Could a novice hoping to build his own home get some comments about using ICFs particularly Nudura forms? Everything I read, people I talk to, and the seminar I attended all make them sound so easy a moron (and I qualify), could use them.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
A standardized approach, quick-to-install hardware, and a simplified design make building custom casework cost-effective.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Don't be so hard on
yourself, morons can't speel
as good as you just did!
ICFs are fairly easy if you have common sense and can think while you work.
Got any psrticular specific questions?
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
1) Wondering if people who have experience with different forms have preferences and why. I was planning on using Amvic, then talked with another distributer who is promising me more supervision and that Nudura are stronger forms. Being the trusting (read gullible), type, I'm tending to go with Nudura now.
2) What have people used for door and window cavities?
3) Exterior waterproofing?
4) What do you think about the form-a-drain product from Certainteed?
On a different note, I appreciate all the comments you provide, Piffin. I enjoy reading your responses on all the forums.
I lik ethe formadrain for some applications - where you can set it level. If the ecavation is off level or uneven, it is harder to work with. Get the version with the sock already on if you can.waterproofing - most brands I've seen just say to roll on the emulsified, which I find rediculous. In the paast. I coated right to footer with the synthetic stucco or the fibre re-inforced stucco, and then used the emulsified below ground.
on the one I'm doing now, we used ice and wter shield on the whole thing, and then screwed expanded wire lathe to the composite attach strips and did a real stucco over it above grade.I build door and window bucks from PT with screws and/or anchor bolts seating them in place. The literature or training from the manufacturer should cover this. I might have some pictures, but am on my way to bed soon now.I've never heard of the brands you mention. Whatever kind, the primary concerns are to have a level footing, and to be sure there are no chances for blowouts. I have always had scrap plywood on site and a screw gun handy, for spot repairs, but never needed it
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I have built my own house with little prior experience. I used form-a-drain for the footings and Amvic ICF. Both worked exceptionally well and I was quite pleased. A couple of thoughts-
If you use form-a-drain or whatever - the footings are the key the the hole operation - take the extra time to make sure the footings are level and square. Measure and remeasure. An inch of on one side can mean fits when framing.
With the ICF, I just followed the Amvic instructions. I was originally going to use another brand, but they went out of business. For me in NH, Amvic gave me both headquarters support (excellent) and local support (not bad). Give some thought as to how you will set up staging to complete the ICF and if the ICF supplier can rent you the staging for a nominal fee.
My biggest problem was 45 deg. corners - When starting the pour, a corner started to go and all had to turn to to shore up the two 45 deg. corners. I was very happy that I had a crew of 4 additional helpers for the pour. Worked well.
For openings and windows - Framed with pressure treated lumber and attached per instructions to ICF. Feel free to ask any questions
Ron
I spent a bunch of time looking into ICFs. Decided to go with building plywood forms, insulating the outside of the poured concrete, and reused the 3/4 ply as roof sheathing.
My opinion is that the "ease of use" pitch put out to owner builders about ICFs simply plays on the insecurity of the novice and is used to steer the past a factual cost analysis.
In my case, I got a bid of about $6,000 for the ICFs themselves, a bid of $13,500 for a poured foundation from a sub, and I built the forms, poured the mud, paid the pump truck, put in lots of attention to detail, and had it done for about $8k.
Of course, I spent more on direct bury insulation and flashing bent to cover it, but that was only about another $1k. I also have a very warm basement.
One of the drawbacks to ICFs is that they don't put the mass of the concrete inside the insulation envelope.
Best of luck with your project!
"A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
"One of the drawbacks to ICFs is that they don't put the mass of the concrete inside the insulation envelope."Say What? That is exactly where the crete mass is placed. If you do poured crete with 2" of XPS over it, you are far short of what a typical ICF walll provides. There are 2.25 to 2.5" on EACH side of the crete. It is very effective, not only in reducing heat loss, soting heat energy , but also in keeping the woprld of noise at bay
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I disagree.
The effective functioning of thermal mass requires said mass to be able to readily exchange heat with the air inside the building. Having the mass insulated from the interior space keeps that ready exchange of heat from happening.
The mass contained inside the insulation of an ICF does have some tempering effect and, of course, the insulation has whatever R-value it has.
In a climate such as the NE coast the difference may be minimal due to the lack, in winter, of a large day/night temperate swing. However, any home in any climate with a large day/night swing or any home that takes advantage of any solar gain will not be able to perform in the manner required for the interior space to receive heat back from the walls at night.
Even in a home with a poured basement in any climate, if the foundation is well insulated on the outside the space inside will not require much heat during the night after the thermostat is turned down.
You can read the studies behind this info in Edward Mazria's book, titled, I think, THE PASSIVE SOLAR HEAT BOOK. You will need to pass over some of Mazria's long gone 70's ideas, but the basic info on heat retention, heat transfer, and passive solar design have not changed. I've built two passive solar designs based on Mazria's book and they function well."A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
but my point is that there is no way the thermal mass you have exposed to radiate back into the room can store and provide enough heat eneregy to overcome the difference between two inchs or foam insulatiuon ( yours0 and 4.5 to 5" of same ( Mine)
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I agree with you on this one.
Not having read a lot about passive solar design, we had a home designed by an engineer and archy with passive solar functions. More important than the foundation walls in our design is the slab and insulation under it. That is the mass area where the solar gain is stored.
I can't see how the walls could act as a heat sink for passive solar energy if they are burried and never recieve direct sun light.
More on this later.
I gotta go to work.
Dave
I can't see how the walls could act as a heat sink for passive solar energy if they are burried and never recieve direct sun light.
Dave, that's exactly what our house has been doing for the last decade. Works very well, although the current 100º heatwave has caused our AC-less indoor temps to rise 2º higher than ever before. We hit 80º!!!!! Same temp it was outside early today. Takes awhile for our mass to absorb the heat. What we don't get is rapid change of temp, at most 2º/day. If this summer turns out to be common, I'll be rethinking earth tubes.
We're doing annual heat storage, rather than the more common diurnal or few days. But it's all passive. And lots of concrete. More dirt would be better.
As for ICFs, I don't use them, for Has' good reasons. Have, and continue to recommend them for DIYers. Concrete houses are good. Won't rot and bugs won't eat 'em. Remodel might be a challenge... PAHS Designer/Builder- Bury it!
61048.10 in reply to 61048.4
"One of the drawbacks to ICFs is that they don't put the mass of the concrete inside the insulation envelope."
Say What? That is exactly where the crete mass is placed.
Paul, Paul, Paul, : )
First, you claimed that the mass is placed inside the insulation envelope, not "my point is that there is no way the thermal mass you have exposed to radiate back into the room can store and provide enough heat eneregy to overcome the difference between two inchs or foam insulatiuon ( yours0 and 4.5 to 5" of same ( Mine)". Thermal mass that's sandwiched INSIDE the insulation is NOT inside the insulation envelope, at least not in the commonly accepted sense. That would be akin to having an ice chest where the ice was put in a slot on the side of the cooler with another layer of insulation between the ice and the inside of the cooler. Wouldn't work worth a damn, would it?
Second, I never stated anything about the thickness of the insulation. I have four inches outside the concrete except for the south side which only has two inches, but is against soil that sits in the sun nearly everyday of the winter. If I was builkding in a location as wintry as yours I'd have put more insulation outside the wall.
I think ICFs are a good product for certain situations, but I also think they are promoted with hype and nonsense a good deal of the time. The primary fallacy in promotion being that "the mass is inside the insulation envelope".
The thickness of the insulation is strictly up to the builder with foam on the outside of the concrete. It's up to the manufacturer with the ICFs, although one could add more on the outside but I've never seen it done.
In AZ there are entire subd's that were built with a special arrangement with AZ Power to take advantage of the exchange of heat. They have block walls with foam on the outside and they have AC that can ONLY run at night at a special lower power price. The cooled mass keeps the homes cool during the day. You couldn't do that with ICFs.
