Mineral wool insulations

What is being called Rock Wool there is probably what we call glass batting here.

Spun Silica, Borosilicate glass no additives IN the rock wool/glass batting. But most formulations use a resin to bind it all together, most commercial products use a phenol-formaldehyde resin according to their MSDS sheets. However this is inert and remains on the spun glass and has no effect on the house, I have seen formaldehyde concentration tracks on a couple of site where they measure exposure, and the levels rise as framing goes up (timber treatments) remain at that level as insulation is installed, jump as carpet is laid (cheap carpet nylon is glued with resin to keep it intact, use Wool carpet!) and decline slowly as excess is outgassed (New House Smell) until reaching negligible levels in a year or so.

I wouldn't worry about toxic ick on glass batting insulation which is packed away behind the wall.

(Note: blue underlined words have links attached...)

Hello Rhys,

I should have done my typical linking when I posted last so folks didn't get confused...

Mineral Wool (a.k.a. rock or stone wool) is nothing at all like the hideous and ineffective pink/yellow stuff (a.k.a. glass matting.)

Rock wool has been around for over 100 years, is a "repurposed" material from the human waste stream, comes in both board and blanket forms, can create a draft proof insulation as it does not have the issues with either loosing R value with humidity (or as the temperatures get colder like glass matting does), and by all accounts in toxicity and sustainability is superior to glass based insulation products and the industries behind them...

I can say about any "manufactured" and/or industry based material, it takes lots, and lots of research to wade through all the hyperbole, "bad" advertising, misinformation, and poor science that surrounds any product in the building industry that somebody is trying to make money off of. This alone can overwell many consumers and confuse them. It take hours and hours (years?) of reading to wade through all the different issues, and unless someone has some rather extensive architectural forensic work under their belt the information that is "just read" can often have little meaning...

I wouldn't worry about toxic ick on glass batting insulation which is packed away behind the wall.

Actually, this is something to perhaps not worry about per se, yet it isn't a "none issue" either, or something not to be aware of when building new or repairing old structures. There is outgassing of toxic formaldehyde by some of the "glass matt" products (et al.), they are more prone to "dusting" and fiber release and they are more prone to promote mold and fungus growth than other insulations. None of these issues begin to address how generally ineffective they are at actually insulating a structure. Among many "green building" (or natural building) professionals there is an adage that if is "smells like bad chemicals" it probably has "bad chemicals" and doesn't belong in the living space or its roof and wall diaphragm matrix. So where something outgases a little or a lot, it typically (if we can) should be avoided...

Regards,

j

So is a product like "Roxul" (1-5% formaldehyde) a good option or are there others with a less toxic binder?

Hi Kris A.

So is a product like "Roxul" (1-5% formaldehyde) a good option or are there others with a less toxic binder?

This is a wonderful question...and issue...with almost all "manufactured" building products of industry. I am not sure about the "1-5%" levels, but I will try to find that source of data. I know it to be much lower of the current products offered.

Phenol Formaldehydes seem to be in WAY TOO MANY building products!! As a professional builder, it is often the selection of lesser evils and/or understanding when it is an issue with a manufacture and when there is a manufacture that is conscious of this and actively either trying to mitigate the toxin or find safer binding agents. Manufacturers are working on alternatives, and it is expected that bio-based binding agents will be available very soon.

So for the safest (a relative and subjective term) form of either natural or sustainable insulations, is to go all natural. The next is to understand the "evils" one is dealing with. Mineral wool insulation, in my view, has three, but they are outweighed by positives...

1. Like any "fiber material," be it saw dust, hemp, sheep wool, glass wool, mineral wool, etc there is the risk of releasing "free particles" into the air when working with it. This can typically be controlled by wearing a proper dust mast of if hyper sensitive, an actual air mask. Even some potters have to do this from the cumulative effects of clay dust.

2. It can be more of a challenge to "fit" into spaces as it does not compress like other materials. This is more a "technic" issue than a draw back, but can create a learning curve for professional trying to stay competitive.

3. The toxins in manufacture and those that may linger after shipping...in this case Phenol Formaldehyde. These binders are a real issue for me, but the manufactures of mineral wool based insulation have actively listed to consumers like me, and architectural health care advocates to make efforts to change the process. The use of phenol formaldehyde or a urea-extended phenol formaldehyde binders have lessoned in the last decade and the concerns over formaldehyde's known human carcinogen risk is a large focus by these manufactures...On of the reasons I am more supportive of them than others (that lesser evil thing again.) The now are employing methods in processing that is driving off nearly all of the free formaldehyde in the material, so these toxic emissions found in other industry based insulation are greatly mitigated in mineral wool products, which have extremely low formaldehyde levels by compression. Some are only presenting with levels equal to what is found in background levels of most modern architecture...Not a big plus in my view, but steps in the correct direction, until the bio-base glues arrive...

Thanks again, for bringing up these details...

Regards,

j

NZ historically over the past few decades has use glass wool as the predominant insulative source, but there are also other products on the market and Wool is rapidly expanding it's market share these days.

One quick look, no big search, and three wool batting manufacturors show up,

http://www.terralana.co.nz/

http://www.naturalwoolproducts.co.nz/

http://www.ecoinsulation.co.nz/insulation-solutions/ecofleece/


Older NZ homes like my mothers on the farm which was built prior to the Murchison earthquake, (We don't know WHEN it was built, but do know it survived the quake in 1929, so it is older than that) used simple dead air space insulation. Wooden lapped weather boards outside, usually 4x2 framing giving a 4" deep dead air space, butted rough sawn interior walls with scrim tacked over and plaster applied (cheap) or wallpapered (posh houses). Old shepherds huts and miners shanties used many different methods, on sheep stations wool was plentiful and was often used as insulation, Quilted into old flattened wool bales and nailed to the interior of the huts.

