Hi everyone This is my first post so go easy on me please. I'm drawing up plans for a house right now and i'm torn between building with SIP's with these guys : http://www.tek.kingspan.com/uk/index.htm Or steel frame and Ytong block. Right now SIPs looks like the better choice but I have heard that the lifespan of these panels is quite short and they tend to delaminate over time, leading to structural problems. Can anyone shed some light on this ? I live in Europe, in a warm mediterranean climate (think southern california), we have very hot dry summers with not too much humidity and wet mild winters where damp is a bit of a problem in a normal concrete house. Grateful for any information and advice, many thanks straydog

Great question! I am surprised it has not been answered yet. Interesting thought though.
Here in U.S. we build more disposable structures as compared to the rest of the developed world.
From a European point SIP longevity is certainly an "immediate first thought" where as perhaps a North American developer may not consider such a topic on the priority list.
As for me, I cannot provide an answer and was hoping to read credible answers from some of the more knowledgeable posters.
Best of luck with your decision!

I find this question curious. Is it an academic one or is someone really wanting to know the "life-span" of a certain material? I mean, if one simply uses logic and past building practices, one would use concrete, stone, etc. Has anyone seen the pyramids? How old are those things? Of course, the question of longevity must be coupled with the cost. Unless of course you are a Pharoh and that isn't a concern. In any event, SIP (OSB, Steel, MgO, etc.), Stick build and concrete are all great ways to build a house. The key in choosing any of these, FROM A LONGEVITY PERSPECTIVE, is appropriately building the structure. Stupid and/or ignorant building processes will render all of these obsolete in short order.

The other thing is, are people truly wanting to build a home for the ages? I mean one that lasts more than 200 years? If so, cool. It will cost you more money regardless of which way you go. You will need to clad this with some higher end siding/roofing. You'll need to make sure the footers, foundation is done correctly and put more into it. How about the "correct" HVAC system? One that exchanges the air appropriately and is more comfortable in the area that it is built.

The poster that mentions that the U.S. builds "disposable" homes. The U.S. also, over the years, made it affordable for more and more people to actually own a home. Are these homes the "best"? No but many of them were never intended to last through the "ages".

Thanks for the replies,

SIPS are a relatively new technology out here in the eastern Mediterranean and there are no reliable sources of information on lifespan, hence my posting on this forum.

Of course, the manufacturer/ builder has told me that the house will last X amount of years, but sales people always tell you want you want to hear. I am spending a lot of money on my house and I need to be sure that it's going to last a reasonable length of time. Now, I'm not looking to build a pyramid which will last millenia but I would like to be sure that the materials will not deteriorate and I can pass the house on to my kids some day.

tmsu - My house will have an external skin of local stone, about 6 inches thick, and we use good quality Italian ceramic tiles on the roof. So I have no doubt that these materials will last, and in any case they can always be fixed or replaced. The problem is if the house experiences internal deterioration with the SIPS panels over time. I don't quite understand how these can be repaired, short of ripping the wall out.

One more question : We don't have mechanical ventilation systems out here, we use individual aircon units in summer and in winter central or underfloor heating. Air exchange is usually accomplished by just opening windows. We usually keep windows open for most of the day. Is this sufficient ?

First, thanks for taking my comments as they were intended.  If you use good quality siding/roofing, this will protect your internal structure from the elements.  I know, sounds like a no brainer but some builders don't make sure....
Anyway, some disclosure here.  I am not a builder by profession and have little experience.  I have built a SIP home (mine) and a stick home (neighbors).  From all that I have read and from personal experience, the SIP home gives you a more structurally sound home than any stick built one.  A concrete one is better than a SIP home, structurally.  This assumes that in all cases, the proper build and installation was done correctly.  The SIP walls are dead straight and absolutely solid.  Again, if manufactured correctly and properly installed, the SIP home will bring you a home that will last well beyond your GRANDKIDS.  However, I do believe the SIP home is going to be a bit,  but not a whole lot, more expensive than a stick home (certainly less than a concrete one).
As for air exchange, as long as you live in an area where you always have the option of opening windows, that should do it.  The SIP home is extremely "tight".  Therefore the air has to be exchanged in some way.  Because the SIP provides such great insulation, your furnace-a/c unit will not run nearly as much.  Which is good for $s but not for air exchange.  I installed an ERV unit that exchanges the air.

