the DIY sips I've seen are not TRUE sips in the idea that they are sheeting be it metal or OSB glue to foam. The ones I have seen people buy a block of EPS and then using a hot wire, they cut channels in in the EPS for basically a metal stud. You get the benefits of the sip as for the lack of thermal bridging. but not so much for the quick building of a true sip. However if you're doing a DIY sip Im willing to bet you're not going to speed so much as pure insulation value. It does have the huge advantage of being structural even after and during a fire. it also has zero de-bonding issues lol

Hi Lbear:

Failure rates of DIY SIPS are low if some basic principles are followed. First off, we need to determine if the SIP is ESP (expanded polystyrene) or polyurethane foam. There are advantages and disadvantages each way. If ESP, the foam must be cut to size fairly accurately. Trying to fill gaps with adhesive will be problematic and may end up being the most vulnerable to failure. Polyurethane on the other hand requires a fixture to clamp in the frame. The polyurethane begins as a liquid and is poured into the clamped frame and expands (foams up) filling the entire volume/area. The foam itself acts as the adhesive to the frame. Under filling the cavity (using too little foam) will result in gaps and failure points. Overfilling the mold will add pressure to the clamped frame. Too much pressure will distort everything if the fixture is not strong enough to withstand the overfilling. At the end of the day I am of the opinion that polyurethane foam is more forgiving in filling the irregularities of the wood (or metal) used as the frame and provides a 100% surface bond naturally in the process. In addition, it is possible to use a more dense foam (like 2lb or 3lb) to add structural capabilities (in compression) to the panel as well. The point of all this is to say failure rate is dependent on materials used and the environment. Wet materials will most definitely prove problematic and almost guarantee failure. Clean dry materials will (for wood) and clean, dry, AND OIL/Lubricant FREE are required for metal. Many sheet metal manufacturing companies fabricate steels and aluminum and although aluminum is clean from the mill, oils will transfer from other jobs running through the shop that are steel. SO...Clean, Dry, and if metal oil free materials are necessary. Lastly, polyurethane foam can be poured into the fixtures at temperatures as low as 40 degree F and higher. Be sure to work within the adhesive range of the adhesive manufacturer if using ESP.

Posted By IADDIC on 20 Feb 2013 09:31 AM
Hi Lbear:

Failure rates of DIY SIPS are low if some basic principles are followed. First off, we need to determine if the SIP is ESP (expanded polystyrene) or polyurethane foam. There are advantages and disadvantages each way. If ESP, the foam must be cut to size fairly accurately. Trying to fill gaps with adhesive will be problematic and may end up being the most vulnerable to failure. Polyurethane on the other hand requires a fixture to clamp in the frame. The polyurethane begins as a liquid and is poured into the clamped frame and expands (foams up) filling the entire volume/area. The foam itself acts as the adhesive to the frame. Under filling the cavity (using too little foam) will result in gaps and failure points. Overfilling the mold will add pressure to the clamped frame. Too much pressure will distort everything if the fixture is not strong enough to withstand the overfilling. At the end of the day I am of the opinion that polyurethane foam is more forgiving in filling the irregularities of the wood (or metal) used as the frame and provides a 100% surface bond naturally in the process. In addition, it is possible to use a more dense foam (like 2lb or 3lb) to add structural capabilities (in compression) to the panel as well. The point of all this is to say failure rate is dependent on materials used and the environment. Wet materials will most definitely prove problematic and almost guarantee failure. Clean dry materials will (for wood) and clean, dry, AND OIL/Lubricant FREE are required for metal. Many sheet metal manufacturing companies fabricate steels and aluminum and although aluminum is clean from the mill, oils will transfer from other jobs running through the shop that are steel. SO...Clean, Dry, and if metal oil free materials are necessary. Lastly, polyurethane foam can be poured into the fixtures at temperatures as low as 40 degree F and higher. Be sure to work within the adhesive range of the adhesive manufacturer if using ESP.

Doesn't the polyurethane off gas and cause the debonding issues?

