RasThavas
New Member
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| 10 Jan 2009 08:02 PM |
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I recently talked to a builder who uses EPS SIPs but won't use PU SIPs. The reason, they say, is that PU SIPs offgas, which results in shrinkage of the foam which leads to delamination. I don't recall hearing this before. Can anyone shed some light on whether this is true, partially true, used to be true or is simply wrong? |
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cmkavala
Veteran Member
Posts:4324
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| 10 Jan 2009 08:20 PM |
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Posted By RasThavas on 01/10/2009 8:02 PM
I recently talked to a builder who uses EPS SIPs but won't use PU SIPs. The reason, they say, is that PU SIPs offgas, which results in shrinkage of the foam which leads to delamination. I don't recall hearing this before. Can anyone shed some light on whether this is true, partially true, used to be true or is simply wrong? It is true that PU will shrink with age, wether that is the reason they delam I do not know, they also loose R-value with age. I can tell you from experience in cutting them , the dust is itchy to the skin . PU will offgas, some mfg. claim to have over come that problem, but I am not sure if they all have. |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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CHL
New Member
Posts:29
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| 12 Jan 2009 07:43 AM |
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Some people who use EPS sips never seem to miss a chance to knock PUR panels - and most of the "knocking" is unfounded or downright lies. Let me explain. First, there are very few polyurethane panel companies in the US but those that do make the product are very professional and can educate you about the product. Polyurethane is a widely used foam throughout the world, from car seats to Icynene spray foam (both open cell) to PUR panels or bowling balls (both closed cell) polyurethane manufacturing is a chemistry that is well known and stable. Some of the best known glues in the world, like "Gorilla Glue" are polyurethane based. This is a HUGE difference between PUR panels and EPS panels. PUR foam is its own glue - where EPS panels require a different material and manufacturing process. When you add components or processes you introduce opportunities for error. Search the web - you'll find many instances and discussions of delamination on EPS panels yet very few for PUR panels. The only way PUR is going to delaminate is if the foam is not mixed correctly and this is a manufacturer issue, not a product issue. In fact some PUR panel companies offer either very long or lifetime warranties against delamination because that is one of the more reliable parts of their product - they just don't worry about it.
Phenolic foams will shrink but this is not polyurethane - again, properly mixed polyurethane foam does not shrink regardless of what some EPS guys say.
Cured polyurethane foam DOES NOT OFFGAS. Again this shows some ignorance but perhaps understood. Polyurethane is a plastic and it will cure usually completely in about 24 hours. PUR foam DOES "LOSE" R-VALUE, but usually in the range of 7-8% from initial blown but that entirely depends on the siding material used and it's permeability. When your initial blown R-value is typically between 7.5 and 7.0 - and you lose 7-8%, you are still almost twice as energy efficient of standard 1lb EPS (typical densities used by EPS panel manufacturers). Look up LTTP - this stands for Long Term Thermal Profile. Listen, your refrigerator is probably insulated by PUR foam, NOT EPS. Think Igloo cooler or the cheap white styrofoam you buy at the gas station when you are taking your kids fishing. Yeah, it's like that.
When PUR foam "loses" R-Value, it is essentially "in-gassing", not off-gassing. Again, let me explain. The foam is shot into a panel in an EXOTHERMIC reaction. This reaction creates billions of tiny bubbles of (hopefully) close to uniform size and density. But when these bubbles cool off the volume of the bubble remains "large" (it should still be very small) but just as lower pressure shrinks gasses the pressure inside of the bubbles decreases relative to the ambient air pressure outside of the panel (see Charles's Law or Boyle's Law for the relation between temperature and volume and pressure for gases). Now the blowing agents typically used inside of the panel have non-polarized molecules that do not promote molecular cross linking (and therefore thermal conductance) - that's why they are preferred. But a small "vacuum" inside of these bubbles over time (again, depending upon the siding used) will draw in ambient air - air that may contain small amounts of moisture. That moisture has polarized molecules that will dutifully line up and conduct thermal energy but again, in incredibly small amounts. Panels cured in dry environments will have different LTTP profiles as opposed to those that occur in moist ones - but again, it's miniscule. This is like a gnat's ass when compared to the in-foam voids and moisture present in EPS foam - get a microscope and look at it and the air is free to move in just about any direction - that's why it has approximately half the R value.
