Is closed cell foam the right choice?
Here’s the pics of my new old house located in Sandusky, Ohio (Cedar Point). One of my first priorites are to insulate the walls as there is no insulation at all right now. I have had an Icynene contractor, a cellulose contractor (which never even called back), and a tripolymer contractor, USA Insulation Eastlake,Ohio. The Icynene quote was $2400 more than the tripolymer guy. USA Insulation will use John Manville blown in the attic.
What do you guys think? Also there is some knob and tube and the USA guy says no need to be removed prior to installation.
Also there is no attic ventelation what so ever right now. Usa Insualtion plans to install 4 soffit vents (10″x5″ roughly) on each eave and 2 roof vents and I want to say he said turbine. Is that enough?
Let me know what you guys think.
edit” ok i got them smaller. sorry guys
Edited 9/27/2007 10:43 pm ET by qtsam2
Replies
I have no way of looking at photo files that large over my dial up, but here are a couple comments for what it is worth -
Ifg you are going to the rouble of opening thing up where you can spray a closed cell foam, it would be foolish not to get the wiring updated at the same time.
If you do decide to faom with K&T wiring, ask an electrician, not the insulator for the best answer.
As a general rule, closed cell is the very best spray foam insulatioin you can get for mnany reasons
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sorry about the pic sizes. i have reposted them all.
the walls are in excellent condition and I don't have the time or money to redo right now so they will not be opened up..... although ideally i would like to rewire and drywall.
oy! you gotta shrink the physical size and the bit-size of those pics if you want most of the guys here to look at them. Looks like a nice little old house though.
It looks like the K&T is only run on the floor in the attic? If that's the case then you are fine cause you are going to spray the underside of the roof with the closed cell foam right? No venting you want a hot roof. Look up buildingsciences.com lots of info there.
How's the condition of the roof btw? If if needs to be redone you should do that before you spray the insulation. Likewise if any of the framing needs to be fixed-reinforced-etc. If you don't the roofers are going to punch holes in it when they are re-roofing. The closed cell manf claim that by filling the bays with spray foam you double the racking strength of the wall-thats nice if its true.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
roof was put on in 2006. attic will be blown in johns manville climatepro
heres the resized pics
View Image
sobriety is the root cause of dementia.
thanks rez!
Very nice looking house. What year was it built?
thank you.
i think 1912, but not 100% sure. i have conflicting dates.
Yeah, I would have guessed a bit earlier than 1912 -- seems about 1902-1907 to me.
For what it's worth, I have used Icynene on several occasions and have it in my own house. We've been very pleased with it (it's been about six years, I think). They sprayed it directly on to the roof sheathing in the attic space (no need to vent, which is great). In some parts of the house, we pulled the lath and plaster and they were thus able to spray directly and shave off any excess. In other parts of the house, we cut access holes from the exterior (we were residing) and they were able to fill the stud bays.
In subsequent remodeling, I found that the approach of filling through holes did not always get 100% fill. It was good, but not perfect. Sometimes, a bit of debris could interfere with the flow and create a small dam. Also, be advised that if you pull off a wall finish, chunks of foam will come with it.
I have experience with Corbond, too, which also seems like an excellent product. We used that instead of icynene once on a permitted project where the required R value forced us to use a higher density foam.
this guy tells me that his product is different, does not stick at all. he sais it also does not cure hard, kinda spongy.
Are you talking about the "tripolymer" -- I'm not familiar with that, unfortunately. I'd have to read up on it.
Edit -- followed the link on your other post about USA Insulation. It's rather hard to find any specific information on the actual product they use. I'm watching a video now, and they say the R value is about 4.8 per inch. That's higher than Icynene, but lower than Corbond (which is about R7 per inch).
It seems like their standard approach is to use fiber wool in the attic and foam in the walls. Did they tell you why they wouldn't just spray the roof lid? We are very happy with that approach, since our attic space is now semi-conditioned. That is, the temperatures are not quite as controlled as in the house, but the attic never experiences the extreme heat of summer or the bitter cold of winter. It makes a much better environment for storing stuff.
Edited 9/29/2007 12:40 am ET by Ragnar17
he never did say why they do it that way, and i didn't know enough to ask. i will though. there is a website for the tripolymer
http://www.tripolymer.com
curious as far as pricing what was the going rate for your installs? my house is 28'x32' and 19' or so to the top plate and i was quoted $4200. that includes installing the 4 vents on the eaves and 2 roof vents. the icynene quote is $6373.00 and no venting installed
Honestly, I can't remember exactly how much the Icynene foam set us back. I think it was approximately $4000, and that was about six years ago. Our house is a 1-1/2 story with a footprint of about 24 x 40. When we last quoted Corbond (a polyurethane), the installed cost was approximately $1.00 per board foot. Icynene is typically a bit less, and is sometimes the best bang for your buck (of the foams) in terms of cost per R value.
Here's a website that you might find of interest:
http://www.foam-tech.com/products/urethane_foam/foam_properties.htm
I don't know if you're aware of this, but many materials have an R value that varies with temperature. Typically, the colder it is, the less R value they actually deliver. Fiberglass is, unfortunately, especially susceptible to this. From the website:
"Independent tests show that at 18 degrees F, with a 15 mph wind, the theoretical R-value of urethane foam drops from 19 to 18, while batt insulation drops from 19 to 7."
I'll check out the tripolymer site.
Edit: turns out I was actually at that site a few minutes ago. Seems like a great product, too, but the site is fairly short on specific information. Since the product seems to be a non-expanding liquid, it may not be possible to apply it to a roof lid. (Unless there was already sheetrock installed, for example, to form a closed volume. Then they could just fill from the ridge and let it flow on down.)
When you're reading up, keep in mind that neither the polyurethanes or Icynene are a formaldehyde product.
Let me know what the sales guy tells you about the roof lid issue. Also, it would be interesting to have them tell you (or calculate it yourself) what the installed cost per board foot is so that you could readily compare that cost to other foam products.
