I want to build a house out of ICF blocks, but normally stick frame everything. is there a better way to build the second story? in mind I would use 12″ on the main floor for max r factor and the step down to 8″ for the second floor and ether use tji for the floor joist or steel joists. the roof will be sip panels or steel trusses with sheeting and galvanized steel roofing with a 5.5 pitch with a barrel vault in the center that I would like for the ICF to be the exterior walls. just ideas if any one has experience with ICF I would like some input I normaly build every thing with dimensional lumber so kind of green in the concrete world but it make a world of scenes to use it in my area. thanks Nathan.
Edited 3/26/2006 12:29 pm ET by montana nate
Replies
Greetings nathan, As a new poster Welcome to Breaktime.
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someones attention that can help you with advice.
ICF subjects have been addressed here on Breaktime a number of different times in the past.
If you scroll down in the lower left corner of your screen there is a search function that will take you to previous threads dealing with whatever you type in the search bar.
You may type in 'ICF' or other keywords of the subject matter and get a supply of data from those old threads.
Cheers
'Nemo me impune lacesset'
No one will provoke me with impunity
Edited 4/1/2006 2:42 pm ET by razzman
Hi Nate;
Our company specializes in ICF construction using a product called NUDURA. There block is 11 1/4 inches in width (6 inch concrete core). There are also thinner blocks available but we use the same width from footing to top plates. We just bolt on ledgers for the floor system and hang joist from the ledger. NUDURA has a system that always for an anchoring method for the ledger. Simpsons Strong Ties have a similar product as well.
We like using the same width block because it allows us an easier installation. Generally the first pour is higher then the floor joist allowing for the cast in place bolts for the ledger. We also use a special bracing system that attaches to the face of the block to plumb the wall.
I think I understand your question regarding the barrel vault. The ICF block can be used for any gable situation. It just means you'll be doing some cutting.
If you have any further questions about ICF construction just ask.
nate - use the same width block for all floors - it makes everything from forming to wiring and plumbing easier in the end. We did 8", then 6" block - shoulda done 8" all throughout.
Dear Nate:
We are homeowners and first time homebuilders. We are finishing an ICF bank barn type design with 5,400 sq. ft. of usable space. We did the whole building except the gable ends with ICF's.
We used Reward 11" blocks that have 6" of concrete. We did our own footers using Form-A-Drain (loved this product), but had cold feet and hired soneone who had "experience"with ICF's to do the first block.
Watched and learned and decided to do the second floor ourselves. On March 15th we poured the second floor with 13'3" walls with no problems.
We used Simpson StrongTie's ICF product for installing ledger boards and hanging joists. We used LVL's for ledgers and TJI's for joists. The system worked great. However, the "self" tapping screws are not "self" tapping as indicated by Simpson. We pre-drilled them.
One drawback is renting the bracing system. Unless everything goes quickly you can rack up a big bill for bracing rental.
Because of circumstances not in our control we ended up builiding during the winter. A big problem was keeping ice and snow out of the walls as you go up, (can't pour concrete on ice). We had to cover the top of our walls with plastic during different stages. This meant securing the plastic against the winter winds. This was a pain and the cause of much concern.
Attached are a few pictures.
Sincerely,
Darbie
Hello darbie, Thanks for the info I didn't get the photo attachment that you sent though if you have a extra minute would you please try againe. I would like to see you home. thanks nathan
Sorry my pictures didn't come through. It may be my server. Or it mya be that it was the first time I tryed to post pictures. I noticed there is a whole discussion on this site about those who have tryed to send pictures and failed. I'll try again when I have time to read these and try again.
Supposedly the "high" R value of ICF walls comes from different factors.
Most heat loss is through the movement of air through the walls, windows, etc. In an ICF house there is no air movement through the walls. By limting air flow in such a large area you limit heat loss.
The second is the thermal mass. The theory is the same for an earthen berm type home. The concrete insulated in the foam form and tied to the footer underground becomes the same ambient temperature as your local area's ground temperature.
A large thermal mass that supposedly is the temperature from the footer to the top of the ICF wall with only a difference of a degree or so from the top of the wall to the bottom.
So if your ground temperature is 50 degrees the concrete in your walls will be around 50 degrees from footer to roof.
This means that you only have to heat and cool against 50 degrees instead of the ambient outside temperature which could be 20, -20 or 100 degrees.
This is supposed to give the building a "performance" R value equivalent to a stick building built to an R50.
