# ICF vs. Wood Framed



## AndyGump (Sep 26, 2010)

My personal opinion is to frame with wood.
Wind loading is really not a problem, seismic is the same.
Easier to build, much can be done ones self.
Less expensive.

ICF is a pain to get electrical and plumbing thru without highly skilled craftsmen (and women).

Of course there are advantages and dis-advantages to each but for my money...wood.

Andy.


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## ddawg16 (Aug 15, 2011)

My garage is wood framed with OSB for shear walls. If we have the big one, I have no doubts my garage will handle the shaking a lot better than my house. 

The minute you nail those Struct 1 OSB panels to your wood framing...strength goes up quite a bit. With proper anchor bolts and hold downs....it's not going anywhere.

But don't just wing it using info from the internet. On a project of that magnitude, get an architect/Engineer to do the design...there is a lot more to it than just nailing 2x4's 16" OC.


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## concretemasonry (Oct 10, 2006)

The flexibility of a wood structure can be a real problem, because it takes very little "flex" to crack the interior joints that are not a picnic to repair properly. Fortunately you do not have either heavy or frequent shakes. At least you do not have hurricanes and storm surges, the concrete or reinforced masonry unless you laminate 3/4" plywood on a both sides of steel plate as sheathing for severe life safety coastal conditions.

Dick


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## robertcdf (Nov 12, 2005)

If you're doing it yourself then stick with woodframe, if you're building your custom home I would do ICF all the way. The insulation benefits and durability are awesome. Use steel for all your inside framing as well so you have perfect walls everywhere.


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## jklingel (Dec 21, 2008)

"The insulation benefits...." Name two (being sarcastic; an old line). That is very dependent on how the heat is getting into the building. If the sun is providing it, fine, go w/ ICFs if you want to deal w/ the above mentioned concerns and you like the "feel" and have the money. If you are providing the heat, then ICFs may or may not have the R value needed for your area and/or your goals. This has been discussed here several times and on other forums. If you need high R, then ICFs need to be insulated on the outside. (Note: I heard a rumor of an ICF company making asymmetric blocks, which is very wise.) Alone, and you providing the heat, they provide no thermal mass advantage because the mass is in the middle of the insulation. As for bug proof, they are not; ants love styrofoam. As for quite, resistant to air movement, and tough, that they are. Remember, though, that air leaks are generally at the wall penetrations, not randomly located in the wall. Lastly, ICFs are environmentally rude; way too much petrochemicals and embodied energy in them.


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## JackOfAllTrades (Jan 8, 2008)

jklingel said:


> This has been discussed here several times and on other forums. If you need high R, then ICFs need to be insulated on the outside. (Note: I heard a rumor of an ICF company making asymmetric blocks, which is very wise.) Alone, and you providing the heat, they provide no thermal mass advantage because the mass is in the middle of the insulation.


I will be putting a stucco exterior which will give me an R-Value of 20, just with the styrofoam stucco. The ICF will give me an R-value of 20. Adding together, I will have an R-Value of *R-40.* If fiberglass can be added when the interior walls are framed, I could be easily at R-50. 

One thing is for sure, ICF homes have a 50%-70% reduction in utility costs compared to the same wood-framed home. 



jklingel said:


> As for bug proof, they are not; ants love styrofoam.


The styrofoam they now use is bug/insect proof. They spray the styrofoam with a chemical. Besides 99.9% of the homes out in AZ use stryofoam because they use it when applying stucco. Even wood framed homes get styrofoam applied to the exterior, which then gets covered with a thin layer of stucco. 

What I meant by "bug proof" is that an ICF home is resistant to termites and rodent infestation/intrusion. There is no way they can make their way through 8"+ of concrete. When the building is constructed on a concrete slab, the ICF walls and floors form one continuous surface; this keeps out insects and rodents.

Every stick built wood framed home I have seen gets invaded by rodents, scorpions, centipedes and even termites. Especially the area where I plan to build (rural). Rodents can gnaw through wood and scorpions make their way in through all the gaps in wood.


