Are you a subscriber but don’t have an online account?

Register for full online access.

 
 
 
 
+ Reply to Thread
Results 1 to 14 of 14
  1. #1

    Default Help with wall detail

    Pros and cons on these two wall details? It is a 2-story structure in a cold climate:

    4.5" SIP's vs. 2x4 w/ 1/2"OSB and 2" exterior XPS

    Thanks!

  2. #2
    Join Date
    Jul 2006
    Location
    Portland, OR
    Posts
    2,397

    Default Re: Help with wall detail

    Really??
    One is better than the other depending on your priorities such as thermal performance, initial cost, availability of experienced workers, access to site, desire to be "green", and a jillion other factors.

  3. #3

    Default Re: Help with wall detail

    ok fine. Compare the two in terms of thermal performance.

  4. #4
    Join Date
    Aug 2013
    Location
    KS
    Posts
    323

    Default Re: Help with wall detail

    The manufactured tested SIPS panel can take more in plane compression loads from a two story, and has better configuration tolerances. By in plane I mean at the lap shear bond lines, failure path. It is also provides a better wall cavity air seal, no convective air/moisture loops, but can create hot cold thermal bridging due to conduction unless there is sufficient thermal mass and break for the climate zone.

    Assuming you are putting insulation in the 2 x 4 cavity, the exterior foam will move the dew point outward allowing drying to the inside. This wall out performs the standard 2 x 4 wall cavity in the latest BSC metric wall test, there they SPF the 2 x 4 stud wall and used 1" XPS exterior (Wall 7 below). I wish they would have tested/compared a SIP, ICF, SCIP too. In cold climates, more exterior foam as in a REMOTE wall would perform better. You can get more compression and insulation in a 2 x 6 wall but, nails won't out perform the SIP composite factory bond in shear until you have so many you made swiss cheese out of wood, or if the wall ever sees bending nails are no good in tension.

    Both would need additional bracing for seismic and high tornado/hurricane winds.

    http://www.cchrc.org/docs/best_pract...OTE_Manual.pdf

    http://www.buildingscience.com/docum...t_20131021.pdf
    Last edited by CASHCOW; 01-06-2014 at 09:06 PM.
    Terry

  5. #5
    Join Date
    Aug 2013
    Location
    KS
    Posts
    323

    Default Re: Help with wall detail

    I noticed the SIPs manufacturers like to refer to them as “steel I-beams” in similarity. I had to chew on that one for a while. I’d agree basically they are to an extent that the biggest asset to the I-shape is it has the greatest mass closest to its centroid, compared to others L, Z, C etc…..compare that to a 2x 4 stick build faced/fastened on one side with OSB, mass is not symmetrical nor is its ability to carry load. SIPS adhesive bond line(s) are in double shear, where the structure carrying the bulk of the load OSB/sticks are in single by fasteners, the foam fasteners don’t provide good shear/bearing strength.

    Steel when you heat or cold work it becomes heat treated, stronger, tougher, changing mechanical/thermal properties, etc. Wood and foam does not, if anything if the manufacturer’s used room temp adhesives that can only take so much heat/cold before they fail. You can get strong bonds by elevated temps/pressure designed adhesives. If you cyclic the adhesive past their cure limits they fail in fatigue.

    If I were to consider SIPS I look for third party structural test reports that included hot/cold cycles. Same with concrete skins or core, the wrong mix or configuration won’t take the cycles and crack. Nice thing about bonded sandwich construction composites is the combined structural/thermal properties if designed correctly, placed in the right type of loads and orientation.


    Hope that helps.
    Last edited by CASHCOW; 01-07-2014 at 05:51 PM.
    Terry

  6. #6
    Join Date
    Jul 2007
    Location
    Toronto, Ontario, Canada
    Posts
    832

    Default Re: Help with wall detail

    So cost is not a consideration. Yet, the couple times I've looked at SIPS for a one-off, they're through the roof.