Just to compare...no formaldehyde or VOC or fungi or mold or bacteria, or sheep , hygroscopic, drys fast, available locally at the big box store less shipping and embodied energy, recycleable: http://bondedlogic.com/pdf/denim-insulation/UltraTouch-Denim-Spec-Sheet.pdf

Hi Terry,

I was intrigued by many of the claims made by "cotton based insulation" manufactures. Please get some samples and try some empirical comparative testing. I have found many of the "claims" are greatly exaggerated about certain very important aspects such as"drying fast," which is no better than wool insulation, and does not have the fire resistance or moisture resistance of mineral wool.

Regards,

j

Lets talk about the legality of false manufacturing claims, ASTM testing standards, codes most have to adhere to. If you were to call ASTM they would tell you they do not enforce or validate by inspection their test procedures, periodic or single point. I have alot of experience doing this for my designs. We (myself as an Engineer, a "buyer or procurement agent" or contracts person that works with legal, and a Quality Control Engineer, would certify a manufacture as "production ready" to conform to a design, just to give you an idea of the complexity and cost of validating "manufacturing claims". Once approved if the manufactures changes the production process after approval, it is in our contract as a buyer the supplier has to notify us. We also contract in that we are permitted to perform spot checks. That is how you "Quality Control" a manufacture as a supplier for "Quality Assurance" which rarely happens in the home buying industry. It is up to the consumer to look at how the ASTM was third party quality controlled and I bet you do not find that level in most cases. I have check and did find a few. When shopping good to look for since you never know when these guys need to cut cost. Uncertainty comes with not having manufacturing control at the job site which most natural builders want, if possible, but control and assurance can come at a cost of having to test to the ASTMs yourself to satisfy codes and the fire Marshall and believe you me the first thing they will ask for are test if it is not in code. Your way out is to move to rural where codes are not enforced and you can not harm anyone else but yourself have at it but there is risk in that. Now the question becomes is it worth your R&D expense unless you plan on manufacturing to show a return on investment. Do this for all your products and your building could cost a fortune especially commercial where there is a higher level of concern for public safety.

The manufacture that lies, oh boy, and causes bodily harm especially in CA schools like Bonded Logic uses as an advertising ploy I feel sorry for when the attorney's get a hold of them. Depending on what state even entity protection (LLC, Corp) may not protect you when it comes to fires that killed children. I would think Borax and the Class 1 flame spread per ASTM E-84 is accurate or again I feel sorry for these guys. BTW: Make your own insulation and fail to perform the test, sell your home it kills someone who do they come after? Perhaps an Architect or GC that performed the insulation without the testing if your lucky, I doubt anyone is that dumb! I know we never do that we value our company and lively-hood too much

Jay does seem kind odd I can't find a perm rating anywhere. My new friend George Swanson author of Breathable Walls notes some test they did compared to FG back in 2009 before Roxul came over from Europe and it dried faster with the 48 hour time frame for mold germination. Not sure how it compares in drying speeds to Roxul. This product has no food for fungi and borax as a anti-fungi and fire resistant so, I do not see the issue even if drying did not occur that fast with regard to mold. The r-value would drop of course temporarily until drying occurred. Of course these perm and moisture content or up take test in a water pan and "controlled environment (pressure, temp, RH) are performed on the bench at a factory that can change depending on what a designer mates them too. That will by far determine drying speeds since some materials are more breathable a desorptive and able to pull moisture out of mating materials and assemblies. Magnesium board comes to mind, OSB low perm like ZIP sheathing or plastic barriers does not. Perhaps I'll get some of this cotton and run some test. A wall assembly designed to dry will allow heat-cool through the wall at slow radiant speeds to 'dry' vapor in a 48 hour window, without significant gain or loss of conditioned air, ACH .2-.3 ideally.

If you look at the data sheets of other locally available Roxul or Thermafiber it is made of iron slag I believe, not "mineral wool" or natural lava "rock wool". According to Roxul same CL 1 fire rating, due to the moisture vapor content of 29%, perm of 41, water absorption >1%, the surface can freeze and I have discussed this with them they agree. There is no vapor desorption rate listed that cannot be tested by touch or visual inspection. You need a psychrometer with a probe to take readings by % weigth (dry vs wet bulb) and rates over time not conducted in popular assemblies at different relative humidities, especially above 70% where increases are normally exponential and deporption rates can be different than absorption rates. If you look at the MSDS they fail to test alot of the "physical and chemical properties". I fail to see such testing on the other "natural wool" products. This product is non reactive or inert for the most part and should be fungi resistant too, however, it does react with hydrofloric acid found in some building products, it becomes very corrosive and harmful to health if it does. It also contains urea more emitting than phenol according to most data on the internet, but they fail to list the "free formaldehyde" that can contribute to IAQ of greater than 1 PPM which becomes a carcinogenic and health concern according to testing.

Looking at the data I'd feel safer with Bonded Logic than Roxul regardless if Roxul dries in 1 hour and BL in 2 since BL is less reactive to produce mold.

To be honest I have my own proprietary MGO mixes that are much better, just not sure I have the funding to get through the red tape building and safety laws. Seems like the better more natural products are not at the local stores and have to be shipped in that in itself is not "natural" nor does it support farmers and the local economy.

http://www.roxul.com/files/RX-NA_EN/pdf/MSDS%20and%20Safety%20Bulletin/Roxul%20Material%20Safety%20Data%20Sheet%2002-13-14.pdf

Hi Terry, et al

Great post! I think others should read your post above and really do their own limited examination of materials then "ask others" for feedback on observations they make like know I and you probably do all the time. You made wonderful points! I am just going to hit on some critical elements for readers that may not want to read your entire post (which they should...if interested in this topic.)

Terry Ruth wrote:....That is how you "Quality Control" a manufacture as a supplier for "Quality Assurance" which rarely happens in the home buying industry. It is up to the consumer to look at how the ASTM was third party quality controlled and I bet you do not find that level in most cases.

