So now it's SIPs turn to get attacked by Dana.   I wish these forums would be moderated so that this type of nonsense wouldn't have to take place. People come here to learn and use different building methods but people like Dana and ToddM are just here to promote their egos, attack others and attack other building methods.

No wonder so many people leave this forum and never come back. Internet bullies abound...

In this forum you need to support your contentions with actual data based on a firm foundation of physical science. It's not enough to just Google and Noodle electron bites off the web. That's what I like about it.

dmaceld,

You are wasting your time. I've spent some time trying to explain this report and how some wishfully interpret it.  I doubt if some of these guys have even read it once.   At least one of em thinks that the Hot Box and DOE2 are are the same thing.  They use data like a drunk uses a lampost for support rather than illumination.  Regards to those that see the light.  

No wishful thinking on my side. As we have been over before (and over and over) the ICFA sponsored a side-by-side test in Knoxville in 2000 of ICFvs studwal housesl. Judging by ORNL's specific demurrer that the comparison found no evidence of a magic earth coupler in ICF walls, the test, in fact, represented wishful thinking by some parties. At any rate, the ICF house performed 7 percent better than the less well insulated stickbuilt in unoccupied tests. DOE2 had predicted 6.8 percent. http://www.greenbuildingtalk.com/Forums/tabid/53/aff/4/aft/79706/afv/topic/afpg/2/Default.aspx

Follow the link to read the apologiists' arguments that the test was the worst conceived and executed such comparison in the history of the planet. By extension, I guess, the ICFA in those years was run by the dumbest collection of trade group execs ever assembled on the planet.

I'm with Dana on this one, all systems have their warts including the new-old idea of offset stud walls with 12" of dense packed cellulose which I've written about before , but that is for a different thread. I started my business career in insulation and gravitated toward icf's. There are systems on the market now that allow for much greater wall insulation values and I think this will increase in the future.

According to the New York State Energy Research and Development Authority (NYSERDA), the cost to do a deep energy retrofit on an older single family home is about $110,000. The conducted a study on 4 wood framed buildings in Utica, NY. The homes were around 1,000 - 1,500 square feet. Even with that amount of cash outlay, they did not meet their goals. The buildings still leaked air at 2.0 - 5.0 ACH50, and even though overall energy use dropped by 60% - 65%, the actual electricity use went up. The payback on these $110,000 deep energy retrofits was shown to be around 140-150 years. Even then, that is a slight of hand number because it did NOT include the cost of GC/Consultation & engineer work which would easily have added 20%+ to the cost, so add at least another $20,000 to the cost. This then bumps the ROI to 175 years or more. Is that stick frame house even going to be standing 50-100 years from now?

Go read the September 2012 issue of Journal of Light Construction about how it cost $300,000 to do a deep-energy retrofit on a stick frame duplex in Massachusetts.

When prices are quoted for new stick frame builds that are high R, tight, and done by a professional energy wise contractor, they throw out numbers like $130 per sqft for construction costs. As they say, the devil is in the details. That price was for "construction costs" and does NOT include the GC charge & the consultation work. The real number is more in the realm of $160+ per square foot but of course that is a detail that is left out.

OK. So after all of this very intelligent spirited debate on many an Items that I am too pea brained to read, would you recommend ICF as a construction tool here in Central, FL? Any other "Big" items that you would use to make your home energy efficient?

Thanks

Posted By sphingers on 03 Feb 2013 10:43 PM
OK. So after all of this very intelligent spirited debate on many an Items that I am too pea brained to read, would you recommend ICF as a construction tool here in Central, FL? Any other "Big" items that you would use to make your home energy efficient?

Thanks

There are many ways to skin a cat. Since you are in a Zone 2 area, you don't need Zone 6 + R60 in your walls. In your area the biggest problems are going to be termites, hurricanes, tornadoes and rain/moisture. To which ICF addresses all those issues. When the hurricanes and severe thunderstorms roll through, your ICF home will be like a fortress. Of course your windows are always a weak link but you can install exterior storm shutters.

As far as what other items to address. What do you plan on doing for a roof? You might want to consider a Steel SIP roof or if you have the $$, an ICF/concrete roof. The latter option depends on design and budget but you can build a 100% concrete wall and roof home. The SIP option is also a very good option and less costly. I would go with a Steel SIP roof but OSB is doable as long as you detail it correctly.

Of course, you get the exact same qualities with a poured wall.... My advice is to go with the flow in your area. Your first contractor was telling you he doesn't you to be his ICF practice house. The next guy may be perfectly happy to make you his practice house, after which you will look back wistfully on the first guy's grasp of reality. The problem with most of the technologies on this site is something called the learning curve. There isn't enough call for them in many specific local markets for contractors to develop proficiency, and more importantly, to gin up the competition necessary to get an ICF house built as reliably and inexpensively as whatever mode of construction IS common and competitive. Florida may well be the exception. Visit your local building inspector. Ask him how much ICF he sees. Ask him for names of engineers who specialize in ICF. (Many are barred from making recommendations, so you may need an oblique approach. "If I looked at the plans of the best ICF buildings, what nameplates would I find?") Most of the engineers I've met have low tolerance for BS.

That said, focusing on walls is majoring in your minors. I'm guessing the most important factors in central florida are cool roofing, overhangs and/or orientation that keep the sun off the windows in summer, attic insulation and efficient hvac.

