Anyone here have any experience with Raycore SIPs? Seems a lot like just building a stick built and doing sprayfoam insulation but I am not nearly as knowledgeable as many here seem to be about stuff like blowing agents and net environmental impact. Quite frankly I am looking for the best product to use for building a very energy efficient home in Central WI. The main thing that I saw that I thought was attractive was there are studs to actually screw stuff to...(I've only been researching SIPs for a couple weeks as I just came across them)...In looking at metal and OSB sips I have concerns especially on the exterior around attaching finishes...we are considering, among other things a faux brick exterior. I have read several places now that you need to talk to the mfg of whatever siding you plan to use so that they can tell you recommendations for attaching them to panels. Maybe my concerns with attaching stuff to the exteriors is mostly just born of ignorance? Just wondering if anyone has experience with RAYCORE SIPs and what their advantages and disadvantages may be in comparison to other SIPs... Thanks!

Raycore SIPs use closed cell polyurethane spray foam (ccSPF, probably at2.5 or 3lb density, if their R-value claims are to be believed. See: http://www.raycore.com/pdf/dowrvaluetestingdata2-1-2012.pdf ).

Note, their 50F performance numbers are at 50F average temp through the material, not a 50F outdoor temp. With a 70F interior that means it'll hit that performance point only at 30F or below. But polyurethane's performance increases with falling temps, decreases with rising temps- in a cooling dominated climate real performance would have to be significantly derated from their stated numbers. (That's why the FTC requires using 75F center temp and a 30F delta-T for insulation labeling purposes, which some SIP and ICF vendors skirt around using some other fluffed number taken a some other temperature point & delta-T, since they're selling a wall system, not insulation. But it's more than just a bit deceptive IMHO. Type-II EPS is R4.2/inch @ 75F center-foam temp, but R4.5 F at 40F center temp. Guess which number most ICF vendors use? But the 40F center-foam temp is only valid in a 70F house at 10F outdoor temps, which isn't an average winter temp for most US locations.)

Closed cell polyurethane is a great material with wonderful properties, but it comes with an ONEROUS lifecycle greenhouse gas foot print when blown with the most common agents. The most common blowin agent for ccSPF is HFC 245fa, which is more than 1000x CO2 lifecycle global warming potential. In an R26 SIP the lifecycle GWP of the blowing agents is many times that of the energy use it is offsetting, if blown with the standard goods.

While there are low GWP blowing agents in the works (DuPont FEA-1100, Honeywell Soltice, and a few others) not all have been released to the market yet, and none have much market penetration. (Solstice was only released late last fall.) Before buying ANY closed cell polyurethane insulation/product, verify the blowing agent first. Used sparingly in appropriate layers there's still an argument for cc SPF blown with HFC245fa for air sealing and moisture control, but not for high-R insulation.

SIPs with EPS cores don't have that issue, since EPS is blown with pentane, with only 7x CO2 GWP.

All SIP panel systems need careful attention to air sealing to achieve their air-tightness potential. All OSB-clad SIP roofs need careful attention to (and redundancy) at the ridge lines to avoid wintertime air-leakage leading to potential rot issues on the exterior skin of the SIP. (Metal clad SIPs don't have the same rot issues.)

Thanks Dana1,

We are leaning towards metal sips, I was just curious if anyone had "real world" (actually build a building) using the Raycore sips because of the studs integrated in the panels without them being all the way through thus preventing thermal bridging you get with 2x6 studs all the way through the wall or at the joints of OSB SIPs.

I also noticed on their site that they call out that the standard is 75 degree testing temp but that they were testing at 50...My first thought was if I was testing at 50 degrees I wouldn't proclaim 75 degrees as the standard...LOL...why not just test at the standard and thus elimnate confusion....

"...why not just test at the standard and thus elimnate confusion...."

Exactly!

But then maybe the marketing hypers would have to find something USEFUL to do, other than trying to jerk higher numbers out of the air, whether appropriate to the application or not.

The polyurethane foam is good and 2x lumber is ok if that is what you want in your walls and roof. However, the lack of thermal bridging is one of the reasons people choose to build with SIPs.