Regarding "itchy" foam (?), what the heck is someone doing cutting panels on a job site? That creates many opportunities for error - voids, delamination (of EPS), moisture ingress, unskilled labor cutting panels wrong, etc. PUR panel systems are "engineered to fit" and different systems have ways to accomodate for foundations or frames that are off. Again, speak to the manufacturers for the straigth scoop and evaluate on your own.
Your builder friend just probably doesn't want to pay more. PUR companies can not always command the premium that their product offers and EPS is CHEAP in comparison. Again, there's a reason that the vast majority of panel companies in the US are EPS and not PUR, but there's also a reason why the vast majority of construction panels sold in Europe are PUR - they don't have the huge chemical industry lobbies that the US does and safety and insurance regulations discourage structural EPS panels. Please do not hesitate to ask more questions if you have them. You're doing what you should be doing - asking for input and researching your questions. Through indpendent research you should be able to weed through the chaffe and get to the kernals - the "meat" of truth that you're looking for. |
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chuck07
New Member
Posts:38
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| 12 Jan 2009 08:26 AM |
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I'm confused. It sounds like in paragraph 4 your explaining how PUR panels shrink. How does that support your premise that they don't shrink? I don't think there is any question that PUR is a good glue. |
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CHL
New Member
Posts:29
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| 12 Jan 2009 08:30 AM |
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In physical size there is no shrinking. The polyurethane plastic - after about 24 hours - is inert - simply a solid plastic. The pressure inside of the bubbles inside of the plastic may change, however (again, we're talking at the molecular level). The bubbles are formed in heat and dry while still warm but over time the gases inside of them cool and the molecules "close in", creating the negative pressure inside of the larger bubble. Let me know if that's still not clear and I'll try to explain another way. Getting ready to board a plane so my apologies if my reply comes later. |
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cmkavala
Veteran Member
Posts:4324
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CHL
New Member
Posts:29
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| 13 Jan 2009 07:05 AM |
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Mr. Kavala, I've taken a look at some of your other postings and now understand a little more about you. You are a salesman and you shamelessly promote your product - very often in entirely unrelated questions - at the expense of truth and science. What you call "dancing" we in the reality based community refer to as science. And perhaps not surprising you did not disagree with anything I said with any substantive information.
You presented many links listing the dangers of the COMPONENTS of polyurethane. Yes, you got me, some of the components of your refrigerator's insulation or your car seats or foam panels (yes, EPS and Polyurethane) can harm you but because in fact the components of the chemical reactions actually CHANGE THE CHEMICAL STRUCTURE of the compounds THEY ARE NO LONGER THE COMPONENTS. OSHA has a health warning against styrenes used in EPS - http://www.osha.gov/SLTC/styrene/index.html - including effects of the central nervous system, etc., yet we know that chemical reactions make EPS inert, just like PUR. Cast not the first stone, Mr. Kavala. You have presented no convincing or supported evidence of your implied comments that PUR foam kills people. And I noticed from the time stamp how quick you were to produce that list so I'm sure with only a little research I would see you've done it before.
I'm reminded of the Wisconsin governor who, when confronted with our government's "concerns" that medications dispensed in Canada were unsafe and therefore Americans should not cross the boarder into Canada to get the medicine they so dearly needed but could not afford here, said "Show me the dead Canadians". Simply tossing out a bunch of links to produce the appearance of proving your point - when in fact it doesn't - (think "Show me the dead refrigerator owners") - does not do this message board or the viewing public any service. And by the way, no US manufacturers of PUR panels use TDI mixes - that wouldn't make sense in the first place - and you may want to do a little research on the flame retardants (so now it doesn't burn, it just vaporizes) used in EPS - not pleasant stuff, and sometimes the same ones used in PUR. |
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cmkavala
Veteran Member
Posts:4324
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| 13 Jan 2009 07:25 AM |
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CHL;
if you went thru all 866 post then you know I offer much more to the forum than promoting steel SIP construction.
If you knew what you were talking about you would know that the EPS flame redardants off gas in 24 hours or less, long before they get to the jobsite.
Unfortuately all the carcengenic chemicals in PU continue to off gas for years while its in your home, ain't nothin green about that!
While some PU mfg. have made the effort to clean up their industry, all have not.
I don't live in a refrigerator, so a small anount of PU in the home is acceptable.