Just curious why you consider SIPs a better choice than AAC.
I am guessing that your neighbors in concrete houses can throw open the windows in a hot dry climate because all that thermal mass averages out daytime heat and nighttime cool. Wouldn't you need central air conditioning and mechanical ventilation in a low-mass SIP envelope?

Um, I have no idea what you are talking about.  Please explain to the ignorant (that's me).

yes it is sufficient

Sorry. Think of a concrete house as a five-gallon pot of water; it takes a long time for it to heat or cool, so you don't worry about leaving the windows open in 95-degree heat, particularly in climates where it heats and cools more or less equally over 24-hour periods. It is no accident that people are still building adobe houses in New Mexico, or that the Greeks and the Italians like thick masonry walls. By contrast, the mass in a SIP house, not counting the floor, is pretty much just drywall -- a one-gallon pot to pick an arbitrary comparison -- so you may have to button it up and condition it. It wouldn't take much energy because of the R values, and you'd be more comfortable, but you have to recognize that SIPs and concrete are very different systems. I don't know anything about Stray Dog's climate or preferences, so none of this may apply. I am just asking.

Stray Dog is putting plenty of mass on the outside of his house, but that's not much help for heating and cooling, as this Oak Ridge National Labs study suggests: http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html
The introduction does a good job of explaining how thermal mass works.
Ytong, aka autoclaved aerated concrete, aka AAC, is a low-density concrete block much favored in europe.

Chris - thanks for the reply.

tmsu, toddm - Thanks also. I live in a concrete apartment block now and in our climate they tend to absorb heat during the day and release it at night, so the summer months are often uncomfortable. In the winter the apartment is quite hard to get warm, and the walls always feel slightly damp. Admittedly, the block I live in seems poorly constructed, but it has turned me off building with concrete. 90% of people out here build with concrete but the cost, labour, time and mess involved are considerable.

A friend of mine recently built a SIPS home and I was very impressed with it. The temperature inside is always comfortable, it's solidly built and it went up quickly and smoothly. He uses very little heating in winter and gets by with ceiling fans in summer, with the odd blast of a/c during the hotter days (and we often have 100+ temps here for 3 months of the year). It seems like a no-brainer to me. At least, if I do not build SIPS, I will go with the steel frame and Ytong block (stick frame isn't very popular out here, I don't know why).

To answer toddm's question about AAC - It's not that I prefer SIPS, I like the Ytong system combined with a steel frame also. But I know the architecht / builder who puts up the SIPS homes, and I find him professional and reasonably priced. I've seen examples of his work, whereby I have yet to find a steel framer I like.

How does AAC compare with SIPS panels in terms of insulation - I don't have first hand experience of this, I was assuming that SIPS would outperform the AAC's but the posted article suggests otherwise. I guess I need to read up more on that.

Guys, I like the discussion. I personally feel that a concrete structure is "better". Sorry if my posts were muddied about that. It would still need to be properly insulated and conditioned to be comfortable and energy efficient (something that applies across the board, btw). I like the concrete for its staying power and it kills sound. I would have done my whole house with ICFs, however, I couldn't have done it myself (properly) and would have been soooomuch more expensive. The next best thing, imo, are SIPs.
A couple observations:
*I was not aware or didn't do enough homework regarding the different 'skins' available. OSB has many redeeming qualities and some not so much. I would seriously consider and look into the steel skinned SIPs if I was building now.

*I have written on this forum before that one needs to be aware that sound (especially low frequency sound), travels pretty easily through SIP walls (at least mine). Two 'fixes', use an "acoustic block" matting and/or fur out the drywall inside the walls to reduce/eliminate the sound.

Straydog mentioned that he would clad the SIPs in 6 inch thick local stone. I think that would be an ideal marriage of materials. The stone would provide mass, absorbing summer heat before it reached the SIP panel, and it would deaden sound. Of course I'm a proponent of steel SIPs, but if any climate would be suitable to OSB I would guess Greece's climate (or elsewhere in the eastern Mediterranean) would be. It's quite arid, so I doubt there would be moisture problems. On the other hand the arid climate would create more of a fire risk, to which OSB is vulnerable. Do you have termites there?