I am guessing that 80% (conservatively) read labels on most products from food and medicine to garden and building supplies and take it at "face value." I hear/read it from folks all the time..."but the label said...."

Ambiguity, obfuscation, and surreptitious misdirects are the way of "advertising" and to a degree that the average consumer just does not realize. Many manufacturers (like the chemical and pharmacological industries) actually set a high percentage of "gross profit" aside for..."penalties, fines and legalities"...as it is easier to "payoff" for a fine or death/accident than to actually produce products to specifications of good science and common sense. A single branch office of a major Pest Control company that I was the state supervisor for in Connecticut back in the late 80's budgeted $250/quarter (a million dollars a year) for "fines and legal challenges" as it was more profitable and cost efficient to pay fines for violation of state environmental and health laws than it was to..."do the right thing." This is the primary reason I completely left the industry and find it one of the most insidious...(only a wee bit ahead of the "building trades.")

Terry Ruth wrote:The r-value would drop of course temporarily until drying occurred. Of course these perm and moisture content or up take test in a water pan and "controlled environment (pressure, temp, RH) are performed on the bench at a factory that can change depending on what a designer mates them too. That will by far determine drying speeds since some materials are more breathable a desorptive and able to pull moisture out of mating materials and assemblies. Magnesium board comes to mind, OSB low perm like ZIP sheathing or plastic barriers does not. Perhaps I'll get some of this cotton and run some test. A wall assembly designed to dry will allow heat-cool through the wall at slow radiant speeds to 'dry' vapor in a 48 hour window, without significant gain or loss of conditioned air, ACH .2-.3 ideally.

Terry, I don't believe most readers understand the extreme value there is in doing their own (or following the work of folks like you and George) when even simple "backyard" testing is done. All I did with some of these "traditional modalities" and applicable manufactured insulations was some simple "back yard" test and the results where extremely enlightening. Two rather easy ones that can be done follow a very simplistic examinations and no complicate equipment other that the observers own 'inherent senses.'.

1. Take a set volume of material (e.g. 200mm x 200mm x 100mm and/or product standard shape.)

2. Take a container that can hold sufficient water to allow complete immersion of the sample.

3. Weight the sample down in the water for 1 hour, 5 hours, and 24 hours. Then simply note the amount of moisture that is absorbed by touch and visual inspection.

4. Record how long it takes to dry...again by visual inspection. This will give a great deal of empirical knowledge to character and moisture reaction states.

The next is more involved and requires more time and a bit more investment, yet is not beyond the scope of an avid builder/investigator...

1. Build a 400mmx400mmx?? "mock wall section" for a give modality of design in a frame.

2. Attache this wall section to a box that can be hermetically seal well enough to trap an simi pressured atmosphere. I used either fish tanks or boxes built of plywood and sealed all seams.

3. Place an electric burner inside the box with a set metric measure of water and boil this until gone. The volume of water should be large enough to allow for observable water vapor to come through the wall section for at least 3 minutes. Make sure that all "framed samples" are subjected to the same volumes of water and time parameters.

4. Observe how the walls, and there materials react, then do a forensic deconstruction...

There is a myriad of similar or modified version of the two very simple examples above that can render an incredible amount of information for the just the average observer to draw very clear conclusions about these different products. For example "cellulose" and "cotton batt" insulation do not react well...comparatively...to many other insulation forms. Mineral wool and Straw Clay Slip are very impressive in my view and observation. As is many of the "kubbhus" systems of infill.

Terry Ruth wrote:If you look at the data sheets of other locally available Roxul or Thermafiber it is made of iron slag I believe, not "mineral wool" or natural lava "rock wool".

I could be mistaken here Terry, but as I understand it, the "orgin material" be it slag, or other mineral based byproduct only has a limited effect on final product characteristic and all are generically referenced as a "mineral wool." In other words, the "slag" or the "lava rock" going under this "wooling process" will yield very similar materials, as it was explained to me. The "base material" and the "wooling process" alternatively can be modified to affect different characteristics in density.

Terry Ruth wrote:It also contains urea more emitting than phenol according to most data on the internet, but they fail to list the "free formaldehyde" that can contribute to IAQ of greater than 1 PPM which becomes a carcinogenic and health concern according to testing.

I agree this is still worth noting and being aware of in a wall design. In the past more than today product "formaldehyde" has been a big concern with outgassing in these mineral bases wool insulations. The major manufactures (do to consumer and government pressure) has gone to great lengths to further mitigate this as I understand it and we may even see this year (or at least in the next few) natural organic based binders, there by replacing the formaldehydes. Even these manufacturers know the impact this can have on sales, yet "retooling" for such changes have been slow...

Looking at the data I'd feel safer with Bonded Logic than Roxul regardless if Roxul dries in 1 hour and BL in 2 since BL is less reactive to produce mold.

I suggest this is an area for individual consumer to perhaps do there own testing as suggested above...

I personally, in my findings with the Bonded Logic product (et al related cotton batt) in real world build applications to fail in the "big picture" intended function as an insulation when compared to Roxul board or batt type insulations. Especally if working in concert with something like "straw clay cobb" or other natural modalites. Bond Logic saturated with moisture and holds onto that moisture (hygroscopic nature) interstitially way more than I am comfortable with (as too does cellulose) in a wall matrix. So material like cotton and recycled new papers in real world wall and roof insulation applications do indeed present as highly hygroscopic, compared to mineral wools which present as more hydrophobic in nature comparatively. I hark back to the old adage in wilderness outdoor rules of thumb for garment choices..."cotton kills." Cotton or "paper" in a surface wall matrix treatment such as "cloth wall coverings" (or wool textile wall coverings) are a bit different and in these applications I believe would be excellent, just as are the "paper plasters."