If you looking for dead Canadiens go to the cemetary |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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SimonD
Basic Member
Posts:113
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| 13 Jan 2009 07:39 PM |
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Hi, I'm a SIPS Designer down here in Florida. I've been in the biz of SIPS for about 12 years. Worked in an EPS SIPS manuf. plant early in my career and now I'm an independent designer who has designed many buildings with both kinds of panels. My opinion is that both types of panel can experience this problem if not manufactured properly. But all things being equal, I think an EPS panel would be more likely to delaminate than a PU panel, because EPS panels require a third component (the glue) between skin and foam core and with a PU panel the foam core is the glue, having one less component that could fail. However, this one issue is not grounds to dismiss the other kind of panel as inferior. The best panel is the one most readily available in your area with the company having some kind of track record for satisfying its customers. (Hey Chris! Know who this is?:-) |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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cmkavala
Veteran Member
Posts:4324
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| 13 Jan 2009 07:42 PM |
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SimonD;
yes your the guy that I shared an office with |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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bpickartz
New Member
Posts:22
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| 14 Jan 2009 10:22 AM |
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I have to say I'm never surprised that the EPS guys say one thing and the PU guys another, but I use either one and after eleven years, I recommend only PU to our clients. I've worked with three different PU manufacturers and have had no problems with the product (I don't count a few onsite adjustments as problems...just construction). I know that many people use EPS and they've been satisfied, but I'm more comfortable with the PU system. I like the more dense foam (thinner panels). I like the fact that my panels are always exactly the right thickness. I like the fact that PU doesn't burn and does only degrade at a much higher temperature than EPS. I'm not a manufacturer and can pick my supplier, so I'm not selling, just commenting.
The myths and quasi-facts that abound about each are, for the most part, just taken out of context and twisted. I've seen that on both sides. We looked at what we want the panel to do and at our experience with both and chose to use PU.
Dollar for dollar, PU is the better bargain. Just my two cents worth. |
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Paulcf
New Member
Posts:27
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| 15 Jan 2009 09:25 PM |
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Whoa there everyone! I won't enter the debate on PU vs. EPS but I will say this: We should all recognize that no matter what the foam, SIPs are what we are all promoting to sell and build with. It's like one posting said: Ford or Chevrolet. Address the specifics with the panel manufacturer. Since there may be challenging agendas here, lets work together to promote SIPs overall.
We offer a 50 year guarantee against delamination and rot for our in ground foundation and frost wall panels, and they're EPS. So we've clearly addressed the 'glue' issue. If Boeing can build a plane and many of the parts are glued together, I am sure the glue in a SIP panel can be sufficient and adequate to do its intended job and besides it's probably a PU based glue, how ironic is that?
Build with a quality SIP and if EPS or PU, you will have a MUCH better house in many ways. |
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ErgoDesk
Basic Member
Posts:149
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| 15 Jan 2009 09:45 PM |
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In Canada the Gov. is planning tax breaks for home renovations but nowhere is there are mention of Energy Efficient Construction in the reno's.
Forget SIPs, ICFs lets Promote Energy Efficient Building.
PS EPS is better because for dollar it lasts longer. |
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| Build Smarter with Structural Insulated Air<br>http://StyroHomeNews.blogspot.com |
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CHL
New Member
Posts:29
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| 16 Jan 2009 09:50 AM |
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OK, you've got me curious on this one. I'd like to hear your reasoning behind "EPS is better because for dollar it lasts longer." I think this is one more misleading claim for EPS but I hope I'm wrong. Foam industry sales persons will tell you that both EPS and PUR will last indefinitely. |
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ErgoDesk
Basic Member
Posts:149
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| 16 Jan 2009 05:05 PM |
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The reason many want to ban EPS, is that it will not break down in time. On the other hand put Polyurethane in the sun and many types will turn to dust in 10 years. Don't always believe a sales person I say. |
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| Build Smarter with Structural Insulated Air<br>http://StyroHomeNews.blogspot.com |
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Louie FischerSIPs
New Member
Posts:12
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| 16 Jan 2009 05:11 PM |
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How far can typical PU SIPs span between support members for roof panels. Most PU companies only sell 4-6" panels. Also, how often do anyone's panels delaminate. We warranty our panels for a lifetime. To all potential SIP builders and homebuyers: Most all companies not making SIP's in their garage will offer the same warranty against delamination. These scare tactics are silly and rarely happen. In the three years I have been selling SIPs our company has not had a case of delamination. Also, I have not heard of any other reputable SIP company selling "structural", panels that have delaminated. All panels leaving our plant undergo quality control measures and our production process is third party tested every 4 weeks. Would all these companies still be in business if panels delaminated. I'm sure there is a horror story out there, but I would be willing to bet out of the millions of square feet of SIP panel sold each year, a small fraction of 1% have a delaminatin issue. Of that percentage I'd bet they are caught upon installation and replaced free of charge by any company |
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CHL
New Member
Posts:29
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| 16 Jan 2009 07:42 PM |
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You are correct. Polyurethane foam, when exposed to UV light, will break down through a process known as UV degredation (many polymers do this). This does not affect PUR sip panels however since the foam is not exposed to UV light when a structure is erected.