This is a question that has nuances to the answer. At the end of the day it really matters what the blowing agent is in the foam in the first place. Whatever the blowing agent is will determine how much off gas. More off gas then more shrinkage. More shrinkage leads to more debonding if the shrinkage exceed the strength of the bond. This is a question that must be though about in the foam making process and the technical answer is this: If the molecules of the gas captured in the cell of the foam is larger than the microscopic openings in the cell wall of the foam, then less gas escapes and the foam shrinks less. If the molecules of the gas are smaller, they escape and the foam shrinks more. So rather then asking what size are the foam gas molecules the IMPORTANT thing is to know the shrink rate of the foam over time. The foam supplier should be able to tell you this and the DIY SIP material supplier must be able to guarantee this. One general rule of thumb is this, the lighter the density of foam the higher the shrink rate...1 lb foam will shrink more than a 3 lb foam. Hope this helps.

Posted By IADDIC on 20 Feb 2013 09:49 AM
This is a question that has nuances to the answer. At the end of the day it really matters what the blowing agent is in the foam in the first place. Whatever the blowing agent is will determine how much off gas. More off gas then more shrinkage. More shrinkage leads to more debonding if the shrinkage exceed the strength of the bond. This is a question that must be though about in the foam making process and the technical answer is this: If the molecules of the gas captured in the cell of the foam is larger than the microscopic openings in the cell wall of the foam, then less gas escapes and the foam shrinks less. If the molecules of the gas are smaller, they escape and the foam shrinks more. So rather then asking what size are the foam gas molecules the IMPORTANT thing is to know the shrink rate of the foam over time. The foam supplier should be able to tell you this and the DIY SIP material supplier must be able to guarantee this. One general rule of thumb is this, the lighter the density of foam the higher the shrink rate...1 lb foam will shrink more than a 3 lb foam. Hope this helps.

Is this a problem with both eps AND poly?

First off we need to ask if this is indeed a problem. In my opinion it is an item to be known and understood at which point it is not a problem. ESP has its own set of knowledge in which one needs to be familiar but no, shrinkage is not one. Cutting the ESP, having clean edges, 100% bonding, using the right adhesive... all need to be taken into consideration. With the right polyurethane foam, not much is simpler than pouring the foam into a frame and letting the foam adhere to the frame.

Makes good sense. Now the end question is what is the right poly? How about using icynene? Im not an materials pro so Im not sure what Icynene actually is.






The other question is how do you get this past the building department?

DIY
 - Gather Materials 
         26-gauge metal sheeting (say $50 for scrap) 
         Can of white paint (home depot $30) 
         Dow Froth Pack 1.75 pcf, R-5 ($820 for 50cf bulk pack)
 - 3-days of cutting/wrestling with metal and trying to figure out how to bend in some semblence of a panel joint.
 - 2-days making jig, trying to keep assembly square while filling with foam.
 - Mark of success: Only lost 14% of foam to overspill (now to figure out how to get it off your hands, driveway and the neighbor's cat)
 - Fruits of your labor: The ugliest 24.5' x 3.5' 6-inch thick metal SIP panel you've ever seen.
 - Spend the next day telling yourself your $9/sf sip panel isn't going to delaminate (as you watch the skin bubble peel off).
 - Buy a few rolls of duct tape for insurance.

Non-DIY
 - buy stock panels from local polyiso SIP plant (~$5/sf).
 - spend day watching 24.5' panels simply slide into place side by side with ship-lap joints.
 - Note that 2.6 pound density, R-8 panels are structurally sound having been produced by same plant for decades.

Difference - priceless

In all seriousness there are some things that make no sense to DIY.  This is one of them.

Icynene foam is based on Castor oil and Icynene cells are open--which means no gases are trapped in the cells, so air-infiltration reduces the R-value to below 4. . Closed cell foam traps vapors and blocks air migration which enhances the insulating capacity. Icynene foam is better for applications where some air must pass through the foam Also, Icynene is not a structural foam so the foam can not be relied upon to act as a structural component of the panel. In other words a fully framed and studded wall is required and the Icynene is simply used as insulation. If this is what you want to do (just an insulated panel and not a structurally insulated panel)then I would recommend an open cell polyurethane foam as it is less expensive and does not have shrinkage like the closed cell foam as mentioned previously. If you are interested in moving forward with a DIY project we can help at IADDIC. you can reach me at engineer (at) iaddicshelters (dot) com.