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## jklingel (Dec 21, 2008)

Dense packed cellulose has borates, which deters insects and rodents; not sure about scorpions. I've never read anyone reporting mice poop and bug nests in cellulose, so I suspect the infested houses have fiberglass; SUSPECT. As for the 50% reduction in utilities w/ ICFs, I only read that from ICF people and anecdotes. The science, as far as I have read, and as far as I can reason, is just not there for them. That is not one of their strong points. A stick house w/ dense packed cellulose is cheaper and easier to build, for DIY folks, and more thermally efficient. There was no comparison when I ran the numbers for my place, but different places have different prices and different environments. ICFs are "the way" to go below grade, IMO. I built a foundation w/ blocks twice; never again. Even the first time through, ICFs were much faster, easier to handle, and no more expensive than blocks w/ foam installed on the outside.


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## JackOfAllTrades (Jan 8, 2008)

jklingel said:


> A stick house w/ dense packed cellulose is cheaper and easier to build, for DIY folks, and more thermally efficient. There was no comparison when I ran the numbers for my place, but different places have different prices and different environments. ICFs are "the way" to go below grade, IMO. I built a foundation w/ blocks twice; never again. Even the first time through, ICFs were much faster, easier to handle, and no more expensive than blocks w/ foam installed on the outside.


I will have a contractor/builder putting up the home, whether ICF or wood, it will be done professionally. 

Some good points have been made. *Here is where I find wood framed homes lacking:*

1 - Building in a wooded area and when using wood frame, there is ALWAYS intrusion through the walls by rodents and insects, ALWAYS. I have yet to see a wood framed home built in that area that did not experience rodent or insect intrusion. Where the wood foundation meets the concrete slab is a weak spot for intrusion. Rodents will gnaw through wood and enter into the cavities/walls of the home and nest there.

2 - Subterranean Termites are a problem out here. On a wood frame home it is always a constant battle in trying to keep them from eating you out of a house. 

3 - Strength. While wood framed homes can be made stronger via ties, straps, headers, etc., they are never as strong as a 12" concrete wall. Only concrete structures can withstand 150MPH+ winds and flying projectiles (tornadoes).

4 - Fire resistance. In a wooded area, fires are a constant threat. A wood framed home is never as "fire proof" as a concrete home. 

5 - Longevity. Concrete & masonry buildings stand the test of time. The longest standing structures in the world today are always made out of concrete. Wood rots, flexes, splits, especially the wood we use today is NOWHERE near as strong as the wood we used years ago. The framing wood we use today is less dense, weaker and holds more moisture compared to the older, more mature wood was used years ago. Back then the trees were 50-100 years old, nowadays we use trees that are 10-20 years old for building. 

The above are some of the disadvantages I find with wood framed homes. While they make "treated wood" to prevent termite infestations, such wood is much more expensive to use in framing. Typically they use treated wood at the sill where the wood meets the concrete slab but the rest of the home is not treated wood. All termites do is walk over the treated wood and infest the non-treated wood above it. :huh:

How does one keep out the rodents with a wood framed home? Is that even a possibility?


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## jklingel (Dec 21, 2008)

Jack: Those are some of the + and - of each, yes. As for "How does one keep out the rodents with a wood framed home? Is that even a possibility? " my understanding is that dense packed cellulose solves that problem. A good place to ask is greenbuildingadvisor.com. BTW: A pro bug killer told me that ants have zero fear of treated wood, so it won't help much, either. Concrete is fireproof, yes, but the foam is not and subsequent fumes are very toxic. I once asked, when I was considering using ICFs for the reasons you stated, if they survive a fire. The answer was "I doubt that you'd want to live in the stink left in the concrete, if the concrete survived an intense fire." Dense packed cellulose is a fire retarder, but I don't know if the stink in it would be any better than anything else. It may keep the fire from penetrating the wall, but would possibly have to be replaced because of the stink. I dunno. I do know that I dare not run my cutting torch on my garage slab or the concrete blows up in chunks. Bottom lines: Fires are pretty nasty, regardless of what is in their way. Their ain't no perfect building material for all situations. We have to pick "the best" (in our opinion) for our goals, budgets, and environment.