EPS's huge opportunity is to develope cost effective recycling centers because it will last for friggin' forever under just about all natural conditions. It certainly is possible to recycle EPS, but as yet is not practical on a widespread basis due to the lack of recycling centers. The term "recyclable" is used often but to little practicle purpose.
We would like to think that all SIP panels, regardless of foam core, would last for several lifetimes, yet this will depend most of all on the quality of construction of the building itself and the integrity of the moisture envelope to prevent a break down of the siding material or degredation of the EPS bead bond. And yes, steel sips or fiber cement sips help to reduce opportunities for this to occur. |
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CHL
New Member
Posts:29
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| 16 Jan 2009 07:53 PM |
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Structural span is directly related to the thickness of the I-beam as determined by the web. This equates to the width of the foam core. Because of the density of PUR foam and its insulating properties PUR panels do not need great thickness to produce large R values. For an R40 or R42 roof panel a PUR panel manufacturer only needs to make a 6.5" panel. Depending upon EPS density the EPS panel supplier will need a 10" or 12" panel to achieve the same R value. But what that buys the EPS panel supplier is greater span and that information should be available on their ICC-ES test data if not on their website. Typically 6.5" PUR panels will not span greater than 8ft laterally unless reinforced internally. Spans are generally cited in the horizontal plane and can be often greater in panel length if the panel is running the pitch of the roof (ridge to eave). |
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SteelSipMan
New Member
Posts:49
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| 17 Jan 2009 07:59 AM |
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an 8 foot span is pitiful! most EPS core steel skin panels will span twice that |
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cmkavala
Veteran Member
Posts:4324
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| 17 Jan 2009 01:58 PM |
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Our 6" steel panels will span 19ft. |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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CHL
New Member
Posts:29
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| 17 Jan 2009 03:07 PM |
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Thanks for keeping it classy, SteelSipMan.
Very impressive Chris. For a horizontal span of 19ft do you have to reinforce the inside of your panel with anything or is it 100% EPS? What density EPS are you using? I know the tensile strength of steel is very strong and I'm sure that's what makes your panels so strong in this dimension. Again, very impressive. |
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SimonD
Basic Member
Posts:113
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| 17 Jan 2009 04:05 PM |
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Although this thread has gotten off topic a little, I will back Chris K. up, and say that 19ft is a workable panel span for a 6" x 26ga. steel x 1lb. density EPS panel used as a roof panel in certain regions of the US. As a designer down here in Florida most of the designs I've done have been in 120mph wind speed zones and 19ft is a workable horiz. clearspan up to a pitch of about 5 in 12.
I think that building is and should be a regional practice where the materials and methods evolve to suit the climate and conditions of the region. The use and availability of different panel types maybe evolving in the same way. Down here in the hot and humid southeast metal sips seem to be getting a foothold, because they address and solve so many of the issues we face down here. We don't need the highest R-values, so EPS foam works and is what is commonly available. Moisture resistant material is a high priority down here and that's where corrosion resistant sheet metal works and is commonly available. Metal roofing has a long history down here, so the use of a metal skinned sip is a natural progression that evolves out of the building culture down here. I think there is a best panel type for each region of the US based on cilmate conditions, regional availabity of materials and regionally established building practices. So there is no ultimately best panel type, but there is a best panel type for a specific region. |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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SimonD
Basic Member
Posts:113
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| 17 Jan 2009 06:20 PM |
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The interlocking metal sips Chris K. and I are refering to achieve that span with no additional reinforcement. Just the steel skin, eps core and the male female interlock.