Edited 9/29/2007 1:48 am ET by Ragnar17
and at zero degrees with ta thirty MPH wind. FG batts are worth just about nothing!This tripollymer is new to me too. After perusing the site briefly, I am impressed with the fact thaat it ios fire resistant, non-toxic, and better R-value than the icy, but they do not answer a ccouple questions in my mind I would want to know before using it.One is whether it shrinks back over time. There was a stud space filling foam used in the eraly seventies that would shrink away from the studs and down from the top plate, leaving voids and creating problems.The other Q is whether it is a closed cell foam or not, and if it performs as a VB.
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according to their rep it is a closed cell, but i can't find it stated as such anywhere. he did say that it does slightly shrink..... how much though i am not sure. he stated to me that it is a vapor barrior. of course he is a sales man and we all know sales people don't lie or exaggerate! lol
I would want to see it written or substantiated, not just claimed. They had on one page a photo comparing their foam to ( maybe it was in your other thread from the install company) cellulose etc. In their own bragging photo I see shrinkage and gapping that makes me wonder. Corbond will continue to expand slightly to make sure it fills the smaller crevices and gapsAlso, one of the great advantages of a foam insulation is to get the infiltration locked out by doing the ceiling or roof and the sill and rim below. Their reliance on the blown attic causes me to ask why. Maybe it is hard or impossible to spray it overhead, or maybe they are comnpromising to make the overall cost less. This system seems intended more for retrofit in stud spaces and masonry than for open new construction. It pumps in more than spray on.IF it is related to those foams I saw from the seventies, it really smells bad after a few years too. I did not read their FAQs on odors or off-gassing. Check to see if it uses urea- formaldehyde or the less obtrusive form.
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yes i will ask for the writtten on that.
i asked the rep if i would need a fresh air exchanger because of how tight the house would be. he explained that because the foam slightly shrank that the house would still breath. i asked him about this causing condensation and rot (being that he claimed it is a vb) and he told me that again there would be some air flow to prevent this. in my limited understanding of building sciencei thought this was kinda contrary.
now as fars as odors and off gasing
Does Tripolymer contain any CFC's?
No. Tripolymer does not contain or use any chlorofluorocarbons in the manufacturing or foaming process.
What is Tripolymer?
Tripolymer foam insulation is a hybrid belonging to one of the oldest groups of synthetically produced thermosetting plastics. Phenolics, as they are referred to, were first synthesized in 1907 in the form of Bakelite. Today, phenolic plastics are well known for their durability, structural integrity, and extraordinary fire resistance. Phenolic plastics are used in electronics, automobiles, machine parts, fire-proof coatings, adhesives, tools, and thousands of other commercial and household items. When made into a foam insulation, phenolics are one of the safest and most efficient thermal and acoustical insulation products available.
Tripolymer¯ foam insulation was developed by C.P. Chemical Company, Inc. in 1966 for use as a fire resistant thermal and acoustical insulation product to be utilized in commercial and residential structures.
In 1975, Tripolymer¯ foam products and their characteristics were expanded and refined with the help of a grant, provided by the United States Department of Energy, under the Federal Non-Nuclear Energy Research and Development Act of 1974 (Public Law #93-577). Recognizing the inherent shortcomings of polyurethane and urea formaldehyde foams, the D.O.E. chose Tripolymer¯ as one of three products from a total of 7,000 to assist in further development. After three years of intense research and testing, Tripolymer¯ 105 greatly surpassed all of the D.O.E. and C.P. Chemical’s expectations, and was made available for commerce.
Unlike Polyurethane, which can be extremely flammable and emit large amounts of toxic gasses when burning, Tripolymer¯ will not drip or support combustion when subjected to fire, and the by-products of combustion are less toxic than those released from the burning of white pine, which is commonly used in residential home construction.
Tripolymer¯ 105, being composed of modified phenolic based methylene bound copolymers, is an extremely stable product. Unlike urea formaldehyde foam products, which have a tendency to decompose over time, samples of Tripolymer¯ foam installed under cement slabs for over 25 years show virtually no signs of damage from water, bacterial action, or mechanical stresses.
Tripolymer¯ Foam Insulation was specifically designed and formulated as a highly efficient thermal and acoustical cavity fill insulation. For 36 years, it has been specified and installed in more than 390 million square feet of new and existing commercial and residential construction.
Tripolymer¯, with its extreme fire resistance, has been used extensively in schools, hospitals, universities, and residential housing as insulation and soundproofing. Also, Tripolymer¯ has been used to increase the fire ratings of interior and separation walls where deficiencies exist.
When tested by independent laboratories (using the A.S.T.M. E-119 test criteria) with Tripolymer¯ installed in test walls, fire ratings were more than doubled in those wall systems. There is no other ‘foam in place’ insulation available that comes close to Tripolymer¯’s fire resistance qualities.
Being of unique and patented chemistry, Tripolymer¯ foam insulation differs greatly from cement and urea formaldehyde foams. Tripolymer¯ has a significantly higher activity index (solid content) than urea formaldehyde products, and does not wet or distort drywall systems as UF foams can during installation and drying. Tripolymer¯ foam is right at home when used in interior and / or exterior wood stud or steel frame wall systems.
That does sound fishy about it shrinking yet still functioning as a VB. Contradictory information in that answer!
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i just asked the rep for documentation, he says he will have to find some. he also says it is definately closed cell and he will show me a sample (how that is going to help no idea) and will get back with me on the literature. i found a tripolymer broucher and it states that it does not lose r value over time but it does state a shrink rate of .5%-1.5%
"he will show me a sample (how that is going to help no idea)"You can put it in water. Measure or mark the water by volume before and after soaking the stuff for an hour.if some water soaks into he foam, it is likely not closed cell
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i will post a link to their specifications. you would think that if it were indeed closed cell that they would advertise the fact. its a phenol based foam and my understanding is that the diy tiger foam is as well. and tiger foam is closed cell. i don't know if that is even relevant but...worst case scenario lets say it is not closed cell, it would still be better than fiberglass and cellulose right? priced over $2,000 less than the icyenene which is also an open cell product would it not still be a good investment? also with some of its other characteristics being considered? curious as to what you and others think.