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## AndyGump (Sep 26, 2010)

I think that you have made up your mind Jack.

ICF just might be the way for you to go.

Andy.


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## concretemasonry (Oct 10, 2006)

Being cheap is easy if it is a short life structure. A little more spent during planning and construction is a good investment in the end. - Maybe that is why the developed world does not use wood as a major residential building material since they build to last.


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## woodworkbykirk (Sep 25, 2011)

a previous poster said that icf's need to be insulated on teh outside, um they are thats the 2 1/2" of foam on the outside of the concrete.... hence I.C.F insulated concrete form......

with icf most regions require the installer to be licensed on the specific product via taking a 1 or 2 day course in order for it to pass inspection, it is a engineered product. personally im licensed both on Nudura and Arxx. mind you once you've used one brand most of them are the same.

for energy efficiency, icf's by far outperform wood framing.. case in point last year i built a 4000 sq foot vet clinic which was 90% icf. this building was replacing a 900 sq ft space. the owner showed us a copy of the energy costs for the first 6 months in the new space in comparison to the old space which was almost 1/5 the size. the new space's heating bill was 1/4" that of the old space

regarding being able to use it for earthquake zones. im uncertain. you will have to talk to the local supplier or engineers to find out if its ok to use, wind should be fine


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## JackOfAllTrades (Jan 8, 2008)

Being energy efficient is key, mainly due to the rising costs of electricity and gas. Wood frame can be made to be energy efficient but ICF does provide an advantage to heating/cooling costs.

As one person mentioned, masonry has stood the test of time. In Chicago the homes that have lasted 100+ years are masonry. The same for the rest of the world, masonry structures have stood for hundreds of years. I believe these wood framed homes of today will be lucky to see 50 years before major work has to be done to keep them standing. 

I will talk it over with my architect and engineer to see which direction I go, ICF or wood frame. I appreciate all the input! :thumbup:


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## woodworkbykirk (Sep 25, 2011)

a key thing to remember is, no matter what the product used to build the house, a quality install is key... there are plenty of guys building houses out there. and from what ive seen only a handful do it well or above and beyond code. there are several builders in my region that do things as cheap as possible and then they wonder why 1/2 the homeowners are calling them 3 years later with all kinds of problems with their house. also following manufacturers guidelines for a proper install do wonders for a building... if you just throw things together the product will fail and then you have issues.. guys that think 3/8" gaps in siding is perfectly fine because caulking seals things there wrong.. caulking is only good for 1/8" - 3/16" gaps, its to seal not to be used as filler.. it dries out and cracks then water gets in

reasons like this wonder why i cost more than the other guy, 1) your getting a higher quality product, 2) if for some reason something does happen i will come back and fix it


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## jklingel (Dec 21, 2008)

wooworkbykirk said:


> a previous poster said that icf's need to be insulated on teh outside, um they are thats the 2 1/2" of foam on the outside of the concrete.... hence I.C.F insulated concrete form...... •• To add to that, they need to be insulated on the outside TO BE MORE USEFUL in the sense of thermal mass when in a heating dominated environment. As they are usually made (symmetrical), any heat that gets into them will go to the outside faster than the inside, generally, as the outside is generally colder than the inside. The delta T determines the flow rate. Thermal mass is always insulated on the outside in a heating dominated environment.
> 
> for energy efficiency, icf's by far outperform wood framing.. case in point last year i built a 4000 sq foot vet clinic which was 90% icf. •• Again, anecdotes do not replace science. Anyone who cares to read about all this is invited to buildingscience.com, greenbuildingadvisor.com, or to just apply what knowledge you have. ICFs ARE NOT GREAT INSULATION for the money, but can work great if you have a lot of sun heating them and not a bitterly cold environment. A wood frame, double stud wall and dense packed cellulose, for example, can be built to a far higher R value much cheaper than concrete, not to mention the embodied energy required to make concrete and all the petrochemical-foam needed in the ICF and outside it (that is what people usually insulate outside w/).
> 
> •• I've run the price numbers, and anyone else is welcome to run their own, too. We've had this conversation before, and others have found the same thing; ICFs are spendy. If you want "earthquake proof", then git 'er done. But, ICFs are not the material for an inexpensive, high-R structures. Anecdotes of one cat's place are meaningless; there are way too many other variables at play to allow anyone to make any claims about anything. I know a cat who has smoked for 85 yrs; so what does that "prove"? Nothing.


