Hi guys, Ive been lurking on this website for a week now and appreciate all the great advice I read here. This is my first post and wanted to tell you a bit about myself. I just closed on my property today, almost 6 acres, sold a brand new build stick home last year (im able to do the majority of the work), and this time around I really want a energy efficient superinsulated home to reduce my monthly outlay in energy costs. Ive been reading about SIPS AND ICF's and ive been going back and forth between the two. I live in northern maine where we have more snow and cold weather than warm weather. My lot is going to need alot of fill to bring it up to road level. I want to build a simple 1 story, 3bedroom ranch home. Im considering ICF up to the roof and then Sip panels for the roof? I have found a builder thats about 4 hours south of me that will do the work, but im trying to become educated before doing anything this time around. Do you think its possible to save a few dollars and do some type of large ICF on slab install? If yes, keep in mind ill have to bring the ground up about 5ft to road level. Im considering, slab with radiant heat, 3kw solar. Some questions im unsure of are, i hear people talking about thermal mass, but is there really any thermal mass if its covered in foam where the sun cant get to it ? Also, how do you install drywall or siding onto this foam? And when you do, wont you then penetrate the foam and lose some energy efficiency? Thanks again

Also, curious about some very very nice energy efficient windows. triple glazed etc..

We have very hard winters here, and the less heat I let out at night the better..



Any other suggestions or tips to point me too would be great.....passive solar, etc.

Hello cwarman and welcome to the forum.

With regards to your chosing between ICF and SIPS if you are on this particular forum ICF will be the wall of choice as most here believe the system is much better than SIPS. With regards to the thermal mass, the ICF does have quite a bit and when a wall is completed it operates at an R value of 50+. The sun hitting the ICF wall probably isn't going to do a whole lot, so that is where you need to look at getting quality windows. Also you need to take into account the way your house is facing the sun and have windows sized accordingly.

As for radiant floors, I have recently had 2 clients in succession want to install radiant flooring in their ICF house. I didn't like the idea personally and I consulted my engineer with tremendous ICF experience and he concurred with my opinion. Puting radiant heat in an ICF makes it somewhat difficult to run because of the thermal mass. It can be difficult to gauge the temperature in this type of senario. I'm sure that there are others here that will disagree, but that's why its an opinion. As for the drywall and siding is screwed onto the webs that hold the ICF together or at least in most cases. I'm sure that there is some ICF block where that won't work, but I can think of one off hand. Screwing into it will not create a loss in energy efficiency.

Good luck and again welcome to the club!

renangle

Ren, Ren, Ren,
Please don't spread this BS to the New Guy! R-50+, In Maine? Not happ'nin baby. You know it and I know it, and Oak Ridge knows it.

SIP guy here cwarman. Yes, Absolutely Super Insulate! When building in a Cold climate it will pay for itself if you do it during initial construction(when it's least expensive). I consider Super Insulating to be around R-40. A 10.25" EPS SIP will do that for you, or, you can go with ICF's, but you'll need to add extra insulation to the inside of the wall.

Either system will suit you well, but study up a bit. If you are Really looking to Super Insulate, know the facts!

Wow, i didnt realize they made Sips with that thickness! There are no local SIP or ICF contractors that are close to me, there are several about 3+ hours south of me that will do the job. My issue is finding a person that can really give me legit help in designing the house, giving advice on heating systems, solar, super insulation and helping me in making sure we eliminate all the thermal bridges etc. So im trying to soak up all i can here, this place seems to be a great resource. Thanks for the advice guys, keep it coming..

ICFs are a superior wall system in every way. SIPs are a better choice for the roof than conventional trusses and insulation, but an IFF (insulated floor form) such as Lite-deck is a superior roof structure, but a concrete roof may be design or cost prohibitive.

cwarman,

Most of your questions have been discussed in the past on Green Building Talk, just not all in this ICF forum. If you haven't already done so look through the SIPs, geothermal, radiant heating, and other forums. You will find general strands of agreement but many specific disagreements with regard to all your questions. It will take a lot of searching, but it'll be worth it. For example, there are discussions about the suitability of ICF vs. SIPs for various climates. For Maine there are some good arguments why SIPs are better. You will find discussions of energy efficient windows, where radiant heat works good, or doesn't, and on and on.