I also relate it to concrete compared to cobb, where the first one will hold moisture in such a fashion that it saturates any wood or other building materials in such a way to facilitate and expedite decay/rot while the other (cobb) tends to "dry out" wood and other building materials around it...just like it does the potters hands that work it. The clay may be wet, but it does not "wet surfaces" around it...it acts like a very effective poultice. My limited experimentation with mineral wools working in concert with "light cobbs" have been very promising, and why I lean toward mineral wools (if using any manufacture insulation at all) over any other types currently offered on the market.

I do agree that MGO materials show a great deal of promise in the realm of manufacture (and safe) insulative materials and as soon as those are available and able to achieve the same R values / 30 mm as mineral wool board or batt, then there will be a distinct shift in this market. I watch MGOs all the time for new breakthroughs.

Regards,

j

I have been using Roxul as my primary insulation for over a decade. Because of that I haven't tried some of the newer products, but out of everything that I have tried, stonewool is the best by far. The comfort batts have a 1% cured urea phenolic formaldehyde binder that is completely dissipated in manufacturing. There is no odor and when you get it all over you, it doesn't itch.

Here is a Discovery channel video about the manufacturing process.

Hi Terry,

I was just reading your post more thoroughly and thought of the one mold situation that I have dissected involving stonewool insulation.

Since stonewool is highly permeable and has no vapor/air barrier, draughts must be stopped at the interior wall surface in cold climates. I was installing the solar heat and electricity, but nothing else; so I informed the GC that he needed at minimum to install a draught barrier behind the cedar T&G. He informed me that this is not necessary on the inside. We argued and he did it his way.

I was called out to install an extra outlet in one of the exterior walls about 2 months later. Everything looked fine until I removed a batt of insulation; the OSB was completely black where the moist interior air had traveled through the gaps and cracks to condense on the OSB, which since it is pre-chewed, is one of the best foods for mold.

It was very cold outside and like you said Terry, the insulation was frozen at the outside edge and actually had to be pulled from the OSB which it had become frozen to, but no mold whatsoever on the insulation.

This was one of those times when a little knowledge is dangerous. The builder was used to using kraft paper faced batts and the client liked stonewool, but neither understood the dynamics of a building in a cold climate.

Bill

Bill...thanks for sharing that anecdote...it is a classic and too common an occurrence...

I am constantly trapped between poor clients, and HVAC sales people and related contractors trying to sell something and get out as quick as they can. I would conservatively say that 80% of our "modern" architecture suffers varying degrees of degradation just as your story reflected. This pointless and foolish notion of building "submarine architecture" (a.k.a. "airtight") is going to take decades to completely reveal the folly of such a bad practice.

It is simply impossible to "seal" a structure from interstitial moisture movement. A number of years back I was privy to a small testing range of methods to "seal wood" with a focus on the nautical trade. It was determined that even high grade epoxies could only be considered 70% to 80% efficient at creating a water or atmosphere tight seal, as moisture still infiltrated and the wood took it on. The only samples that ever achieve anything in the 90% ranges was dipped in wax at a minimum 8 times and then the results reflected a 98% "sealing." However, this of course degraded rapidly and the water vapor entered.

In Bill's story the primary issues as I read it is the OSB, which is an absolute "Petrie dish" for mold, fungal and bacterial activity...and...with its many glues and design, forms just enough of a seal to inhibit moisture migration because of its very low permeability. Now we have new forms of OSB that are suppose to replace the silly "vapor barriers" (i.e. Tyvek..worthless for their intended purpose anyway) and these are creating even worse conditions inside the wall not to be seen for years or decades...or...until some sensitive soul inside starts presenting with respiratory issues because the "iron lung" (HRV system) has failed or is unable to mitigate the pathogens now populating the indoor atmosphere...

Bill spoke of the primary (and traditional solutions) to these challenges..."draft proofing." In humid warm and midrange areas we do this more on the outside, while in the colder north and related areas this is facilitated more on the inside. "Thermal mass" designs can be very effective at this mitigation, yet must be designed and facilitate properly. Lime plasters, oakum caulking, felts fabrics, and related methods have done this extremely well for millenia.

If we took Bill's example story, even in a 2x stud built wall, and had not used OSB but traditional oblique sheathing boards as originally found on original stud framed architecture; which by the way, was often mortise and tenon joined as the stud where being handled by builders that still understood timber framing and good joinery...plus the stud where "actuals" not "nominals; then made sure the there was a "rain screen and cold roof" system on the exterior of the thermal envelope" plus some form of "thermal break" layers (e.g. mineral wool boarding) this alone would have mitigated greatly the frozen insulation. If this had all been finished off on the interior with the beautiful lime plaster work that Bill has shown us here, we would not only have a highly permeable wall (breathable) but a completely draft proof wall that would also be extremely efficient. If the own had upped the wall thickness and and insulation in the roof many of these structures can reach a "net zero" capacity...

Regards,

j

Jay and Bill, I have a little story I am just dying to tell. I'll try and stay on topic with it.

Last week I was on a mainstream site explaining material failures: http://forums.jlconline.com/forums/showthread.php?64773-SIPs-Seam-Failures
In the "Building Science" section where some claim to be "building scientist" you can read all the errors and rant. You can see in my blog we are building a SIP insulation wrap around Timbers I needed some help writing since I am not the best writer and am at times complex due to my Engineering report writing and training, and I was looking for more failures and experience. SIPs is polyurethane foam (said to be completely non-toxic) and OSB panels that are having issues in the field rotting at the seams and roofs in 8-12 years. I explained the reasons why and one proclaimed “expert” named "Bill" you can read about gets up and tells me how I “talk down to them in a language they cannot understand”. A common friend Mark calls to discuss this since I finally agreed after my 25 year old son whom does not claim to be a “building Scientist” said he had to read it several times. So with some help from another Architect that did understand and agreed I simplified what I was trying to say in some bullets which fit the audience I was trying to target, everyone from clients to other Engineers, which is a challenge in itself. You can read my final report in the blog in my signature below. I can tell you I would never use SIPS especially made of these materials, there are better choices that is another thread.