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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Dick Mills
Basic Member
Posts:217
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| 17 Jan 2009 07:31 PM |
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A 19 foot span must put a lot of stress on the fasteners at the top and bottom. I assume these are roof panels with a 40 pound load or there about. Each foot would need to support 760 (or at least half of that) pounds of load before factoring in wind and other loads. Can a 26 gauge skin support that? |
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cmkavala
Veteran Member
Posts:4324
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| 17 Jan 2009 10:00 PM |
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SimonD;
our core is 1.25 lb. density
Dick;
The stress is on pullout/pull thru and are worse on OSB skins, we basically use the same fasteners that the OSB guys use only we also use 1-1/2" fender washers.
the loads are transfered thru the core to the skin if the maximum load is imposed.
yes, panels will support and are engineered with a safety factor of 2.5 |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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SimonD
Basic Member
Posts:113
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| 18 Jan 2009 01:00 AM |
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Chris K,
I've heard that 1.25 lb in density is the 'magic number' to achieve the best strength to weight ratio in a metal sip panel, so that's great, your not skimping on the foam density like some other companies do.
As Chris K says, in metal sip construction large washers are put under the heads of the sip screws to provide increased resistance to pull-thru and if necessary the on center spacing of the screws is reduced. |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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RasThavas
New Member
Posts:5
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| 18 Jan 2009 07:11 PM |
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Thanks for everyone's replies. If you wish to reply further about what you may know about PU delamination (or lack thereof) please do. |
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Rsipgeo
Basic Member
Posts:104
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| 28 Jan 2009 02:14 PM |
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I think it bears repeating that span length has nothing to do with delaminating. It depends on thickness. Eps panels are thicker than PU panels generally. |
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cmkavala
Veteran Member
Posts:4324
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| 28 Jan 2009 02:41 PM |
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Posted By Rsipgeo on 01/28/2009 2:14 PM
I think it bears repeating that span length has nothing to do with delaminating. It depends on thickness. Eps panels are thicker than PU panels generally. Rsipgeo; not sure what you mean by that, but certainly overspanning will delaminate by shearing foam from skin or will buckle the panel most PU/ steel panels have much sorter span capabilities compared to the same thickness EPS /steel panel |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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CHL
New Member
Posts:29
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| 29 Jan 2009 11:15 AM |
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The last shot in the note above doesn't make much sense. Whether the foam core (or web) of a panel is PU or EPS or XPS, the span capabilities of a panel are driven by the siding material (flange), and primarily the bottom one. The modulus of elasticity and tensile strength of steel is orders of magnitude greater than that of foam so the type of foam core bears little significance if the thickness is the same. The thickness of the foam core - regardless of type (of the foams under discussion) - will increase a panel's span length.
There are polyurethane panel companies that are happy to make you a steel SIP that will span similar distances as an EPS panel of similar thickness. Also some companies out there will give you steel siding on the interior side for span distance and OSB (or similar) siding on the exterior for ease of roof installation. Many opportunities out there. |
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SimonD
Basic Member
Posts:113
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| 29 Jan 2009 04:30 PM |
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Foam density plays a part too. I say that the higher the density of the foam core of a SIP wether it is PU or EPS, the less likely it is to delaminate, not from poor bonding of skin to foam core, but from the shearing away of the very top surface of the foam from itself if overloaded.
Overloaded shorter spanning panels (8'-10') are more likely to delaminate than overloaded longer spanning panels (17'-19') because of the way the foam core is exploited by the forces of shear and bending. Short things can shear, long things mostly bend. |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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SimonD
Basic Member
Posts:113
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| 29 Jan 2009 04:50 PM |
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A simple field test to check the general quality of the lamination of a companies SIP is to get hold of a peice of scrap and tear the skin off of the foam core. Then look at the underside of the skin. It should be completely covered in foam with no skin showing. With a poor lamination the underside of the skin will have clear areas or streaks where the foam didn't bond. If for some reason the SIP tears almost equaly in half down the center of the foam core which is unusual, then the density of the foam core is in question. |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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cmkavala
Veteran Member
Posts:4324
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| 30 Jan 2009 08:34 AM |
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Posted By CHL on 01/29/2009 11:15 AM
There are polyurethane panel companies that are happy to make you a steel SIP that will span similar distances as an EPS panel of similar thickness.
We have never found one with equivelent span capabilities, if there is one ......Name some please |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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kevinbourland
New Member
Posts:31
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| 11 Aug 2009 08:50 PM |
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My Polyurethane panels "spooned out", bowed, or whatever you call it, the first Winter, over 1/2". Tearing sheetrock from corners, pulling away from wall.....countertop etcc.....Then goes back in During Summer!!!