At this point, I need to point out that the Raycore product may be a "panel", but it is NOT a SIP (structural insulated panel). SIPs are written into the IRC under section R614. They are described as a foam core with 2 wood facings (minimum 7/16"). This is what a SIP is.

Posted By JBS on 20 Mar 2013 11:26 AM
The polyurethane foam is good and 2x lumber is ok if that is what you want in your walls and roof. However, the lack of thermal bridging is one of the reasons people choose to build with SIPs.

At this point, I need to point out that the Raycore product may be a "panel", but it is NOT a SIP (structural insulated panel). SIPs are written into the IRC under section R614. They are described as a foam core with 2 wood facings (minimum 7/16"). This is what a SIP is.

The IRC does not control the definition of what can be advertised & sold as a SIP.  Raycore advertises them as a SIP. If you think there's an FTC definition being violated by using that term (not likely) that would be the appropriate place to make the objection. 

The IRC definition DOES create an issue with other types of SIPs when dealing with pointy-nosed building inspectors, but I've yet to hear of any project being condemned for use of SIPs that did not comply with the IRC definition.  The section covering SIPs in IRC 2012 is now R613, not R614, but does contain the same verbiage retarding skin materials:

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R613.3.2 Facing.
Facing materials for SIPs shall be wood structural panels conforming to DOC PS 1 or DOC PS 2, each having a minimum nominal thickness of ⁷/₁₆ inch (11 mm) and shall meet the additional minimum properties specified in Table R613.3.2. Facing shall be identified by a grade mark or certificate of inspection issued by an approved agency.

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The lack of an inherent thermal barrier against ignition on a Raycore SIP they skate on by using a Class-I fire fire-rated foam. This would not be an issue for OSB or steel SIPs due to the thermal properties of the skins.

The thermal bridging on some of Raycore's stuff is just plain ridiculous, a total waste of foam.   With 16" o.c. fully-bridging 2x6 studs, even at an optimistic 20% framing fraction the whole wall performance would come in under R20, despite a center-foam R of about R40.  At the same wall thickness a 2x4 cellulose-insulated studwall wall with 2" of exterior iso comes in at a bit over R20, even with a 25% framing fraction, and it would have 1/3000 the lifecycle global warming potential.

I did not mean to imply that Raycore had violated any FTC regulations. Only that the word SIP does mean something. The SIP industry has been established for decades and there is a trade organization for SIPs, SIPA (Structural Insulated Panel Assoc.) A SIP is commonly understood by builders, architects, code officials and homeowners as a foam core laminated to two structural skins.

I mentioned the IRC to show that the term SIP is not vague. It means something specific. Where is the Raycore product covered in the IRC? How is it accepted by code officials? Is is not accepted under the guidelines for conventional 2x framing. Of course, since that is what it is.

And yet, like "realtor", the term "SIP" is widely used to mean things other than what those who may want to claim the term for themselves intend. SFAIK "SIP" (unlike "realtor") has not been trademarked.

Where are specs for steel skinned SIPs addressed in the IRC? Know of any projects using them being canned for lack of parameters spelled out in the IRC? (I don't, but I'd be very curious to the details of problem-cases, if they exist.)

Neither SIPA nor the IRC control the usage of the term outside of their narrower definitions. Language is a social contract, not a legal one- words mean what those who use & hear them THINK they mean, even if others work from narrower or even different definitions.

Building codes rarely precede real-world practices, and are under a constant state of revision to incorporate real world changes in technology and usage. Eg, the CA Title 24 2008 for heat pumps requires inspection steps for verifying refrigerant charges that simply make no sense for ductless mini-splits, but that hasn't stopped the higher-efficiency technology from being installed by the 1000s in CA. But the conflicting verbiage will be adjusted for Title 24 2013 (which will go into effect in 2014) to accommodate the practice. While I don't expect the IRC to make specical case allowances for steel SIPs or Raycore panels, I also don't expect them to be barred from installation in the real world either. OSB-skinned SIPs and stress-skin panels didn't exactly get prior approval along with a whole bunch of detailed parameters from the IRC or other code bodies to be installed either, eh?

But the Raycore panels are still just a big waste of high-GWP foam IMHO, and not a green buiding product. (But feel free to use different definitions for "green", eh? :-) )