Anyway, I told Mark I post at that level often on Permie.com without these issues which brings me to my point and the one that Bill made. Mainstream GC, Builders, "Building Scientist" do not understand what they are doing, they can be pig headed too. I have tested the waters here and there and I think I am qualified to make an assessment. You have to have higher knowledge to survive in the Natural Building means, methods, and materials. Jay, Bill, some others, completely understand my post and I theirs since we speak the same language. Have more perspective from natural buildings.

The material testing, building instructions, are not handed to you by a manufacture or "Building Scientist". I have a lot of experience developing material properties per these ASTM, ISO, specs and putting them in a design and to a product in the field that gets monitored, retested, reissued at times. Done all the moisture property, fire cell, fungi cell, load cell, testing. Not alone with other professional teams that included instrumentation, test set-up, which is a challenge in itself to get the right results and understand them. There is not a lot of documented tested Materials or Assembles testing I’m referring to accepted (building code, ASTM, etc.) , nowhere close to that in mainstream or the stuff you find in Home Depot and the oddest part is they still screw it up as noted above by taking an all-natural material like Roxul and mating to OSB. Guy's, this should keep our restoration businesses gainfully employed well into the future. Jay is absolutely correct had an earth or lime plaster been used it has no fungi food and can manage water and vapor unlike OSB. That along with the proper exterior systems that does the same. When there is no pink fluffy stuff to drop resistance fast when wet, produce mold, react, it really becomes quite simple mating inert materials that are chemically stable.

Often in my experience we mate metal and phenol resigns in graphite honeycomb panels in aircraft and auto, we provide an isolation ply of fiberglass to stop dissimilar material reactions when we attach metal brackets to composites. We use to foam cores 40 years ago but learned our lessons. George and his Chemist have developed isolators made out MGO you can read about in his book. They take a studded wall and give it some mass, and since the MGO is non-conductive and inert is does not rot or thermally bridge. You can leave the borax at home: Even if they just got some borax at Walmart or bornon and sprayed these cavities it would help. As far as I know they are safe and stabilize PH levels.

Good post guys! I completely agree! In simpler words you guys and preaching to the choir and singing my song One of these days we should try and get together, being so far away makes it difficult. George is not far away from here in TX. I have a design I'm taking to him to review soon yes in part developing MGO and other natural materials to code compliance we hope.

Anyone have experience with Calcium Silicate boards or insulation? It says below it is a competitor to rockwool?

http://en.wikipedia.org/wiki/Calcium_silicate

Gents,
I am interested in finishing the gable end and roof of my log home with natural and breathable materials. I am a beginner at this and would appreciate any input you may have. I like the idea of Roxul with MGO board. From what I am understand from your guys' posts, the MGO can directly replace the drywall and OSB and the plastic vapor barrier can be omitted? So basically, could I have the Roxul sandwiched between sheets of MGO with plaster finish? What about the roof?

I am in the cool humid climate of coastal Pacific NW.

Thanks.

Hi Terry,

I read the JLC, as I get there updates sent to me daily. In general, they are a collection of "mainstream contractors" and related building industry types that​....care not​... to listen to concepts outside the..."norm they know and understand," for the most part. I know Ted Benson personally and his use of "SIPS" (or perhaps misuse would be more accurate) is no different than many other "highly commercialized" timber framing companies out there. He still defends them when around other Timberwrights, that challenge their alleged "good product record," because of the "contractor background" he comes from...they have made him​ (and those like him)​ very wealthy...I will say no more publicly on ​these types of practices​, as there is not "good" or "sustainable" about them...they definitely are not within the realm of natural or permaculture principles...

I read most of the linked post from JLC and found your views germane and accurate, and I am not surprised by the reaction some there shared to your posts. You are reflecting their "poor judgement" and practices, and they care not to "own it." I am even seeing (or reading) some of the same language and terms I use, now being repeated by others, like yourself, that actual care about the structures we facilitate. This is really upsetting the "apple cart" for all those that now may have to actually address these "bad practices" that they have been "selling" to clients as "good practice" and the alleged "best way" of doing things...When in reality it was only fast, cheap and profitable for them and the industries behind them...which is about 80% of the construction trade and what they do...

When I got to Bill Robinson post, I actually had to go back and re-read your posts as I could not detect a "tone" other than perhaps a bit of frustration with the "silliness" of it all...His snide jab at the end speaks volumes to what he was trying to project to his..."in the know." My friend, because of your "technical writing" background, and knowledge skill set, there are many that will be challenged by your perspectives, especially if what you write about is counter to how they..."do business." Many of these "alledge experts" and contractors are neither experts nor should they actually be "selling" what they do in architecture as economically viable for the customer (it is of course for their bank accounts.) I read nothing in your post that was.."over my head"...or not something to share with others in our field...I actually had to "bit my fingers" as the forum title is "Building Science"...So, what the heck are some of these members on about when we use "technical terms,"...??...I mean really..."building science"......doesn't that kind of mean we are going to speak and write at an academic level that isn't necessarily aimed at "Joe Contractor" down at Home Depot? In that forum group they need to "rise" to your skill set and knowledge base...or...ask questions, not try and tear you down or the "message" of our posts...

SIPs is polyurethane foam (said to be completely non-toxic) and OSB panels that are having issues in the field rotting at the seams and roofs in 8-12 years.

I really become incensed when contractors and manufacture make these "non-toxic" claims...which all comes out of the "rebranding" of products that wish they actually were..."non-toxic" so they could legitimately be in the "green building" realm. Neither the industry, nor the materials that employ in any of the SIPS of the current mainstream market are..."non-toxic."

Terry, I look forward to what you can do with MGO materials...I am sure it will really be better than what is currently available in foams (and too often falsely advertised.)

Regards,

j

Calcium Silicate boards or insulation

In general I have worked directly with it once, and found it agreeable in general. It is not a permeable material like mineral wools, and also has almost the exact same melting point and resistance to heat, so no gain there either. In general a big industrial material for the concrete industry, and food/pharmacological complex...for the most part. Perhaps the future will find new uses with a smaller carbon footprint and more "natural building" application...​​

I actually had to "bit my fingers" as the forum title is "Building Science"….

Thanks for the laugh Jay this had me rolling on the floor this morning. We repair a lot this so called “building science” so I get on the site to see what’s coming next. EG: SIPS

Kris Arbanas wrote:Gents,
I am interested in finishing the gable end and roof of my log home with natural and breathable materials. I am a beginner at this and would appreciate any input you may have. I like the idea of Roxul with MGO board. From what I am understand from your guys' posts, the MGO can directly replace the drywall and OSB and the plastic vapor barrier can be omitted? So basically, could I have the Roxul sandwiched between sheets of MGO with plaster finish? What about the roof?

I am in the cool humid climate of coastal Pacific NW.

Thanks.

Correct, the MGO board and Roxul would make an excellent assembly I'm discussing with George very soon. Problem is finding a quality board up there by you. George Swanson has lots of experience with it so I am getting with him to view his builds soon. He may be able to point you to a close by suppler or develop a plaster. He has a tape/mud for the seams in his book “Breathable Walls” and recommends a mineral silicate paint is all you need. I have talked to some that got boards from China where the salt content is so high it only last a few weeks. A lot of the distributors are out of Florida and get imports from China I don’t trust. I’ll see what George has to say. If you can find an experienced designers-builder like him up there that would best. I’m going with a board to satisfy codes for now, and use some methods the local trades can understand.

Correct, the MGO board and Roxul would make an excellent assembly I'm discussing with George very soon. Problem is finding a quality board up there by you. George Swanson has lots of experience with it so I am getting with him to view his builds soon. He may be able to point you to a close by suppler or develop a plaster. He has a tape/mud for the seams in his book “Breathable Walls” and recommends a mineral silicate paint is all you need. I have talked to some that got boards from China where the salt content is so high it only last a few weeks. A lot of the distributors are out of Florida and get imports from China I don’t trust. I’ll see what George has to say. If you can find an experienced designers-builder like him up there that would best. I’m going with a board to satisfy codes for now, and use some methods the local trades can understand.

Yes looks like my local supplier in Vancouver http://magobp.com/technical-details/# sells "Magnum Board" that is made in China and distributed out of Florida http://magnumbp.com/products/magnumboard.html. They do offer a 30 yr warrant which seems promising though.

Hi Kris,

I will try and hit on some very good points thus shared.

First, heed not "warranties!"

Seldom are they more than "toilet paper stock" waiting conversion...The "loop holes" in the fine print interpenetrate in such a fashion as to mix fact with fiction in the most devilish of ways, and would give the best "Contractual Lawyer" a nose bleed just reading them, let alone fully explicating such drivel...Put little stock in them or those that share such. I have only known few honored and that was by a very small (and honorable) roofing company and one floor company, in 40 years around the building trades...

Please note...I always validate my advice as very basic, unless I have blueprints, CAD, and other details of a project...plus much more intimate relationships to it...so the following is just basics.

Kris Arbanas wrote:I like the idea of Roxul with MGO board. From what I am understand from your guys' posts, the MGO can directly replace the drywall and OSB and the plastic vapor barrier can be omitted?

Hmmm....well...the Roxul I can get behind almost 100% when applied correctly and in the proper format for a give application. The MGO is a much "newer" concept. I think MGO has incredible potential, but for me it is still entirely too new a concept and not all applications (or sources) have proven consistent, nor reliable. It also comes down to not "reinventing wheels." Don't misunderstand, I think some good things may still come out of the R&D with this product...It thus far, however, is not an improvement of lime renders and other well understood traditional modalities.

Kris Arbanas wrote: So basically, could I have the Roxul sandwiched between sheets of MGO with plaster finish? What about the roof?

So...no, not at this time...would I recommend such a scenario with current products, and even if some do become available in due course it still may not be the most "natural" or "cost effective" method. We will have to see what comes...At least that is my view of it at this time.

I think a "mineral wool board" and then perhaps a batting, with a natural plaster and/or wood finish on the interior would be sufficient and the exterior being clad in similar fashion. The roof is thus the same with with a good cladding of wood, and I am not against a builders felt or oil paper as was once done. Both rainscreen and cold roof should be part of the design. This is all under presumption that a fully natural method or mix of such, like clay straw, or others could not be facilitated.

OSB and the plastic vapor barriers are utterly useless in my view, and always have been as they currently exist in the building modernity of today. They simply can not fulfill their intended mission for very long, no matter how much "attention to detail" a builder gives them...or wishful assumptions of..."they should work." They are convenient at creating "fast walls" that are profitable for builders...they are not durable, sustainable...and only present a false illusion of "good practices," in building today.

I take wood and plaster from modern homes under remodel and it is often most foul in less than a few decades, yet boards out of vintage homes and barns can be repurposed and these boards have already seen 200 years of service. The plaster is just as enduring of form and quality as these boards, and often only need some repair...modern plaster board does not have such qualities. When modern methods can present this type of durability...then I will take notice.

Regards,

j

Great thread, thanks everyone!

Terry Ruth wrote:after my 25 year old son whom does not claim to be a “building Scientist” said he had to read it several times.