It happens that the rate at which heat is absorbed by concrete and then released back out makes an 8 to 12" wall nearly perfect as a heat sink. Any insulation at all on the inside of that mass negates the positive effect.
"A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
Back to the original post, I personally have had quite a bit of experience with ICF's, and am currently using Nudura's system. I was using Arrx brand before this. I am a custom homebuilder who put up our 1st icf basement about 8 years ago. We have done a couple dozen since then. Nudura has some advantages over Arrx and other systems such as:
18" x 8' long block size = 9' basement wall height which around here is prefered. The 8' lengths mean faster stack times, and they come with a hinged type web system that ships flat but unfolds with ease at site. Their corner blocks are interchangable left or right. They actually snap together on top of each other with a click, so windy conditions aren't as big a pain. They make their own waterproofing membrane system in 3' rolls that is similar to ice and water bit a little thicker and it has a facing of a woven type material that gives extra puncture protection. It sticks like crazy except when down below freezing, then we try to preheat it in our trucks. Our supplier rents out the combination form braces/scaffold that go with the system.
As for footings, we use L shaped rerod to tie the walls to footings every 3' o.c., and Piffin is right about getting the footings level. I usually run a 2x4 around the perimeter at the top of wall just above the tooth and finish the concrete to that. It takes an extra hour at most and we shoot it with the level in case of any fluctuation in block/footing. I'm pretty fusy on my foundations and we shoot for 1/8"
tolerance on overall height. I'm sure Boss is right about seeing some real poor jobs in his travels, but we actually poured a basement wall system today, and when checking final measurements after the pour we're off 3/16" on overall diagonal and within an 1/8" on all dimensions. No kidding.
One thing that manufacurers don't tell you is any system with a tooth layout means that there is a unit of layout that you may need to adjust wall lengths to. For instance, Arxx teeth measure 1 1/4" spacing if I remember right, and Nudura's are 1". This doesn't always match your blueprints exactly, so you need to pay close attention to any adjustments that need to be made so that opposite walls line up, etc. We typically go to the size just under if there is a discrepancy, and adjust with our final sill plates.
Also, as was said here, don't be afraid to use a little extra reinforcing with plywood at areas like wall sleeve penetrations etc. Make sure that you stagger courses enough so that you bridge joints by at least 8", and if you can, work with a concrete supplier that has some experianced pump/conveyor operators used to these systems. I prefer to pour in 2 lifts to give the first, lower pour a little time to start setting and then go back and finish the upper pour.
As to the heat sink argument, I'm also in the cold Northeast, am no engineer, but have lived with this system for 8 years now in my basement. If I were to build again now it would be in my whole house.
My basement is about 12-1300 sq.ft., walkout grade along southfacing 50', with 1 6' patio door, 2- 5'x6' windows and 2-3'x5' windows. I used 1" foam under my 4" slab, installed radiant heat pex in slab on it's own zone, and have not had the floor heat on after the first winter. With just heat loss from water heaters (2) and radiant manifolds for upstairs heat, my basement has not dropped below 65 degrees since and doesn't get above low 70's in summer. We are currently in the hottest summer in 30 years, temp. in the low 90's for the last few days until today, and yesterday afternoon it was 73 degrees down there. So, as far as I'm concerned, it works as a heat sink. Period.
As to the r-values, I'll agree, it's confusing when you see written r-values of say 24 but hear of performances of 40, but again, don't tell me it doesn't outperform a 2x6 wall with r-21 insullation. There is almost no thermal bridging, air infiltration, moisture trapping, etc. Be aware though, that if you use it for a whole house, you should look at an HRV system for ventilation.
Overall I think it's a great product but like anything, it must be done right, or else.
>> my basement has not dropped below 65 degrees since and doesn't get above low 70's in summer. We are currently in the hottest summer in 30 years, temp. in the low 90's for the last few days until today, and yesterday afternoon it was 73 degrees down there. So, as far as I'm concerned, it works as a heat sink. Period.
I've been in lots of cool basements in hot weather. ICF has nothing to do with it. The house I grew up in was cool in the basement in the summer. It's due to soil temp, not type of construction. Just the floor alone (it's concrete, right?) goes a ways to cool your basement.
ICF foundations do function as heat sinks, they simply function poorly in that one regard. If you'd rather not know about that and not know why, it's up to you."A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
First, no need for the attitude, I was simply stating fact. As to any basement being cool, note I said this is a basement with fully exposed walkout wall along entire 50' length with a large amount of south facing glass. Not your standard basement space . Does the floor act as a heat sink? Definitly. I also understand that with insulation on the inside of the wall the wall doesn't perform the same as a wall with only exterior insulation. However, my point is that in real life over 8 years time, this system performs great, in both summer and winter. Also, my understanding off the heat sink principle is you can have too much conrete involved, to the point it doesn't perform efficiently. How much time did you have involved in building your forms, insulating and pouring, waterproofing, and applying a finish to exterior? When it comes time to finish off interior if wanted, it will cost more also by the time you stud up for walls, provide space for wiring, etc.
The job we poured yesterday involved 30 man hours to go from the top of footers, till the concrete trucks pulled off job and walls were poured. That includes installing the waterproof membrane. Tomorrow we will take down scaffolding, remove bracing, and the parge system gets applied.
In my business time is money, and the speed that this system goes up in helps to offst the higher material costs. Bottom line is, I KNOW how well this system performs from first hand experience of my own and my local customers that I've built for, not by some manufacturers printed brochure claims, or some engineers reports.
It's good to have a system that works for you. As I said before, there are good reasons to use ICFs in certain circumstances.
If you want to discuss "too much mass", we'd have to get into a discussion of annual heat pendulum as a distinctly different thing from daily heat pendulum.
I'm glad to see that you do understand the loss of heat exchange that happens when the inside of the concrete is insulated."A liberal is a man too broadminded to take his own side in a quarrel." Robert Frost
I used ICFs in my home about 4 years ago. I loved using them. I put in a 8'6" finished basement. I have four 3'x4' windows and a sliding door. The product is great to work with. A number of friends used the same product after my experience.
I used a product called Arxx (formally Blue Max). It is waterproof, soundproof, solid and makes it very easy to finish off the inside with drywall.
A few notes:
I tell my wife our next house will be entirely built from ICFs...
Have fun!
Arxx is the brand I use. I have a few comments in regard to your list;There are ways to adjust for a footer that is off, but they are extremely timeconsuming and frustrating. Far better to be sure the footer is right. I have carved the first or an end over solid ledgte without using footings in some situations.re- bracing - I use very little of it, bracing as we pour or on one side only. I can't imagine a wall blowing over. I run vertical rebar out of the footing, then my horizontal rebar is tied to it, and the blocks themselves are tied together to each other and to the rebar. For it to blow over, the vertical would have to be pulled out of the footer, or a high wind would have to demolish the wall piece by piece.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin,
I do remember shaving the bottoms of the first course for some 'impefections' in the footer, but you are correct that it would be a major PITA to correct an out-of-level footer.
A section of my wall did fall during a very windy storm. I did not use vertical rebar out of the footer (I used Key slots). The idea of using the vertical rebar in the footer is a good one.
The bracing was important for a novice like myself. I am sure it could be done with out it, but I like it for getting the last two courses on, and like the confidence it gave me when adjusting the walls after the concrete was poured.
Michael
A novice is smart to brace the walls.
