I finally read through this after being directed to by Jay on another thread on moisture challenges in natural buildings. Jay whom is absolutely correct about these so called industry “Building Scientist” experts and today’s materials being promoted. Since Brian provided links to GreenBuildersAdvisors.com. I’ll feel free to tell of a recent experience. I just received a phone call early this week from Martin Holladay, GBA Advisor, recognized building expert by some threatening to ban me if I did not stop proving him wrong along with another poster that is an expert in health related issues from building materials he and his site pushes as being “green”. The latest being a discussion on the formaldehydes (MDI) used in OSB and foam, and related to this topic of using foam (EPS, XPS) below foundations along with polyethylene barriers.
OSB: Here is blog below where now after years of recommending OSB it is failing air seals or blower door test, not only here in the states but in Europe too. Europe, Germany Passivhaus more specifically, brought the whole “air seal” concept popular today and certification to America named PHPP, now it is being re-written since they realized it does not work in all our climate zones. I believe BSC is behind that effort, named PHIUS. In summary, field contractors and Engineers, some from Europe, are adding membranes (paints, mastics, etc.) or solvents that break down the reactive constituents in OSB and manufactures are not quality controlled, free formaldehydes that become air born and toxic. Martin did not point to any of which in the article he wrote. He did offered a “back yard tape air test” to give his readers insight as to what tapes are the strongest and would last the best over time, noting incorrectly “they get stronger over time” like some natural materials. His ridiculous test showed tensile (pulling off) property info, not the weaker “lap shear” or misalignment that causes failures. Martin gives praise to the ones adding membranes they do not fully understand as being competent in matting materials that voids the manufactures warrantee of exposure rating to moisture. You can read more here: http://www.greenbuildingadvisor.com/blogs/dept/musings/osb-airtight
Let’s take a closer look at his latest blog related to this subject matter at hand: “Placing a concrete Foundation on Rigid Foam”
Feel free to read why I received his phone call here below, but this latest blog provides more proof of what I stated he does not like post that proofs this method wrong, due to some unknowns and lack of understanding. Feel free to correct my understanding of the data, since it is data that matters most.
be nice if all we had to do is check one property (e.g.: compression) in structures but, that has never been the case…Look below at the bottom of the “compression” page the blogger makes reference to….
Compressive and flexural strength values for expanded polystyrene are based on short-term load conditions in accordance with typical ASTM test standards. As do most load bearing building materials, EPS foam insulation products creep under long-term, continuous load conditions and, in critical applications, this characteristic must be considered in design calculations. Design professionals should recall that greater strength properties are available from EPS foam by increasing density. Data that reflects deflection resulting from continuous, compressive load exposures for EPS insulation is available.
Foam manufactures give compression values at max deflection (10%) or yield strength, when you are past yield or max deflection tensile cracks occur and propagate fast. Oh and the BTW, you will not be able to see them they are buried, stating as the blogger did that the bottom is fine by the looks of the sidewalls is wrong! Interesting how they compare foam to soil, if it can take it so can foam. Well that is simply not the case, both have completely different geometry (foam comes in 4x8 sheets, soils does not) and react to loads completely different. A more comparable material in the design would be the concrete above, it can deflect 6-10xs more than foam, and has a compression strength above 3000 psi, not 25, so why put a weaker material of continuous load bearing geometry below it? BTW, foam will not see “even compression” nor deflection, nor creep over time. Some areas will crack, some will not, we know this from concretes history. Before foam takes out uneven loads it will creep and deflect, crack, decompose as seen from the manufactures data sheets.
Creep is another property that can fail foam over time we do not see an analysis for, none of the manufactures, BSC, GBA, just guess work. Combine loads of compression, deflection, creep, tensile, need to be evaluated and tested….not just compression.
Steggo Vapor Barrier used: http://www.stegoindustries.com/5%20-%20StegoWrapVaporBarrier15Data4-2013HR.pdf
Looking at its tensile strength of 70 psi. If the foam does deflect 10% or creep that is low it will rip. Take a look at what it reacts to, acidic rain waters and soils to chemically break it down over time….
2266 grams or 27 lbs. of lab tested impact resistance by dropping darts at it. Combine tensile stretch from deflection and a point load the values are less. These values are at yield like foam, which we do not design to, try 1/3 of that for a safety factor. Add some compression pressure and temperature while you’re at it to simulate a real world environment.
CONDITIONS AND MATERIALS TO AVOID: May burn or react violently with fluorine/oxygen mixtures with 50 – 100% fluorine. May be decomposed by strong oxidizing agents, such as nitric or sulfuric acids, halogens, and chlorinating agents.
Blogger states: (There's a heavy layer of sprayed-on waterproofing between the concrete walls and the exterior foam.)
Really? Where is the data on the life expectancy and chemical break down of the foam you coordinated with the manufacture? Ignored?