I'll gladly admit that I too, not being any sort of scientist, sometimes read your posts a couple times over. They're dense! Ditto for plenty of other things well worth reading outside my primary area of expertise. While I'd agree your writing could sometimes be polished or simplified, this is a forum, not something you're getting paid to polish; I imagine your thought-provoking and informative posts take quite enough time as it is!

Bill, I'm glad to hear that in your experience this stuff really doesn't mold, despite misuse. Promising.

Jay, RE: warranties, good to hear this from someone with experience. I've always thought that the incentive to weasel out of warranty on this sort of thing would be huge; it's not like walking in to a local store with some unsatisfactory $50 or $1000 item, where the store can expect other business in the near term, and likely has some recourse with their own supplier or the manufacturer... Realistically, a contractor/builder is not banking on building another house for you, and the manufacturer is competing at a much higher level than an individual customer... mostly on price. Will any of them come through for you if it's not in their financial best interest? I leave morals aside; as you mention, that seems to be the exception. Reading warranties, and insurance terms, can be so enlightening... if depressing.

I find it rather appalling that there are gov mandated '2-5-10' new home warranties up here. 'Coverage includes 2 years on labour and materials (some limits apply), 5 years on the building envelope and 10 years on the structure of the home.' Wonderful! A home I can count on to last for at least 2 years, except for whatever those limits may be! And to not entirely fall down for a whole ten years! Sign me right up, I think not... So sad that a old building can be a valuable source of salvage, while a newer one is mostly garbage, much of it toxic.


On to an actual rockwool related question: I'm currently planning to use Roxul Comfortboard between the wall/ceiling ribs and under the floor in my shortbus conversion; I'm nearly at that point, but having trouble finding it in the Glorious Peoples' Rebulic of Western Canuckistan. I may also use some Roxul Comfortbatt in the curved part of the ceiling; that at least is readily available. Then I intend to put a 3/16" layer of closed cell polyethylene, aluminum faced(charmingly named Lobucrud), on the inside of this, with aluminum tape on the seams; then the inner wall/ceiling, which is aluminum sheet, and previously was screwed directly to the 2" steel ribs with no insulation/gap at all. I'll add some sort of spacer to avoid compressing the polyethylene. Bonus; less galvanic corrosion on the ceiling/wall panels.

This thing was originally a wheelchair bus, built by morons at Corbeil who had apparently never heard of mold, or galvanic corrosion; it's a horrible mishmash of steel and aluminum for the walls and roof, with fibreglass ends. It was originally insulated with standard fibreglass batting, except the floor which had none. I tore this all out; some of it was black all the way through from mold, and saturated with water from leaks; the rest was only somewhat black in patches I presume to have grown from condensation.

Opinions?

I tore this all out; some of it was black all the way through from mold, and saturated with water from leaks; the rest was only somewhat black in patches I presume to have grown from condensation.

Dillon what did you do to treat the fungi on metal? I'd grind those areas down and remove any effected area. Brush alodine conversion coat then try and get a mineral silica paint on that will allow the metal sweat and insulation to dry to the outer gap you mentioned. Do not put dissimilar metals like AL and steel (probably galvanized or anodized) or even the probably 2024-T3 anodized aluminum and aluminum foil face in contact that have different charges and can cause galvanic corrosion. I would not put a plastic or any taped foil face(unless 2000 series pure aluminum) fungi food and developers that would keep the high perm Roxul from being able to dry either inward or outward to an effective ventilation gap. Remove any interior vapor impermeable interior panels or paints. Get some borax at walmart treat it all as a fire retardant and anti-fungi. 10 0r 20:1 what ever sticks. Roxul does not like hydrofluoric acid so keep it away from metal you never know if it is in a chem treat like for the AL.

My RV toy hauler is the same way, so are FEMA trailers, can't wait to rip out the rot Last time I was in Seattle working I had mold everywhere.

Dillon Nichols wrote:
I find it rather appalling that there are gov mandated '2-5-10' new home warranties up here.

Opinions?

2 - 5- 10?


Basic home building standards here START at 10 years, just for roofs not to crack leak or rust. We had a big kerfluffle some years back about 5 to 10 year old houses rotting because of substandard building practices being allowed for by loosening standards after materials industry lobbying and they got tightened back up again pretty quickl A bunch of cheap manufacturers found they had a lot of unsalable cheap product on their hands they had made after getting the standards relaxed, PLUS they had to fix their shoddy work.

Houses are to be designed and engineered for a minumum 50 year inhabitable lifespan! Minumum! Or they do not receive building consent!


Indoor wearable amenities like light switches and taps/washers etc aren't covered, but the structure of the dwelling should outlast the average builder.

Your govt mandate should add a naught to those numbers!

The mold seems to have been almost entirely on the removed fibreglass insulation; I've found none on bare or painted metal. A bitch to get all the FG out since it was glued in place, though.

The only other places I've spotted mold/mildew/fungus have been the exposed fibreglass of the end cap, and some plastic/rubber bits; I've been spraying these with borax solution. It definitely helps, but the steeringwheel plastic seems to be a real mold-banquet!

The aluminum roof panels are painted or perhaps anodized rather unimpressively, and then this was covered with some sort of black spay-on liner; fairly thin, but much heavier than paint. The galvanized steel ribs are unpainted; is 18 year old galvanized steel a risk for hydrofluoric acid such that I need to paint them where the edges of the Roxul will contact them?

The steel is very nearly all galvanized; I'm grinding off the rust in spots where the galvanizing is shot, mostly the corners of the ceiling ribs/beams, and where screws from the rubrails where put through everything with no sealing at all. Intending to use POR15 cleaner/metal prep/paint on the floor, and some cheaper and less nasty rustoleum galvanized primer on the minor spots on the ribs/wall panels.

I'm isolating steel and aluminum wherever possible; unfortunately to do this perfectly the entire vehicle would need to come completely apart, which is not in the cards. I haven't got the time, tools, or workspace (doing this all outside) to remove the outer shell, which has steel fasteners in aluminum panels, and aluminum panels presumably inadequately isolated from steel ribs.