I use some foam in a can here and there to seal up forms and stick it to footings
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Am I too late to this party?On the issue of thermal mass of ICF's, et al, I will strongly side with Hasbeen and VaTom. That's not to disparage ICF's, be/c they'll beat most of the alternatives, but I'd bet a fair chunk of change (and in reality I have put my money precisely where my mouth is) that an ICF wall without the interior insulation would best an ICF wall with the interior insulation. Oak Ridge National Labs would likely agree based on their articles and testing...an exterior insulation/inner-mass wall gives superior performance to an insulation-mass-insulation wall.As to a novice building with ICF's, I think that undertaking ANY major construction for a novice would be intimidating, depending on the definition of novice. Getting it all straight and plumb and level w/o blowouts would seem to be a longshot for anyone without the carpentry skills Andy mentions.
Am I too late to this party?
Getting it all straight and plumb and level w/o blowouts would seem to be a longshot for anyone without the carpentry skills Andy mentions.
You were conspicuous by your absence (to paraphrase somebody famous). LOL
Seems I'm in a rather small minority here. I don't see foundations, either ICFs or traditional forms, as particularly difficult. Certainly there was nobody remotely resembling a carpenter on this site. The one thing that is necessary is to understand what the finished product needs to be, and then take the time necessary to achieve that end. First time is gonna be slow.
For the number of DIYers I've encountered, no particular problems. Problems along the way, sure, it's construction. But the product worked well in the end. I got a lot of poor advice when starting out, something this forum would have avoided. Actually had a concrete salesman tell me to never, ever vibrate concrete. Fortunately I'd read a good bit, preparing.
I had a friend go ahead and build his own traditional house on a "professional" foundation. It completely missed the footing in one corner. House is still standing, but I wouldn't have tried it. PAHS Designer/Builder- Bury it!
>I don't see foundations, either ICFs or traditional forms, as particularly difficult.Yeah, but you aren't the one who's doing his work, either. From all I can tell, you would be cheating to toss yourself into the beginner category, no? A self-proclaimed "novice"--however he defines that--with an "InOvrHisHead" handle is wondering how easy ICF's are. I figure that prudence is the better part of valor, and he's better off hearing that it could be problematic for the unskilled, and then he can determine if he's truly unskilled or just being a bit coy. If he's thinking, "Well, I've never framed anything before, and I'm not sure which end of a stud points up, but surely I can stack giant legos and drop some dirty water into them," then we're probably warranted in urging caution. You don't wanna be in over your head when 50 yards of concrete are on their way and you don't know if your forms are right, if ya know what I mean. And the seriousness of the question increases with the height of the walls. Heck, we don't even know if he owns a transit...or a level!I remember a visitor here during construction...they were framing their own addition...the wife saw one of my window bucks with the level resting there and remarked to her husband, "Hey look, it IS possible to make it level." He looked none too pleased. :) I'd encourage them to tread carefully.Our intrepid thread originator will have to determine his own comfort level. Best he hear some cautionary tales so he knows what to look for. If he's still game, then best of luck to him, and a big pat on the back. But if he feels even in-ner over his head, then he'd be well advised to add an experienced hand.Edit: Remember, besides "novice" he also referred to himself as a "moron". Maybe it's just a bit of self-deprecation...who knows. He also switched brands be/c of a salesman's pitch and doesn't know about buck alternatives ( http://www.vbuck.com being one option he should consider). All those clues together would lead me to be cautious if I were in his shoes. You gotta admit that you're cut from a different cloth, Tom...just a whole different place in confidence and experience.
Edited 7/29/2005 4:13 am ET by Cloud Hidden
From all I can tell, you would be cheating to toss yourself into the beginner category, no?
Clearly, I am now no longer a beginner. But when I poured this place my total concrete experience was: 20 yrs prior, operating a shovel under existing foundation walls on an 11 acre apartment site in Denver. I really envied the concrete guys.
Here, I attempted to hire the concrete work out and found no local takers for anything I could afford. The very few wall guys were frightened. I wasn't about to settle for block. At the time I was running a cabinet shop for a builder and didn't even do the installation of our boxes, solely shop work, the only place I like. Absent anybody to form the walls I wanted, bought a how-to book, read everything I could find, hired 2 guys who knew less than I did, and had at it. And we make some mistakes.
Obviously I cannot speak for In, nor do I know his aptitude. What is clear to me is that anyone with reasonable eye/hand coordination, a positive attitude, and reasonable patience can manage concrete forming and placing. One of your domes I certainly would not attempt.
We all start somewhere. Even if "Well, I've never framed anything before, and I'm not sure which end of a stud points up, but surely I can stack giant legos and drop some dirty water into them," then we're probably warranted in urging caution. You don't wanna be in over your head when 50 yards of concrete are on their way and you don't know if your forms are right, if ya know what I mean. And the seriousness of the question increases with the height of the walls. Heck, we don't even know if he owns a transit...or a level! is the case, I see no reason to discourage him from preparing himself and making the attempt. 50 yds of concrete would be a daunting amount for me to place today, but it clearly isn't necessary for a foundation. One truck at a time (per day, per week, whatever) will make a foundation. It'll just take longer. Can it fit his schedule? That's up to him.
All those clues together would lead me to be cautious if I were in his shoes. You gotta admit that you're cut from a different cloth, Tom...just a whole different place in confidence and experience.
I understand your point and I'm not suggesting that you're wrong. A product of my upbringing, my father (a typing teacher) built 3 crappy houses for himself. Had little idea what he was doing, but last I looked they were still standing. Major foundation repair necessary on one. Another is slowly rotting away. Pity the unfortunate guy going in behind, trying to fix his mistakes. Mostly I was too small, or not around, to have learned much from his not great examples. A BIL just fried a new pump partly due to my father's unorthodox wire useage. Oops, that was 240v. But the major thing I learned was: understand what you don't know and proceed accordingly. He didn't, or didn't bother.
Like you, I have no knowledge of In's capabilities. What is clear to me is that concrete walls aren't all that difficult. ICF's, I have in fact successfully recommended for several novice owner/builders. Those same people I discouraged using plywood forms, primarily due to the required crew, not the complexity. ICF's work fine for solo assembly. No large problems resulted from any of those pours. They also were not attempting annual heat storage.
What is necessary is the ability to understand what you don't know and the patience to go learn it. Some of us have had the opportunity to work with someone proficient, others have not. My experience was that the trade groups and most certainly the ICF mfgs. have made great efforts to ensure a good experience. Following their guidance works. Fortunately, I believed them over a couple of the "experts" I encountered. For instance, a readymix dispatcher actually told me that watering down the concrete would not affect the strength at all. I was also told some wrong galvanic "facts" from the retired roofer I borrowed the tools from for my recent copper roof, something else you'd likely not recommend DIY. Nor would I, if faced with cu's latest project, but a simple roof is just that. I also don't recommend DIY flatwork, if you want it flat.
My attitude, mostly stubborn perseverance, is my main secret. Well, that and surviving long enough to have tried a number of different things. Accumulated knowledge now clearly helps immensely. Don't forget my first (ever) building (concurrent with my concrete here), concrete is much simpler: PAHS Designer/Builder- Bury it!
>What is necessary is the ability to understand what you don't know and the patience to go learn it.>My attitude, mostly stubborn perseverance, is my main secret.We agree with each other. InOvr has to decide that for himself. When I rehabbed a house, people tried to talk me out of an old house. When I started a computer company, people tried to talk me out of Macintosh as the platform. When I built round, people tried to talk me out of GC-ing and into square. etc. That just made it more of a fun challenge.In each case, I listened, researched, contemplated, and then made a decision. Stubborn perseverance can go a long way, and InOvr has to determine if the advice here is a wake-up call or much ado about nothing. Depending on his temperament--risk taker vs risk averse--the same advice could drive him either way.I agree it's doable...you only have to look at Frenchy's house to realize that not much is beyond a determined person. InOvr has to take this info and decide if it's what he WANTS to do, and if he thinks he can achieve his quality standard.
you make some really good points about the experience level of the novice, but I took from his writing that he was fairly intelligent and is researching via this forum in order to learn and prepare. Those are good points in opposition to the negative signals you picked up.