Water Vapor Transmission
ASTM C-355
perms - in.
15.9 - 16.9
http://www.tripolymer.com/tripolymer/specifications/product_specifications.htm
OK then - the perm rating says it all!A rating of less than 1 perm defines a vapour bar..
Over ten and it is quite permeable to vapour transmissions.
Fifteen is only an air barrier.For comparrison, Typar has a perm rating about 13. It is DESIGNED to let vapour pass through it so moisture is not trapped behind it in the wall.http://www.bdcnetwork.com/article/CA6450462.htmlI still have no doubt that it would be better than FG batts, but question whether it will outperform chopped FG BIBBs system or denspak cellulose. those are rated about R3.5, but eliminate infiltration and convection loops in walls.
With this foam product shrinking, there is room for doubt how well it does that. It sounds very similar to those 1970s insualtion jobs where I saw a lot of shadow patterning on walls showing exactly where it had shrunk back and failed to stik to studs to seal things up.
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ok. i got the actual job scope now,
insulate exteriorwalls with foam at r5.1 per inch. band joist in basement insulated r-19 fiberglass batting cut and fitted between floor joists if accessible. usa to drill 5/8" hole in foundation and foam the seam ofthe brick on block/brick on tile or fill the block foundation to grade with usa foam insulation to r5.1 per inch if possible from the outside. usa will match mortar and patch hole. customer will not be charged for the insulation of foundation and band joist with walls & attic insulation, therfore no refund will be given if unable to insulate. using johns manville climate pro, insulate attic up to prescribed rvalue (r38) usa to install john manville batting around hatch dorr (if applicable) to ensure loose insulation doesn't fall out of attic. if applicable, usa will staple johns manville batting to back of the access door at no extra charge. any knee walls will be insulatedwith john manville comforttherm encapsulated r-13 batten insulation.
what do you all think now?
almost forgot
usa will install 8 12x8 inch soffit vents in overhang of home. usa will drill holes in soffit area and place vent over vent holes. also install 4 d/a roof vents
Edited 9/29/2007 10:28 pm ET by qtsam2
I think even less of it all now.First, because the faom sounds like les value than Corbond and other polyurethene foam, especially given shrinkage and lack of stickingSecond because there is some dopuble talk in those specs around whether they will foam the foundation or notThird because the batts at the rim joist will do nothing to control infiltration there - an important locationForth, because the attic wording is to blow insulation UP TO R-38. it should read "to a minimum of R38"
see the difference? TRhe way they have it worded, they might get it lofted up as much as R38 in one spot. The right woirding reads that there will be no place where the attic insulation is less than R-38
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I found this interesting, too:
http://www.monolithic.com/plan-design/rfairy/index.html
"R" Fairy TaleThe Myth of Insulation Values
"During the 1970s in Idaho's Snake River Valley, my firm insulated the walls of many new homes with 1.25 inches of spray-in-place polyurethane foam. In 1970, the popular number for the R-value of one inch of urethane foam was 9.09 per inch. Using this value, we were putting an R of 1.25 x 9.09 = 11.36 in the walls. This was much less than the R = 16 claimed by fiberglass insulators....
... I told him about insulating one of two nearly identical houses built side-by-side. We insulated the walls of one with 1.25 inches of urethane. Its near-twin was insulated with full, thick fiberglass batts by a reputable installer. Not only did we use just 1.25 inches of urethane as the total wall insulation, but we had the builder leave off the insulated sheathing. At the end of the first winter, the urethane insulated home had a heating bill half of its neighbors. Again, such evidence is not terribly scientific, but it is very real.....
One and a quarter inch of polyurethane sprayed properly in the wall of a house will prevent more heat loss than all the fiber insulation that can be crammed in the walls — even up to an eight-inch thickness."
Can someone copy and paste this article here for me? Nisson, J.D. Ned, JLC, Attic Insulation Problems In Cold Climates, March 1992, pp. 42-43 ... I have been reading up on the "convective loop issues with fiberglass insulation and every time I find a link to read this article is the source quoted for the facts given. I however have been unable to actually find the article itself. Interesting side note is that virtually every foam and radiant barrier manufacturer cite this article as the proof of their claims."Poor is not the person who has too little, but the person who craves more."...Seneca
http://www.google.com/url?sa=t&ct=res&cd=4&url=http%3A%2F%2Fwww.iowafoam.com%2FR-Value%2520Myth.doc&ei=H-X_RsL7CImSiwG7xKDpBg&usg=AFQjCNE4l-OCnOHkUQ59-btHFuXTSX0YIQ&sig2=fsCQjMQTrbLIZZc3tcAfnQ
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Piffin, Thank You . I will get to reading . Edit: Well that link brought me to the same article cited and reprinted on virtually every foam and radiant barrier manufacturers sites I have gone to . I have read that article word for word on probably 15 different sites. I still haven't been able to see the actual test or information on where and how the data was compiled. Just to remind other posters, I am not opposed to foam , nor a huge advocate of FG. I am just trying to find out where and how the test that everyone who sells foam and radiant barrier insulation cites with such authority was conducted and what were the actual results. I once was a Man. Rep for fire places and know from first hand experience that "Private Independent Testing Laboratories" are not automatically and necessarily non -biased. The manufacturer I sold for bought his own testing lab through a relative, tested his unit and got certification that no other lab would have given him . (Yes he had tried!) so please pardon me if I express some doubt as to the "facts" here."Poor is not the person who has too little, but the person who craves more."...Seneca
Edited 9/30/2007 2:19 pm by dovetail97128
A while back I found some testing reported DOE website showing the lost of R value in open attic FG insulation.Oak Ridge has some "whole assembly" test chambers. "I am also aware of the fact that foam insulation properly installed so that it is bonded to both an interior and exterior surface will have none. This applies only if the foam completely fills the cavity. I understand that is much easier to accomplish with foam than FG."It does not need to be bonded to both the exterior and interior.Air loops are not a problem in them self.It is when the loop between a mostly warm surface and most cold surface.Thus the problem with thermal windows with large gap.But say a 2x6 wall with 3.5" of foam would have almost exactly the same performance 2x4 wall with the same 3.4" of foam.With that much insulation the the tempature of the interior side of the foam would be almost the same as the exterior side of of the DW. So the convective drive would be very low. Even if the fan was used force a high level of air current it is still excahnging energy between two surfaces of almost the same temp so there is little energy transfer..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill , It could be that the test was conducted at Oak Ridge and that it was just made popular by Nissam. You are correct about the convective loop . Thanks for the clear picture. But in a sealed cavity then FG would be just as effective wouldn't it?"Poor is not the person who has too little, but the person who craves more."...Seneca
Edited 10/1/2007 12:35 am by dovetail97128
" But in a sealed cavity then FG would be just as effective wouldn't it?'But the FG bats is open from side to side, top to bottom. So will it does imped the flow somewhat it does not really stop it. There is no structure to it, just a number of random strands.OTOH open cell foam is number of tiny cavities with opening from one to the next. So the air flow path is so long and tortured that it effectively zero.I have not seen any test, but I would not be surprised that to find that chopped and dense packed FG (BIBS) does not have that problem. The short strands are packed tight enough that air flow is drastically reduced.Note, none of this has anythng to do with air flow from infilatration.But the same things in the insulation and not external that reduces infilatration would also reduce convective loss of insulation value with large tempature difference..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
BIll,
Maybe I am very wrong in my thinking (and it wouldn't be the first time) but I see a vast difference in the amount of air that will be moved by convection in a sealed stud cavity with properly installed FG and a claim that FG is no good because it is used as a furnace filter.I am just looking for the test results and parameters of said test . Yes, air does move through FG batts, but just how much when the only driving force is a convective loop? To me that is the question."Poor is not the person who has too little, but the person who craves more."...Seneca
" a claim that FG is no good because it is used as a furnace filter."I want it on the record that I never made that claim.It is a crazy statement that Frenchy likes to make.That comparison is like saying that mineral oil and gas both oil products. So instead of using mineral oil on my cutting board I can use gas..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill,
I apologize. I didn't mean to state or imply that you made the statement about the furnace filter/FG example. It is used often in the literature of the foam insulation manufacturers as a hype statement for their products."Poor is not the person who has too little, but the person who craves more."...Seneca
Edited 10/1/2007 9:28 pm by dovetail97128
I would strongly urge anyone interested in the whole issue of wall insulation to read this link that Bill posted.
I am going to re-post it . Interesting comparisons in Table 2. http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/Whole_Wall_Therm/index.html"Poor is not the person who has too little, but the person who craves more."...Seneca
Yes, air does move through FG batts, but just how much when the only driving force is a convective loop? To me that is the question.
A temperature gradient is a powerful thing in a fluid medium. Think of how a hot air balloon works. There's no pressurization -- just added heat to lift up several hundred pounds.
When you think of the almost neglible amount of heat required to lift a single air molecule, you can imagine how easy it is for the convection loop to start up.
Did you see the two message that I posted?.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Yes, and thanks for the additional research. But I haven't had time to follow the links yet.
First I want to Thank all of you guys for helping me with this issue. Piffin, I haven't had time to check my personal e-mail yet , came here first . But Thank you again for the extra effort on my behalf. I especially appreciate the partial excerpt from the article. Ragnar, I think Bill has the answers I have been seeking. Bill , Thank You , I feel a bit vindicated and that information you posted is in line with what I had thought the real issue was. Back in the early 70's I built according to the "Arkansas Framing Method".
This program recommended that the exterior wall studs be notched at the bottom for wires and that exterior wall electrical outlets etc be minimized to the extent possible. Every sole plate penetration was sealed with foam as was every notch thru the stud after the wiring was done, and the batt insulation had to be cut and carefully placed around the boxes.
I couldn't find an insulator who would do this so my crew and I insulated our houses. Quality control was therefore assured. No water or waste pipes were to be located in exterior walls if at all possible.
This left us many totally sealed stud cavities that could be correctly filled with batts. I have no problem at all with understanding the loss of R value in blown in insulation in a vented attic. Any good breeze will create a serious wind chill effect across the insulation. It was the claim about the wall cavities that amazed me. And again for the record , I do consider foam to be a superior method , but unfortunately not one that is in every budget. It is quite possible for me to say that I would do batts in the wall cavity (properly installed) and foam a "hot" or unvented roof in the future if I return to home building again. ( I actually may consider sealing my own attic space up and foaming it if heating bills get much higher!) Thanks again , I have once again learned a valuable bit of information here."Poor is not the person who has too little, but the person who craves more."...Seneca
ragnar17, piffin
so i tell the usa guy that i will probally not be using their product. he says to me that it is actually a closed cell foam on the outside but not the inside??? he says you can't really compare phenol based foams with urethane foams. (that may or may not be true) i said isn't tiger foam phenol based and itclearly states itis a closed cell foam, he of course is not familiar with that product.
so convection loops aside, how would you guys insulate my old house?
We have chased so many options I need to go back to start and read your options and requirements again. If cost is not the biggest issue, then Corbond or another polyurethane foam is best from ground level to peak.Failing that, the icy spray foam but I would use a VB with it.A compromise that some have suggested is spraying the polyfoam an inch thick or so, and then filling the rest of the space with FG.What I do for the economy minded is to have chopped FG BIBBs blown/packed, and then run Thermax foil faced polyisoanurate panels over the studs to break the thermal bridge and tape the seams.