We are also trying an unvented cathedral ceiling sprayed with 2 types of foam. This will be sprayed directly to the underside of the roof sheathing. This is based on a similart theory.
Stop the air flow and you stop the heat loss.
The first foam will be 2 inches of a 1.7lb. closed cell foam followed by 4 inches of a 1.2lb open cell foam. This will supposedly give an R30 roof.
For many areas this does not meet the code requirement of an R38 for roof insulation.
However, again you get into the discussion of numbered R values versus real world "performance".
Regular batt or blown insulation will allow cold air to circulate through the insulation setting up convection of cooler air through the insulation and your warmer air will flow out.
The closed cell foam stops all air exchange and therefore stops the convection of your warm air.
My understanding is that the fiberglass batt insulation was given R values based on "lab" condition testing with no wind or humidity. These R values are not real world performance values.
I agree with others posting that you should stay with the same size ICF walls the whole way up.
We also used the Simpson products for ICF's and liked them. One part # is for dimensional ledger boards and the other for LVL's. Just make sure you order the right one. The part that goes in the ICF is the same for both types of ledger board.
We meet some guys who were using Nudura for fire wall construction. They liked it because it came in longer sections. The one thing they didn't like was that the Nudura blocks "locked" together so tightly that if they needed to make a change they couldn't get the blocks apart.
This I didn't observe for myself so take that into consideration.
http://forums.taunton.com/tp-breaktime/messages?msg=24441.75
'Nemo me impune lacesset'No one will provoke me with impunity
This is supposed to give the building a "performance" R value equivalent to a stick building built to an R50.
The best way I have seen this explained for doubters is that in the real world, fiberglass doesn't come close to performing to its stated R value, ICF walls do, so R22 in ICF is roughly equivalent to R50 fiberglass. But salespeople will overstate their product, and this can backfire.
We'll see how that plays out in our house - so far it holds temperatures pretty well...
Treat every person you meet like you will know them the rest of your life - you just might!
A bit of a rant here, if you have the time!!! You have to be careful what people are claiming about the "apparent" R value of ICF walls. Note the word "apparent"
From Home Energy magazine:
"The most favorable location for massive wall systems (which include ICF's) is Phoenix. The worst location for these systems is Minneapolis."
The best effects in apparent higher R value is in climates with high cooling loads!!! The wall mass absorbs the heat from the 100+ temps during the day and releases it to the exterior during the much cooler nights. In fact, the best system for cooling climates is to have the high mass concrete on the exterior of the building and all the insulation to the interior.
In northern climes, from about Nov- mid Nov onward, we have a temperature regime where there is 1 way movement of heat from the interior of the house to the exterior as it's is always colder out side than inside. The high mass concrete does not absorb heat from the interior during the day and then release it back in during the night!!! So in this mode of 1 way heat flow, the high mass adds very little to the overall R value and acts more like plain concrete- R value about 1 for 6 inch thickness!!!!!.
Environmental Building News (EBN) alsodid an article on this about 6-8 years ago.
The Portland Cement Association (PCA) sent an engineer to the Architecture Faculty where I lectured to talk about all the "green" benefits of concrete and getting it rated in the LEEDS system (which will rate all buildings, material use, etc for sustainability and other environmental /green issues). The audience was faculty, students and local practicing architects and civil engineers.
During her talk, she listed 6-7 journals/periodicals that she recommended as good sources/refereneces including EBN, probably her favourite. Later she went on to talk about ICF's and the apparent 50-55 R values being achieved. I spoke up at this point about the EBN article which she hadn't seen or read. At the head table was the local PCA rep (an old college acquaintance) whom I had given the the article to about 1.5 years previous. He had not yet responded back to me about the claims!!! At my questioning, they decided to sidestep the issue and not talk any further on it!! At the end of the session, many people came up and thanked me for the interjection as they felt there was something "unbelievable" about the claims but they just didn't know what questions to ask or where the theory might break down.
A claim being made by ICF contractors inn PCA supplied adds was that they saved trees. In fact true! In reality, trees grow with free sunlight and a properly managed forest will go on for millions of years.
Cement on the other hand require the "klinkers" be heated to 3000 deg F before they are ground into cement for concrete.
Aggregate (both sands and crushed stone/gravels) are now becoming scarce) They are being shipped from Alaska to California and Japan. Here in Nova Scotia, there is a growing oppostion to a proposed large crushed stone facility in a quite scenic area. The destination of the crushed stone- NY!!! This is an energy intensive endeavour that leaves large scars in the landscape. Tourism is a big industry here!!!