As you say, it will be up to him to know himself.One thing I have noticed in this thread, is that it seems as though most of the nay-sayers are thoise who have not lived in a house with ICFs and those who are amoung the strongest supporters of the system are happy dwellers within such systems. I know that if I werre to build again for myself, it would most likely be an ICF house.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Paul, from the standpoint of energy usage, I don't think there were any naysayers, just people who saw better alternatives on the spectrum of possibilities. Here's the fundamental question...which do you think is a more energy effective wall composition: insulation-concrete-insulation, exterior-insulation-concrete-interior, or exterior-concrete-insulation-interior?
Good straight question. There are variables for the answer such as what the climate is and whether the same amt of insulation is used in comparable systems. I made the mistake of assuming the Has been's insulation exterior was only 2" because that is what I had seen in most of those done that way. But given the same thickness- say 4" of foam on exterior, vs total 4" with 2"in and out ICF style, then the thermal mass would be an advantage there, unless in a coastal climate like mine with large swings in temp and humidity. When that mass is cool and functioning as a cooling agent, when sudden high humidity hits, the walls would be sweating and encouraging molds, something we fight against here constantly in many cellars. To do that kind of system, there would also need to be total climate control within th ebuilding envelope, not just a passive design. So the foam interior temperws things. There is still a thremal mass benefit in ICFs, just not as strong as when the mass is fully withing the envelope.
of course, the whole idea of thremal mass for comfort gets rejected too by those who have not lived with it, probably the same crowd who claim that bumblebees cannot possibly fly.A seminar on passive systems that I atended in CO in the seventies focused largly on a wall system ( whole house, not just cellar) that was 8" interior CMUs, then 4" foam, then exterior veneer CMU( stone in the study done)
That sample building did better in that particular climate than any of the other alternatives. I do not believe that ICFs were around for that. I first heard about them when I saw one 8-10 years later.But all that misses the point of the OPs question which focused more on whether he could do it as a novice with ICFs and not on whether there was another way to do it more efficiently. my own straight forward opinion is that anyone with basic concepts of construction who is intelligent enough to follow instructions can do ICFs well.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>my own straight forward opinion is that anyone with basic concepts of construction who is intelligent enough to follow instructions can do ICFs well.I wish InOvr would come back and flesh out "novice" and "moron" so we'd know how he really feels about all this. We're all answering based on our interpretation of his words, and reaching different conclusions, not because we disagree with each other, but because we're making different assumptions.Edit: did you notice the interesting juxtaposition be/t the threads that rip diy's for attempting construction tasks--best left to professionals, of course--while this thread essentially concludes, "Hell, anyone can do it."?>But given the same thickness- say 4" of foam on exterior, vs total 4" with 2"in and out ICF style, then the thermal mass would be an advantage there, unless in a coastal climate like mine with large swings in temp and humidity. The testing by Oak Ridge is that mass walls operate at their absolute best in regions with large fluctuations. It helps the mass stay at moderate temps. Mass walls behave their worst in climates with constant cold temps, be/c there's little chance to recover heat from the sun, etc. >When that mass is cool and functioning as a cooling agent, when sudden high humidity hits, the walls would be sweating and encouraging moldsWhy would the mass be cool and encounter high humidity? I'm speaking of my exterior-insulation-mass-interior wall assemblies, where the mass would never be cool, and where air infiltration is limited and the humidity controlled sufficiently that the situation described would never be encountered.ORNL also found that mass-insulation-mass walls, such as from the seminar you mentioned, behaved almost identical to, but just slightly worse than exterior-insulation-mass-interior walls. Not enough to fret over, but still measurable. I'm using that kind of assembly in some projects via TridiPanels...shotcrete on both sides of insulation.Finally, I could create an ICF effect in any of my houses by spraying foam on the interior, too. Then I'd have an insulation-mass-insulation assembly. Right? How that would improve the energy characteristics of the building? Actually, we know from tests with papercrete and other interior coatings that it interferes with the benefits that come from thermal mass. Again, I'm not disparaging ICF's--no one here is. Just saying that they'd be more effective (energy-wise) without the interior insulation (assuming reasonable exterior insulation).
Edited 7/29/2005 11:57 pm ET by Cloud Hidden
Cloud,
You raise some interesting points, but aside from all the comparisons and arguments we've seen in this thread about which ways work better as to where the mass si located, it seems to me location and lifestyle make as much or more difference in the end. Maybe we're splitting hairs here.
For instance, in my climate in upstate NY, take a working couple who are only in and out of the house a few times a day, the icf house is going to take a certain number of btu's to maintain say 68 degrees in january. The same conditions in a house with exterior foam of same r-value and 8" of wall mass inside envelope is still going to require the same btu's to reach the same temperature. Now, if the energy required to reach that temperature isn't costing much to begin with, as in my experience with the icf's, the I think the other cost factors would be which system is more cost effective to build AND finish off. In my mind, unless the owner is using sweat equity in building his or hers own form systems, the icf's end up cheaper in the long run if the electrical, drywall, etc. systems require firring. Now maybe not if just a stucco type finish is applied to concrete, but I think you would still spend more on wiring, unless there again it's done by owner. For me as a builder, I look at it more from the standpoint of I'll be paying my men or a subcontractor, and owner sweat equity doesn't come into it anyway.
Now if the mass is also part of a passive solar collection storage system, thats another story too. But I honestly think it's splitting hairs for energy costs unless your house is opened up to the elements for periods of time thru day or night, where the mass being exposed would temper temperature swings better. By the way, we built a couple of earth sheltered homes back in the early eighties that used external foam over poured walls, one also using some trombe walls and they did perform quite well.
As to the original poster, I also think the project could be within his reach, if he can read a level and tape, has a basic uncomplicated plan layout, and has some local support from his supplier. Ideally, any training info would be great, and a trip to a job in progress would be a big help. As you guys have said tho, he's the only one that can decide his comfort level.
This would be a fun discussion to have with you over a beer. When I think of this, I'm not thinking of owner-built, furring, sheetrock or anything beyond where the insulation is and where the mass is. I don't have any of those other considerations slowing me down or affecting the bottom line. But I think the horse has been sufficiently beaten for now, and we can adjourn till a future date when the drinks are cold and there's nothin' better to do than split a few more hairs. :) I do appreciate your perspective.
Thanks for your input on ICFs and how their thermal mass compares to other systems, CH. I'll be reading them a few times more to try to grasp the concepts.
I'm college-educated and working in an office as a computer programmer. In high school I passed up shop classes for college prep. Since becoming a home owner I've done some of my own wiring, plumbing and roofing. I've also helped out a little on some HfH houses. During the past couple of years I have been trying to gear up to take on the task of being GC with my wife for our own house, by reading up on building, and tackling some more projects around the existing home.
Our house design for the past year is a simple L with no garage. We're on 3.6 acres and will build in front of the exising home, and then take it down. We currently use a machine shed for our vehicles and plan to continue to do so.
I guess I called myself a moron because I don't have building experience and sometimes get lost in the unfamiliar terminology. People, i.e. ICF distributers, tell me something and I tend to believe them because I have no evidence to the contrary. I knew if I threw a question out in BREAKTIME, I'd get all sorts of views and knowing more than one side will help with final decisions.
Hope this explains a bit more of where I'm coming from.
Hope this explains a bit more of where I'm coming from.
It does.
You've also got a great example of how this board works, all in one thread. If somebody posts something questionable, he'll hear about it. Gives you a great method to filter advice.
Good luck.PAHS Designer/Builder- Bury it!
Thanks for coming back and checking in...few things worse than someone asking and then disappearing.Only suggestions are to know your limits and to lose some of the gullibility. You need a healthy dose of skepticism or you're gonna end up believing and being sold all sorts of things. It's fine if you have someone watching your back, but that ain't the case if you're the GC.Have fun with the experience, however much or little of the work you take on. It can create a lot of memories.