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"he says you can't really compare phenol based foams with urethane foams. (that may or may not be true)"That is PURE BS.He can compare R values, He can compare aged R values, He can compare permability and why, in this application, one is better than the other and how affects the structure.Etc, Etc, ETc..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill, You know a little bit about sparks and wires and that kind of stuff.Did you catch the fact from first post in this thread that he has knob and tube wiring in his walls?
I have never dealt with that in conjunction with insulating and wonder if it needs replacement first with romex
The only time I have had anything to do with K&T was when we were in total gut mode and replacing it.I did get my forearms singed once on a circuit that was supposed to have been history!
;)
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I lost track. I though he said that it was in the attic and not being done at this time.Anyway the rule is that K&T not be insulated.But one state (Washington?) says if it is inspected and found in good condition then it can be insulated.AFAIK walls are the same as attics..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Well, that is another demerit for this USA company then. Their rep told this guy not to worry about the K&T
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But in a sealed cavity then FG would be just as effective wouldn't it?
Fiberglass is a very open weave; the air just goes through it. This categorically does not occur with a closed cell foam, and my understanding is that it is very limited with open cell foams.
Did you read that "R-value fairy tale" thing? I was pretty shocked by the author's experiences with insulating refrigerated buildings.
Ragnar,
Yes I did read it . I have read that same claim from the manufacturers of "radiant barrier insulation as well. I know that properly applied foam is a superior insulation, I just can't quite swallow the claim made about the the convective loop in a sealed ,FG insulated stud cavity is all. Just would like to read the test and it's parameters."Poor is not the person who has too little, but the person who craves more."...Seneca
I just can't quite swallow the claim made about the the convective loop in a sealed ,FG insulated stud cavity is all
Maybe I shouldn't have called off the tiger after all. ;)
You understand that the cavity being sealed has no bearing at all on eliminating convection cells, right? The convection cell requires no air flow in/out of the stud bay. So I'm assuming that the difficulty is in seeing how the air can move around within the fiberglass batt itself.
Maybe it will help with the visualization if you imagine things as they would appear under a microscope. What appears like a tight pack to our eyes is an open weave to air molecules. With the fiberglass, there's plenty of air space and air passages for movement to occur. It's not always a direct route, of course, but there's lots of space for the air molecules to get around, nonetheless.
"in a sealed cavity then FG would be just as effective wouldn't it?"NO, NO, NO, NO, NO!
Air will move through the FG fibres in a batt, so the loop exists there. With a foamed surface, the air has to move across the face of the foam, but the foam is a barrier to heat loss and there is nothing to accelerate the loop movement. With batts, the air just moves through the insulative material and the loop continues. Slowed, but still moving.
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NO, NO, NO, NO, NO!
Easy, tiger. ;)
http://www.cufca.ca/foam/R-Value%20Fairy%20Tale.pdf
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Piffin, Again that is the same article. I am looking for the tests and results that were the foundation for this article that is the source cited by all the other articles and reprints. Nisson, J.D. Ned, JLC, Attic Insulation Problems In Cold Climates, March 1992, pp. 42-43 ..."Poor is not the person who has too little, but the person who craves more."...Seneca
I see. I Knew I was posting same text in both word and PDFG formats as I found Googling the author's namebut I was under the impression that that was the text of said article. Gotta go back and check now.I have the older archived FHB, but not JLC, I think
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I do have the jlc CD from back then and found the article.Because of copywrite concerns, I will e-mail you rather than publishing copy here this site.E-mail me through here so I can reply directly
no attachments go through prospero For others interested, most of the material presented is similar or same as that in the texts linked above which I think are actually more extensive in content. The JLC article is limited more strictly to heat loss concerns only in attics.
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Edited 9/30/2007 2:46 pm ET by Piffin
Piffin, Thank You !! I sent my address."Poor is not the person who has too little, but the person who craves more."...Seneca
It is attached in reply and on the way as I type
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Piffin,
Haven't gotten it yet , but my local server often takes some time to process things. I have discovered why I thought I knew the name of the "tests" author. He is the author of: "The Super Insulated Home book" A man who also advocated the use of steel stud energy efficient homes, the use of a new batt insulation made up of some different plastic material and a few other items. Have perused 5 Pages on google and still no tests or results yet. I understand how wind can increase heat loss by moving air across the exterior surface of a building, and across the surface of insulation in a vented attic space. I cannot however get myself to believe the claims being made by the foam manufactures when they all cite just one test result.
Smells a bit more than fishy to me. "Poor is not the person who has too little, but the person who craves more."...Seneca
But they are not all from one source.if you will get a copy of the book, "Walls that work" you will see other references.
I believe there were a couple of footnotes to other work in what I sent you last night too.
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Piffin , Still no mail from you . My server often will block mail so I just have to wait and see if and when it shows up. In the mean time I will continue (as my time allows) to look for the source of the test. I appreciate your help in trying to send it to me."Poor is not the person who has too little, but the person who craves more."...Seneca
I sent last nite at 7:10PM as a reply to your message.I am re-sending now as a reply, then will try as a brand spanking new message instead of reply
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here is a brief quote from that JLC article where it mentions the background studies that originally confirmed this."There is a problem with loose-fill
fiberglass attic insulation in cold
climates. It appears that, as attic
temperature drops below a certain
point, air begins to circulate into
and within the insulation, forming
“convective loops” that increase
heat loss and decrease the effective
R-value. At very cold temperatures
(-20°F), the R-value may decrease
by up to 50%.
The problem was first documented
twelve years ago at the
University of Saskatoon in
Saskatchewan. Using infrared
thermography, researchers
observed hexagonal cold patterns
on the ceiling of a house insulated
with cubed loose-fill fiberglass.
They suspected that the cold
spots were caused by air circulation
within the insulation.