I am nearing the end of my own ICF house building project. My research began over two years ago, my building permit was in hand the end of 2007, and construction begun in late Feb, 2008. I know this is a bit immodest, and may be regarded as chest pounding, but for starters look through all the forums for posts I have made, several in threads I started, and many in response to others. I have commented in discussions related to nearly all your questions somewhere. I have sincerely attempted to be rational, reasonable, and only partially biased! This should get you started on what will be a very challenging and rewarding information hunt! Take your time and don't short change yourself.

I am a few years behind dmaceld in my build, but he has done a remarkable amount of research and his posts have been helpful to me.

My personal view (I work in the commercial consruction field) is that :

1. SIPS will typically have better R values than ICF because they have more insulation thickness.  As Panelcrafters says, you would need to add additional insulation to the typical ICF.

2. Thermal mass is generally considered to be a good thing and the concrete core of ICF provides some, BUT....the interior insulation of ICF defeats much of the thermal mass "benefit."  Any additional insulation should be added to the OUTSIDE of the ICF.   I have also seen studies that suggest that over a 24 hour period (if that is a consideration) more than 2" of thermal mass material is not used.

3.  If you look for brute strength for hurricane/tornado protection, ICF is better than SIPS.  In any case, the roof and especially its connection to the walls is usually the weak link.

For me (near the gulf coast) I would ideally like an ICF with 4" or 6" of insulation on the outside of the concrete and 2" (or ideally no) insulation on the inside (6" total is probably overkill in my location).  There is a Euro product that uses a clay tile as the interior form, but does not seem to be available here, yet.  There are also ICF systems that have thicker exterior insulation.  I am also considering a composite ICF made locally (assuming they survive the current financial situation).  I would probably add a layer of insulation to the exterior of the composite form.

Given your location, superinsulate and make it tight no matter how you build.  2x6 and spray foam with interior furring strips to attach the interior drywall might be good for you, too.

Make sure you visit http://www.buildingscience.com/bsc/ and do lots of browing there.

Good luck,

Bruce
(who is putting on his flame-proof underware)

Since I've been on this forum, it has never been my intent to BS someone about ICF as that would be wrong. When I stated that an ICF wall operates at an R 50+ I believe that statement to be factual, note that I did not say that it has an R-value of 50+. Panel Crafter and I will simply have to agree to disagree with regards to my statement as it has been a long standing difference in opinion between SIP folks and ICF folks. I have had several conversations with Richard Rue, CEO of Energywise Structures on this topic as I consider him to the a leading expert on this subject. Mr. Rue is a member of the NAHB and PCA and he has a background in thermal dynamics when working for NASA. When stating that an ICF wall operates at a R 50+ you must take into account the R value (lets say R 27), the reduced air infiltration, the thermal mass, K value, and all the other things that someone with his expertise is aware of. When you add everything up, there is a school of thought that system operates with an equivalent R-value of 50+.

At the end of the day, I would put an ICF wall up against a SIP wall everyday of the week and twice on Sunday. Again, it was not my intent to mislead anyone which is why I worded my post carefully. It is possible that I misinterperted my conversation with Mr. Rue, however I don't believe that is the case.

renangle

I have, and so have the experts including ORNL.

• Air Infiltration(or lack of) does not increase or decrease R-Value. Apples & Oranges.
• Thermal Mass has little benefit if it's covered with insulation and it also has little benefit if the outside temperature does not rise above and drop below the Indoor design temperature in a given day. Something that won't happen in Maine in the Winter.

Let's just agree to disagree.

Renangle,

I'm an ICF guy, but I have to agree with PanelCrafters here.  You are talking about the overall efficiency of the entire wall system, not R-value.  Air infiltration has nothing to do with the R-value of a wall, however it does help increase the efficiency of a wall system.  On a side note the entire argument for using thermal mass to add to r-value (or even wall efficency) doesn't mean much in a climate where outdoor temperatures never reach your desired room temperature for months (long cold winters).  Of course this is just my opinion, although I strongly reccomend the use of ICF and I feel that the house will be much more efficient, I still don't like seeing the R-50 claims.

 

To the original poster...

I use Quadlock for my ICF building, they do offer some thicker panels for an R-40 wall (manufacturer claim), the foam is 4 1/4" thick on each side of the concrete.  I'm curious how others would interpert the R-value of this wall system?

I think the "logic" of the "effective or equivalent R50 value" myth works like this.........

If:  You take a standard 2x4 stick wall with R13 fiberglass insulation and call the actual thermal performance of the wall "R13" (which it is not because of thermal bridging, infiltration, etc.),

Then: an ICF with a real R value of ±20 (which does not suffer from bridging, infiltration, etc) should have an effective value of R50.

ICF is a LOT better than a old fashoned stick and fiiberglass wall, but it does not offer a real R50 unless you get near 10" of insulation.

Personally, I run away fast when people tell me things like that.

Bruce

I'm an architect planning my own home in a hurricane prone, high wind, cold winter area (Rhode Island). I'm a believer in ICF's as a building system for reasons of high insulation, low infiltration, durability (think rot), strength. I plan to build my own home partly out of ICF's. That said, I do not believe the claims of inflated R values of 50+. The ICF industry did itself a great deal of harm in making claims based on the mysterious "thermal mass" effect boosting R values by 50% to 150% over the value of the insulation alone. In order for thermal mass to contribute it must be exposed to the interior (a concrete slab floor with ceramic tile works great). Once you cover the mass with 2" of foam, it will no longer function. Most ICF manufacturers have quietly stopped touting thermal mass but a few have continued to beat the drum. ICF's are a good product overall - just know that you're essentially getting an R value equal to the total insulation thickness, period. Figure your infiltration load separately - as you always should.

It was once said that 'you would have to insulate a stick frame house to 'R-50' to be as energy efficient as an ICF home'. Thats it, no more no less. From this people went crazy with the whole R thing. I wish it would just go away. If I had a dollar for every time I had to explain to a potential customer.... well you get my point. I like to explain it this way, lets say the temperature outside in the summer is 30/86 degrees but with the humidity it feels like it is 40/104 degrees, how would you prepare yourself if you were going out?? If it was 40/104 I would be drinking a lot more water in the work day than if it was 30. But the temperature is still only 86 but it 'feels like' its 104. Now back to houses, if you live in an ICf home which has an R value of +- 20 but will 'perform' in the 40's, at what temperature do you have to set you termostat to keep it nice and cosy inside. In the middle of winter in my non ICf house I have it in the high 20's to keep warm, my neighbour who lives in the same size ICF home keeps it in the low 20's. Why? you may ask, well lets think about that for a monent......I know air infultration from a stick framed house for one. I could name some other reasons, but I am sure we all get the point. Although the 'R value' of an ICf is comparable to stick built, it performs better. So lets please stop beating the R value drum, "my SIP's better than your ICF" BS. At the end of the day there are much better ways to build than stick (which should go the way of the dinosaurs). Just do some research on the product you want to use, best thing to do is talk to people living in an ICF and ask how much it costs them to heat and cool and stop worrying about R values.
Paul Stevens

No one beat 'that drum', but when the 'R-50 drum is beat', it's time to beat the 'Reality drum'. Nothing more, nothing less. I'm an ICF proponent, and I'm also a SIPS proponent.

PanelCrafters, I wasn't directing anything towards you personally, just making a general statement. Sorry if you took it personally or were offended.
Paul Stevens

I don't think you can make this an absolute statement. Mostly I agree it's true, but not 100% of the time.