I'm done splitting hairs too. Maybe my hairline will quit receding now.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"Why would the mass be cool and encounter high humidity? "When I watch the weather reports, mioane seems to be a funnel, where every air mass in the continent exits right up through here on the way out to sea.So we get the cold dry air from the north end of Canada after they are finished using it, followed immediately by humid warm air left from a gulf hurricane stranded in Tennessee when they get tired of calling it a tropical storm.Then a high pressure system offshore for a few dys can pull more cool dry air out of Canada again while Minnesota whips up a good storm and pitches it underhanded across the great lakes where it whipps up all the moisture it can off them.Anyway - our humidity can range from 30%RH to 85%RH and back every few days here. When it happens early in the summer season, the crete is still cool. Water can run right down the walls.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I gotta add this. In my applications I don't care what the outside humidity is or how it changes. That doesn't affect interior humidity with the controls and construction we use. We have high and low humidity here, but keep indoor humidity at 40% plus/minus 5 year round. And our mass isn't cold, either. There's not a chance that a properly conditioned building of the type I'm familiar with will have condensation on the walls. As a learning experience, it'd be interesting to see one that is that affected by changes in exterior humidity (i'm assuming it can't be very tight construction) and will have condensation on walls (i'm assuming an hvac system that doesn't prioritize humidity control) to see how that happens. I'm just not used to seeing the mass affected by the current weather with that immediacy...it's completely protected by insulation and that buffers it from such an effect.
AC isn't that common in Maine.And when you mention conditioning air, you are getting into a whole new realm of the concept introduced by the mass and passive heating - that of saving energy
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I said conditioned, but not air conditioned. Dehumidification is more important to me than cooling, for example. I like to control humidity so that doors and floors don't swell and shrink, for example. No excessive energy usage either...to the contrary, much less than typical. Do it right and ya don't need much, and you end up with a building that doesn't suffer from any excesses.
If you have never used ICF ,make sure you get the ones that have flat insides . Do NOT get the goofy "post and beam " or "waffle wall" type ICF . Very hard to get concrete to flow . Also check for free flow design in the tys that hold the form together .
Jim, I remember you saying you always have lower rh than we manage. Not really a problem here, more a PITA as our airstream one is undersized, requiring occasional backup. I've looked a little at large dehumidifiers. To date I've never spent more than 50 bucks on a used unit, 50 pint. The wholehouse web sites indicate I can get twice that with less electric consumption and a lower temp operation. For something like $1500, which looks like a lot when we only spend $1/day for dehumidification during the relatively short season.
Output air temp is a concern as we don't AC. The websites don't address that. What are you running? At what ACH?PAHS Designer/Builder- Bury it!
Right now the unit is sitting behind all the junk...errr, valuable possessions...I stacked in the closet when I sanded and finished the floors, or I'd look it up. It's Aldes brand. The most I can tell you is that it doesn't run that much, probably the same as the A/C averaged over the year. If air infiltration is controlled--easy to do with our construction, ICF's, and SIP's--then humidity and temp are much easier to keep in the target ranges.
LOL... your air design was my question.
If air infiltration is controlled--easy to do with our construction, ICF's, and SIP's--then humidity and temp are much easier to keep in the target ranges.
Right. Zero infiltration problem here. But you do airchanges don't you?
Ours is .5ACH, which is where we get the humidity. Our dehumidifier, such as it is, is before our air-to-air heat exchanger, so we lose most of the added heat. You know what happens to outside air here when you bring it inside and cool it down. Rh takes a climb.
Aldes, I don't know. I'll look for them.PAHS Designer/Builder- Bury it!
I'd have to defer to my HVAC dude for some of the details you ask. I simply don't remember.
Could you say a bit more about dehumidifying the air versus air conditioning. Few of the houses I've lived in to this point have had air conditioning. Call me tight or an eco-freak but I like outside air and the idea of keeping the energy usage to a minimum.
In, the reason I asked Cloud about his air system was that we functionally have similar homes. He doesn't do the annual heat storage that we have, but both are extremely tight. And we have similar climates, central Va and Asheville.
You haven't filled in your profile, which helps immensely to know where the writer lives. Click on your name to get to the proper spot. Clicking on my name, for instance, will tell you my location. Then you can decide whether my advice is worth much for somebody living in Maine, for instance. Comparing heating and cooling degree-days is important.
When I designed this place I followed then Canadian code of a total air change every 2 hrs (.5 air changes/hour, ACH). Our annual heat storage involves huge amounts of mass, which functions (passively) as both our heating and cooling systems. We have no need for ac, likely one of two houses in the whole area. The other is a similar PAHS I built for a client. This is well beyond "earth sheltered".
Depending on where you are, humidity is a problem. Here and Asheville, certainly. Coastal Va and NC, considerably worse. We monitor indoor humidity constantly. Cloud keeps his below 50% with a considerably larger, and more initially expensive, dehumidifier than we have. We settle for a slightly higher level, which while above the mildew threshold, is not a problem. We find our upper 70ºs tolerable as long as the humidity is kept low. This time of year everybody else around here needs ac to remain resonably comfortable, which also solves their dehumidification needs.
Dehumidifiers add heat to the air. We run ours through an air-to-air heat exchanger to lose most of the added heat before circulating it throughout the house. Even with 20k cu ft to ventilate (and Cloud's is considerably larger), my fans are tiny. Both we and Cloud dehumidify as a part of our overall air systems.
For you, without knowing your climate, I have no real suggestions. If you don't need ac for its cooling, you can do fine with a properly installed dehumidifier. Cloud likely spent around $1500. I've never spent more than $50, usually for a used one from Sears. With ICF's you're building a very tight house. I hope an air system is part of the design. Our local code enforcers consider an operable window to satisfy requirements. Pretty ridiculous, considering that a large portion of the year windows are never opened here. Ours, never, and we have the freshest air I've encountered. Also lets us filter pollens, smoke, dust from the air before it gets into the house. My seasonal allergies were motivation.
Regarding "Call me tight or an eco-freak but I like outside air and the idea of keeping the energy usage to a minimum". Take a look at yearly heating/cooling costs. Typical is one month's income, just to satisfy one's creature comforts. We're less than one week. I much prefer to have the time (or money) for something else. Plan your house so it takes care of you, not the other way around.
(Yielding soap box...) PAHS Designer/Builder- Bury it!
>Pretty ridiculous, considering that a large portion of the year windows are never opened here. Ours, never, and we have the freshest air I've encountered. Also lets us filter pollens, smoke, dust from the air before it gets into the house.Tom and I are in complete agreement on many items, and particularly this one. To many people, it seems paradoxical that keeping "fresh air" out by not opening windows results in extremely fresh interior air, but it's absolutely the case. We pretty much do nothing and get fresh air. Likely there are ways to measure "freshness", but I'll go empirically...whenever we return home from a trip away to relatives' houses or hotels, the first thing my wife comments on is how good the house smells, kinda the way a new car smells better than an old one. And my daughter's best friend, when she walked into our house the other month, said something like, "Your house always smells so good...better than ours." They have a very nice, new, well-maintained traditional home. I think Tom will agree that it's not because we use antiseptics (we don't), or sprays (we don't), or bake cookies (not often enough), but rather because there's simply an absence of stuff that makes for odors...no mold, no decay, no pollen, no road smells, etc. And we accomplish this while using less than 50% of the energy/sf (probably less than 30%/cu ft) for HVAC of any of our neighbors.
I think Tom will agree that it's not because we use antiseptics ...
Tom certainly does. DW just returned from a road trip where she stayed at my mother's house. Also spent considerable time with a sibling in the same area. Both houses, modern with AC, very obviously lack our air quality. This time of year neither ever open a window. Advertisements for plug-in air "fresheners" crack me up. Kinda like spraying perfume instead of bathing. Just ain't the same.