I agree with Torben. SIPs have too many ways to go wrong with be a good DIY option. Want an air-tight, well-insulated DIY structure? Build a CMU (cinderblock) wall. Exercise just the barest amount of caution required to keep the walls plumb (a rock and a string is good enough for checking). (Don't even worry all that much about square.) Please do put in some seismic reinforcing wire ladder between the courses, and vertical rebar and poured concrete on corners, either side of window/door openings, and otherwise at least every 4th column. (Every other column is even better.) You can do all of that yourself, really, with probably the same effort and mess required to DIY your own SIPs panels. In a lot of "developing countries" there are a lot of folks around who are surprisingly skilled masons.

Now fasten 4" EPS or PU rigid boards to that thing and finish with stucco, siding (wood/vinyl/corrugated steel/old tires/whatever is lying around), brick, or more CMU. Heck, even adobe in a dry climate. Exact details depend on climate and the type of siding you choose. If you're lucky you have access to some kind of building wrap. Some of those materials may be hard to come by in remote areas, but so will EPS, PU, adhesives, and the perfectly flat and square sheet steel or OSB you'd need to make SIPs. Presumably those materials would need to be imported, whereas concrete and cinderblock are commonly available in a lot of places. Also you'll need a very clean jobsite that isn't too humid, which you're not likely to find in, e.g., Haiti. Cement-based mortar hardens nicely in wet, humid, dirty conditions.

That structure will survive the next earthquake and hurricane and be passed on to your great grandchildren, with easy repairs along the way using local materials and unskilled labor (if you don't care about aesthetics). This structure is expensive to build in the US unless you provide your own labor, but fairly cheap otherwise. Labor is plentiful in developing countries.

Hi Torben: I am old enough to remember when there was no such thing as DIY. Home Depot and Lowes were't around and so craftsmanship was required. Then somebody came along and said, "hey with a little help people could do...by themselves". So too it is with DIY SIPs. You are right that this is not right for everyone and many folks love the finished panel. That said many folks also love the idea of creating and doing for themselves. Like many things, once the secrets of doing something are unlocked all kinds of cool things are possible. So, at the end of the day both finished panels and DIY have their place.

IADDIC,

I think you are mixing a number of unrelated topics to support DIY SIPS.

1. DIY - I'm all for it if it serves a purpose (i.e. cost less or better workmanship, DIY SIPs offers neither possibility).

2. Low Cost or 3rd World Housing - A very expensive component like foam and higher tech processes rule this out.  Rammed earth, Adobe, straw bale or other local, cheap materials make much more sense.

I could not disagree more with the idea of trying to convince people to DIY their own SIP panels.  The best case is they just waste time and money.  A building official would be a fool to allow DIY SIPS.  The worst case is they manage to actually build it and it becomes a life-safety issue.

The only secret to SIPS is correct material and machinery to do the work consitantly and correct.  The DIYer does not have these.

It's kind of like DIY structural steel beams.  All you need is iron ore and a good fire.

Hi Torben,

DIY: Well this seems to be one of those conversations where we convince folks what NOT to do...Tradesmen can do many things and SIPS are no more challenging than pouring concrete. Tools are required and the better the tools the better the job no doubt. however people have been mixing concrete by hand in wheelbarrows for a long time and I can imagine the companies that suggested no one should try this at home. Further to suggest that folks can not achieve a quality product that meets code is shortchanging a mans capabilities.

As for the Developing countries. Energy is in short supply. People spend hours scavenging for wood to heat the home and cook. Energy efficient products go a long way to alleviate world energy needs seeing as buildings consume almost 40% of the world's energy resources. Now let me also offer that things like straw bale and rammed earth and other "local materials" have not proved adequate for 1/3 of the people on this planet. Therefore my assertion is that energy efficient DIY has its potential as a viable alternative.

Now in ALL cases DIY is not for everyone but creating SIPS is a skill that can be learned like any other...carpentry, woodworking, cement, brick laying...relating the making of panels to making steel is not a good comparison. Although blacksmiths have been DIYing it for years.... BECAUSE...framing, backing, mixing and pouring are skills that many people already posses and teaching how to pull all the pieces together is a matter of education AND the need for high end expensive equipment like a mill are not needed.