Pls see above after the bullets. I want to make it clear that I am not anti-ICF, but I do like to get the facts straight, at least as far as I can determine.


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## JackOfAllTrades (Jan 8, 2008)

I appreciate all the input. Each building method has its pros and cons. My main concern is strength in regards to earthquakes/high winds, rodent proofing and longevity. As far as R-value goes, ICF just like wood, needs additions in order to get high R-values. Whether it be cellulose or styrofoam backed stucco. 

With ICF, can one still install cellulose in the interior walls for added R-values?


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## concretemasonry (Oct 10, 2006)

An R-value only has real application for lightweight construction and the test to determine it is just a quick short term snapshot. The value is convenient for advertising and the use by people for a short term analysis of the materials to determine and approximate wall heat resistance while neglecting the heat capacity and concept of thermal inertia that is frequently used on passive solar homes. The thermal heat storage/inertia is one reason why heavier home always outperform the calculated performance because simplifying assumptions are made in the testing and calculations.

I think the most ridiculous use of R19 fiberglass in a stud wall that can only obtain an R9 or R10 even under ideal conditions and short term test.

Dick


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## AndyGump (Sep 26, 2010)

What did he just say?

Andy.


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## forresth (Feb 19, 2010)

I've looked heavily into ICF construction. The claimed R equivalency is just plain unrealistic, but it would be much more realistic were you are at than were I am at. going hot to cold in a 24 hr period in the desert vs. months straight of below 0 temps for me.

Don't go cheap on the re-bar if you want earthquake protection. since it is earthquake resistance you are looking at, don't skimp on the ceiling/floor joists and their anchors either.

are you going with a concrete roof too? otherwise you'll get creatures going in through the roof on you.


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## jklingel (Dec 21, 2008)

JackOfAllTrades said:


> With ICF, can one still install cellulose in the interior walls for added R-values?


 •• Jack: I would not insulate inside the concrete, as that puts all the thermal mass on the outside, negating what positive effect that would have thermally, and also violates the "rule" of having the exterior wall 5x more vapor permeable than the inside. Were I insulating ICFs, I'd put more foam on the outside. I would also suggest that you read about this on buildingscience.com and greenbuildingadvisor.com, as those folks have the real experience and knowledge. I get a lot of info from those sites, and though not perfect and sometimes you get slightly different opinions, they sure seem to be the best we have at present. Learning is an evolving process, so ideas change now and then, of course. People once thought that visqueen on interior walls was the Holy Grail for every environment, etc. As much as I hate using foam, I think that is what you'll need. BTW: I'll have 10 to12" under my entire slab and outside any stem wall I will have, so you sometimes have to bite the bullet; there's nothing else to use below grade, so.....


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## jklingel (Dec 21, 2008)

AndyGump said:


> What did he just say?
> 
> Andy.


 Dick is not a fan of R value, and has a point. However, I contend that it is a valid metric, if understood, and beats a guess from a 3rd grader. People in the building science community seem very comfortable with it and the folks that run this spendy software when designing houses seem to get fairly accurate results. Always keep in mind, though, that advertised R value by any industry is suspect. For example, fiberglass batts work as advertised, but what is not advertised is that they can never be installed perfectly and they are not dense enough to prevent internal convective loops, so in reality the R value OF THE WALL is much less, as Dick stated. (This is why the "Pink Panther" companies are selling foam sealing kits with the batts; they are fessing up to their not really being all that great, and need assistance to perform closer to claims.) That said, if you don't air seal well, ANY insulation is not going to "be the best it can be", borrowing from the Army. Foam needs seams caulked and taped; cellulose needs similar air barrier measures, etc.