In 1982, researchers at the
Owens-Corning Fiberglas Research
Station in Granville, Ohio,
observed a measurable decrease in
R-value when a full-scale ceiling
assembly, insulated with loose-fill
fiberglass, was subjected to very
cold attic temperatures.
The most conclusive evidence
came last year from Oak Ridge
National Laboratory in Oak
Ridge, Tenn., and the Building
Research Center at the University
of Illinois.
Using their “Large-Scale Climactic
Simulator” (LSCS), which
can test full-scale attics, Oak
Ridge scientists measured the system
R-value of 6 inches of cubed
loose-fill fiberglass as the attic
temperature was lowered from
45°F to -38°F. The results, shown
in Table 1, indicate that the
effective R-value decreased progressively
as the attic air
temperature was lowered. At -
18°F, the measured R-value was
only 9.2, about half the measured
R-value at 45°F (R-17.8). Infrared
thermograms of the insulation
showed the same type of hexagonal
patterns that were observed in
Saskatoon — the footprint of air
convection in fibrous insulation.
Some researchers speculated
that the problem might be limited
to cubed-type insulation, but scientists
at the University of
Illinois observed very similar
behavior with tufted loose-fill
fiberglass. The problem seems to
occur with any low-density, loosefill
fibrous insulation.
Buoyant Forces Vs.
Fibrous Insulation
Air convection can theoretically
occur in any fibrous insulation
if the temperature difference
across the insulation is great
enough. Loose-fill attic insulation
works by trapping tiny pockets of
air. As the temperature difference
across the insulation increases
(attic air temperature drops), so
do the buoyant forces pushing
trapped warm air up and out of
the insulation. At some critical
temperature difference, these
buoyant forces overcome the
holding power of the insulation
fibers and convection begins
(Figure 2).
The specific attic temperature at
which convection begins depends
on the insulation thickness, permeability,
and density. In both the
Oak Ridge and University of Illinois
tests, convection occurred
whenever the temperature drop
across the attic insulation was
greater than about 38°F.
Frigid Region Problem Only"
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http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/92/920510.html"Convective Loss in Loose-Fill Attic Insulation
by David W. ConoverDavid W. Conover is an architect concerned with affordable housing, particularly with regard to energy conservation.
Yes, Virginia, there is convective loss through loose-fill fiber-glass attic insulation, and researchers at Oak Ridge National Laboratory have quantified it. They have also tested remedial measures-additional layering or "covers"- that reduce the losses.Commonly held assumptions about how insulation works are being refuted, and some long-standing mysteries solved by experiments at a new, large testing facility at Oak Ridge National Laboratory (ORNL). This article is a progress report of recent testing there of low- density, loose-fill fiber-glass attic insulation."...http://www.ornl.gov/sci/roofs+walls/tour/LSCS.htmlDetails of the LSCS..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Thanks.Of course it is not me that needs convincing.I think Dovetail is on the verge of a paradigm shiftlet us pray...;)
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Well hold on to that convincing stick.All of the references that I found was about LOW DENSITY LOOSE FILL FG in attics. And the report that I posted shows some improvements by covering the open surface of the FG reducing convective currents.And I had problem finding anything on walls, but kept common up with the R value of FG drops at cold temp without giving any references other than the test on low density attic fill.Finally found this.http://www.arkansasedc.com/energy/files/Clearinghouse/Thermal%20Shorts.pdfIt is; "How Thermal Shorts and Insulation Flaws Can Degrade an ôR-19ö Stud Wall to a Measly ôR-11ö"Copy and paste was so bad that I will rephrase it.They tested a wall assembly with poor installed bats with rounded corners and voild around wires. Now they did find a reduction in whole wall R values by those flaws.But then the specifically tested for convective looses caused by the rounded corners where it was placed in the stud bay. Tested at 100* inside and 20* outside. Very little affect.So they not only had the potential of the convection in the bats, but also the vertical air chambers where the bats where not fluffed up in the corners.So it appears that PART of the limitation of FG is has been overstated and is limited to open face, low density attic fill.However, FG bats still has the problems of getting it installed without void and that, by it'self, does not do anything to control infiltration or moisture movement that other insulation can help with.It is based on the Oak Ridge testing of full wall assemblies.http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/Whole_Wall_Therm/index.html.
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I am thinking the best way to test this in walls would be to attach a series of thermo-meteers at various points inside a wall surface in and outer to keep track of the loop activity with and without the FG batts
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Piffin ,
Got it ! Thanks again. One interesting aspect of this is the test results point mention that loose fill cellulose insulation is immune to the convection problem and as a matter of fact actually showed an INCREASE in R-value with the 20 deg. temp. differential. Fascinating reading so much to learn and keep up on."Poor is not the person who has too little, but the person who craves more."...Seneca
Yeah, I think that I pointed out earlier that cells and denspked FG BIBBS do not have the convection problem. Loose chopped FG in an attic can have it though, because it settles less when not packed.
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...worst case scenario lets say it is not closed cell, it would still be better than fiberglass and cellulose right?
Sure seems like it to me. But it would be wise to get some documentation on how the R-value varies with temperature. As I cited with the fiberglass example, loss of R-value at low temperature can be huge.
It's also somewhat concerning to me that the tripolymer shrinks. The airtight product achieved through expanding foams is one of their major selling points.
priced over $2,000 less than the icyenene which is also an open cell product would it not still be a good investment?
How much of this $2000 price difference is a result of the blown-in fiberglass being used in the attic INSTEAD of foam? Fiberglass is much less expensive than foam, and the attic is the part that needs the most volume.
As Piffin and I have both mentioned, spraying to the lid is also a major benefit of spray foams for a number of reasons.
i think this is how it responds in different temps, but honestly i don't really understand the data.
Thermal Conductivity (1)
ASTM C-177
R, Hr. - Ft.2 - °F/BTU
@ 75°F mean
4.6
@35°F mean
4.8
@0°F mean
5.0
From the chart you posted, it looks like the tripolymer insulation does not lose performance at low temperature -- which is good.