I never laid claim to DIY SIPS as being a panacea to everybody's housing problems no more would I suggest someone not erect structures using brick, blocks, stick, factory made SIPS, rammed earth or whatever made sense for the individual/project.

Mixing concrete in a bucket is not the same as creating a SIP. It's apple and oranges. Ancient civilizations were mixing concrete and creating concrete and masonry structures thousands upon thousands of years ago. Concrete & masonry are basically a naturally occurring but man-made version of stone and rock.

A self-made SIP is like saying one can create their own GluLam beam or there own piece of OSB by laminating strands of wood and using some glue to hold them together. These are precision structural elements that require factory conditions, equipment, and precise construction.

Until IRC or IBC recognizes DIY garage made SIPs as viable structural elements in construction, I just don't see it being a valid choice in construction.


What I DO SEE happening here is that people will attempt a DIY SIP and it will fail, the structure will fail, or it will look like total garbage. This will then be posted into the media and it will give SIPs a bad name. So even legit and professional factory SIPs will suffer from the bad press because of DIY SIPs.

Lbear:

I'll have to respectfully disagree. Unleashing the power of DIY'ers has always created a plethora of great outcomes and combining skills and offering access to materials has often resulted in incredible achievement. I favor to believe in the ability of men and women to create and develop good outcomes despite challenges. There will be some failures for sure (like my first attempt to pour a concrete slab for a patio) but I firmly believe the opportunity exists to learn the skill and art and bring innovative new solutions into play. Thus I take the can do attitude above the can't and resist advocating we all give up because something appears hard.

I agree, progress requires failures. DIY's are at the source of almost every innovation ever. I applaud their attempt. I advise them caution but urge them to try new things, in new ways.

I however do think that when failure could result in a loss of life then other measures need to be in place to keep the house from falling in on it self.

Maybe start with a IP (insulated panel) rather than a SIP.

I don't have an issue with DIY. I have an issue with someone selling a package for others to do DIY SIP panels. I'm pointing out that this cannot be done safely or economically. It upsets me to see a product being peddled based on the ignorance of the purchaser with such significant risks to the purchaser.

I should clarify that I'm not against DIY construction itself. I think DIY is great and in a lot of cases leads to a much better result than the "pros" get, because you care more about getting it right if you're the one that's going to live in it. The "pros" on the other hand (in general) care about getting the job done quickly and cheaply, doing no more than required by code and the the written project specifications, and getting the quality just good enough that they don't have callbacks/warranty claims and don't have legal liability. (I'm generalizing -- that's what I would call a "typical" contractor. Not all are like that.) But DIY projects need to use appropriate techniques, and self-build SIPs are not appropriate. The building technique I outlined (and variations on it using, e.g., AAC) is an awesome DIY technique (particularly if you keep it to a single-story structure on a slab).

I'm not against DIY assembly of factory-made SIPs, by the way. I think SIPs may be better for that than stick built. But making the panels yourself? I don't think so. One of the big benefits of SIPs is factory-made precision and consistency. That is also an absolute requirement if the building is going to be durable and structurally sound. So go buy factory-made SIPs and tilt them up by yourself (with the help of some friends, I hope). Go ahead. But don't go making your own SIPs. Or if you do, don't rely on them for structure -- use them only as insulated cladding over another structure of some sort.

Or I suppose you could start by building yourself a workshop (that's another name for "factory") for making your "DIY" SIPs in a controlled environment with the right tools (including quality testing tools). There are some folks here that can tell you what you'd need to buy, and maybe even where to pick up used equipment.

Hi Torben: If you concur that DIY is not in and of itself bad and packages (like sacks of concrete mix, bricks, electrical wiring/fixtures, plumbing (gas included) roofing...) are packaged for the consumer, then what in your opinion is needed to educate the consumer. Warnings and instructions can be included, training even. I agree that selling to the uninformed is a bad (very bad) thing. People build all kinds of structures using all kinds of materials and end up with very poor construction. So what precautions could be implemented without just telling people that they can't do this or that?

Even if I could, I wouldn't use homemade tires for my car either. There are some things that are best left to be manufactured, by experts with the proper equipment. A DIY'er should not put other people as risk for their failed attempts.