The foam forms are made from.......oil!!! Is this a good use of the product or should we use re-cycled materials such as cellulose or glass for our insulations as much as possible. The "Oilsands" of Alberta are now being looked at as the next Saudi Arabia for US oil supply. (if you invested in any of the oilsands stocks 1-2 years ago, you are now up 200-1000%) Huge amounts of energy are required to extract oil from the sands. This produces a very large increase in the release of greenhouse gasses plus the burning/use of the produced oil releases more- not good!!
Judge for yourself on the growing use of concrete filled ICF's.
Anyways- my 2 cents for today
EXP
To Experience30
I just saw a special on the oil sands in Canada. My personal belief is that our continued reliance on oil is a doomsday scenario.
So this gets me to why we built we ICF's.
We bought into the conept of ICF's because the arguement is that although the concrete and blocks do use up non renewable resources that because of the long term energy savings on a well insulated ICF home you will come out ahead on an environmental/energy level because of your decreased usage of heating and cooling requirements over time.
I'm still confused on the ICF issue. My understanding (small as it is) was that it doesn't act as a typical "thermal mass" in that it isn't designed to absorb daytime heat and release heat in the evening as in a passive solar house design.
The difference is supposed to be the isolation of the concrete by the foam from both outside and inside temperatures. The theory proposed to us was that this allows the concrete to assume the temperature of the ground mass (the earth), to which it is attached and isolated from the temperature swings either hot or cold.
This is supposed to provide a wall that has a constant temperature (thermal mass) and no air flow between the outdoor and the inside.
If you read what is written about fiberglass batt insulation many people argue that it doesn't have near the R values suggested by the lab ratings in the real world because of the air flow and the affect of things like humidity, installation, thermal bridging of building components, etc.
I plead ignorance to the energy and resources needed to make fiberglass but I can't imagine that it is a "green" industry. I've also heard people say that fiberglass is the new asbestos.
The spray foams are sold as very energy efficient but are also for the most part made up of oil based products. Even though the "green" ones now have no harmful HFC's and are propelled by water most of the foam is still mainly made of oil products with some organics such as soybeans or others tossed in and they call them more sustainable.
We didn't really research the recycled cellulose blown in type of insulation such as nuwool or cacoon. I had some concerns (may be unfounded) about the chemicals added for fire retardent and mold prevention.
Fire retardents are now a huge problem in our environment and are said to be in almost everyones blood on the planet and also found in breast milk.
I was looking at some old Fine Homebuilding issues and found one that has an "expert" saying vinyl siding could be considered a green product. I'd have to got back and see what reasons were given but I obviously didn't buy that arguement cause I can't even remember what it was.
We still hope that building with ICF's will save energy/oil/coal/gas over the long term. We haven't finished and heated the building yet so time will tell if it beats a fiberglass stick house.
What do you think is the "greenest" way to heat? We have big air pollution problems in our area especially with particulate matter so "wood" is not considered a good option by the American Lung Association.
Any thoughts?
Thanks for your input. It is a confusing world out there.
It will be interesting when we get some unbiased info from the LEED (Leadership in Energy and Environmental Design) program (or some other) to see if the extra $$$ for an ICF system has truly substantial positive attributes overall versus a truly efficient stick built house with as much cellulose in it as possible (all above ground walls and attics). I have seen some studies that put ICF's up against regular spec/merchant houses which are not that well built or effcient.
The most recent one, I think, was in Energy Design Update in which they put an ICF house against a regular house but the ICF has better windows, insulated window blinds for nighttime and a passive solar design/orientation. These last three features would save a lot of energy in a regular house also! A bit of an unfair comparison!!! Have yet to see where they put an ICF against a certified high energy efficiency (HEE) house such as an R2000 house here in Canada. see end.
"This is supposed to provide a wall that has a constant temperature (thermal mass) and no air flow between the outdoor and the inside."
The insoil portion of the ICF will essentially have a constant temp since the soil temps under the frost line may only vary 10-20 degrees over the year. but the above ground temps may vary 70 degrees (+40 to -30) over a few days/weeks in some areas of the country. In the second scenario,(all things being equal such as the same R value from the center of the wall to inside and outside surfaces) when you get above ground, the center wall temp will be somewhere around 1/2 way between the interior and exterior temp after a day or so of steady cold. A few days of +40 will give +55 center wall and a few days of -30 will give somewhere around +25 to +35. So not that constant all the time.