Did the Icynene quote include spraying foam in the attic? Were they going to spray it to the lid, or somehow put it between the ceiling joists?
Depending on the answer to the above questions, comparing the $4200 USA bid and the $6373 Icynene quote may not be apples to apples.
i think it does incude spraying the attic. the quote states
attic floor and vaulted ceilingsections, approx. 5" thick
if some water soaks into he foam, it is likely not closed cell
Piffin,
Just to help the discussion here, let me point out that Icynene (for example) is an open cell foam, but it is also described as being hydrophobic. If you put a chunk in water, it will just float and won't really absorb anything. I know because I've tried it myself. The installers also told me an interesting story where one of the local inspectors did the same thing during a presentation to see if the foam would absorb water -- it did not, and the inspector was satisfied.
From icynene.com:
Water Absorption Properties
Icynene¯ is hydrophobic and does not exhibit capillary properties. It does not wick and is water repellent.Water can be forced into the foam under pressure because it is open celled.Water will drain by gravity rather than travel horizontally or vertically through the foam. Upon drying, thermal performance is fully restored.
you know the perm. test ratings i posted are inaccurate. the atsm c-355 test does not even exist anymore. it has been replaced by astm e96.
not so sure now what they are even selling.
I think I saw mention that this product was first brought online in '66 so surely the ASTM standard test did exist at that time and they are carrying info forward with the product.
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Piffin wrote:
One is whether it shrinks back over time. There was a stud space filling foam used in the eraly seventies that would shrink away from the studs and down from the top plate, leaving voids and creating problems.
Could you be thinking of UFFI (Urea Formaldehyde Foam Insulation). My previous house had this and yes, there were gaps around the edges and plates.
Anyone have an answer to this? I am curious about this test result. """Independent tests show that at 18 degrees F, with a 15 mph wind, the theoretical R-value of urethane foam drops from 19 to 18, while batt insulation drops from 19 to 7.""" Just how does one get a 15mph. wind passing through a closed stud cavity? I mean I could see a bit of air leakage but 15mph.? and what volume of air?"Poor is not the person who has too little, but the person who craves more."...Seneca
There is a well reognized phenomenon referred to as a convection loop. It happens in twin-paned windows, in envelope house design, and in stud spaces.When the exterior surface of the wall is cold, the air inside that stud space loses heat energy by radiation and conduction to that exterior surface, and thence to the great outdoors. As that air is cooled in the space, it sinks to the bottom of the stud cavity.A similar exchange is also occouring at the interior surface. Inside heat is being transferred to the air in close contact with the SR or whatever interior surface of the wall there is. As that air is warmed, it rises in the stud cavity.This air movement - up on the inside and down at the outside - sets up a continuous current of air that transferrs energy to the exterior of the house. Slower than an open window, but it stil happens.Batts will slow down the movement of that air, but not come close to stopping it. The greater the wind and the greater the temperature differential, the faster the convection loop transferrs energy.Now FG batts are tested for R-value at a differential of ten degrees, if I reccall. Maybe it is 12 or 15 degrees.but for R-value when it is needed, it ought be tested at a diff of more like fourty degrees. Corbond has had this done by independent testing labs and that is where the info probably comes from as they have published it in their "Walls that Work" book and CE lectures.There is no convection loop in closed cell foam and almost none in open celled foam.
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The greater the wind and the greater the temperature differential, the faster the convection loop transferrs energy.
Your description of the mechanism behind convection loops is accurate. However, I think they're typically more fragile than you seem to suggest.
An increased temperature gradient will, in fact, increase the activity in the convection loop.
However, as wind speeds increase (and thereby increase pressure gradient and resultant air infiltration), I would suspect that the lateral passage of air through the wall cavity would greatly disrupt (or even eliminate) the convection loops.
I have a lot of experience with laboratory investigation of hydraulic flow phenomena. From this experience I can tell you that it doesn't take much to disrupt a circulation cell. What I can't tell you is whether qualitatively comparing air flow with water flow is accurate, however.
Good point but the injection of cold air, while it may interrupt a convection loop, cannot be good for any system of measurement of heat loss eityher.I do know that at the Walls that Work class, orbond pointed out a chart showing greater loss of resistance as wind speed increased, based on the testing
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Corbond pointed out a chart showing greater loss of resistance as wind speed increased, based on the testing
Another thing I don't know about these tests is whether air infiltration is tested and evaluated as an independent parameter.
Obviously, as the cold air is driven in, thermal performace suffers. From a testing perspective, the easiest thing would be to determine the overall heat loss and then just calculate a single R-value based on system performance. Maybe that's the gist of what the Corbond chart was saying.
Piffin, I am aware of the convection loop ( As a matter of fact one of the biggest reasons one does not see thermopane windows exceed an air gap of 5/8" is that 3/4 gap is the point at which convection loops really take hold and effect performance. This applies to reflective insulations or barriers as well). I am also aware of the fact that foam insulation properly installed so that it is bonded to both an interior and exterior surface will have none. This applies only if the foam completely fills the cavity. I understand that is much easier to accomplish with foam than FG. Fiber glass will however slow the convective current to almost nothing if it is properly installed in an empty (by this I mean a stud cavity that has no wires, plumbing etc in the same cavity).The biggest problem with FG is that it is impossible to completely fill any cavity that has wires, plumbing etc in it. I don't trust the test results done by anyone who markets a competitive method of insulation, what reason do they have to construct the test to maximize the performance of a competitive product? I am not knocking foam insulation, nor advocating FG. Just questioning the veracity supposed data.
"Poor is not the person who has too little, but the person who craves more."...Seneca
The testing was not doneby Corbond though. It was paid for by them but done at an independent lab.Ask the manufacturers of FG batts the same Q in reverse. Why do they only test R-value at a ten degree differential?Answer is because at greater gradients the R-value falls away.I also argue that FG batts will slow the loop to almost nothing. Yes, it will slow it, but not to almost nothing. I can put a hose to R11 FG and blow air right through it enough to move paper.