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## ddawg16 (Aug 15, 2011)

I like to use this analogy regarding R value....

You buy a car with xxx horsepower.....but just because you have that big engine, it does not mean all of the power gets to the wheels.

Same with insulation. The R value is a relative # to give you an idea what you 'should' be able to get in insulation value. But like most things, it is part of a total system. You could have R50 in your walls...but it could be worthless if you have holes in the wall.


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## jklingel (Dec 21, 2008)

Dawg:So the blown and injected 454 Chevy engine (running nitro) that I just put in my Subaru wagon won't work well? Damn. I thought I had a hot street rig there.


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## concretemasonry (Oct 10, 2006)

The big Chevy will not turn the same times the "stock" engines that are used in road racing. Brutes are fine as long as the street is smooth and there are no turns. - Not quite as bad as a NSCAR unit that can really only turn left with a bank to help.

Time to go because the Indian Formula 1 race on TV from Delhi starts at 4:00 AM tomorrow. I hate to see cars governed down to about 19,000 rpm, but there is a reason.

Dick


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## JackOfAllTrades (Jan 8, 2008)

jklingel said:


> Were I insulating ICFs, I'd put more foam on the outside. I would also suggest that you read about this on buildingscience.com and greenbuildingadvisor.com, as those folks have the real experience and knowledge. I get a lot of info from those sites, and though not perfect and sometimes you get slightly different opinions, they sure seem to be the best we have at present. .


So what you are saying is to add more insulating value on the exterior wall. The ICF block has 2 1/2" of styrofoam on each side. How would one go about adding more to this? I was going to finish the exterior with stucco. Which out here is usually 1/2" styrofoam, chicken wire and 1/2" stucco.

As far as water barrier goes, it appears that it is a good idea to wrap the home with such a barrier. That is what the one study shows, that ICF blocks homes are not completely "water proof". Which seems weird to me as styrofoam in and of itself is water proof and the ICF blocks lock into place, so water intrusion would seem highly unlikely. 

The ICF contractor I talked to said he would use 6" of 3,000 psi concrete, with 1/2" rebar - 16" O.C.. This would give me a wall thickness of 11" as the styrofoam is 2 1/2" thick on each side.


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## jklingel (Dec 21, 2008)

First, I am not an expert at anything, let alone ICFs. I have never insulated them more than what they are, but I understand, and it seems logical, that you can screw through your foam into the plastic channels in the ICF, as people do when insulating w/ foam on the outside of stick houses (REMOTE wall, for example). The rub w/ ICFs as far as insulation is what I mentioned above, about the heat going out of them more than into the house. Putting foam on the outside tends to reduce that, but there is no point in doing anything if they already have sufficient R for your area, esp if the sun is being used to warm up the concrete; that is free heat, and concrete and sun do well together (but watch for overheating, of course). I would then goo and/or tape the seams of the added foam. As for a weather resistant barrier, I'd sure use one. All those joints in the blocks will possibly leak by wicking water in, if it gets past the outer layer; accidents happen. When we built below grade w/ ICFs we were advised to use bituthane membrane over the blocks to water proof them. It is a rubbery, sticky membrane that comes in rolls. The ICF provider sells it, and I see something like it used wherever ICFs are below grade. Above grade, I think Tyvek, or the like, would be fine, plus a rain screen, like vertical 1x4s (if that is appropriate w/ stucco).


