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? https://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