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Piffin, I do not know why the FG manufactures do not do testing on a comparative rate or scale as the foam manufactures. You may well be right, because they do not want to have the answer. And yes I also can blow air through the FG batts. But try it when the batt is sealed inside a stud cavity with 1/2" sheathing/air barrier/siding on one side and 1/2" drywall on the other. I suspect Even the Wolf would have died trying."Poor is not the person who has too little, but the person who craves more."...Seneca
" I suspect Even the Wolf would have died trying." Suspet all you wan5. The tests show the results. There IS a convetion loop in FG stuffed bays
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There's some interesting reading here, too, for those interested:
http://www.monolithic.com/foam/book/chapter_10/index.html
excerpt:
"Twenty-five years ago, Commonwealth Edison realized the sealing power of polyurethane and gave Gold Medallion approval to homes whose walls were insulated with one-half inch of polyurethane. Unfortunately since then, consumers, insulators and even code officials have given up on trying to measure the huge amount of heat lost through the walls of most homes. Instead, the magic “R-value” which is totally immaterial as a measurement of convected heat loss was adopted.
But wind blowing through a structure can negate any R-value. We can specify R-12, R-19, R-27 or even R-50 and that might make us feel good -- until the wind blows through the house; then we have nothing. Even twelve-inch-thick walls filled with fiberglass are a waste of money if wind can blow through those walls."
Dovetail,
The test conditions are simulating the effects of a 15mph wind. That means that there will be a pressure gradient that will result in some air passage through the wall system (depending on porosity), but it does NOT mean there's literally a 15mph wind blowing through the wall! ;)
he says it is because their product does not stick
I agree with the idea of insulating the under side of the roof and bingeing the antic into the heating envelope.
BTW have you heard of this: http://www.retrofoam.com/
OK, given those three, the cellulose would be the most economical if that is your concern.
I guess it has not been clear to me so far, but are you insulating walls with existing surfaces still on or gutting things?
The wiring should be checked and opinion offered by an electrician first.
Bill Hartman is responding here and he may be able to comment on that
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well as far as the money goes.... i want the best but i can only afford the middle of the road at this point. i do want to demo the lathe and plaster but theres no way i would have the time or could afford to that, and re-wire, and insulate.
what was intially appealing about the usa stuff was the guy says you don't have to rewire with his product ( your right i should have consulted with an electrician first) and that you can fish wires through it later on if need be. so it was like getting the best of both worlds or so it seemed. i could insulate now and then down the road rewire and demo the lathe and plaster.
so all thinks considered i will probally just do blown in cellulose at this point.
"you can fish wires through it later on if need be."That guy is so full of it!
I would prefer by far to help homeowners and contractors find common ground and understanding, but The more I hear of what has come out of his mouth, the more happy I am to steer you away from him. Cellulose is not my favorite insulation, but in your case, it sounds like just the ticket.
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Hi Piffin,What are your reservations about cellulose?Steve
partly personal.
I have done a lot of remo work where it has previously been blown in. Breathe a little or wear some of it home and you know what there is to dislike.Also, it has been treated against fire spread, but I have seen the results of it burning three times in my life. I do not belief it to be fireproof and don't feel comfortable with ground up newspaper for insulation on that basis.Thirdly, if it ever gets wet, it will hold that moisture more than any other insulation I know of. I've seen to many places where it contributes to mold. To be fair, there is usually some other problem with the house when the cellulose can get that wet to begin with, but it means that sometimes it is not always the best choice. Given a choice bnetwen Denspak cells or FG BIBBs, I will take the latter fo ran increase of about two cents and nearly the same R-value.
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I've done quite a bit of cellulose, and know the messiness and nastiness of it. I hate doing an attic on a hot day. I come out looking like a living lump of bat guano. But I like it's air sealing quality. Will blown fg air-seal as well as cells?Steve
not quite as tight in an attic fill but fine in a wall or closed cathedral
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Piffin,Does BIBBS need a vapor barrier? I've taken to not using poly and just calling the paint the vapor barrier, since it's acceptable practice, and I feel poly creates more problems than it solves. I'm comfortable with this method and cellulose. What do you use with BIBBS in the walls?What worries me about cellulose is the undetected leak and fostering of mold in such an instance. Though I've opened up several cellulose filled walls that were in in walls with no sheathing (claps only, like they liked to do in these parts 150 years ago) and in spots where I know it's not been water-tight, and the cellulose, while crusty, like dried out papier mache, was not damp or moldy.I'm very on the fence about cellulose in walls with no sheathing. I'm very comfortable with in in a properly detailed new wall where the windows are properly wrapped, panned and flashed.Steve
I forget the name of it, but my insulator guy has a mesh taht is a semi-VB. I guess you'd call it a vapor retarder. Will slow penetration by water vaopours but will still let it dry out if it gets damended. Good for moderate limates.When and whether and where to use a VB depends a lot on the climate and individual circumstances
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Well, I'm always working in relatively cold climates, with some degree of reversal in the summer. I don't worry much about vapor barriers anymore. If anything I try to not to create a vapor barrier on either side, so that things can dry out in either direction as conditions permit. I'm convinced diffusion is not a major moisture transfer mechanism, rather the main thing to worry about is the air barrier. I like DP cellulose for the monolithic air barrier it creates, but I don't like a lot of other things about it. It's messy, I hate having to go into a wall that has it. And I worry about unseen leaks making a mold nightmare.If I thought that blown in FG served as an adequate air barrier without the use of poly or some other failure-prone mechanism, I could embrace it wholeheartedly.I like spray foams a lot, but they are outside the budgets of many of my clients. Steve
Same here, the spray is the insulation of choice but we only use it on a third of the jobs - the ones where cost is no concern.
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