I'm planning to ignore the very thin aluminum facing on the outside of the polyethylene layer, on the theory that it's not going to be doing its job anyway(radiant barrier) if it's in contact with steel, and can thus be considered expendable.

Terry Ruth wrote:unless 2000 series pure aluminum

I'll keep that in mind; whether I can find such tape up here is another question! I do intend to avoid plastics as much as possible after observing mold thrive on them.

Terry Ruth wrote:Remove any interior vapor impermeable interior panels or paints.

I was figuring with the outer shell being an effectively impermeable barrier, half of it steel, I'd be better off with an interior vapor barrier aimed at keeping as much as possible of the moisture buildup from condensation confined in the living area where I can be aware of it. That way, I can wipe it down, dry it out, take steps to improve ventilation or add dry heat until it goes away. The only possible place for moisture to escape outwards is a seam where the outer wall passes outside the edge of the floor, which strikes me as grossly insufficient for an escape path for moisture moving through a permeable interior wall, and the Roxul, then hitting the cold outer wall... Any further thoughts would be welcome.


Rhys: a naught on the end sounds about right to me; as it is, the notion that a home might need a warranty in that short length of time is more worrying than the presence of it is comforting, to me!

I'm no chemist but I would think the zinc on steel has no hydrofluoric acid. Here is what happens to FEMA trailers with interior barriers in hot-humid climates. http://www.buildingscience.com/documents/insights/bsi-021-thermodynamics-its-not-rocket-science

It takes less than 48 hours for this to occur, I would not plan on watching it and keeping it continuously dry, germination you can not see.

You did say the borax is removing fungi?

Hi Dillon,

I think I will just follow along on this one. I lived in my first trailer back in 1967, several through the 70's, a few summer trips with friends in the 80's, and then my Dear "Wife" had to have one instead of a Yurt about 15 years ago...

I can say that I have never been in a single one of these that made me feel comfortable. Each one I listed above, either on res., family/friend owned, or vacationed in, that did not end up in a scrap yard, with some of the trailers reused for hauling wood.

This is the true essence of "transient architecture." It is both mobile, and it never last more than ten years without major issues or needing to be scraped. I have seen some of the more contemporary ($$$) types that seem better, but they are all plastics, foams, ans steel also...so, I don't give that format much hope.

I don't mean to be a downer, yet almost every principle of "breathable walls" is undone with most "tiny houses" done on trailers, and my experience has shown they don't last...or...if they do the actual interstitials areas of the walls are a big unknown, as every time I have looked into one older than 5 years...well, they ain't pretty...

Sorry to be such a bummer on the subject...

Dillon Nichols wrote:The mold seems to have been almost entirely on the removed fibreglass insulation; I've found none on bare or painted metal. A bitch to get all the FG out since it was glued in place, though.

The only other places I've spotted mold/mildew/fungus have been the exposed fibreglass of the end cap, and some plastic/rubber bits; I've been spraying these with borax solution. It definitely helps, but the steeringwheel plastic seems to be a real mold-banquet!

The aluminum roof panels are painted or perhaps anodized rather unimpressively, and then this was covered with some sort of black spay-on liner; fairly thin, but much heavier than paint. The galvanized steel ribs are unpainted; is 18 year old galvanized steel a risk for hydrofluoric acid such that I need to paint them where the edges of the Roxul will contact them?

The steel is very nearly all galvanized; I'm grinding off the rust in spots where the galvanizing is shot, mostly the corners of the ceiling ribs/beams, and where screws from the rubrails where put through everything with no sealing at all. Intending to use POR15 cleaner/metal prep/paint on the floor, and some cheaper and less nasty rustoleum galvanized primer on the minor spots on the ribs/wall panels.

I'm isolating steel and aluminum wherever possible; unfortunately to do this perfectly the entire vehicle would need to come completely apart, which is not in the cards. I haven't got the time, tools, or workspace (doing this all outside) to remove the outer shell, which has steel fasteners in aluminum panels, and aluminum panels presumably inadequately isolated from steel ribs.

I'm planning to ignore the very thin aluminum facing on the outside of the polyethylene layer, on the theory that it's not going to be doing its job anyway(radiant barrier) if it's in contact with steel, and can thus be considered expendable.

Terry Ruth wrote:unless 2000 series pure aluminum

I'll keep that in mind; whether I can find such tape up here is another question! I do intend to avoid plastics as much as possible after observing mold thrive on them.

Terry Ruth wrote:Remove any interior vapor impermeable interior panels or paints.

I was figuring with the outer shell being an effectively impermeable barrier, half of it steel, I'd be better off with an interior vapor barrier aimed at keeping as much as possible of the moisture buildup from condensation confined in the living area where I can be aware of it. That way, I can wipe it down, dry it out, take steps to improve ventilation or add dry heat until it goes away. The only possible place for moisture to escape outwards is a seam where the outer wall passes outside the edge of the floor, which strikes me as grossly insufficient for an escape path for moisture moving through a permeable interior wall, and the Roxul, then hitting the cold outer wall... Any further thoughts would be welcome.


Rhys: a naught on the end sounds about right to me; as it is, the notion that a home might need a warranty in that short length of time is more worrying than the presence of it is comforting, to me!

You should try using 4 thieves oil in a spray bottle. You only have to use 15 to 20 drops of the oil diluted in approx 200ml of water and that will take care of any mold that has spread throughout the vehicle. You can add drops of the oil in a humidifier too and let it run for 2 or 3 days and that will kill all the mold whether it is inside a vehicle or building. Google it and read up about it. You'd be surprised how powerful it is. Some contractors have used it in industrial humidifiers to clear out mold infested buildings and it worked better than anything else they tried.