The ICF is inherently air tight in the wall sections but you still have to use good airsealing techniques for window/door installations and the the roof/ceiling systems. These are from early HEE house practices. These stick built houses are as tight as ICF houses.
"what is written about fiberglass batt insulation"
A fiberglass batt installed properly and protected by a good exterior air/wind barrier will perform quite well. One award winning R2000 builder here in Halifax, NS uses only exterior air barriers and has won the yearly award for the tightest house in the province; he only stick builds.
Some of what you hear about fiberglass comes from unscrupulous installers "fluffing" long fiber loose glass in attics, giving about 1/2 the required density for the "sold" R value. This allows air convection currents to operate in the upper layers of horizontal attic blown glass; these get stronger as the temps drop. The solution to stop this effect is to blow 2-3 inches of cellulose over the glass!!
"fiberglass is the new asbestos"
There are warnings on bags to wear a dust mask when handing fiberglass. This is from reduction in fiber size to make the fiberglass "softer" and less irritating to skin. With smaller fibers, you may inhale more but there is no proven connection to cancer/emphezema as with asbestos. With asbestos you now have to wear "space suits" with breathing positive pressure air packs. Quite a difference!!
"chemicals added for fire retardent and mold prevention"
The chemicals added to cellulose are quite benign- mostly borax and boic acid. Borax is recommended in the "Self-help Allergy Book" as a substitute house cleaner for Mr. Clean and all his smelly cousins. It was your grandmother's washing soda and she probably lived into 70-80-90's.
I contradicted the top poster on another housing forum and straightened him out on the "chemicals" in cellulose. He was telling people to definitely not use it but didn't know what chemicals were in it!! I was new to the forum (1-2 days) and then was banned from it since I showed him up on a few other items also in my short visit there.
"greenest way to heat"
I heat 85-90% with wood in a high efficiency clean burning stove- not EPA certified but probably close (Vermont Castings). I season my wood well, etc., etc.
In NS, the Lung Assoc. does not discourage wood heat but encourages EPA stoves and good burning practice. I did a couple of TV interviews on this issue. Have a look at EPA certified stoves and have a talk with your local lung association.
The best heat system in a new house today is a well designed/executed HEE house with a passive solar component. Once you have that the heating system becomes a small issue (unless you have a McMansion) as you usually cannot justify the cost of a larger HEE heating system such as radiant floors/condensing boiler(unless you want that comfort feature) or ground source heat pump. Sometimes, electric baseboards may be economically justified but not the best environmentally if they burn dirty coal for the electricity.
"It is a confusing world out there" You bet it is if you haven't worked in HEE housing/insulation/airsealing like I have since 1977. There are a lot of "Popular Energy Misconceptions" on the street. I have a list of 83 now and thought of a couple others while writing this.
Energy efficiency/conservation is now a subtrade as is electrical/plumbing/security systems but most contractors try to hang on to it as if they still should be the "king of this castle". I see so many things where money has been poorly applied to energy efficiency or not applied at all!!
A little aside about this program-R2000: This program and its predecessor has been operating here since 1981 and is basically responsible for many of the innovations being used in low energy housing world wide today. e.g.:
-airsealing techniques such as rim joist wrap
-Broan of RI bought out our two best HRV companies. Carrier, Lennox and a few other large US HVAC companies used branded Canadian HRV's.
-Joe Lstiburek of Building Science Corporation got his start in housing/building science in this program
-In 1992, the Japanese licensed the system from Canada
-The American Lung Association "Health House" program (started in Minnesota) essentially copied the R2000 program principles when they saw what was going on north of the border in Winnipeg, Manitoba. Joe Lstiburek is Co-chair of the Technical Guidelines Committee for the program.
Darbie,
I have read reports from the Oak Ridge National Laboratory which confirm what Experienced reported above - ICFs function best in a climate where an uninsulated house would have to be heated at night and cooled during the day, like a high desert climate.
I agree with him that the benefits of the high mass of ICF construction are reduced as you move into a more purely heating or cooling situation and the houses function more like one of those flimsy wooden houses people are still tossing together, except that the ICF will always be more airtight.