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## AndyGump (Sep 26, 2010)

jklingel said:


> First, I am not an expert at anything, let alone ICFs. I have never insulated them more than what they are, but I understand, and it seems logical, that you can screw through your foam into the plastic channels in the ICF, as people do when insulating w/ foam on the outside of stick houses (REMOTE wall, for example). The rub w/ ICFs as far as insulation is what I mentioned above, about the heat going out of them more than into the house. Putting foam on the outside tends to reduce that, but there is no point in doing anything if they already have sufficient R for your area, esp if the sun is being used to warm up the concrete; that is free heat, and concrete and sun do well together (but watch for overheating, of course). I would then goo and/or tape the seams of the added foam. As for a weather resistant barrier, I'd sure use one. All those joints in the blocks will possibly leak by wicking water in, if it gets past the outer layer; accidents happen. When we built below grade w/ ICFs we were advised to use bituthane membrane over the blocks to water proof them. It is a rubbery, sticky membrane that comes in rolls. The ICF provider sells it, and I see something like it used wherever ICFs are below grade. Above grade, I think Tyvek, or the like, would be fine, plus a rain screen, like vertical 1x4s (if that is appropriate w/ stucco).



Hey J, do me a favor and break up the next paragraph for me would you?

Thank you sir.

Andy.


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## jklingel (Dec 21, 2008)

AndyGump said:


> Hey J, do me a favor and break up the next paragraph for me would you?
> 
> Thank you sir.
> 
> Andy.


 Sure. Sorry about that; my etiquette slipped away in my haste.

First, I am not an expert at anything, let alone ICFs. I have never insulated them more than what they are, but I understand, and it seems logical, that you can screw through your foam into the plastic channels in the ICF, as people do when insulating w/ foam on the outside of stick houses (REMOTE wall, for example). 

The rub w/ ICFs as far as insulation is what I mentioned above, about the heat going out of them more than into the house. Putting foam on the outside tends to reduce that, but there is no point in doing anything if they already have sufficient R for your area, esp if the sun is being used to warm up the concrete; that is free heat, and concrete and sun do well together (but watch for overheating, of course). 

I would then goo and/or tape the seams of the added foam. 

As for a weather resistant barrier, I'd sure use one. All those joints in the blocks will possibly leak by wicking water in, if it gets past the outer layer; accidents happen. 

When we built below grade w/ ICFs we were advised to use bituthane membrane over the blocks to water proof them. It is a rubbery, sticky membrane that comes in rolls. The ICF provider sells it, and I see something like it used wherever ICFs are below grade. Above grade, I think Tyvek, or the like, would be fine, plus a rain screen, like vertical 1x4s (if that is appropriate w/ stucco).


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## stadry (Jun 20, 2009)

you'll invest a bit more for icf - typically 10%,,, however the amortization of the addl exp is about 18mos of energy savings,,, after that, is always less $$ out of your pocket,,, then add in the addl strength & lack of exterior noise,,, if electrician can't learn to pull wire in 2hrs, get another guy,,, when we applied our stucco coat, the mesh was stapled directly to the icf's exterior surface.

i've built w/wood & icf's & our next home will be icf,,, as dick (concmasonry) posted, are you building for short-term or not ?


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## jklingel (Dec 21, 2008)

Jack: Another option, if available in your area, is the ThermoMass wall, where foam is sandwiched between concrete. THAT sounds like it will solve any bug problems. As for the numbers reported above, they are not that way for me, so I guess everyone has to run their own. Greenbuildingadvisor.com has some good info on ICFs. Enjoy the new pad. j


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## JackOfAllTrades (Jan 8, 2008)

itsreallyconc said:


> you'll invest a bit more for icf - typically 10%,,, however the amortization of the addl exp is about 18mos of energy savings,,, after that, is always less $$ out of your pocket,,, then add in the addl strength & lack of exterior noise,,, if electrician can't learn to pull wire in 2hrs, get another guy,,, when we applied our stucco coat, the mesh was stapled directly to the icf's exterior surface.
> 
> i've built w/wood & icf's & our next home will be icf,,, as dick (concmasonry) posted, are you building for short-term or not  ?


That was my other question. How do you find electricians, plumbers and drywall contractors that know how to work with ICF?

To answer your other question. This would be a custom home that I would live in until I died. :huh: In other words, it is long term home. If it were short-term, I would just buy a tract home.


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