Also, they used a mastic on the plastic but I fail to see any data to show it is not reactive to the listed additives that can cause a chemical break down?
Thermal? What thermal break is needed, what delta t does the foam need to absorb from the concrete footing, or are they guessing at an r-value?
Condensation? What temperature does it occur on footing’s in this climate zone? Where exactly is the dew point with and without the foam and plastic? What is the basic design requirement that has to meet? Or they don’t know and are guessing?
Termites: Look at the foam data: http://www.epsindustry.org/building-construction/insect-infestation
Per the map the vast majority of the USA is moderate to heavy infestation. Here is what the manufacturing alliance has to offer, “Leave it to code or field inspectors or a specification” that failed to test to time or climate zone specific.
Blogger states: When we researched termite effects on foam we discovered that termites don't go very deep. For example, in their recommendation about anti-termite treatments, the University of Missouri Extension recommends applying anti-termite insecticide only down to a maximum of four feet.
Interesting, well your design goes against the design guide you pointed to. Since your design provides no gap I think it’s safe to assume it provides a path for termites and other critters to gain access to the wood and compromise the foundation.
“The Code defines approved as acceptable to the building official, code official, or authority having jurisdiction. Guidance tools available to Code officials are found in ICC-ES evaluation reports of either the foam plastic products or of the products which provide protection for the foam plastic.”
Barrier health related issues, see MSDS that can leach into the home in small particle per million….
Barrier MSDS statement? The additives in this product are encapsulated in a thermoplastic film with limited release under normal conditions of transportation and storage. Increased release may occur when the resin is melted, ground to a smaller pellet size or subjected to decomposition, as by excessive heat. The specific potential for release under user’s conditions of handling of this material should be evaluated by a qualified health specialist.
How many that are being advised to put foam and plastic under foundations have hired the proper professionals per manufactures spec? Or making material modifications not fully understood? I’d estimate 99.9%. There have been several Structures Engineers noted on the site that will not stamp foundation on foam drawings that get ignored.
In other words, no data on installation, handling concerns need a “specialist” same if not more for installation to reactive chemicals. I see no UV additive so it breaks down in the back of an installer’s truck.
Can’t point to the commercial road foam industry where professionals are for public safety as empirical evidence for homes either, as the blog and Martin has.
I really enjoyed this “Old Aircraft Engineers” blog that "Bites Martin Back" on bad advice got little response other than “Whoops” from Martin working on an update, Illustrates once again advice is in constant flux: http://www.greenbuildingadvisor.com/community/forum/general-questions/38872/solar-thermal-buffs-bite-martin-back
I think more often than not other professionals are proving Martin and other “Building Scientist” wrong or challenging there advice in public and they don’t like it. How can they profit from the foam and plastic industry if posters are constantly showing the shortcomings of the materials they are promoting? How do natural materials promote a manufacture other than on the job site as the builder and manufacture, local quarries and farmers perhaps that struggle to keep a float? I think it is great to move profits to them from the big manufactures and corporate greed that has ruined this industry and many countries. The cost of a home in America is nuts for the junk you get that even effects your health. Is your health less important than saving a few bucks on energy?
If you look at Martin’s experience it is nowhere near what Brian stated above. He has a background in building, not engineering or design, labs. A lot have physics PHD’s, no mechanical or structural design, nor with lots of proven designs that have been monitored or tested over time. Mating of materials is a specialized science reserved to not only physics, but chemistry, and Engineers that have to make them work. You do not have look long at Martins advice to see his lack of “expertise” in these areas, yet he advices on them. What he should do is point people to the appropriate professionals when he is out of his league, which is often, due to lack of lab and field data. Jay is correct “leave the science to labs and professionals”. Not that they are always correct but changes are greater.
GBA allows I’ll call a seldom blog that has to do with natural building methods, do a site search. If you look in the Q&A section you will find Martin offering no solutions to the readers that are natural. The main product that seems to be the solution to everything is foam and plastic, many readers have brought that to his attention and challenged him it does not good. They should rename the site to foam&plasticAdvisors.com since last I check there is nothing “green” about neither. Anyone with any sense of basic logic should raise a red flag here, foam and plastic cannot be the only answer. I think they have the natural blogs or allow some of the natural building experts on their site to maintain the “green” status quo. Not much of what they advise is accurate and Jay is correct many cannot agree and the advice changes constantly. I cannot wait to see the fall out of all this home placement on foam and plastic being pushed by them, just like the same formaldehydes issues are showing up in OSB. It will keep the foundation repair industry alive and well far into the future. I think it should be obvious that foam and plastic are not the answer to issues we have had historically. We can do better than that, scary so many follow such bad advice. I came here since I want to discuss natural building methods and not be called out or ask to stop proving the problems with toxic foams and plastics that are harming our buildings, environment, health, and longevity.