In the climate I live in, (I'm in Nova Scotia, too) it can be quite warm daytime and quite cool at night for a couple of months of spring and fall. ICF construction can extend the no heating season on both ends of the season compared to a wooden house, saving significant amounts of fuel. That benefit will reduce as the winter progresses.
And, as for the energy consumption of the product, there is one hill of a lot of energy expended to get a tree turned into 2 x 6's and delivered to a job site. Nothing is pure. except maybe a soddy.
I had never heard about the ground heat conduction theory. I would guess the benefit of that would vary as the exterior temperature does.
If I may wade into your question about the greenest way to heat, I think the biggest savings and longest lasting savings will be found on the drawing board. Paying attention to the house's orientation re the sun, reducing the amount of shell required to enclose the space, burying as much as you can...........There are thousands of things.
There was an excellent discussion here a few months ago dealing with exactly this subject. A lot of good ideas there. I am going to try to find it again.
Ron
Hi Ron:
"I agree with him that the benefits of the high mass of ICF construction are reduced as you move into a more purely heating or cooling situation"
Just one comment on this statement:
The benefits of high mass are increased as you move into a purely cooling situation as in 99+% of locales, the exterior nighttime temperatures are usually quite a bit lower than the highest day temp, allowing heat stored in the outer insulation/concrete to move back out. That's why in the simulations, ICF's performed best in Phoenix; full exterior concrete/stone with all the insulation to the interior performed a bit better than an ICF.
Have to go see your house sometime!
Brian
Brian,
The Oak Ridge studies said the same thing. It's just easier to form with the concrete in the middle - keeps the cost controllable.
I wouldn't be looking for any further improvements in the heat loss of the walls. I'd start looking for better windows and doors. Low e, argon filled still only give an r-factor which is laughably low.
I'm in the Prospect Road part of the phone book.
Ron
"The most favorable location for massive wall systems (which include ICF's) is Phoenix. The worst location for these systems is Minneapolis."Are you sure that is said Phoenix or was it Tucson or maybe Flagstaff.Someplace where there are wild daily swings.A while back I was a list someplace of the improvement with high mass walls and it showed very miniumal improvement in the extreme northern and southern states. More so in the middle of the country.And large one in the SW mountain areas.
They modelled Phoenix into the computer simulations and not the other AZ locations.
The massive wall system gets better in the areas with the biggest cooling loads in drier climates. In hot humid climates, the A/C latent heat load for air dehumidifcation detracts from the overall mass effect.
And true, the farther north you get, the less the mass effect.
Go to the Home Energy website and pick through the articles there. There is an early article, second or third in the list when you search for ICF's, that I got the quote from. There are tables of the simulated locations that didn't show properly on my screen. Don't know if it's a site problem or mine. But you can see the effects by location.
With more than a (similar) passing interest in Northern Acommodation I have also looked at ICF construction. Although becoming mainstream, I still have multiple concerns over the total energy package and use of nonrenewables, as you seem to share.
I have begun thinking of the value of a TROMBE wall system that places the thermal mass totally within the conditioned space. Bear with me as I run an idea by you that you may feel free to critique or ignore with no offence taken. (or given!).
The one big difficulty I have with my whole line of thinking thus far is the value of the Trombe wall is best on South facing exposures and is totally useless on North facing walls (in predominately net heating climates such as our own.) You still require well insulated walls on most of the building's exterior.
Suppose one had a controlled access to that space (normally unused) between the glazing & the thermal mass of the Trombe wall. What I'm suggesting/considering is an access that could be filled or emptied of an insulation such that you could regulate the uptake & release of energy through the space depending on seasonal requirements.
During the net heating season, empty the access space on sunny days to allow solar heating of the thermal mass during daylight hours & filling it with insulation at night (or on overcast days) to prevent heat loss when no solar heating is possible.
During the net cooling season, empty the space at night to allow heat loss from the wall mass to take place to the exterior and re-insulating the space during the day to prevent energy uptake from insolation. Operable glazing might be of benefit here as radiative cooling effects can be quite good during nights with clear skies. I haven't rationalized that benefit/cost in my mind yet, however.
This allows the thermal mass to regulate the conditoned space and attempts to minimize its heat loss or gain to the building exterior when it is not required.
I am envisioning some fan driven blower filling device to move a light weight insulation into/out of the space through a smooth walled duct from a storage chamber located in a basement area (as an example).