    Thanks for the BSC study. Best takeaway: air tightness equalizes thermal performance.
    "The fatal flaw of all revolutionaries is that they know how to tear things down but don’t have a f**king clue about how to build anything." Jim Goad

  7. #7
    Join Date
    Sep 2009
    Location
    Portland, Maine
    Posts
    1,335

    Default Re: Help with wall detail

    The recent JLC issue outlines a few handy ones, they sure are fancy.

    I'm not poo-pooing them just yet but they seem to use a boat load of materials (lots of caulks, sealants, tapes) and look very labor intensive on the integral portions of the framing of the structure. Not to mention some of the materials are EU only...shipped from there to here?...green?

    If BSC is correct (what I questioned in another thread) air tightness is where it's at. Why can't we achieve that in one fell swoop on the outside with one measure of peel and stick? I'm not following why we need an interwoven, layering system of tapes and sealants

    The details I see are VERY detailed for a "neck down" kinda laborer and honestly, only effectively executable on simple forms like a box shaped house. Not down playing a simple box house, I like those myself.

    The other factor is cost. I'd love to see a S.F. cost for doing something like those details, AND what is provided on the inside.

    Like Allan mentioned a while ago (we disagree on some stuff but I agree with him on this) most people want "nice" stuff inside...granite, top end Grohe faucets, Maestro dimmers, Sonos sound systems controlled by iPhones, etc....people want their stuff.

    If these details can find their way into simplicity, I think we'll have a winner. For the record, I can't come up with a simpler detail than wrapping the entire envelope (an old one...which seems to use less "stuff" than two of the ones shown) in peel and stick for the air tightness factor...why do we need all of the other barriers?
    Portland Renovations, Inc.
    www.portlandrenovations.com

  8. #8
    Join Date
    Aug 2013
    Location
    KS
    Posts
    323

    Default Re: Help with wall detail

    Quote Originally Posted by Dutchman View Post
    If BSC is correct (what I questioned in another thread) air tightness is where it's at. Why can't we achieve that in one fell swoop on the outside with one measure of peel and stick? I'm not following why we need an interwoven, layering system of tapes and sealants
    The BSC report did not take the envelope of house, air seal it, then look at ACH or CFM50. It basically induced moist CO2 air in 8 wall ‘cavities’ quantified and compared their performance based on metrics measurements from instrumentation (thermsistor, humidstats, air flow psig, etc.. (convective loops which sip is low, convection or bridging which sips is high, material thermal and mechanic properties, r-value degradation, etc. The SIPS panel is simple sandwich construction of foam and skins, not sure what you mean by interwoven and layering systems of tapes of sealants. A stick build would need more of that to get the same result. I heard the latest issue had some wall stuff in it I have not seen.

    Peel and stick (assuming you mean adhesive tape) depending on the adhesive and bonding strengths, materials and surface contour and porosity being bonded, can be a risky business proportional to thermal and mechanic cycling over time causing failure. It might work in some climate zones with low temp extremes. Anytime you can avoid bonds lines that are room temp cured exposed to the elements do it. In a retro fit with no better choice do it.

    The SIPS I looked at had DIY which might be difficult getting past code and not a good idea unless you are well versed in structure. There with the proper tooling and design you might beat the cost of a stick build in mass production, labor, and materials. Your upfront investment in a bonding jig, pressure plates, etc would pay out at some unit number you could calculate. Factory shipped better quality from more expensive tools and automation, more cost is my guess.

    There are better choices out there that allow the client to keep all those fancy fixtures and enjoy the rewards of low energy bills, those are for the successful builders of the future.
    Terry

  9. #9
    Join Date
    Sep 2009
    Location
    Portland, Maine
    Posts
    1,335

    Default Re: Help with wall detail

    Quote Originally Posted by CASHCOW View Post
    The SIPS panel is simple sandwich construction of foam and skins, not sure what you mean by interwoven and layering systems of tapes of sealants.
    Look at the section (that's the name for the drawing they showed in the article) of two of the "fancy" ones and imagine them in three dimensions, you might see what I mean.

    They are not very complex, but not very simple, which is what this system should evolve to be.