Clouds' house I don't know, but our air system was way more than paid for my utilizing fixed windows rather than operable. Egress has to be dealt with, but other than that, we're fixed.
It's not unusual here either for guests to remark on our air quality. What is amazing is the lack of response I've gotten after making suggestions how others could improve their air. If the ductwork's in, it's not very complicated or expensive. Breathing's pretty basic. Sis and BIL take steady antihistamines. HELLO? Anybody home?PAHS Designer/Builder- Bury it!
VaTom - I have been reading this thread with interest since we live in a similar climate - I am building an ICF home in Western MD - what do you use for air exchange? Do I need dehumidification? I have searched the web for info, and much of it is confusing or even contradictory - HRV, ERV etc... I am setting up things with the HVAC guy soon and I'd like to know what I am talking about when I call.
Also - is blowing fiberglass insulation into my attic (trusses) the proverbial hole in the bucket? Should I investigate Icynene or its equivalent - how does the cost break down?
BTW I am amazed at this product - they really are like legos, (Amvic) and they really hold concrete well - the boom pump didn't like the mix much, so we pumped with a 6" line, no reducer, 50' drop - violent - and no problems with the forms, except for a corner where I forgot to brace, and we had to slap some lumber on a bulge. I'll be ready next pour (1st floor walls) with a better mix and bracing - and a smaller pump.
-Brian
Hi Brian, that's what's fun about this place. You never know who's tuned in. BTW, I'm not a GC or even a carp. Only sometimes play one on the internet.
I'll leave your insulation question for someone else. 100% of the houses I've built (2) were underground. Each used a truckload of xps boards.
Western Maryland in the mountains? I don't really know what your summers are like, having only driven through. For good design, everybody needs to know what the local climate offers. One major difference between Cloud and myself was size of the budget. I built for cash and my pile wasn't large enough so lots of things were cobbled.
My heat exchanger is one example. Popular Science published plans in '86 which are remarkably similar to the Lossnay. If you're a DIYer, I can email you the article. I have met exactly one HVAC guy who knew what I was talking about with a total air system. His daughter had severe respiratory problems and he had to learn. Consulting is something I do a bit of, and have been amazed at the HVAC ignorance in their own field. I hope yours is better. Cloud apparently has somebody who knows what he's doing.
We do a total air change every 2 hrs. Figure your volume and make sure the fans are sized correctly. More often air changes obviously won't hurt. For our 20K cu ft, these are very small fans. We pressurized slightly with different size fans, which makes all leaks go out. I'll refrain from going into detail why this is better for non-stick houses.
Briefly, my air system consists of: a cheap pleated filter (5 micron), dehumidifier (used Sears) manually turned on when our indoor humidity rises, heat exchanger (cobbled), and ductwork to distribute the fresh air (even into all closets). The dehumidifier lives outside, switched inside, to avoid as much operational heat coming in as possible.
Like you, I read everything I could find. Pre-internet for me so maybe less confusing.
Your pumping sounds like a nightmare. Very glad it worked and speaks very well for the forms. You're learning fast. I hate pumping for those reasons. After 4 experiences I quit and bought a crane. When I drop (not pump) concrete I get very obviously better walls. This has been discussed at length previously here so pumping fans can save their breath. I ain't doin' it no more!
There's a 2 story ICF house in town here where they actually pumped one lift 25' high. The forms, Blue Max, held but you can see daylight in spots. Those are the only places they know are defective. Bound to be more. I know enough about reinforced concrete to understand that structurally it isn't a problem. Just annoying as hell to pay $700+ to pump and then get an inferior product.
Anyhow, heat exchangers I do know a bit about. Let me know if you want the PS plans, or if you want to compare a couple of brands' details.
I've gotta go over the mountain (Blue Ridge) for a foundation consultation now.
PAHS Designer/Builder- Bury it!
>Cloud apparently has somebody who knows what he's doing.Yeah, he seems to have done all the right stuff. What I know I learned from him. Sure didn't know it to begin with. Also didn't know how completely fantastic the system would perform, or I woulda used more fixed windows. There are probably 7, not counting bedrooms, that have never been opened.I've really only become passionate about proper hvac through building and living here. With our thin-shell domes, no one prior paid ANY attention to hvac. They'd typically use the cheapest A/C unit they could find and brag about how small it was. But then they'd have other issues with air quality, etc. One had a CO reading of 1200, iirc. They'd try to solve that with a retrofit HRV. The whole notion of controlling humidity, and controlling the quality of the air as it comes into the house was unheard of for these structures until Guy Cox (my hvac sub) did it here. My clients are now paying attention to this, too, but with whatever slant on it that their own hvac sub will bring. It is hard to get people to believe that they will actually prefer to not open their windows. It's a hard sell at times.ps. When we selected the dehumidifier, we were sizing it for about 100,000 cu ft. That probably influenced the spectrum of viable units. :)
VaTom - thanks for all the info - I've seen the PS plans - There doesn't seem to be much to the heat exchangers - maybe I'll take another look. Domes & in the ground are fascinating - I helped build a masonry heater for a guy who built his dome with 2 huge inflatable forms - I'd have loved to have been there for the pour. When I read Mother Earth News as a kid, I used to dream of building an earthship in southern Colorado somewhere. Back to reality...my house is almost 50% in the ground, and I hope the mass and insulation above will carry their share of the load. The mountains of Western MD might sound cool, but it hit 95 yesterday!
Humidity is my major concern, but I'm thinking I'll vent baths and kitchen together and bring fresh air into the basement with an exchange somewhere in the middle. Maybe just an aluminum panel separating the two ducts...? I just wonder if it should be linked to the HVAC return to save ductwork (AC only, since I'll have radiant heat) Lets see... 32K cu ft of air = 1066 cfm fans for 2 ACH? How did you keep your humidifier outside - where does it enter the system?
The next ICF pour (next week if all goes well) will be with a trailer pump and 2" hose, 3/8" 4000psi mix heavy on the sand, and I'll have my ducks in a row.
Brian, sounds like you're on top of it. You're right, there's not much to heat exchangers. I used aluminum (roofing) for my exchanger. The rest is the only ductwork that lives here. Definitely tie it into your HVAC system. Might make your HVAC guy turn somersaults, but that's OK.
Our dehumidifier is mounted on a retaining wall outside, with a copper roof for the weather. Works are open to prevailing breezes, hoping to lose the extra heat. Dark tonight, but I can take a pic tomorrow. Not pretty, as I have yet to figure out a hinged shield, but effective. The filter is mounted on the dehumidifier, then ductwork into the house. Rocket science this isn't, just figure where your parts need to be and design accordingly.
Venting your baths and kitchen together sound fine. All here are part of the air system. Bear in mind that kitchen vents require separate filter, and, per code as I understand it, need to vented separately. We don't, but that's in consideration of our cooking and filter cleaning. When this is converted to a rental, the air system will be changed accordingly.
Humidity should be a major concern, to anybody. Our digital monitor came from Grainer's, about $40. It's required one battery change in the last 12 yrs.
Storm here tonight.
Best of luck with your next pour. Ducks in a row is good. PAHS Designer/Builder- Bury it!
Brian and In, I forgot to mention something that works great for us. Heat pump water heater. Ours is a wall hung unit that feeds a standard elec heater tank. Roughly 3x the efficiency of the electric heater, but what's really interesting is the byproduct. Cool dehumidified air.
We've found ours to reduce our dehumidification needs by 50%. Making payback happen in the first season of use. Now, I found mine on ebay, so normal pricing would be more like 3 yrs. But still a very reasonable idea if your house is designed such that you can utilize one. We use ours seasonally.
Here's a gov't site that goes into quite a bit of detail: http://www.pnl.gov/fta/3_res.htm#manu
Hmmmm... site is not currently working. Hope it comes back.PAHS Designer/Builder- Bury it!