Ever stand outside next to a house wall when the sun is shining bright and it's 5, 10, 15° F? Feel how warm the wall can get? I haven't taken any measurements but I'll bet even in cool weather the wall can get warmer than the house interior. That means heat will move to the inside warming the concrete thus making use of the thermal mass (heat storage) of the concrete in helping heat the house. Now, on the North side, and at night, it's a different story. One measurement I did take is on the 1 1/2" thick insulated garage door of the house we're in now. It faces west and is painted  dark green. One summer afternoon the outside surface temp approached 140F and the inside surface was nearly 120F. The sun was pumping heat into the garage even though it was 80+ inside.

It would be interesting to see real data on this aspect of heat transfer in an ICF wall.

Kind of along this line the other morning, temp about 28 to 30, there was frost all over the insulated portions of the roof of my new ICF house. It has ~R40 Icynene on the underside of the roof. No frost on the eaves and gable overhangs. I looked at the roof over the bathroom and a large triangular section was frost free. What I was seeing was frost being melted by infrared heat, or sun rays, I don't which for certain, reflecting off the Hardieplank gable wall of the garage! The ICF wall, even though it is painted a beige/yellow color, was decidely warm. The next day when I checked before the sun was up all the roof was frosted so it was not a case of inadequate insulation over the bathroom.

I didn't and I wasn't, thanks. I just saw a statement that I disagreed with, and I 'called it'.

Who of our clients, customers knows the real value of R? I understand there are scientific explanations behind it and such but to talk to a sincere home buyer who is not scientifically inclined the value of R means almost nothing. It is the same as the statement:" I ate an apple ". Well, how big was the apple? What was its consistency? Was it cold or was it room temperature? The questions could go on and on - you catch my drift. To the person who ate the apple all that matters is that he ate the apple and felt good about it. Similar is the R value. R13 - good, but R 20 better, yes?

So, the R value discussion started in stick framed houses when a certain pink company advertised the value of the needed and measurable insulation. Everybody jumped on the R bandwagon. Certainly, as we all know, the R value of fiberglass is contrived in perfect conditions. There were no gaps, the product was not to compressed etc. And then the prescribed R was achieved at the perfect temperature of 20 Celsius (~70F). Wow, were we bamboozled with data and bullshit for years to come until we had a closer look at the "performing" R in a wall. It turned out that an R13 wall with fiberglass was only performing at a R6 or thereabouts and the R value was deteriorating due to moisture capture and material compression whereby gaps started to appear at the top of the wall because the fiberglass was settling to the bottom due to the weight of the moisture traveling with the air.

So here is the thinking: EPS or polyurethane is constant - if left alone in a wall it does not compress nor does air travel through it in normal conditions. It will perform the same way in 50 years as the day it was installed!

Obviously if these products perform better in the R department than the elusive fiberglass or other products that achieve their R by trapping air, it stands to reason that the constant R must be a better R than the shifting R. I am purely talking from the perpsective of a home buyer here. Is it then so wrong to use a claim of "R equivalency" by saying:" In order to compare the fiberglass R to an EPS R you need to install double or more fiberglass and still will not obtain a constant R. Therefore, even so scientifically not exactly correct, would it be so wrong to claim an "R50 equvalency' in ICF or SIPS if this, that or the other? I think not, simply because the consumer purely "trusts" the statements of R and does not understand its implications now and in the future. Just food for thought here!

I honestly am not in one corner or the other. Ill build with SIPS or ill build with ICFs if I can find out whats best for my situation in northern Maine. We have no hurricanes up here, only cold weather than can get down to -20+ in the winter.

Im curious about passive solar to go along with it. I know that Sips dont supply much if any mass for passive solar, but could do something with the floors with tile or what have you.

Again, im looking for a simple open floor plan, ranch style home with 3 bedrooms.

This is my second new home that iwll be built in 5 years. The first one I stick built and wasnt happy with the energy efficiency of it, even tho I used alot of fiberglass insulation. This time around, im going to go slow and take my time, and work on getting rid of all the thermal bridging that I can, and making this house heat with a candle.

Whats the most difficult is that there are NO local builders using ICF or SIP building practices, so im having to talk to people 3+ hours away.

I appreciate all the comments so far, and im continuing to search on this site and read all i can.

Thanks again, im sure ill have more questions:))