    People complicate simple things in every discipline to make themselves appear smart, happens all day long.
    Portland Renovations, Inc.
    www.portlandrenovations.com

  10. #10
    Join Date
    Nov 2004
    Location
    Boston, MA
    Posts
    4,614

    Default Re: Help with wall detail

    Dutch

    My favorite wall system is multi-wythe brick. It gets wet, it dries out. There are no complex layers, just one mass. If you get a defect, you rake it out, replace a brick or two, then patch it up. It will go 100 years in the right conditions with no repointing. Neglect it, abandon it, forget about it, then go clean it up and go another 100 years. Try that with the disposable crap we make today. With true arched openings, there are no steel lintels or flashings to rot away. It is stable with temperature given its thermal mass, and quite frankly, there is no better wall to look at. That's my opinion and a fact. Beautiful, structural, you name it, it's all that. Blows the doors off the metal wall panel and curtain wall touting "sustainability" what a joke. And let's face it, if all walls were mass masonry in this world the building scientists would be on welfare.
    I will never buy a Nissan Cargo Van.

  11. #11
    Join Date
    Aug 2013
    Location
    KS
    Posts
    323

    Default Re: Help with wall detail

    Worthy: It works both ways, these OEMs can make it look too complex to DIY, or the DYI can make it look too simple and the next thing you know your panels are coming apart at the seams. If I went the DIY route I’d want to see an indi test report per panel DIY build plan with a Bill of Materials down to the OEM including tooling, bonding pressures, and heat. Then I’d want an assembly and trade installation plan as part of the DIY kits I purchased, listing all additional adhesives, calks, plies, etc.

    Ted: Never heard of that but I like this over foam core and concrete skins (SCIPS) and SIPS w/osb skins. Im losing confidence in “engineered” OSB and foam manufacturing after seeing all these moisture related issues I think are from bad designs or manufacturing.

    Concrete wythe walls make sense from a thermal, structural, sound proofing….I read they can be difficult to water seal? Needing weep holes, flashing, and paint on surfaces? They can be single or multiple depending on climate zone and structural loading I presume. Do you have a design guide, also wind, thermal, and seismic test for sizing in those conditions, or build plan literature you can point me to? Where do you recommend I go to learn more, and to get data for inspection? Don’t you think labor and maybe material cost will exceed standard 2 x 4 insulated stick builds?

    I remember anold town by LA here is So Cal crumbled from brick and concrete back in the early 90's earthquake I think it was named Whitter, CA. rebuild with shock absorbers. But in hurricane and tornado alley it might be alright?
    Last edited by CASHCOW; 01-14-2014 at 10:16 AM.
    Terry

  12. #12
    Join Date
    Nov 2004
    Location
    Boston, MA
    Posts
    4,614

    Default Re: Help with wall detail

    Terry

    You can find more info on the BIA (Brick Institute of America) website. The old buildings used "muti-wythe masonry" or "mass masonry", which is basically solid masonry, where the newer systems use "masonry veneer". Basically a nonstructural facade of masonry laterally supported by a back up wall system.

    I was referring to the old way of doing things which is obsolete for building structural reasons and labor costs. Nonetheless, I like the old way better.
    I will never buy a Nissan Cargo Van.

  13. #13
    Join Date
    Aug 2013
    Location
    KS
    Posts
    323

    Default Re: Help with wall detail

    Quote Originally Posted by Ted S. View Post
    Terry

    You can find more info on the BIA (Brick Institute of America) website. The old buildings used "muti-wythe masonry" or "mass masonry", which is basically solid masonry, where the newer systems use "masonry veneer". Basically a nonstructural facade of masonry laterally supported by a back up wall system.

    I was referring to the old way of doing things which is obsolete for building structural reasons and labor costs. Nonetheless, I like the old way better.
    Just wanted to say thanks! Now back to SIP n Stick or was it Peel N Stick :)
    Terry

  14. #14
    Join Date
    Apr 2009
    Location
    midwestish
    Posts
    7,124

    Default Re: Help with wall detail

    Back to SIPs... now if you just suck out the filling and get a good vacuum you can reduce the thickness 50% or more and likely have a much friendlier product to dispose of at EoL....
    “I find the curiosity of our men with respect to this animal is pretty much satisfied.”
    ~ Meriwether Lewis

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts