A Fork Stuck in the Road
or Doing the Wrong thing Right
It seems to me that most people in the USA are following the Foamy Path
How did we get here?
What can we do about it?
edit to add soundtrack
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Have a Green Day ;--)
John - Having been introduced to SPF insulation over 10 years ago and been a pretty strong proponent of it for most of the time since then, I have recently realized that we embraced it so thoroughly because it is a easy way to improve the performance of our buildings without working too hard. It allows us to design them poorly, place mechanical systems in the wrong place, and avoid the minute details of air sealing and proper installation that more traditional products require. That doesn't mean that there aren't bad SPF installations, there are plenty of those. But, in most cases a bad SPF job outperforms a bad fiberglass batt job by so much that we don't notice the difference. While I still recommend SPF insulation to most of my mainstream clients, I am taking a serious second look at it and will probably not use it on the house I am hoping to start construction on this year. A combination of concerns about toxicity, emissions, petroleum content, and a desire to do something different are leading me this way. I found it interesting at last year's NAHB Green Building Conference that many attendees who were fairly new to green building were excited and enamored with SPF while many of us who have been around the block a few times are reconsidering it in the context of whole building design. Most early adopters embraced it and some are now looking beyond it, while the next wave of green builders are still basking in the glow of SPF's high performance. It will be interesting to see where things are in another 5-10 years.
Do you have any hard evidence on the toxicity issue, especially in new construction.
It's certainly possible to build a very tight home without spray foam.
It's also possible to do air sealing work without spray foam, but it's a lot harder.
If you are doing air sealing work in the basements, crawl spaces, and attics of existing homes, spray foam is a very useful product. I'm not saying it's indispensable -- but performing air sealing work without spray foam is going to take longer and be more expensive than the way the work is done now.
How nice to hear that yet another GBA advisor is having second thoughts about petrochemical insulation. Too bad, though, that the "green" building movement still encourages it's widespread use.
Answered by William Swietlik - Dec 2 09
SPF Health Hazards
I am a member of the Federal Interagency Spray Polyurethane Foam (SPF) Workgroup and Co-Chair of the EPA SPF Workgroup. The mission of these federal groups is to ensure the knowledgable and safe use of SPF, a valuable insulating material.
Spray polyurethane foam (SPF) insulation, both open cell and closed cell, is made from diisocyanates (50% of the formulation), polyol oils, amine catalysts, flame retardants and blowing agents (the other half of the formulation). Dissocyanates are the leading cause of work place asthma and are a well-known sensitizing toxicant to humans.
Once an individual becomes sensitized to diisocyanates there may be no safe exposure level. Sensitization can occur from excessive and/or chronic respiratory and dermal exposures. Diisocyanates are odorless. The amine catalysts (which have an odor) and the blowing agents, can also have health impacts, but these are used in smaller quantities in the formulations. When installing SPF using high pressure and temperature spraying, unsafe levels of these chemicals are released into the air in the building or home.
This is why NIOSH and OSHA are recommending full personal protective equipment (PPE) including fresh air supplied hooded respirators for workers and helpers doing the installation. NIOSH, OSHA and EPA recommend that un-protected workers or occupants leave the building when spraying is being done and not return until all residual vapors are ventilated and all dust particles (from shaving the finished foam) are cleaned up to safe levels. The exact timing of this is not known for each specific building application as this depends on the amount of vapors and particles generated to begin with, the amount and type of ventilation, the size and configuration of the building, the foam curing factors and the installation and clean up techniques of the workers.
EPA, NISOH and OSHA consider this an area that needs further quantitative research. These chemicals can also migrate to other parts of the building, such as a floor where the foam was not sprayed. This is why NIOSH and OSHA are recommending containment and positive ventilation of the vapors out of a building when spraying is ongoing. Whether or not there remains off-gassing from the finished foam that was applied days or months earlier that could affect sensitive, or sensitized individuals who occupy the building, is also a question I believe requires further investigation.
EPA's current thinking is that once properly cured, ventilated and cleaned up, and enclosed behind wallboard or roofing materials, residual off-gassing at unsafe levels is not very likely. However, there are reports on the internet by some individuals that days, even months after installation of SPF they could still smell lingering odors from the material. I have personally inspected a large attic in a home that was sprayed with open cell foam on the underside of the roof (and left uncovered) weeks before I visited. Upon my entry into the attic, I could detect a distinct chemical odor. This was the same odor I sensed when I watched the real time spraying of closed cell foam in another house. Exactly what was causing this odor and whether or not it is unsafe, is another question I believe needs further research.
I think it will be hard to retrofit and repair without using "foam"
we could certailnly use a lot less foam... not-so-foamy
My focus is on New construction and which "Road" we should follow
I think we should allow the road to flow to the "Right Side'
Just look what is being held up as "the example"
Look at BSC and Building America
Toxicity of Spray Polyurethane Foam
- Wikipedia http://en.wikipedia.org/wiki/Building_insulation_materials:
All polyurethane foams are composed of petrochemicals. Foam insulation often uses hazardous chemicals with high human toxicity, such as isocyanates, benzene and toluene. The foaming agents no longer use ozone-depleting substances. Personal Protective Equipment is required for all people in the area being sprayed to eliminate exposure to isocyanates which constitute about 50% of the foam raw material.
- Wikipedia http://en.wikipedia.org/wiki/Polyurethane#Health_and_safety:
Fully reacted polyurethane polymer, CAS # 9009-54-5 (CAS registry number), is chemically inert. No exposure limits have been established by OSHA (Occupational Safety and Health Administration) or ACGIH (American Conference of Governmental Industrial Hygienists). It is not regulated by OSHA for carcinogenicity. Polyurethane polymer is a combustible solid and will ignite if exposed to an open flame. It begins to break down at about 240 °C (464 °F). Decomposition can produce isocyanates, carbon monoxide, nitrogen oxides, and hydrogen cyanide. Firefighters should wear self-contained breathing apparatus in enclosed areas. Polyurethane polymer dust can cause irritation to the eyes and lungs. Proper hygiene controls and personal protective equipment (PPE), such as gloves, dust masks, respirators, mechanical ventilation, and protective clothing and eye wear should be used.
Liquid resin blends and isocyanates may contain hazardous or regulated components. They should be handled in accordance with manufacturer recommendations found on product labels, and in MSDS (Material Safety Data Sheet) and product technical literature. Isocyanates are known skin and respiratory sensitizers, and proper engineering controls should be in place to prevent exposure to isocyanate liquid and vapor.
- OSHA http://www.osha.gov/SLTC/isocyanates/index.html:
Isocyanates are compounds containing the isocyanate group (-NCO). They react with compounds containing alcohol (hydroxyl) groups to produce polyurethane polymers, which are components of polyurethane foams, thermoplastic elastomers, spandex fibers, and polyurethane paints. Isocyanates are the raw materials that make up all polyurethane products. Jobs that may involve exposure to isocyanates include painting, foam-blowing, and the manufacture of many Polyurethane products, such as chemicals, polyurethane foam, insulation materials, surface coatings, car seats, furniture, foam mattresses, under-carpet padding, packaging materials, shoes, laminated fabrics, polyurethane rubber, and adhesives, and during the thermal degredation of polyurethane products. Health effects of isocyanate exposure include irritation of skin and mucous membranes, chest tightness, and difficult breathing. Isocyanates include compounds classified as potential human carcinogens and known to cause cancer in animals. The main effects of hazardous exposures are occupational asthma and other lung problems, as well as irritation of the eyes, nose, throat, and skin.
- Engineering And Construction Bulletin, US Army Corps of Engineers, 27 May 2010
Toxicity Clearance: Only SPF insulation and coating that has received a toxicity clearance from the U.S. Army Public Health Command (Provisional) (a.k.a. U.S. Army Center for Health Promotion and Prevention Medicine) will be used on Army tents and temporary structures. SPF will only be applied by qualified personnel, certified and trained by the SPF insulation manufacturer. Installers will avoid inhalation by equipping themselves with respirators in accordance with (IAW) the manufacturer’s requirements and recommendations, and IAW Occupational Safety and Health Administration (OSHA) standards for the SPF industry. Installers shall avoid skin and eye contact of the SPF chemicals by wearing appropriate protective clothing and eye protection IAW the manufacturer’s requirements and recommendations, and IAW OSHA standards for the SPF industry. The recommendations of the toxicity clearance listed for each approved foam/coating system will be strictly followed. They will include establishing no-entry work areas, erecting windbreaks if weather conditions warrant, and not allowing entry into work area until foam and coating is fully cured (typically four to six hours after application). New Army contracts will be contingent on the winning vendor providing the appropriate toxicity clearance documentation.
From EPA, OSHA, NIOSH, CPSC presentation:
Misleading Marketing Claims
• “No off-gassing”, “non-toxic”, “safe”
• “green” and “environmentally friendly”
• “is plant-based”, “made from soy beans”
Chemical Composition of SPF
• Side A – Isocyanates
o Methylene diphenyl diisocyanate (MDI)
o pMDI (50% MDI)
• Side B – Polyol Blend (variable/proprietary)
o Polyols (certain % biobased)
o Flame retardants
o Blowing agents
o Amine or metal catalysts
A + B = POLYURETHANE FOAM
Health Effects - Isocyanates (Side A)
• Isocyanates cause asthma and are the leading attributable cause of work-related asthma.
• Isocyanates are potent lung and skin sensitizers (allergens) and irritants.
• Isocyanates can trigger severe or fatal asthma attacks in sensitized persons at low levels.
• MDI is a hazardous air pollutant – Clean Air Act.
• NIOSH issued an Alert in 2006 to prevent MDI exposures for a similar spray application.
• The European Union has issued new regulations for consumer products containing MDI.
Potential Health Effects - Polyol Blend (Side B)
Proprietary Chemical Ingredients:
• Amines (catalysts) – sensitizers; irritants; can cause blurry vision (halo effect).
• Flame retardants – some are persistent, bioaccumulative, and toxic
• Blowing agents – global warming potential and other considerations
Two-Component: U.S. production reached 365 million lbs. in 2008.
Exposures – Spray Application
• Generates vapor, mist, and particulates exceeding exposure limits.
• Isocyanates & amines can migrate to other rooms or floors.
Exposures – Trimming Foam
• Cutting, scraping foam that is not fully cured generates dust, particles that may contain isocyanates.
Long term stability of polyurethane foam:
• Fully cured polyurethane foam is not considered a problem unless disturbed.
• Heating, welding, or grinding generates free isocyanates and other hazards.
• Fires and thermal degradation can generate and release hydrogen cyanide, carbon monoxide, amines, and isocyanates.
Many applicators, helpers, do-it-yourselfers, consumers, homeowners, and decision makers are unaware of the potential hazards. Some marketing information is misleading – focuses on “green” aspects and does not address potential hazards. Material Safety Data Sheets do not contain consistent health and safety information.
The SPF industry needs to ensure:
• There is clear hazard communication for all SPF users – applicators, helpers, do-it-yourselfers, consumers, and decision makers.
• Consumers are not usually familiar with MSDS and need clear hazard warnings.
• The work site is restricted to only those wearing appropriate personal protective equipment.
• Guidance is provided on re-entry time.
• Marketing claims are accurate and balanced.
We can/could Build
Affordable, Comfortable, Low Energy Homes
With very little or even NO FOAM
Thanks for Standing UP
I knew that you and Michael Chandler would come to your senses
I almost agree with your sentence
I would change "working too hard" to "THINKING too hard"
I don't think we will have to work any harder ...
We may have to think harder
Thank you for this post !
When You come to a fork in the road~~~ TAKE IT...
It's not easy but it's simple.
The more that is learned about potential ill effects that will be caused in the future, in one form or another by the growing use of "toxic foams", the more responsibility, we as builders, remodelers, advisors, and designers of any sort have placed on our shoulders. Like it or not. At this point there are no valad arguments of justification for the mass use and promotion of unknown danger to the health and well being of anything.
As was the case with the spread of the Plastic Shack syndrome, the real damage is yet to be seen.
Thank God that there are people regularly tending to this very important site with regard to these issues.
The real shame of this very serious issue is that , once again, greed driven profits trump health and well being. GBA is currently " Doing the dance" in the middle of the road for some reason. I guess as always, corporate money trumps goodness.
There are reasonable balances to consider that deserve more than equal time in this case.
The persuit of "easy" over health is way out of balance.
GBA has to be very cautious about taking a stand at this fork in the road, there are buisness risks
envolved. They, like most people are trying to be so cautious about taking risks that they never end up stepping out in faith. I believe that it's time to choose a healthy direction of advise to give, that will truely begin to make life more meaningful.
A site that seems to have respectable influence in "Green Building" should be leading the way, not stuck dancing on the fence or in the middle of the road.
If you're not living on the edge, then your taking up too much space.
I know this is very anecdotal but I’ve been using Icynene for a couple of years in my new homes here in Houston and have had no problems or negative feedback. My customers are ecstatic about low utility bills and claim they are (primarily electric for AC) are much lower than neighbors/friends. And I’ve gotten no complaints about off-gassing or toxicity. I know other builders here who have experienced the same as I have. I just sprayed a 9,500 sq ft home, I was in the house for a couple of hours immediately after the Icynene was sprayed and I experienced no noticeable sensitivity to the foam. I am interested in results from other builders who use this regularly in new home construction.
FYI, there were about 20,000 new homes built in Houston last year and I know of dozens of builders who use Icynene. My antenna is up for some of the negative side effects mentioned here but to date I haven't heard any from builders and homeowners actually using the product. Again, I'm talking new construction.
I am not-so-green
don't focus ONLY on the toxicity
There are many other downsides
I am a thrifty guy (Cheapskate)
It is the $ Performance Limits of Foam that first drove me away.
The test of time will only provide the demonstration that you seek. By then, the potential damage will or could be done. Real simple~ is there a risk of damage to health as a result of using these products in the future? Are these products dangerous to the humans that are doing the installation today? Are there potential points of failure that are associated with inproper mix or blend of these products? XXX Three strikes up front from my perspective XXX
Your un-educated clients disserve better Allan. They can afford to pay for it, why not provide it?
I’m a very pragmatic builder and I don’t have the luxury of contemplating every remote possibility from the hundreds of products I use. Your argument could be used for just about everything I use in a house. What about the tile roof I imported from Spain to use on my homes, maybe there is some Spanish fungus that is going to cause some harm. Or the reclaimed wood beams/timbers that were removed from some old tobacco farm and shipped here and used in someone’s kitchen.
Many architects here spec out Icynene and clients request it. One big reason it is popular here is we typically have 4-5 HVAC systems and duct work in our attics and Icynene allows us to encompass this in the building envelope. I research the material, I talk to many other builders and people in the trade, and based on positive response I use it. Until I get some tangible, substantial negative feedback from my clients or those actually using it, I will probably continue to use it.
Yes John it is expensive and of course that is always a factor.
Let your conscience be your guide Allan, I understand your delema. We are the net result of what we think about and do in our daily journey. The folks selling you their bill of goods know exactly what pitch to give. If you surround yourself with turkeys you'll never soar with eagles. No matter how much money or stuff you have.
How about a mud and straw pit to roll around in while the story "The Three Little Pigs" is being told?
One day Alice came to a fork in the road and saw a Cheshire cat in a tree.
"Which road do I take?" she asked.
"Where do you want to go?" was his response.
"I don't know," Alice answered.
"Then," said the cat, "it doesn't matter.”
I know, I know, I know,
I'm probably the only person invested in this site that has never used foam or plastic building products by design. ( by default, probably though)
Some would think that being un-educated is as easy as the choice to foam, It ain't.
Robert, now there's a story that I can relate to!
I'm not interested in "surrounding myself with turkeys or soaring with eagles", I am interested in building very high quality homes and having satisfied and happy clients who refer me to their friends. I've achieved that on a very high level.
Why do these threads always degenerate into personal swipes at people?
John, great thread. Thanks for sticking your neck out.
You did a great job summarizing where we are right now in the green building/foam world. Its funny I have traveled the same path - embraced it fully, did several homes in a row (that are all actually performing very well) and even though I have not really had any problems have found myself questioning the product and wondering if we are going to regret using this down the road. I do still use it when customer's request it or an architect specifies it, but try to educate everyone on the potential issues and make it clear that it is their decision to use it.
Funny though, now the "experts" have second thoughts about it, and those of us that actually pay attention and try to reseach our products and have a better understaning on building science than most, are actually dismissed as not being up to date on things when we bring up otential issues. If the masses are ignorant and anyone else questions the status quo it is easy to be written off as someone that does not understand. Running into some of this resistance now - would be nice if there were some better documented issues that have arisen recently.
The other issue we run into is there are many homes that actually perform very well with only 5" of foam in the roof for instance. Even though I try to educate my customers and tell them they need 8" to meet code - once again, they believe the foam salesman more than me and explain to me how 5" of foam actually outperforms R-30 fiberglass like I haven't heard that one before. Carl - I think our mild climate (I'm in NC) may actually allow the underinsulated houses to perform better than most other climates since we only have extremes a few times a year. May be harder for us to change the tide than in some other climates. I do think we have one of the more dangerours climates as well since our walls/roofs need to dry in different directions throughout the year. The fact it changes so much may actually help some poor conditions perform better than they should if that makes sense.
Great topic John.
Allan, I think it's just a sign of the times. Just put on your aligator skin.
Danny, tell me about it. I am respectable citizen turned cuckoo-clock. Aligator skin comes in handy.
The promotion of doing what is really the right thing is lacking, but known very well on this site. If your feathers get a little ruffled by the truth, I'm not sorry about that. I don't enjoy laying out the dump~ but less enjoy the promotion of potentially damaging building practices. Never have been a YES man.
I take the fact that some people choose to ignore the potential danger very personal. They seem to move along with blinders on while waiting for reports of peoples hair falling out to convince them that what is being done might just be wrong.
In terms of Green Building, I think the tendancy to make light of, or seek peace with the use of these products is irresponsible at best.
My brutally honest opinions can very easily be snuffed with documented facts that prove these products have health sustaining performance.
Just as you feel that my profound concerns about these foamy products lead to personal swipes, I would consider the support, use and profit achieved at a very high level, as a result of the use of these potentially dangerous products tragic swipes at the future. The highest quality home is the healthiest possible home for all whose hands will ever touch it. You have yet to attain that goal.
My statements are meant as intentional generators, degenerate is what occurs when successful interaction ceases to exist. Are there currently un-answered questions with regard to percieved health issues associated with the use of foamy building materials?
Besides the fact that much building science research is funded by the petrochemical industry so most studies are inherently biased, and besides the long litany of complaints in the "Out-gassing of bad stuff from spray foam insulation" thread, and besides the recognized short-term toxicity of these materials - we may never have PROOF of an immediate cause/effect relationship.
There's a reason that the best funded medical research - finding a "cure" for cancer - hasn't and will never find such a cure. And that's because cancer doesn't have a discreet cause. It is an epiphenomenon of modern civilization, and ironically it's a disease of affluence and consumption.
The more we pour artificial petrochemicals into our built and natural environments, the more our immune systems break down and the higher the incidence of chronic and degenerative disease.
It's not so much that any one product or material is unhealthy or toxic (though many clearly are), but rather that the entire way we build and the entire consumer culture is morbid.
But I'm happy to hear that Allan Edwards has made a lucrative business out of pushing petrochemicals to the obscenely affluent - it's one way to thin out the herd.
I won't say we need to build Passivhaus but I think the Euros are way ahead of us in terms of some of the materials they build with.
How many times have you posted something about the size of your homes.
Are you bragging? Perhaps you would like to tell us what type of car you drive. Or about the $65,000 Mastercraft ski boat you have parked on a slab in the back yard.
We get it- you build ridiculously large homes.
And [email protected]#$ it. Pump them full of spray foam. Waste your clients money. Be ignorant to non-foam air sealing strategies. Install HVAC in your attics. Have a ball.
There are "clues" about an affordable not-so-foamy strategy
in this recent paper.
And in this recent report
Interesting debate that as always of late divided all instead of uniting. With some exceptions, Carl's post could be my words exactly verbatim. We all have an interest in improving what we build. Foam has been a huge leap past fiberglass batts. Those of us like Allen know this as fact from building both ways over the last few decades. We old foam users like Carl and I are rethinking foam now. I am definitely interested in building fully green in the cellulose direction. Someone in Allen's city needs to lead the way there to a green strategy that is without foam. But it is Texas and it might not happen there over night since oil is ... well Texas.
I wish we could post with the intent to say our peace without the need to kill a 9 year old wonderful girl.
We need to learn how to like each other while we persuade us all to move thru this next century successfully as a world community.
There must be an alternate way for us to communicate other than spewing venom over the internet.
More useless noise from the closet lurker.... make your case for this post AJ. Carls words are Carls and Allan claims his. I hope that you understand mine, but if there is something that needs clarification, let me know. My resolve with you, whoever you are, is to achieve successful interaction.
I'm prepared to make the honest effort. Can you?
This is a lesson in being careful for what you wish for.
Much appreciated thread but it got so long so quick.
Will have to visit later to read all the entries.
"More useless noise from the closet lurker" One of my points is why would you post like this?
You don't want us to get along? I prefer getting along.
As to what Carl said. He said exactly what I would have posted. Why does my saying this get me in the dog house?
Why is this place so evil?
I am very willing to get along with all.
And how am I a lurker???????? I have been here longer than you and post good posts. I can show you if you look that I post prior to others and those that you repect post identically.
I build... I like the idea of sharing our ideas. I am here mostly to improve my own ideas and want all of us to do so.
The endless uncivilness is amazing. Let's be nice no?
Aj, The tone of killing a 9year old wonderful girl?
OK lets start fresh, My name is Roy Harmon and I care very much about the future potential harm that will come from greed driven building techniques that have not yet been proven to be safe,
whats your name?
Exactly my point Roy... People getting so into their being right and others not getting it that they spew venom and kill little girls.
I can be talked to politely. I can talk to you politely. That is what I desire all of this planet to do. I would like no more little girls to ever be shot again.
You think it's OK to get in people's faces here? Like calling me a lurker? Why would you think that I would appreciate your first sentence to me? You most likely wrote it to offend me and gain some approval for saying it from others here yes? no? Explain why you can't be nice?
Edit add... TTY tomorrow.... out for now... good luck.. I do understand you like green Roy... I do too and someday may even build a straw bale workshop.
My point is simple. Let's be polite. Let's debate... politely.
With regard to Green Advice, I would have to say that this issue is perhaps the single most important in need of address. It's not OK to be stuck at the fork with this one any more. Apathetic Green doesn't cut it. If some are offended by the drawing of a line in the sand, or making a stand , then please explain the flip side. You can't steer a parked car though.
Issues this important can no longer be debated with a gentle touch, to easy to run away from. Arguments based on unproven assumptions are pointless. Read the data provided early in this post regarding health and safety concerns yet to be addressed and explain why to me please.
Oh, I didn't quite catch your name in that last post, that's not very polite.
Roy,,, harping for a name is being impolite. having a name like "Dana" is not being impolite. Flaming someone is impolite. Harboring anger, attacking... etc.
I mention Dana as a name because anyone wanting to learn about homes should know him. Dana is someone who posts on many sites and is most likely the best most useful knowledgeable person on the internet bar none. His name? Dana. No last name, no difference than aj. None.
Go to JLC and Breaktime and try flaming some long time posters over there that go by names like aj or Dana or Andrew etc. You will be the impolite trouble maker. Not those that you attack my friend.
My name, is aj Roy. You know me as well as I know you. I can be polite and accept Roy as your name. What is it with this name issue? GBA sets the policy. Not Roy.
And I even started the improvement in the "name" box. Adding one's location as a last name... Some like this. It sure makes it handy to know where someone is located when talking moisture or insulation.
Sorry,... but two of the most informative names on building sites are not following the same philosophy of needing full driver license names (one is, one isn't.) Dana and Robert Riversong. One you like their name and one you don't but both are great sources of info.
One other example: one of the most knowledgeable posters on the JLC Web forum is Oberon, who is an insider in the glazing industry. For years, Oberon has been very generous sharing his detailed knowledge about glazing specifications and performance. I suspect he works for a major glass manufacturer or testing lab, but I don't know his real name.
I suspect that he prefers to use a screen name so that his employers don't criticize him or second-guess him concerning the technical information he provides.
Oberon is a great resource at JLC.
Martin & AJ,
you and Others are polluting this thread with an off-topic discussion about names
To the playground you should go
I'm sorry you feel polluted.
Am I the only one who doesn't know what you mean by the "playground"? Does that mean I am being banished for breaking John's rule?
I think we could build affordable high performance homes with paper, sticks, plywood, gypsum board and a little "gooey stuff" or gaskets in the right places.
If we want our homes to be affordable and not-so-tricky….
We should AVOID cathedral ceilings, conditioned attics and attic storage.
Brooks... this thread would be flameless if not for Brett and Roy. Martin and I are just trying to explain a few points because of the posts by Roy.
Reread the thread John. You are not the moderator here. I am amazed that you would actually tell Martin where he can and can not post. Amazing. Amazing.
Polite starts with each of us including you John. Let's post about Building Science and being polite for the entire week. Let's stop being impolite, all of us. Yes?
AJ, you must realize you are also part of the equation. If Roy or Brett were poking a stick at you then the polite thing to do is ignore them or take it somewhere else. Take the high road.
(No offense Roy and Brett. I don't want to insinuate either of you didn't have just cause. Just trying to make a point.)
Edited to include (bracketed portion).
John, I heartily agree.
I would love to hear more.
I would also like to hear if anyone has an opinion on why we don't consider more closely what the Europeans are doing with products like Pavatex.
Is it that we don't want to appear to be followers?
Is it that the foam companies are too well established in the market?
Is the "green building" movement on this continent partially responsible for devoting to much attention to foam details?
Yes, Pavatex or something like it should be considered before foam.
but even pavatex is more processed than plywood and may include unintended consequences.
You seem to be a big promoter of the questionable green building practices here. I can understand why your contributions, or any of the GBA Advisors would be intentionally kept to a minimum on this topic. You don't have a solid green argument that is without flaw.
These people that you compare with AJ most likely do not behave as AJ has proven to, ( the admitted use of various screen names with the intent to harrass). I have expressed clearly concerns related to this thread topic in hopes that someone with your expertise and knowledge would respond with sound ADVISE or suggestion.
I hardly consider contributing to the pollution that AJ has brought to this thread worthy. Sometimes perhaps nothing is better said.
I would like to request advise from the GBA advisors with regard to the health issues that have been brought to this thread.
AJ- If your contributions demonstrated enough worth to offset the strange stuff that you contribute, well maybe, just maybe you could sleeze by without using a real name. Don't use your lack of self confidence to drag good topics that need complete attention to the gutter.
I will continue to demand your name with no respect for ajbuilder.
Martin, If you have a question about the content or intent of my posting simply respond. I seek your advise. Avoiding this very important topic is no longer acceptible. The stuff is dangerous at many levels including some that are not even known yet. How can Green Building Advisor participate in the process of recommending such questionable practices?
GBA is a big Web site, still young, attempting to address green building issues. I think a fair reading of all of the material on GBA will show that this Web site promotes healthy buildings with healthy indoor air quality. We also promote practices that minimize the negative environmental consequences of construction.
I can't count the number of times I have advised people to use cellulose insulation, which is my favorite insulation by far. It has the lowest embodied energy, the lowest environmental impact, is affordable, and performs much better than fiberglass batts.
I'm an old backwoods hippie who moved to the wilderness in 1975. I cut down some spruce trees and peeled their bark and hewed my joists with a broad-ax and adze. I hauled stones from the river to build my basement walls and my two chimneys. I still heat with a $100 wood stove, and I've never used grid-powered electricity.
I find it strange that some people think I'm in the pocket of the petrochemical industry. I just isn't so. Goodness knows I've had DuPont so mad at me, their representatives were writing letters to my old boss to try to get me fired. Icynene wishes I didn't have a keyboard.
Anyway, we'll do our best to try to have more GBA articles on environmental consequences of our materials choices. I think Alex Wilson has done a great job with his articles showing the global-warming potential of the different types of foam insulation. We need more articles like that, and we'll do our best to publish them.
The AJ discussion has moved to the playground.
criminal, n. A person with predatory instincts who has not sufficient capital to form a corporation. - Howard Scott
One of the problems is that we live in a nation which - likely from its founding, probably from the days of the Robber Barons and certainly since the 1886 Supreme Court (non)decision that corporations are persons - has allowed regulations and codes to be written for the benefit of the corporations (if not written by the corporations as is much modern legislation).
The rock-ribbed conservative Republican residents of rural Pennsylvania discovered this when they fought the permitting of monstrous agribusiness hog farms and won the appeal only to discover that they had merely showed the corporations how to avoid the same mistakes for the next round. When the people finally understood that there was no beating the corporados at their own game, they instead passed the nation's first county ordinances banning corporate ownership of farms. A later attempt by the state to overrule these home-rule ordinances was overwhelmingly defeated when a cross-spectrum coalition of the people rose up against it.
But the corporate stranglehold on democracy will not abate until a whole sequence of court decisions is reversed or we pass a Constitutional Amendment outlawing corporate personhood. The worst of these Supreme Court decisions (all supported, by the way, by the ACLU) were Buckley v. Valeo  which ruled that political money is equivalent to speech, Kasky v. Nike, Inc. , in which the Court upheld a lower court decision that corporate free speech included the right to lie, and Citizens United [January 21, 2010] which opened the floodgates of corporate influence on political campaigns. Further, the ACLU [July 26, 2010] opposed passage of the Disclose Act, which would have at least required revealing the source of such unlimited political spending.
"…corporations have no consciences, no beliefs, no feelings, no thoughts, no desires. Corporations help structure and facilitate the activities of human beings, to be sure, and their “personhood” often serves as a useful legal fiction. But they are not themselves members of “We the People” by whom and for whom our Constitution was established."
- Justice Stevens, in his dissent to the January 21, 2010 Supreme Court ruling, in Citizens United v. Federal Election Commission, that corporations are persons entitled by the U.S. Constitution to buy elections and run our government.
"Thus corporations finally claimed the full rights enjoyed by individual citizens while being exempted from many of the responsibilities and liabilities of citizenship. Furthermore, in being guaranteed the same right to free speech as individual citizens, they achieved, in the words of Paul Hawken, 'precisely what the Bill of Rights was intended to prevent: domination of public thought and discourse.' The subsequent claim by corporations that they have the same right as any individual to influence the government in their own interest pits the individual citizen against the vast financial and communications resources of the corporation and mocks the constitutional intent that all citizens have an equal voice in the political debates surrounding important issues."
- David C. Korten, When Corporations Rule the World, 2001
It wasn't just Eisenhower who warned us against a corporate take-over of government.
"I see in the near future a crisis approaching that unnerves me and causes me to tremble for the safety of my country. As a result of the war, corporations have been enthroned and an era of corruption in high places will follow, and the money power of the country will endeavor to prolong its reign by working upon the prejudices of the people until all wealth is aggregated in a few hands and the Republic is destroyed. I feel at this moment more anxiety for the safety of my country than ever before, even in the midst of war. God grant that my suspicions may prove groundless."
- U.S. President Abraham Lincoln, Nov. 21, 1864 letter to Col. William F. Elkins
"They (corporations) cannot commit treason, nor be outlawed, nor excommunicated, for they have no souls."
- Lord Edward Coke
I hope we shall crush in its birth the aristocracy of our moneyed corporations, which dare already to challenge our government to a trial of strength and bid defiance to the laws of our country.
- Thomas Jefferson, letter to George Logan, November 12, 1816
"The end of democracy, and the defeat of the American Revolution will occur when government falls into the hands of the lending institutions and moneyed incorporations."
- Thomas Jefferson
Unless you become more watchful in your States and check this spirit of monopoly and thirst for exclusive privileges, you will in the end find that the most important powers of Government have been given or bartered away, and the control of your dearest interests have been passed into the hands of these corporations.
- Andrew Jackson, farewell address, March 4, 1837
"Fascism is on the march today in America. Millionaires are marching to the tune. It will come in this country unless a strong defense is set up by all liberal and progressive forces... A clique of U.S. industrialists is hell-bent to bring a fascist state to supplant our democratic government, and is working closely with the fascist regime in Germany and Italy. Aboard ship a prominent executive of one of America's largest financial corporations told me point blank that if the progressive trend of the Roosevelt administration continued, he would be ready to take definite action to bring fascism to America."
- former U.S. ambassador to Germany William Dodd in 1938
Big money and big business, corporations and commerce, are again the undisputed overlords of politics and government. The White House, the Congress and, increasingly, the judiciary, reflect their interests. We appear to have a government run by remote control from the U.S. Chamber of Commerce, the National Association of Manufacturers and the American Petroleum Institute. To hell with everyone else.
- Bill Moyers, PBS Commentator
Importing anything from Europe is definately heavy with "unforseen consequences".
A more locally produced "Pavatex" could divert a waste stream - like some rock-wool insulations do.
One thing about wood insulation is a contribution towards carbon sequestration.
Thank you for the responce, I look forward to the addition of more fairly balanced information being brought to this large and important Green Building web site. I truely hope that the genuine Hippie instincts will demonstrate a degree of prevelance over the corporate giant.
The health and well being of those without knowledge of these issues should be placed first and formost with regard to all so called Green discussions.
The responsibilities are personal and in no way corporate with regard to the things created through our writings.
Thanks to RRiversong for his substantive posts on the chemistry of the spray foam and associated information about impacts on human health.
This information only starts to uncover the environmental impacts of the production of this building material.
WORKER SAFETY, CONSUMER PROTECTION, and HUMAN HEALTH are very important issues and overlap GREEN issues.
GREEN as I interpret the word is borrowed from the use of the term in the GREEN political movement originating in Europe in the early seventies. GREEN indicates an inclusion of the importance of non-human elements in our world. GREEN means respecting, preserving, protecting, and understanding biodiversity, the functioning of ecosystems, clean air, water etc. even when only for the sake of human centered interests.
As complicated as the information gets in RRiversong's earlier posts we still haven't investigated the impacts of:
- the discovery and development of these compounds in an industry of chemical engineering
- the impacts of sourcing the raw components
- the impacts of spray foam manufacturing
- the waste byproducts of creating the spray foam formulations
How many production plants are there? What are there impacts on their local environments? How much of this stuff or its byproducts are introduced into the environment? Impacts due to the eventual landfilling of some of the product or inadvertant combustion?
One aspect that I didn't see commented on is the global warming potential (GWP) difference between the different spray foam and rigid insulation products on the market. Alex Wilson points out (in a buildinggreen.com article that I can't find a link to at this moment) that XPS and High Density Spray Foam both use hydrofluorocarbons (HFCs) as blowing agents and these have a significantly high contribution to greenhouse gasses. If I recall correctly the use of HFCs is scheduled to be phased out by a certain date. Open Cell Foams like Icynene use water at the blowing agent. However the lower R-values for open cell foams make dense pac cellulose a superior choice for new construction applications.
Locally invented, replacement for fossil foam... mushroom foam is being developed. Google it.
J, just an FYI, Icynene makes an R 5.2 water blown product now besides the one we all know about.
Just sayin, not recommending it.
Thanks for the FYI. Learn something new here all the time.
It's not a foam. It's just mycelium. But when manufactured (grown) into SIPS, the real issue will be what kind of boardstock is used. If it's the usual OSB, then it's only half a solution at best. I recommended to the inventors that they consider a hemp boardstock.
It' still made of the same toxic petrochemicals. From the Icynene MD-R-200 MSDS:
"Safe for occupancy after 24 hrs, no emissions detectable after 30 days."
30 days of emissions?
I predict like Robert is mentioning, that we will see a green Sheathing product along with a SIP made green this way.
There is a market for it.
Maybe this kind of info could be compiled and placed into it's own catagory on the site.
"The stuff is dangerous at many levels including some that are not even known yet. " - Roy Harmon
This has to be one of the most ignorant statements I've ever read. If it's "not known yet", how do you know? What an arrogant *&%!!!!!
So now there's a "pro" that knows what isn't known, and another who is a tax deadbeat, liberal nutcase. It's typical of liberals though - do as I say, not as I do. Taxes for thee, but not for me.
Oh good another 3rd grader
Playground or Tavern?
Seems like you had a tough day~ been spraying foam or something, watch out for the twitch that's yet to come.
Now please explain your reasons for assuming that petro chemicals have long term safe effects, or go sit on a tack. err... tax
Liberals? So what are you a conservative?
Great, lets turn this is to a talking points political discussion. We can break out all the overused, blanketing, stereotype, cliche, unoriginal insults and labels...
I'll start. Conservatives are greedy. Republicans are right-winged religious nuts. Tea Baggers are uneducated racists with the collective IQ of a ten year old. Republicans don't know their elbow from eyebrow when it comes to climate change.
I'll keep going...
Or perhaps we should leave politics out of this discussion.
Or perhaps we could meet in the tavern or playground, where you can call me a liberal hippy, and I can call you a Neanderthal.
I'm not in the spray foam business, so I have no dog in that fight. I will concede that there may be additional dangers from the use of spray foams, in fact, I'll go further and say that there probably are. LIke many things, it often takes years of use, unfortunately, before the problems with a product are fully known. But that is far different from saying "The stuff is dangerous at many levels including some that are not even known yet."
How does Roy know that it is dangerous in ways that are NOT KNOWN YET? It is a non-sensical statement.
Thank you for acknowledging precisely what we've all been saying on this thread. In fact, there was little difference between your last statement and Roy's, except his was more accurate. Yours suggests that, at some point of sufficient experience with a product, all problems will be known. Roy's suggested that we can never know all the repercussions.
So the only response here that's been clearly "ignorant" and "arrogant" was your gratuitous attack on liberalism, which was the founding philosophy of America. Jefferson, Madison and Franklin were liberals and George Washington called himself so.
At that time "conservatism" meant an allegiance to monarchy. Today, authentic conservatism is an allegiance to our founding principles of liberalism, and the so-called neo-conservatives are those who support economic aristocracy (which is our current politico-economic state, though more accurately described as fascism or corporatocracy).
Concerning Affordable Comfort
I think a big obstacle is the Architecture.
Most strategies for high performing homes include vaulted ceilings, conditioned attics and other features that demand Expensive Foam Solutions.
I think Carl Seville's new house "shape" could achieve Not-So-Costly Comfort
Stick a Fork in it
Nice comparison on the fork meter.
OK OK, I made a "non sensensical statement" in a post to Martin. I surrender. Sometimes the very real concern for long term effects of petrochemicals ( both human health and otherwise) causes a passionate plea for accuracy in the advise being promoted to the un-educated by this and other similar sites. I believe that there are so many potential points of what could turn out to be dangerous failure with petrochemical products already proven, that the future will reveal additional issues. The stuff is dangerous because of this and at the very least an un-educated consumer should be presented fair and balanced information that puts potential danger at the for front.
The use of petrochemical products in the human living environment is not natural.
These chemical products have demonstrated points of failure that cause negative health issues.
The full impact of these negative health issues have yet to be seen because there is currently no way to regulate critical installation quality.
There very well may be un -known health risks in the future associated with the exceeding use of these products.
In my opinion petrochemical products should not be in any way associated with the discription of Green Building but the power of corporate influence tends to corrupt most good things through greed. FACT
This GBA advise web site is todays example of what that power is capible of.
I asked the question, "what the hell is Green Building " yesterday and recieved no responce.
Could it be that there is a Corporate Green that makes it's own rules up as it goes along, focusing more on sales and marketing strategies that decieve the public?
Could the Green movement really be the Corporate scam that it's turning out to be?
Why would this web site promote the use of anything that has proven to be even potentially dangerous when they know that there are safer, thereby better ways of building Green?
Why William Randall?
What the hell is green building anyway?
I like the look of Carl's house design, what are the features for reasonable comfort?
One continuous flat ceiling combined with goo-as-you-go ADA
Mechanical can go below the ceiling pressure plane and there is room for not-so-costly insulation galore above the ceiling.
The walls can be thermally broken framing with dense-pack-cellulose.
Illustration from recent John Straube paper
But what are those dormer-like things protruding from the roof? And there is a "bump-out" on the right which seems to be supported on brackets that cantilever out through the foundation - thermal bridge?
If you're going to design a cubic house, then KISS.
Unfortunately, it's not that simple. Of course "maximizing profit" is the legally-mandated responsibility of any for-profit corporation, and that helps explain why anything that can be cleverly marketed will create its own demand.
But there is also a widespread and largely unquestioned cultural mythology around "better living through chemistry" or through technology in general. And even well-intentioned designers and builders are subject to the prevailing mythos of the culture.
As several have noted, spray foam might cost more but it also saves time and effort and gets the job done quicker (maybe). So it's as much about perceived efficiencies as it is about technical wizardry and corporate marketing.
And we're witnessing here at GBA a number of conscientious designers and builders who swallowed the foam pill now questioning its appropriateness in "green" building.
We've had a number of discussions of this topic. My answer is complex and nuanced, but the gist of it is this:
Green means modeled after the green, living earth which uses only the available daily solar energy for all it's needs and produces no material that does not become food for the next generation. And it means a system which maintains the delicate balance we call the Web-of-Life, taking no more than it gives and leaving a flourishing environment behind.
Unfortunately, this definition allows no human culture more "advanced" than hunter-gatherer or simple horticulture. It's easy to argue that the history of civilization has been the history of the browning of the earth. The very first textual history of Western civilization was the Epic of Gilgamesh which described the deforestation of the cedars of Lebanon (abode of the gods) in order to build temples, palaces, and warships. The rest, as they say, is history.
I noticed the cantilevered bay/thermal bridge also.
to me the best feature is the flat ceiling plane
I am not sure what the ground temperature is for Carl's climate.
If it is similar to Dallas.... why not slab on grade?
Carl Seville's home is a historic four square that he is renovating.
I agree it is a handsome building but it also represents a design approach that did not consider the a structure as a thermal envelope.
The fenestration for this building is not based on the logic for solar heat gains/ heat loss.
It is not possible to ventilate the hip roof properly and likely one of Carl's biggest thermal compromises in his retrofit is the wall/ roof intersection.
Architecture today is a significant enabler not obstacle for thermal envelope improvements. Designing with energy modeling software that accounts for passive solar gains informs the designer (and client) how the house should be in order to meet performance goals.
Concerning 'affordable' I think our culture is too tied to the idea everyone has the right to own their own house. Affordability can be at the compromise of energy performance. If reduction in energy use is considered to be for the greater good of society than that begs the question what are minimal performance goals that need to be achieved. If affordability falls below this than maybe we should consider a unit within a multi-housing complex or "subsidized" housing.
I think 'green' architects hear this a lot "I have a $150,000 -- $200,000 budget how green of a house can I get?". Unless they are a rural Riversongesque lifestyle type maybe the answer is "not a single family abode."
Given the obvious gamble that home ownership is today (and the fractured myth of a house as an investment for anyone but the bankers), it's likely that more people will consider rental units. But energy efficiency and affordability are in no way contradictory - unless we start from the unsupportable assumption that every family needs a 2500 SF house.
It was just a couple generations ago that the American dream was a 1200 SF 3-bedroom, 1 bath house with a short driveway for off-street parking and a big enough back yard for a swing set - and even that is bigger than most small families need.
Did you say a "fork" or a "Ford" stuck in the road?
That side of the house gets NO windows and an 8' high picket fence.
I agree that Carl's house is not-so-small
It is not a renovation ... it is proposed new construction.
and there is no reason that the attic can not be ventilated.
or why he can not have a very good thermal envelope.
With this type of infill construction in older neighborhoods
the window orientation will not always be ideal.
Carl is also dealing with "other forces" that are not so different from many neighborhoods.
Homeowner's assoc and Heritage commissions...yada..yada
and neighbors from hell ;--)
"I believe that there are so many potential points of what could turn out to be dangerous failure with petrochemical products already proven, that the future will reveal additional issues. The stuff is dangerous because of this and at the very least an un-educated consumer should be presented fair and balanced information that puts potential danger at the for front.
The use of petrochemical products in the human living environment is not natural.
These chemical products have demonstrated points of failure that cause negative health issues.
The full impact of these negative health issues have yet to be seen because there is currently no way to regulate critical installation quality.
There very well may be un -known health risks in the future associated with the exceeding use of these products."
I don't disagree with any of this, and I have concerns about the use of petroleum products in building materials as well.
Oops. My mistake.
I recall reading Carl's blog and remembered it concerning 'historical' in one regard or another so I incorrectly recalled it being a historical renovation.
Yes I'm sure the neighborhood preservation codes dictated the glazing percentages in each orientation and how big the house was as well.
So to ventilate you would have continuous soffit vents and a number of vent hoods near the peak?
My comments on venting and insulating at the roof/wall intersection assumed the home was typical turn of the century framing (i.e. without energy heal).
I agree completely that the homes 100 years ago were quite adequate in size .
Whether a smaller abode is appropriately a single family home or other depends largely whether its an urban or rural context. The different contexts also speak to a different set of environmental impacts so a single 'performance minimum' wouldn't suffice.
I assume also that being able to build affordable in an urban and rural context has different sets of issues. Being in the city I default to thinking what is typical of my context.
Given the alleged value of urban land, the only affordable urban dwelling is a cardboard box under an overpass.
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Now thats what I'm talkin about! Not fond of the blue tape though...
Air barrier tape, Roy. Gotta keep the envelope tight.
OK, I'll buy that but how can I keep the Phosgene gas away?
With a custom sleeping bag, of course.
Speaking of forks in the road...
I was just reminded that one of the most brilliant writers of the last millennium, Daniel Quinn, author of the Ishmael books and winner of the Turner Tomorrow Fellowship for the single best piece of visionary fiction, teaches us in a Socratic way about the fork in the road that Homo Sapiens was faced with 5,000 years ago when some of us shifted from the tribal hunter-gatherer life that had sustained us for millions of years (the Leavers) to the hierarchical agricultural/civilized way of life that has brought us to ruin (Takers).
Quinn makes it clear that he doesn't believe there's any going back, but that we must rediscover at least one essential element of tribal living. He differentiates a community (those who live together) from a tribe (those who make a living together), and suggests that we need to gather again into tribes in a shared economy of mutual support. And the only two contemporary examples he could think of for tribal living were circus "families" and homeless encampments (though both were probably more authentically tribal in the 30's when hobo villages sprouted along the nation's railroad tracks).
So, tribal people, it's back to cardboard boxes under bridges - and sharing the day's gleanings from the detritus of modern "civilization".
Interesting, A few years back I did a project at 30th & M St. in Georgetown, DC. Georgetown Square, right on the C&O Canal. This was facade restoration so the days were spent outdoors. On the commute into DC I passed a sign that read, "Washington DC, were the homeless come to die" every day. About a block from the project there was an amazing camp that seemed to draw me in. The dynamics of this homeless incampment actually made me feel things that I would otherwise never experience. An instinctive, cautious, curiosity tempered by the feel of tribal brotherhood or something. I've never really tried to explain it, but that last post kind of nailed it. I payed a couple of the guys to keep the construction compound in order and we became friends. If it weren't for the friendship I don't think that I would have been welcome at all into the encampment. I viewed the opportunity to quietly observe and just be there as a gift. I was amazed by the survival innovation that had been created out of the basic need to survive. Most of these folks were very, very sharp and seemed to have formed or evolved into a culture of their own. Life did not consist of being governed
and laws were of no consequence. Call me crazy but there was a feeling of freedom there that I haven't quite felt since. Kind of a blend of the circus family meets primitive tribe. I'll have to write about this in detail for my grandson.
Anyhow Robert, thanks for sending me back toa glimpse of my past. I actually believe that the re-discovery is occuring in record numbers. Some of the shelters that I've seen would amaze you.
Foam has great value in these encampments as well. Nothing goes to waste.
O yea, I ordered myself one of those sleeping bags from Ebay...
Robert - Haven't been back to this post in a while, regarding your questions on my house
1 - The bump out is gone, except for the porches the house is a square box.
2 - The dormer things in the roof are vents that I am currently planning to install to exhaust the air from a whole house fan, probably the Tamarack model with the insulated cover on it.
3 - I stil have not decided on my structural and mechanical systems, they will depend on what sort of participation i get from various vendors and manufacturers. If I go with stick framing, i will use either cellulose or fiberglass insulation with, hopefully a mineral wool exterior insulation sheathing for the thermal break. I am leaning towards ductless mini-splits for the HVAC, ready to try something other than central HVAC and have more control over individual rooms. Hope to start construction this spring and will be writing regularly about the process.
To J Chestnut and John Brooks -
Glad you figured out that my house is new, not a renovation. The historic commission did not dictate the quantity of glazing on each face, but my design limitations implied the basic layout. Being in a mixed-warm humid climate (except for this week where we are totally iced in), I am very sensitive to excessive solar gain. All my west facing windows are covered by deep porches, as are first floor east windows. 2nd floor east windows will receive suncreens to cut down on solar gain. 2nd floor south windows have an adequate overhang, first floor do not, but I have a good stand of deciduous trees on the south property line that will help with the shading. I would love to do some renewables but between my historic district requirements, large trees on the south, and budget, they will not likely be part of the project. The house is, however in probably the most walkable community in Georgia and will house my office as well as my residence, so I believe that my overall impact will be significantly smaller from both a transportation and operation energy standpoint than many other "green"homes.
As to the size, It is about 2200 SF, 3 bedrooms, definitely not small, but by no means particularly large. Maybe I'm just compensating for living in a 700 SF 1 Bedroom house for the last 5 years, that also happens to be my office. It's getting a bit crowded with my blower door and two bicycles in the living room, my office in the breakfast room, and no place for my grown kids to stay when they visit. So back off and give me a break.
We have spent a lot of time discussing the spray fowm within the wall cavity. To have a not so foamy house we should also address the sheathing? I first started using rigid exterior foam upon realizing the importance of a thermal break but I have never been a fan of the low perm rating. In our climate (mixed/humid, 3A, NC) we have always been taught to let our wall dry in both directions. Seems like some of the experts that previously advised this have decided that if the wall is designed properly that it now ok to break this basic rule of thumb. I am curious to learn more about the mineral wool exterior sheathing (or any similar products) that Carl mentioned.
Seems to have some of the same benefits - R-Value, thermal break and potentially could be a greener product and will allow the wall to dry to the outside if necessary. I am assuming this is not structural and we would still need to install plywood/osb first.
Or let-in bracing or diagonal boards, where codes permit.
If semi-rigid mineral wool board would become more commonly available in the US, it would be a good alternative for foundation insulation and frame-wall thermal breaks. It has good R/inch of about 4, is fire-proof, insect and rodent resistant, sound proof, and it breathes.
It has about 3 times the embodied energy of cellulose but less than fiberglass or any other common insulation. It's often made from industrial waste product (slag) from steel mills - up to 84% recycled material. It typically uses a phenol-formaldehyde binder, but has very low off-gassing. I think it may be worth considering even for subslab insulation.
I hope you noticed that I pointed to your house as a good example
I did not call it too big,
but rather.... not-so-small.
If you are going to HOLD your construction methods and materials UP as an example for others to follow...
then I do have a problem with your reasoning.
Isn't this "HOW WE GOT HERE"
I am very glad that you noticed
I did not limit this "FORK" to SPRAY foam
Would it be possible to identify conclusions,if any that are resulting from this thread?
Are most people choosing the foamy path?
If so- why?
What are we doing about it?
It seems that many very important topics wither away before an analysis developes. I think that the GBA advisors, and their advisors probably do put their heads together regarding important topics, but I'm a little curious how a green direction is determined. Is that something that is left to the individual assumption or is there a common end goal to this green endeavour?
Fork it over...
Roy - maybe we just have a Spork in the road...
John - regarding my reasoning, there is no single correct answer to how to build a house. I have an opportunity to try some new products which will help my budget. If it was unlimited, then I would do exactly what I want, but, unfortunately, it isn't, so depending on what products become available to me, I will make appropriate decisions to get the best performing home I can. I will not include products just because companies provide them to me. I have several possible paths to take, and as decisions are made, they will imply those that follow. Lots of if/then statements in the process.
Good point Robert (#100 let in braces)
Was just looking at the Habitat house that John posted on another thread - looks like they have 2" of rigid foam on their exterior. I think they used plywood on their corners for their lateral stability. Probably 1/2" plywood plus 1.5" of foam on the corners to flush out with the 2" everywhere else. Pretty good idea.
Down here typically only do 1" of foam - wonder if we could do 1" of mineral wool sheathing in the field and on the corners use 1/2" plywood and 1/2" mineral wool sheathing.