I been testing a lot of earth construction, hard to find help and others to communicate with. It is not going to happen on GBA or BSC, they are not interested in methods that do not promote a factory product that their sponsors pay for. Martin told me it cost them money to keep the site up and I am not helping pay the bills. I told him I understand his business aspect but, he is still wrong about a lot of things he did not want to hear or his readers reading. He said GBA wants to control what the readers read and not what I have to offer, more natural methods are not it. Try and go on the foundation thread and ask for deflection and creep data on foam installations and the vapor barrier life test in these installations, offer alternative naturals methods that have higher compression, deflection, creep, bending resistance, and live cycle and see what response you get. Do it often, daily, you will get a call from Martin as I did eventually. I’d take Jay’s advice any day of the week over his.
There is plenty of data out there that show weaknesses in foam and plastics, you just have to focus on it and have the ability to interpret it. That comes from experience in itself, no need to speculate.
Burra Maluca wrote:
I came here since I want to discuss natural building methods and not be called out or ask to stop proving the problems with toxic foams and plastics that are harming our buildings, environment, health, and longevity.
It's for exactly those sort of reasons that we recently changed the name of this part of permies from 'Green Building' to 'Natural Building'. We want the emphasis to be on better ways, using natural products, not simply green-washing using synthetics.
Terry Ruth wrote:On the flip side of the coin, I'm no chemist so correct me if I am wrong but, from what I gather not all synthetics or man made building materials are bad for our health, building's, and environment. Lime for one example is manufactured in a kiln by lime producing factories, the CO2 emissions are not as high as portland cement nor are the toxic additives to our health that can emit to our breathing air. Seems there is a big push to produce plastics and by-products safley, binders, etc that are "low voc" such as paints and floor finishes that are synthesized by organic chemistry that are surfacing. They use water or other natural materials as the transport to get binders to flow vs. toxic solvents and petroleum based oils. They cost more to manufacture right now, but it will come down.
Here is an example of a floor finish polyurethane: http://www.greenbuildingsupply.com/core/media/media.nl?id=42846&c=772072&h=8fc61a99d17db58722bf&_xt=.pdf
-Low VOC: 110/g/l or .91 lb/gal .....that is pretty low
-Per OSHA: No known cancer causing agents..OSHA is fairly reliable and conservative to protect themselves and others.
-Stable @ temps below 177 c/350F ....above it decomposes.
-Reactive to high alkaline and acidic water ....not normally found in floors.
I mentioned OSB, some (not all) manufactures have taken the "free formaldehydes" that can emit and cause harm down to less than 1%, Harmful MDI less than 6%, and lowered other harmful additives....some are still debating the toxicity of.
Would it be a non-natural solution to coat clay with a low voc water based polyurethane to solve the low impact resistance of clay as a solution to this permies floor issue? http://www.permies.com/t/20776/earthen-floor/report-earthen-floor-months-living
I experience that same low impact or point load resistance with rammed earth clay alone will not solve. I did not get better results with lime or fly-ash pozzalan additives, or portland cements, so I suspect a thin pottery clay will not have the impact resistance. BTW: Fly ash we use in natural building is a waste by-product from coal burning, using it promotes coal burning since it is not free.
When it comes to floor or clay wall finishes I have yet to see a method that is strong as plastic or high levels of portland cement, no dirt? I added a concrete acrylic sealer to RE since I did not know of better way to get a hard durable surface. I tried a polyurethane and it did well too other than it darkened it I did not like. I seen some sealers out for rammed earth that are factory products used over in Europe but, that has a lot of embodied energy to ship to my US location. I also added a lime spray since I could not even brush coat my RE without it falling apart...I also tried adding straw, and soil with lime at different ratios. Lineseed oil darken it and did not do well, it will take alot of maintenance over time anyway. I ended up using a white portland cement with fiberglass strands stucco, it was the only one that would not crack when it dried. This wall is exterior.
My rammed earth interior wall does not crack like concrete, it dents, like the OPs floors above from chairs, which can be good and bad....Once you get past the surface sealer it crumbles easy....We get hail here every year, some large, as many states. Large over hang will help not prevent point load damage. Makes me Leary to try a floor unless there is a strong surface sealer on it that last for decades with little maintenance as polyurethanes have. However, we have yet to see how the low voc water based ones will hold up, paints too.
Finish floors I'm thinking wood is safer than clay. I'd say limecrete but there you need a fiber to keep it from cracking. A rough floor with fibers showing I'm not sure would look nice.
More on organic polyurethane: http://en.wikipedia.org/wiki/Polyurethane
Organic compounds: http://en.wikipedia.org/wiki/Organic_compound
Organic Matter: http://en.wikipedia.org/wiki/Organic_matter