Ya sounds like a great Product!!!!! |
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| Kevin |
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CHL
New Member
Posts:29
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| 12 Aug 2009 08:29 AM |
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I'm sorry you've had a bad experience, Kevin. PUR foam, just like EPS foam, is a cast or molded foam and both products are well known to be dimensionally stable after manufacturing assuming a proper process has been followed. One major difference between the two is while many EPS manufacturers are purchasing bun stock from a major supplier and then gluing siding to the bun stock (very often using polyurethane resin glues), most (not all) PUR manufacturers are blending and injecting PUR foam in their factories. If their mix is off, you can get a defective panel. I have been around a lot of both types of manufacturers and for 99+% of the time they all do a great job as their companies depend on them producing a quality product.
It is interesting, however, that you note that the panel is flexing due to seasonal changes. This sounds entirely to me as if you have either a varying coefficient of expansion between one side of the panel and the other (possible siding material effect), just like a thermocouple or dielectric material. You may very well have things going on in your wall (probably on the outside) that you do not know about. The thing about both PUR and EPS foam is that they are dimensionally stable across a VERY WIDE RANGE of temperatures and unless you have contaminants in the foam you absolutely should not see dimensional drift or creep in the foam due to temperature variations.
Any other engineers/scientists out there have thoughts on this? |
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ecobuilder
Basic Member
Posts:102
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| 19 Aug 2009 05:34 PM |
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Rasthavas,
I just recently worked on a PU SIP's house that did have delamination problems. Although this was probably more due to the moss growing on the roof than the product it'self. The roofing shingles were completely covered with moss, making the OSB saturated. When I stripped of the roofing shingles some of the OSB came with it. Not only in the areas where the roof was wet, but also spanning out from this area. This was a 25 year old house that may have had something to do with it. The fix, while not simple wasn't really that complicated either. We stripped back all of the loose OSB, applied new plywood, covered with tar paper and then built a cold roofing system on top of this, screwing 2x4's on the flat threw the SIP's into the beams. At location were there were no beams, we simply screwed from the inside out to secure the 2x's. The panels themselves suffered no structural problems, but if the spans were not so short it may have been. Also these SIP's houses built back in the 80's didn't have any type of air exchange system, making me wonder if this may have had something to do with it also. This is my only experience with SIP's delamination but I have only been working with them for 15 years or so, maybe some of the other more experienced people on this site could elaborate on actual experiences with this problem rather than debate which product is better? As for me, I don't sell SIP's but I do install them and improper installation may also have caused some of the problem. Also the OSB used back then is not the same as it is today, and the glues are much better as well. If done correctly I don't think you will ever have to worry about delamination. (rare occurance mostly due to neglect of roof).
Tom Pittsley
[email protected]
www.eebt.org |
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| "Don't be afraid to go out on a limb. That's where the fruit is." Jackson Brown |
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RasThavas
New Member
Posts:5
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| 22 Aug 2009 02:47 AM |
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Thanks for the info ecobuilder.
It's been some time since I posed this question. The urethane SIPs manufacturer of my choice answered my question of whether to build with urethane foam or EPS. The urethane SIPs simply can't span the length I need for my roof system so I'm not going with them. Even though they might have the best wall system in the business, it's the roof where the insulation counts. So, I'm going with EPS for the roof AND the walls. In my neck of the woods... that means Korwall.
I'll start a different thread to monitor the progress of that venture.
And no, Chris Kavala. I'm not going to consider steel SIPs. 
Ras
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Sip Supply Inc
New Member
Posts:44
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| 22 Aug 2009 06:08 AM |
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Posted By RasThavas on 08/22/2009 2:47 AM
And no, Chris Kavala. I'm not going to consider steel SIPs.
Ras
Steel Sips!, when did they start making steel SIPS?  |
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ErgoDesk
Basic Member
Posts:149
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| 22 Aug 2009 03:04 PM |
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Excellent choice Ras! EPS retains Insulating Values much better that the other ... |
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| Build Smarter with Structural Insulated Air<br>http://StyroHomeNews.blogspot.com |
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RasThavas
New Member
Posts:5
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| 23 Aug 2009 05:59 PM |
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Posted By Sip Supply Inc on 08/22/2009 6:08 AM
Posted By RasThavas on 08/22/2009 2:47 AM
And no, Chris Kavala. I'm not going to consider steel SIPs.