Yes, it's more complicated to model an ICF wall structure to high accuracy, but high-accuracy isn't really required to get within a few percent of measured performance for the whole house.

DOE2 modeling of mass effects good enough for characterizing ICFs at the macroscopic level, even if it's not very satisfying to the science nerds. The magnitude of the error is less than the inherent error of window & door U-factors in a particular house, and lower in magnitude than the inherent errors in site factors such as the thermal conductivity the soil when simulating the energy use of any real house & real site. Don't lose sight of the forest by the complexity of the patterns in the bark of the nearest tree- from a macroscopic point of view it really doesn't matter- the mass effect errors of a DOE2 simulation of ICF will NEVER be as far off as the errors in marketing-hype numbers even on simple things like steady-state R-values.

Accuracy implied by ever more sophisticated modeling is usually an illusion when looking at the bigger picture, but the bigger picture elements are still the same- the amount of mass in an ICF wall can't make R22 EPS perform like R40-lower-mass systems over any relevant time period, even if it might from a peak-load contribution from walls point of view under some narrow sets of circumstances.

Posted By Lbear on 02 Feb 2013 05:22 AM
So now it's SIPs turn to get attacked by Dana.   I wish these forums would be moderated so that this type of nonsense wouldn't have to take place. People come here to learn and use different building methods but people like Dana and ToddM are just here to promote their egos, attack others and attack other building methods.

No wonder so many people leave this forum and never come back. Internet bullies abound...

It's not SIPs that I take issue with- only marketing exaggerations used by some SIP manufacturers to imply higher performance than gets realized in the real world.

SIP vendors have rarely taken the flights of fancy of radiant barrier folks or some (and clearly not all) ICF vendors.

I've both recommended and used ICF- have yet to build with SIPs but I have no problem with using them and have recommended them. (Speed of assembly is a HUGE advantage with SIPs!)

If there's nonsense taking place it's using the 40F average temp R value for EPS for characterizing ICF rather than the 75F average temp number allowed for insulation vendors- sufficient nonsense that it needs to be called out, even if the effect on total house performance is pretty small.  I guess my BS-alarm is set to about 5%- call it a hair-trigger, but I can't find any legitimate reason for making that exaggeration in the case of ICF.  If they used that to characterize the exterior half of the EPS for the average winter-time only performance it would have some legitimacy, but that wouldn't be enough to get them to round up an R22 ICF to R23.

Fair enough- I'm here to promote toddm's ego, but can't tell if it's being reciprocated.

Dana and I have had disagreements but I have never doubted his knowledge or his good intentions. Dana's advice is a major plus for this site. I've benefited myself.
Speaking of which, I haven't seen Wes for a while but here is a shout out for counseling me to enlarge my downstairs bath and give it a second, public entry. Here is the result:




The pony wall covers plumbing stubbed up through the floor into what was supposed to be a wall between bath (small) and closet (tiny). The long suffering Mrs. M came up with idea of doing it in tile, plus the notion that what 5x12 room really really needed was a granite racing stripe.

Posted By toddm on 04 Feb 2013 02:00 PM
Dana and I have had disagreements but I have never doubted his knowledge or his good intentions. Dana's advice is a major plus for this site. I've benefited myself.
Speaking of which, I haven't seen Wes for a while but here is a shout out for counseling me to enlarge my downstairs bath and give it a second, public entry. Here is the result:




The pony wall covers plumbing stubbed up through the floor into what was supposed to be a wall between bath (small) and closet (tiny). The long suffering Mrs. M came up with idea of doing it in tile, plus the notion that what 5x12 room really really needed was a granite racing stripe.

Picture worth a thousand word. Explains why we don't use the Knoxville Report. Just like the fancy tissue dispenser it was not well researched so we tend to use the more practical approach of leaving the tissue on the counter ;-))

I have been examining many options for a small 2-storey, motel style project we're designing to build.

After countless hours of reading posts, gathering opinions from some very intelligent contributers, weighing the pro's and con's from stick built with ample PU spray foam insulation, to osb sips, mgo sips, etc... it seems to me that the overall performance levels achieved (big picture) by using ICF's is the way to go.

I agree there is no one perfect fit for all wall systems, but from all I have learned online, ICF's have me converted. Now for the fun part...pricing!

One of the unique advantages to using ICFs for Hotel/Motel projects is the acoustic properties. A 6" ICF wall willl have an STC rating of 57 or better and that makes for a very quiet building.

6" ICF with STC of 57? Most spec's I have seen list 6" ICF of 50-52. Feel free to correct me on that.

The local Fairfield Inn & Suites here in Russellville, AR was built using LiteForm ICF a few years ago.

https://plus.google.com/111261312952616603770/photos?hl=en

6" ICF with STC of 57?

You may be thinking about the naked wall. 6" ARXX walls were lab-tested at 55 STC. That is with sheetrock both sides. If you add some space on one side or another it can go up to the 70's.

Posted By ICFHybrid on 19 Mar 2013 11:10 AM

6" ICF with STC of 57?

You may be thinking about the naked wall. 6" ARXX walls were lab-tested at 55 STC. That is with sheetrock both sides. If you add some space on one side or another it can go up to the 70's.

Is that with standard 1/2" sheetrock?

Is that with standard 1/2" sheetrock?

The 55 STC is specifically with 5/8" on the source side, but only 1/2" on the receiver side.
Getting up to 71 STC required the addition of a " 2-1/2" non load bearing steel stud cavity".