the final report, NHAB researches concluded that this 20% difference was caused by the R-7 difference in wall R-values ( ICF wall R-value was about R-20, conventional 2x4 wood stud wall R-value was about R-13). However, simulation data developed by ORNL for a similar 121m2 (1300 ft2) one story house suggests that for the same climate a difference between R-20 and R-13 should yield a maximum 8 to 9% difference in annual whole building energy consumption. This suggests that most likely thermal mass related energy savings during the NAHB ICF study were in the neighborhood of 11%.
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chuck07, please read that Oak Ridge study. You are just guessing about thermal mass. And who said ICF gives only benefit because it is sealed? I didn't. Where did you get that?

And who said ICF should be built with no reinforcement? I didn't. Quite the contrary to what you think I said. And who said ICF can be built in the same time as SIP? I didn't. Where did you get that?

No, it is true that ICF takes longer to build. And it is true that it takes a higher skill level. But it is also true that it insulates better, is far stronger than SIP, is non-combustible, and will last 1,000 years.

That is my takeaway from this.

Quantum,

Do you have a link to research that supports your assertion that polyurethane (isocyanurate) foam offgasses formaldehyde?

Thanks,

Dick Mills

Not offhand, but the studies are out there. I'm not interested enough anymore to look it up.

Formaldehyde primarily comes from OSB, and that and other nasty chemicals from the iso foam.

It is kind of difficult to have confidence in posts where the authors are incapable of providing evidence supporting their claims.

Dick Mills

Understand. But is this the only objection you have, out of all I've said?

The problem with that is that if a person exaggerates (my grandmother used to say that exaggerates is just a fancy word for lies) about one thing, then you have to question everything that they say. And, at best, making an unsubstantiated claim is exaggeration.

I am just here to learn, and if I were to claim that "EPS is hazardous to small children and animals", I am sure that you and others here would demand that I support that assertion with evidence. I am just asking for the same thing from you.

Dick Mills

I think they are two different companies/products.  ABT was at the metalcon show and it was EPS, I think it is Dietrich/Dow combo.  I'm not familiar w/ ACTech.

Quantum,

It appears your only interest is in bashing SIPS but I guess that makes sense if you make your living building with ICFs.  That's fine, but you should realize they only drink the ICF Kool Aid in the ICF forum.  I do think ICF is a clear improvement over stick or block but as long as this is SIP versus ICF let me tell you why I'm not planning on using ICFs.

• Better insulation.  Most SIPs use EPS foam just like ICFs only more of it.  Some panels use even better types of insulation, that off course as you pointed out lose some of their insulation value over time.  What you didn't point out is that after all this loss the R-value per inch is still far more than EPS.
  

• Less wasted space in the walls.  Why would I want a 12-inch wide ICF wall with only an R-value of 19.25 (ASHRAE R-value of 3.85/inch) versus a just under 12-inch SIP wall with an R-value of over 36.

• Materials that work as a system.  SIPs provide the strength at the skins where the greatest stress is experienced and the foam enhances this strength.  ICFs derive their strength soley from the steel and concrete (which is full of tiny cracks if the steel is providing any strength).  The foam is on the inside where it prevents the concrete from serving as a thermal mass for the occupants.  It is also on the outside to entertain the termites.  The foam in ICFs is of no structural use and the location of the concrete versus foam is backwards in terms of the best use.  You ought to protect the foam not the concrete and steel.
  

• Building Cost.  You can always spend more but I would rather not.

• Earthquakes.  Heavy mass objects don't do so well when shaken.  Look at the pictures of all the twisted concrete and steel from reinforced concrete structures that experienced significant earthquakes.  There has been great improvements in how to add enough steel to overcome this liability with heavy mass / brittle structures but it is still a liability that SIPS do not have.  You are correct that there is more coverage in the the code for ICFs with earthquakes (could it be the Kool Aid).  SIPs coverage in the code is well behind ICFs.  Mother nature however is not constrained by the code.  There were a number of SIP dwellings in the 1995 Kobe Japan earthquake (over 7 on richter scale) with no damage.  SIPs are a more elastic structure.  There are plenty of pictures of twisted steel and concrete from this incident.
  

Slenzen,

I built my cottage's walls and roof out of ACTech panels,  on the inside I just primed and painted the steel, no drywall, looks good to me.  I built this house so that if by some chance it did get wet inside from a hurricane I can go in with a water hose and rinse everything off. 

Cmkavala continues to knock ACTech panels, but let me tell you they are a first rate product, I will be glad to share any information you might like on them.

Slenzen;

I stand corrected it is a dietrich company, they do not make roof panels, but they are unlike the panels that Donaldson mentioned, his are encapsulated in steel not with EPS

Seaglade;

Which statement about ACTech is untrue?

Dick, I am not here to sell you on anything and so why should I further explain? I am here to learn about SIPs. I think I pretty much have it sussed out now, and I have been completely honest in my assessment with you. Maybe I've hurt some feelings along the way, but if that's the case you have made an emotional decision for SIP, not a fact-based one IMHO. It is foolish to debate people who have made an emotional decision.

Chuck, I am always looking for a better way. People tend to look for an answer and when they think they've found the best, they stop looking and hunker down defending their position at all costs. I honestly wanted to know whether SIP is better, and at first I got a reflexive Yes. But then people started offering evidence which just shows clearly to me, the contrary. It is a relief to hear that most SIPs use EPS, and that eliminates the offgassing issue as long as it's not OSB-clad, but not the others.

You say, "What you didn't point out is that after all this loss the R-value per inch is still far more than EPS."
Apparently you did not actually read the study above.