Ras
Steel Sips!, when did they start making steel SIPS? OK, the metal clad ones! SIPS of Steel! That sounds like a good slogan. |
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Rsipgeo
Basic Member
Posts:104
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| 01 Sep 2009 07:40 AM |
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Span has nothing to do with de-lamination issues. It only relates to thickness. Thinner SIPs (PU) are better for walls - more square footage. Use a EPS SIP for the roof if you have to.
As a builder I see these kinds of threads as kind of stupid. Sometimes I use steel studs and sometimes I use wood studs. Sometimes I use PSLs and sometimes I use dimensional lumber. You would be better off promoting the industry as a whole rather than scaring off potential customers who come to this site. |
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Torben
Basic Member
Posts:216
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| 01 Sep 2009 11:19 AM |
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These comparisons without any real numbers made me curious to look up what the real span tables show. This is apples to oranges when you don't compare the same panel skins/thickness and load/deflection criteria. I looked up 26 gauge steel, 6-inch thick panels with a 40 psf combined load for three panel manufacturers
Structall - 1.0lb EPS Panel
(Appears to be L/180 deflection limit, actual load was 39.4psf)
maximum span is 17 ft, 4 inches
Precision Foam Fabricators - 1.0lb EPS Panel
(L/180) maximum span is 17.97 ft
(L/120) maximum span is 10.39 ft
Alumashield - 2.6lb Polyurethane Panel
(L/120) maximum span is 13 ft, 11 inches
It appears the higher density (or better adhesion) polyurethane core give the polyurethane panels an edge in span ability. I think it would be difficult with any of the above panels to span 19 feet in Florida and meet wind loads (let alone ever be able to put solar on the roof). Maybe a thicker gauge skin panel could make 19 feet.
The difference in R-value is rather extreme. The alumashield panel has a tested R value of 49 (@75deg). The EPs panels would be 23.1 (1.0 lb EPS at 75 deg is 3.85R/inch). |
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dhiorth
New Member
Posts:3
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| 01 Sep 2009 12:01 PM |
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This has been fascinating to follow. It brings up a lot of things I'v been trying to get answers to. Unfortunately there's some disagreement on the answers.
Let me ask you experts a question. I am planning a 1 story retirement house on a full walkout basement; call it 35' X 35'. It will be located near the top of a ridge line. I was looking at poured concrete throughout or cement board over 2X6, but recently looked at SIPs again. Here's the I need answers to:
1. What is the estimated lifespan of a house. I'm looking for a minimum of 50 years. For instance. if a tree falls on a stick build house you replace the roof. If it falls on a SIP built house what happens?
2. What's the maximum wall length, given 8-9 foot high with typical doors and windows? could I build a wall of of two 9' high X 18' long SIP pieces?
3. Do I need to frame it out as a post and beam, do I attach the SIPS to corner upfight beams, so they somehos all hook together? the industry is very uninformative on this
4. EPS vs PUR PUR seeems more fireproof, EPS seems more structurally sound. Offgassing should be a chemically documented fact...so what do the chemists say.EPS has a lower R-factor but is less expensive, you just make the walls a little thicker. The rest seems to be an argument similar to "how many angels fit on the head of a pin?
Any takers on this one?
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Sip Supply Inc
New Member
Posts:44
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| 01 Sep 2009 12:46 PM |
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DHIOTH;
1. 300years , I have had a tree fall with minor damage on my own home
2. 53 ft. we typically balloon frame up to 3 stories
3. our are T&G friction fit, they are completely structural
4. We use EPS no offgassing |
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dhiorth
New Member
Posts:3
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| 01 Sep 2009 05:48 PM |
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Dear sip swupply inc
I have no idea what youy just said.
Let me explain it this way: I'm very technical, I understand why the technical facts are critically important. But you are all lost in the trees and missing the forest.
Sh** happens. I know what happens to a concrete, masonry or wood frame building when it happens. Swo what happens whedn thaqt freak 100MPH |
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dhiorth
New Member
Posts:3
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| 01 Sep 2009 06:03 PM |
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Worry, had a stroke 2 yrs ago, typing is no longer my forte
The SIP industry publishes very little about why a homeowner can trust SIPS to last the vagaries of nature. If I'm going tp build with
SIPs I qwant to understand their characteristics, strengths, weaknessses, assets, risks, etc. swo I can do it RIGHT.