Scrap XPS/EPS or packing "peanuts" came to mind initially as the insulation of choice but I haven't solved the electrostatic problem I envision that would cause the insulation to adhere to the glazing and other surfaces. I'm not keen on a anti-static film coating for the beads due my other concern for "Dusting" of the beads over the long term as they move into & out of storage. UV degradation while the beads are in the access space is another concern that leads me away from Polystyrene. Perhaps blowable fiberglass or cellulose would be better choices.
Air turbulence in the space and storage chamber & a need for operable screening to prevent the insulation from blowing right through the chambers would need to be overcome, I would think.
As you can see this is still in the early conceptual stage
The thermal mass wall could be any masonry mass; recycled brick, stone, rubble, block etc. with a mostly decorative inner face and since the blower moves such a small mass for a relatively short time, it could use little energy.
The thermal lag of heat flow through the mass to the conditioned space would have to be considered, and allowed for of course.
The access space could be designed to whatever R-Value you required by setting the thermal mass back from your glazing an appropriate amount.
Obviously this could not be the sole heat source for the building, however, it might be a way of including a semi-passive solar energy component into a new house design if the thermal wall isn't objectionable. The blower fan could just be shut off if it turns out to have a poor savings value on a simple timer function and operated manually.
(On second thought, an adaptive control, (sensing Temp. Deltas or light levels) would be more useful.)
Any opinions would be appreciated.
Edited 4/24/2006 10:38 am ET by STAINLESS
Edited 4/24/2006 10:41 am ET by STAINLESS
As an 8 in concrete wall has an R-value of about 1, going to a 12 in concrete wall in ICF would not gain much. You could add insullation, either foam board, or other.
You don't seem to understand the concept of ICF walls. They contain about 4.4 inches of extruded poklystyrene at an R-value of about 5/inch. so the wall system rates R-22 to 25 or so depending on finish treatment.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Don't understand what concept?
I assume that Montana Nate idea was to go to thicker ICF to get more R-value. All he would get is more concrete, not more insulation. The extra concrete would not add significantly to the R-value.
goldenboy, the thought was that if i steped in wall sizing i would use the edge as a ledger to in set tjis or do pre poured concret flooring set into place for the second floor as well building the barrel valted gabel ends would be less to cut through.
"I would use 12" on the main floor for max r factor and the step down to 8" for the second floor"
I guess it was the part about "max r factor" that got me responding.
Seems you have lots of people advising you to keep all blocks the same, there are easier ways to build a floor in an ICF shell.
Nate - look at the simpson ledger product for ICFs. It beats the old ledger bolt method - fast easy and strong. Keep those block the same size floor to floor - you'll be glad you did.
I think its called ICFL and ICFLCW or something like that on the simpson site.
Treat every person you meet like you will know them the rest of your life - you just might!
Your responce seemed to bbe say ing that 12" of concrete was not much more insulation than 8" of concrete and ignored the value of the foam. Sorry if I misunderstood your intended message
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Montana nate,
I built my foundation with ICF's I was a newbe..
Well er, I started.. Then I wrenched my back and was bedriden for over a month while winter bore down on me..
My Wife's sister offered to help. No prior experiance either, in fact her only other contruction experiance had been to paint a few rooms in her previous house..
She made serious progress in just one afternoon. A few minor errors that were dealt with, mostly due to my being stoned on the drugs the doctor gave me but I don't know if you can ask for a better testimonial.
Clicking on your name and then filling in the profile information can help those of us who respond to get a more accurate idea of your situation.
I considered going with the standard polystyrene ICFs but then reconsidered when I realized that I lived in a carpenter ant deconstruction zone, and carpenter ants are notorious for building vacation homes in soft material by tunneling through them. (They built some condos in some fiberglass bats that I had sitting on the ground to use in my pumphouse.) When I check a couple of years ago, there was only one company that claimed their product might with stand carpenter ants and termites through incorporating borax in the polystyrene. (Don't remember which ICF it was for sure, it might have been Polysteel.)
I decide to go with a different style ICF, one that mixes cement and polystyrene to create an ICF block similar in size to those typically made from polystyrene. Among the companies that make the more solid type of ICF are:
http://www.durisolbuild.com/
http://rastra.net/rastracom/web-site/
http://www.cempo.com/
http://www.techblock.com
Rastra claims an R value of 22 but only if you believe in the magic of "thermal mass" increasing the R value. Otherwise the R value is closer to 11. Durisol uses specially treated wood chips instead of polystyrene and uses insulation from rock wool inserted in the channels.