I'll throw some information in my profile. Hadn't realized till recently this function was available.
Helps immensely. Thanks.PAHS Designer/Builder- Bury it!
Do you build with either SIPs or ICFs or combinations of both? I'm looking at ICFs for the walls and was considering SIPs for the roof. (I haven't thoroughly explored the costs involved, might as well dream big.) My ICF guy is trying to steer me away from SIPs. He says they don't have a good method for keeping moisture from inside the house getting into the panels. From some of your postings, seems like you might have an opinion about this. Keep in mind, I'm just the messenger.
Neither. I do a form, spray foam against that (inside), and rebar and shotcrete against that. Result is kinda like an ICF without the inner layer of foam. And curved. But that's me.To the guy who talked about moisture with SIPS, I'd ask what moisture levels he's anticipating inside and why there's enough of an imbalance be/t interior and exterior that it'd be driven into the walls.
There are three basic types of ICF's: Flat insulating concrete form systems, like ARXX, which are paneled blocks and which create a form for a full thickness pour like a traditional formwork, but with a few differences like not having to tie rebar, bracing being (in the case of ARXX) a proprietary system which offers midpour adjustment, catwalks, etc.; Waffle grid system and Screen grid system, the latter two, I've only read about because they don't provide for a full thickness pour and consolidation with a vibrator has not always been successful; they're the source of many of the horror stories on the internet and TV have documented nasty pours with excessive voids and alligators. (kind of the concrete block of the ICF world, IMO.
I work with the ARXX system because they've got a mfg. plant in state....ICF forms weigh very little, but a semi-load for a home basement will be quite costly if it has to be shipped across the continent.
ARXX and others require some classroom time to get certified, largely because early generation ICFs, like SIPs and other innovations, had some development problems along with some wantabee mfr's, so reputation and good results is important to the mfr as well as the builder.
ICFs are a good system for a DIYer, but the classwork, the DVD, the workbooks and some site visits where ICF structures are going up should be visited.
They have some quirks: on high walls, you can expect the top of form to pull down 1/2" to 3/4" during the pour. And they will tip slightly; that's why you need adjustable bracing, because, during a pour, one or two guys will be busy adjusting the braces to keep the wall plumb.
Knowing how to block out, and tape and do intersecting walls and how to install ledgers for floors and/or decks, cutting chases for wiring and plumbing, and how to waterproof.....all a little unique.
Despite what I've read here, the insulating qualities of an ICF building, at least in my maritime climate, have no peer.
I've done number of highwall foundations the traditional way, but it's really a treat to squirt a continuous bead of adhesive foam to secure wall forms to footing (even in the rain!) and, after the pour, have very little teardown and clean up and stake pulling ad nauseum!
I've never actually worked with ICFs, but have measured several foundations for trusses where ICFs were used.
On the worst one I measured, the front of the house was 14 1/4" wider than the back of the house. We had serious problems putting a roof on that one.
On several others, the builder has bragged that they were "daed on" dimensionally. But most of them have been a couple of inches out of wack.
My point here isn't to trash ICFs, but to show that they apprently need a lot of bracing to keep them in line. Once the concrete has set you're pretty much stuck with whatever you've got.
There have been a ton of discussions about ICFs here over the years. A search of the archives should turn up a lot of reading for ya.
Boss raises good points. I've done some ICF work, and it's more carpentry than concrete work. Pay attention to details in preparation, rent the scaffolding that doubles as bracing, and keep an eye on the walls as you pour. Also, if you think one brace is adequate, use two. You get one shot to do it right whenever you use concrete. Check FHB's main site for articles on ICFs. There's a pretty good one written by Rick Arnold recently, and another one from about 6 years ago by a fellow I know fairly well.
AndyAndy Engel
Senior editor, Fine Woodworking magazine
An updated profile is a happy profile.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
None of this matters in geological time.
I think the source of problems like that is from inexperienced DIYs rather than the product. The same crew using regular forms or CMUs would be off the same amt.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"I think the source of problems like that is from inexperienced DIYs rather than the product."
But that's exactly what this guy is.
"The same crew using regular forms or CMUs would be off the same amt."
I've never seen a poured foundation that was anywhere NEAR as bad as the one I mentioned. And every ICF foundation I've measured has been off. Even the one that GCs claimed were "dead on".
So I'm a bit leary of them based on my experiences.
I believe in censorship. After all, I made a fortune out of it. [Mae West]
right on the first pooint, but are you suggesting that as such, he could do a better job with forms?I have seen "professional" foundations with forms done as bad as you reported.
And I hacve seen some DIY disasters with OCFs. On one, they failed to keep the walls protected from snow and ended up with a foot or more of the white stuff in the forms the night before they were to begione pouring. At least they were smart enough to cancel the concrete for the day, but dealing with that problem cost him a weekbut overall, A diy ios better off with ICFs and he will end up with a superior job if he is careful. You statenment that since you have seen ICFs botched so no DIY should ever use ICFs is like saying that since some teens have auto accidents, no teen should ever be allowed to drive.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"You statenment that since you have seen ICFs botched so no DIY should ever use ICFs..."
I never said that.
In my first post, I only mentioned that they required a lot of attention to bracing.
Later on I mentioned that I haven't seen one yet that was really square. I've measured several that were done by GCs that had used ICFs more than once.
I've never seen anyone try to DIY their own poured foundation yet. But if I did, I would expect problems with that too.
I don't lie, cheat or steal unnecessarily.
I've never seen anyone try to DIY their own poured foundation yet. But if I did, I would expect problems with that too.
Having done it, I don't. These are curved walls, 30' apart, that needed to remain parallel for the bar joists to work. Took some measuring and bracing, certainly not perfect, but no problem setting the roof.
Here's my first experience:PAHS Designer/Builder- Bury it!
That was a paraphrase of all you did say, Boss. I didn't put it in quotes.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
We built a large castle out of Quad-Lock ICF's a few years ago. Stacking the ICF's is pretty straight forward the tougher part is bracing to make sure walls are straight and opening are plumb and square.
The corners were easy but really slowed us down, particularly if it was an off angle. For cost effectiveness I would recommend designing a plan that does not have a lot of corners and jogs. It was also slow going attaching a roof from a one story section to a two story wall.
Consolidation is key. In many areas where we exposed the concrete (to tie in a wood framed wall or roof) we found some rock pockets. We were gunshy about stinging it too hard since this had caused some blow outs in early pours.
We poured over 1200 yards in 30-35 pours. The flexibility of the forms allowed us to pour a 24' radius tower section with 35 feet tall concrete walls.
I recommend ICF's for sound, insulation and thermal mass. However, I am presently designing a new home for my family and I am using a wood frame due to cost.
Wood is Good
Adam Greisz
Owen Roberts Group
10634 East Riverside Drive # 100
Bothell, WA 98011
http://www.owenrobertsgroup.com
I have never built with ICFs but the guy next door did. Maybe it was the brand, but, IMO, the house came out like $hit. Floors & walls were both outa wack... some waaayyy outa wack. I think it was more than just the ICFs.... It started wrong with the clearing of the lot and got worse from there! I think a major issue was inadequate bracing of the "forms". Had a few blowouts during the pour too. The HO asked me for a reference for a trim guy - I gave him one. Then had to suffer through the feedback from the trim guy. My bad...
The local HfH chapter builds several ICF houses a year here in KCK. They started out using AARX forms, then found a less expensive brand---sorry I can't remember the name.
Like the others have said, the footers, they poured the floor also (after locating the rough plumbing and wiring conduit) have to be dead on. Setting the forms is easy, adding the rebar involves lashing the forms together and to the rebar with plastic ties, different lengths for two lashing patterns.
Windows and doors are framed by making a 'buck', the rough opening made with pressure treated 2x8's----we used 4" wall forms. These bucks are installed as the forms are being installed--with anchor bolts extending into the concrete cavity.