I've lived thropugh 345 hburricdanesw, a (very) small tornado, several 100mph 2wind storms, several lightning strikes and a few other things. Concrete, masonry, wood frame survive. I don't know about SIPs.
Moisture/mildew happens. Wood (i.e. OSB) rot occurs I havge no interest in a logt home because it would be a series of perpetual maintenance issues... what about SIPS.
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cmkavala
Veteran Member
Posts:4324
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| 01 Sep 2009 06:40 PM |
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dhiorth;
attached is a FEMA report regarding best construction and SIPs performance during hurricane Charlie |
 Attachment: File0373.PDF
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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ecobuilder
Basic Member
Posts:102
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| 01 Sep 2009 11:21 PM |
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There has been a good deal of documentation about the structural abilities of SIP's. Don't believe me ask a structural engineer. Here in MA SIP's homes have to have a structural engineers stamp for approval. The structural engineer I hired had not done any work with SIP's but after doing the calculations decided when he builds his home he will be using them. They simplify many of the hurricane attachment methods needed to meet hurricane standards. While I am not an engineer but just a builder that prefers these over most methods of construction for many reasons, here are a few. Exceptional thermal performance over stick frame construction, speed of construction over stick frame, air tightness, strength,straight as an arrow. While I have seen problems with them, typically after years of roof neglect. What I can tell you is that I have had to fix many roof problems with many buildings and people just don't seem to understand that roofing materials don't last forever on any house. If your roof is leaking it will damage any home. I like SIP's from R-control, all of the structural data and connection methods are posted on their web site for anyone who whats to find it. http://www.r-control.com/ you need to register to get all of the technical data in the library. With a little work you can find all of the construction details and structural loading charts for design purposes. Be careful there are SIP's companies out there that have not done all the engineering and use information from other manufacturers engineering spec's. As for SIP's lasting 300 years I doubt it. They have been around for some time now, about sixty years. Many people would say back as far as the 1930's but those aren't the SIP's we use today. They were developed in the 1950's and have been improving ever since. How has conventional construction improved? has the lumber gotten better? In my short 30 year history of building I have seen dramatic decline of lumber, don't believe me go to the lumber yard and pick through the pile to find straight ones. Do this a Home depot or Lowes only if you have an afternon to waste. So basically it comes down to this. If you don't have faith in SIP's don't build with them. If you can't find the information that makes you feel comfortable with them don't do it. But I would suggest that you find a SIP's house in your area and talk with the homeowners, find out from the people that live in them, what they think. The ASES national solar tour is coming in October and they also have homes built with SIP's open for tours. Take some time to find out all the facts before making your decision. For me it's a no brainer, +-5% difference in construction costs and about a 50-60% savings in energy costs. Do the math then make your decision. I have done it for myself and the estimated cost savings have about a 5 year payback if your construction costs increase by say $5,000. Here in New England ( Patriots nation) this equates to about a $1,000 a year savings on heating cost on a typical 2,500 sq/ft home. Tom Pittsley [email protected] www.eebt.org |
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| "Don't be afraid to go out on a limb. That's where the fruit is." Jackson Brown |
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cmkavala
Veteran Member
Posts:4324
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| 02 Sep 2009 08:47 AM |
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Tom;
well said! |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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azbuilder
New Member
Posts:21
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| 21 Sep 2009 11:19 AM |
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Posted By ecobuilder on 09/01/2009 11:21 PM
So basically it comes down to this. If you don't have faith in SIP's don't build with them. If you can't find the information that makes you feel comfortable with them don't do it.
For me it's a no brainer, +-5% difference in construction costs and about a 50-60% savings in energy costs. Do the math then make your decision. I have done it for myself and the estimated cost savings have about a 5 year payback if your construction costs increase by say $5,000.
Its ironic that if many folks put as much time into looking for flaws in stick construction as they do SIPs, this argument would be much shorter.  As for the energy savings, you don't have to be in the polar zone to reap the benefits. Even here in mild central Arizona my heating energy bill is $1560 less annually than my neighbor who has a very similar house in style and aspect. Built in the same year it has been a great case study for me to quantify some real world differences outside of the rare air of manufacturer spin and "independent lab tests". They are a semi-retired couple and we are a family of five and this includes hot-water heating.
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| Green building across Northern Arizona - VerdeHome.com |
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