Straydog, the insulation value of a SIPs panel is somewhat better than AAC (depending on thickness of course) but only in a straight R-value comparison. But AAC does have very good insulation value, especially in a climate like yours which benefits from thermal mass. The benefit of steel framing and AAC is that it is a completely non-combustible structure, which is a big plus in your region.

Stick frame isn't popular in Europe because they discovered centuries ago that it burns up real quick in a fire, and it isn't too solid in an earthquake. It's generally looked upon as appropriate only for a temporary structure.

tmsu - very useful comments regarding sound prevention. Noise pollution is an issue here and should be considered.

hi jelly
Yes, we have termites here. The SIPS builder told me that the panels are treated somehow to resist them, this is another thing I have to look into in more depth. Fire is a major hazard here, as are earthquakes.

Steel skinned SIPS are not available here, so not an option. But to be quite honest I am slowly starting to think that maybe steel frame with AAC might be better. I can keep the stone skin outside to further add to the insulating properties of the house and I guess it would be drywall inside. I am just struggling to figure out what kind of roof might be best.

Your comment :

Stick frame isn't popular in Europe because they discovered centuries ago that it burns up real quick in a fire, and it isn't too solid in an earthquake. It's generally looked upon as appropriate only for a temporary structure.

Very well put

Once again thank you all for your time to answer

they are used widely in europe

AAC is R1.25 per inch, depending on structural requirements, or considerably less than SIPs, but insulation doesn't tell the whole story. Oak Ridge developed a multiplier called DBMS (dynamic benefit of massive systems) specific to local climates to allow comparison of the two. The multiplier for Phoenix is 2.53, so 10-inch AAC block, adjusted for mass, is the equivalent of R32. The Southwest is the best case climate in the US. (Dry and hot, big swing between daily highs and lows.) I suspect mass works well in your part of the world too.
Then again, I am using AAC where it doesn't fit well, in Pa., so you should feel free to ignore it where it probably does. Couldn't help shaking my head, though, at all that mass you are putting on the wrong side of the insulation.

http://www.greenbuildingtalk.com/News/tabid/58/action/view/id/72227/Default.aspx

Guest;

what does this have to do with life span?

There are structures built in W. Texas and S. New Mexico that are 30 years old and still standing and still occupied by people. The process for building is the same and as a matter of fact our partner is actually living in one of them.

There is no reason to believe a SIPs home will not last as long as any other building method. We have adobe homes that are 70 years old, mine is as a matter of fact. But it will soon be replaced by a SIPs home with a comparable thickness to mimic the adobe look but give me all the benefits of a world class, jam up and jelly tight home. There was a time when adobe was the best way to deal with desert conditions, not anymore!

I understand cycling, it is the only type of testing you can do on relatively new technology. We have a track record and we believe in the OSB product we already have out there. Another indicator is cracks in stucco and such. No cracks indicates stable building processes and technology.

EPS is closed cell. It is roughly R-4 per inch and will be until time ends and the world ends.

I must say I am surprised that you are considering the AAC solution compared to the insulation qualities of SIPS. Generally, AAC blocks, unless they are quite thick will not give you anywhere near the level of insulation you will need in your hot climate. The fact you are also cladding in 6" of stone will mean your walls could potentially be over 15" thick, meaning a large loss of the net area you are going to get in your room sizes. The overall R value of your construction may not be much better than the concrete house you currently live in.

Combining AAC with a steel frame is also very tricky in a climate where there are large changes in temperatures in a single day. Differential expansion between the steel and the AAC will be crack heaven unless special attention is given to expansion joints and the two systems are isolated..

If you do use a steel frame it is imperitive that this is fire protected. I have seen many examples in the region you are talking about where they replace concrete frame with steel frame and place the steel in line with the infill blocks. There is little or no insulation at these hot bridges and also only a single skin of plasterboard to fire protect them. In the event of a fire, a house with inadequate fire protection on steel will curl up like spagetti. This also goes for suspended intermediate floors in steel.

You definitely should look again at SIPS as I dont think there are many other alternatives in your region that could offer you super insulation, structural strength, longevity and ease of construction. Assuming that there are not many alternative ways of building in your area, if the company you were talking to have a good product, and are professional in the way they work (check their track record and get them to give you more references other than your friend) you cannot go too far wrong with SIPS.

But choice of finishing materials and quality of workmanship is very important to get a building with a long life.