The forms they used have exposed webbing, inside and outside. That webbing is part of the internal structure and is used as the area to which the drywall and siding is fastened---they used screws.
To keep the walls straight during the pour, wall jacks are installed every six feet by screwing the wall adapter to the wall---in a plastic web---and the floor adapter to the concrete floot with Tapcons. The wall jacks have a threaded collar in the center---turning it pushes the wall out or pulls it in. There are scaffolding brackets that mount on the wall adapter to get access to the wall as it gets over chest high. Simple string lines ran on the inside of each wall about 6' high insure the walls are straight.
There are companies that will rent those wall jacks/scaffolding adaptors----as well as the CIF company supplying them.
They used HardiePlank lap siding---screwed into the plastic web or a two part stucco coating as the external siding. Our local building codes do not require any waterproofing on a CIF wall, as the styrofoam itself is waterproof. They did add a sheet of 6 mil plastic to areas that were backfilled.
While setting the CIF forms is not exactly a DIY job----to set up the forms for a 1200 sq. ft. house takes the experienced HfH of eight to ten crew members a bit more than a day----that part might be better contracted out.
A 4" concrete CIF wall finished with siding and sheetrock,supposedly has an R value of about 40.
A 4" concrete CIF wall finished with siding and sheetrock,supposedly has an R value of about 40.
"Effective", maybe. Add up the parts and see how little you get.
When they first came out, the claim was R50 for just the forms and concrete. They lied.PAHS Designer/Builder- Bury it!
Don't sweat the sales crap from the ICF vendors. Amvic forms are plenty strong enough for the job. There are something like 50 form manufacturers out there and each design has its advantages and disadvantages. Strength isn't an issue if the manufacturers instructions are followed, the frames are properly braced and properly reinforced at the cut joints.
Forms like Amvic are symmetrical top to bottom and end to end- there are only forms and corners, no lefts and rights. That makes things simpler, plus you can rip a course to correct for a massively out-of-level footer, or to give you an odd ceiling height as was required in my case (I wanted a full 8' ceiling above floor and the forms only come in 16" heights generally). Symmetrical forms mean that you only need 1/2 course of blocks to do that, which saves some bucks.
From my shopping around exercise, another decision you have to make is whether you buy forms of a design like Amvic with the ties already installed, or a design like others where the forms are shipped as flat pieces of foam with the ties shipped loose. This makes a big difference in the volume of the blocks as shipped to you and hence the shipping cost. But then you've got to factor in the labour of installing all those ties.
You can rent the adjustable braces and I recommend you do so too. I was going to build my own and then re-use the lumber for framing, but I'm glad I didn't. The braces work well and are worth the rental money in the labour savings alone. The scaffolding feature of the braces saves labour/time during the pour, reducing the amount of time the expensive concrete pump needs to spend on site. For mine we poured ~11 cubic metres of concrete in under two hours. We adjusted the walls straight before the pour and they didn't budge during or after the pour.
From what I've seen and what my consultant told me from his experience, the big issue with ICFs is that they will not tolerate excessive vibration. Follow the manufacturer's instructions with respect to vibration and do not over-vibrate or you risk blow-outs.
My Amvic-formed 8" x 8' basement walls were vibrated only by pounding on and vibrating the vertical rebars and by vibrating the webs of every form with a sawzall with the blade taken out of it. I've removed the foam in a few places to tie in garage grade beams, to put in boxes etc. and there is no evidence of pocketing. Use a properly configured pump, pour with the right size aggregate and the right slump, pour in lifts allowing the material to flow into the corners, and everything will be fine. 6" walls packed full of webs and rebar are much more risky as far as pocketing is concerned. The difference between 6" and 8" walls as far as area available for the concrete to flow properly without heavy duty vibration is pretty significant. Spend the extra money and go with 8" walls.
As far as whether or not ICFs make sense for you, if you're a DIY like me I wouldn't even attempt to build single-use formwork to save a few bucks on ICFs. I even used ICFs for the relatively easy job of forming my garage/shop grade beams. They were only modestly more money than just the LUMBER to construct my own single use forms, plus they saved me all that labour PLUS they saved the labour of insulating the grade beams. In fact, they're only modestly more money than the retail cost of the foam used to make them.
Best of luck to you.
I had a Nudura foundation built for an addition 1300 sq ft that I am building. Happy to answer any questions on how that went.
Bob B.
Did you choose Nudura over other forms for a reason or was it simply available in your area? Did you do part of the work? Your mail makes it sound as if you had the foundation done, but you're doing the rest of the addition yourself. After seeing one done, would you try it yourself now? Were there any problems with the forms? Did you consider doing the entire addition with ICFs? any particular reasons you didn't?
Thanks, and I hope your project goes well.
In OvrHisHead.I had the foundation done by a not so local contractor, He is about an hour away. He had been recommended by a colleague and I did want to use a Canadian product if possible. (No offense to those south of our border - Buy the cars your neighbour builds - was the idea). The contractor used Nudura. It looked like it had been well thought out. I did not do an extensive product comparison. As lots have said the key factor is the bracing. The nudura lego blocks for the 20 X 40 ft addition arrived in two pick up truck loads. The bracing was another truck load. After the nudurs was set up and the re bar at the corners around windows etc was installed. The contractor and crew spent what seemed to be a long time leveling, squaring, straightening the whole thing. The bracing was a metal stud that ran down the Nudura wall top to bottom with what looked like a protor jack attached to the top end. Ther was a brace about every 4 feet. It also served as scaffolding for the pump hose handler.After the whole thing was set up. The pump truck arrived and the pour started. As the pour progressed a couple of fellows kept checking the braces for level and the walls for straightness and adjusting the braces.With the set up they had the whole thing went very smoothly and quickly. Would I try it myself? Now I' ll try just about anything!! Setting up the Nudura and the rebar would be simple enough. I would not try to DIY the basement without the bracing system. I do not know if it can be rented.
The other thing was, While the pour was going on the crew gave me a running commentary on what was happening, how the walls were loading up, where the pressure points were, where blow outs could be expected, how they were dealing with it. These guys were pros, they had done the 60 ft wall of a new church, they had done commercial buildings, they knew what they were doing and how to react to what was going on. And they knew how the product would react.
Sure, maybe I could do it and have it work out. If I were to do it I would have had to build a heck of a support wall inside and out to ensure that the end product was what I wanted. Having them do it cost about $8,000 CND. I did not want to gamble with tons of cement much of it over my head. It seemed the better route to hire a crew that really knew what they were doing and not have to worry about it.In the same why I hired out the shingles, cedar on the mansards and asphalt on the roof and the plumbing rough in. I had a crew foam insulate the walls and ceiling. I did the electrical from the panel out and hired an electrician to check it out.I did want to do much of the work, including the framing myself. I work all day writing on paper, reading paper, putting reports on shelves, in filing cabinets. I get great satisfaction building things and being able to see what I have accomplished a year, 2 years ten years later. By then most of my 'real work' has been shredded and recycled. The other factor is cash flow. I can spend so much per year on the project. I would consider having a house done completly with Nudura, I has seen some and they are everything the brochures say they are. The up front cost would have been greater, affecting cash flow and I would have missed out on the framing.An ex-boat builder treading water!
The existing house is 140 year old tenant farm house. It's just not that nice a house or we'd probably be looking to add on to it or remodeling it rather than building new. Also planning to take kitchen cabinets out to use in the new utility room.
You probably noticed I said 'take it down' rather than 'tear it down'. Anything which someone else might use I hope to be able to save. Some of the woodwork is not too bad, but a lot of layers of lead paint.
I have been following the work of a very talented finish carpenter turned GC build his first spec house (sold before trimout). He used the Nudura product and is sold on their ICF's.
I intend to use Nudura also, mainly because the rep will come out two days before pour and check out my bracing and will hang around for pour day to help out.
Chris