You say, "Why would I want a 12-inch wide ICF wall with only an R-value of 19.25 (ASHRAE R-value of 3.85/inch) versus a just under 12-inch SIP wall with an R-value of over 36.".
Well, ICF with 1.5 density actually has an R value of 5/inch, and most ICFs are at least 2.5" per panel; some are 2.75". Plus there is the thermal mass benefit of the concrete. The total effective insulative value is R-50, in addition to the other benefits of concrete. Please read the study cited above, by Oak Ridge National Labs.

And pffthpt, what's the use in responding to your other questions, which I've already covered?

As I say, I am not here to sell you on anything. I pushed you and challenged you to get the best possible answers to these questions, and I am happy now. I am not here to argue or fight. I am looking for the best answer, from a scientific standpoint.

Quantum,

Are you now claiming that there is a study out there that inidcates that EPS outperforms Polyurethane in R-Value per inch of insulation? 

Because if you are, then that is untrue as well.  PU may not be able to maintain a 7 R-value over it's entire lifespan, but the EPS Molder article that Chris posted the link for merely points out the fact that over the long term PU performance drops to an R-value of 5.6 per inch.  The data that the article draws from also shows that if the temperature differential (inside vs. outside) is greater than 40 to 50 degrees F PU performance bottoms out at 6.2.  

That is still considerably more than the 3.5 to 4.1 or so that 1# EPS (expanded) can provide.  On the other hand, a 5.0 from XPS (extruded) is possible with a 1.25# foam but most SIPs and ICF manufacturers that I am aware of use a 1# expanded foam.

Dick Mills

This claim of R-50 for ICFs is a mix between myth and fraud.  Myth because it simply is not true.  Fraud because those in the ICF keep presenting it as fact anyway.  The figure is based on testing by CTL Laboratories in Chicago paid for by the Insulating Concrete Form Association (ICFA).  The baseline is a stickbuilt wall with a dubiously assigned R-value.  A wall with fibergalss bat insulation does not perform with a whole wall R-value nearly as high as the fiberglass insulation itself (but it was used as a baseline anyway).  The testing used varying tempterature differences to get a value of as high as R-50 (compared to the whole stick built wall being assigned an R-value based on the just the fiberglass bat).

This dishonesty is my biggest issue with the ICF industry.  ICFs are a great product but why can't its proponents confine themselves to honest claims.  R-value/inch for a particular substance varies with temperature however you choose to take the false baseline R-value for an ICF at something like 40 degrees and compare it to the true R-value of the same substance in a SIP tested at 70 degrees.  This is like taking your air conditioner cost of only $40/month when it is 82 degrees outside and saying it is clearly more efficient than someone elses air conditioner because their costs $150/month (when its 105 degrees outside).

EPS has an accepted R-value of 3.85/inch at 75 degrees F regardless of what form it is in.  Polyurethane loses some R-value and the study you are referring to says as a result the comparable value to use is 5.6/inch (not the 7+/inch some suppliers claim).  Last I checked 5.6 is still substantially greater than 3.85.  It is unusual to state something is inferior because over time it loses some insulative value and ends up being only 45% better.  ICFs have only 5 inches of unprotected EPS insulation.  SIPS often have substantially more (protected EPS).  You'll have a far easier time building a gable wall or a roof out of SIPS.  I have no vested interest except for looking for the best material that I can economically use to build myself an efficient home.  I've looked hard at SIPs, ICFs, and some other alternatives and for my particular plans and climate metal SIPS appear to be the rational choice.

Dick, I guess you just do not want to read or understand the study cmkavala cited. And no, most ICF blocks are 1.5x density. 1x is not strong enough to sustain the concrete pressure.

And chuck, it looks like you are unwilling to read or understand the study that PanelCrafters cited. The measured temperature-isolating value of the thermal mass was considerably higher than the insulation's resistance to heat transfer, according to one of the most highly-respected government labs in the nation. R-value does not tell the whole story and is a crude, outdated measure, although this is hard for many to understand so this additional benefit is converted to R-value in arriving at R-50. I am sorry that this knocks the pegs out from under your belief system. And no, EPS 1.5x does not have an R value of 3.85/inch. That is all I am going to say about it because this is becoming argumentative. I have tried to tell you. You should just use the system which you believe is the best, and leave it at that.

Quantum,

I have been assuming that you could read and understand, but obviously I was mistaken in that assumption. So I will quote from the EPS Molders website from the article that Chris posted earlier. The link for it is here:

LINK

And I am quoting:

In November 1987, the National Roofing Contractors and the Midwest Roofing Contractors Association issued a joint technical bulletin on in-service R-values for polyisocyanurate and polyurethane foam roofing insulation boards. In that bulletin the associations recommended that designers and users use an R-value of 5.6 per inch for polyiso and urethane products, not the higher value often referenced by manufacturers' literature.

5.6 is the R-Value that they picked out from the Building and Safety Division of the Municipality of Anchorage released Policy 83, "Insulation - Maximum R-Values", in February 21, 2001. It appears that they no longer publish this Policy 83, but instead have a Handout entitled "R-Value Comparisons". This handout can be found at:

LINK

I attempted to paste the information from handout but it didn't format well, so I will attach a picture of it.  And, I was mistaken about the differential temperature that I mentioned in an earlier post.  Actually (as handout 3 says), the 6.2 R-Value is at 40 degrees F - which is probably the temperature that matters most for insulation in Alaska. 

But, I do stand corected in my statement about your EPS density, and apologize for mistakenly saying that ICFs use 1# EPS.  A 1.5# EPS is considered a type II with an R-Value of 4.2 and 4.6 at 40 degrees F, still considerably less than a 1.25# XPS, and not even close to polyurethane.

Dick Mills