Breathing Walls by George Swanson, Oram Miller and Wayne Federer

Source:http://www.breathingwalls.com/index.html" target="_blank" rel="nofollow">breathingwalls.com

Summary
source:breathingwalls.com
"Breathing Walls offers practical alternatives to conventional modern building practices that keep homes airtight. Walls built today are energy-efficient but cannot handle the inevitable intrusion of moisture, resulting in mold, ill health for occupants and structural damage. Instead of "build tight, ventilate right," we say make your envelope "waterproof but vapor permeable." We work with, not against, the forces of nature."

Where to get it?
breathingwalls.com

Related Videos


Related Threads
Breathable Walls
General Discussion: "Natural-Traditional"vs"Heavenly Industrialize" in Means, Methods and Materials
Condensation, and other moisture related challenges in natural building...

this is the book being discussed in this thread Breathable Walls

Thanks Judith!

I have not read this book as it is just coming out, but I couldn't recommend the information more highly. This is the direction that the human built environment needs to take in order to avoid the impending catastrophes that are currently affecting the health of the buildings and occupants as well.

I do have a beef with the video and many "natural builds" that don't have enough insulation and mass to perform properly for their given environment. As George points out in his excellent book, a wall assembly should not be completely vapor open as this can also cause issues in some climates, but be vapor open on the interior of the wall and have a vapor absorption limiting skin on the external surfaces of the wall. Clay walls with no lime or other treatments are susceptible to damage as well.

The photo of my own home is what happens when you saturate clay plaster and then try to wipe it up.

Bill, could you recommend any other videos? I can take that one down...I had a hard time finding any that might fit the thread and I wasn't sure about that one.

Sorry Judith, I watched the rest of the video you posted and it is excellent information. I should not have commented until I had seen the whole thing.

As for videos, this woman knows her stuff.

Hi all, first post here, please let me share my thoughts.
I live in Italy and just graduated from Architecture and Building Engineering, and took a couple of courses on timber constructions and and architecture, in which we talked a bit about energy efficiency/passive houses.
Eager to know more about sustainable architecture and permaculture, I started reading Paul Wheaton site and this forum, then came across this thread. It really confused me.
I was taught homes need to be airtight in order to prevent heat losses, and a proper layered walls avoids the moisture to be trapped between layers and mould to develops on the surface.
Then I took a look at chapter 7 of the book, and found that the author addresses what the real problem is: vapor retarders are misused in a conventional building. It has nothing to do with air. In fact, if air could be the main vector of vapor if you don't pay attention at the connections.
The incorrect use of the vapor barriers are the product of relying on the old Glaser model, a method that doesn't take account of the many variables of the heat and moisture "transmission" (i.e. variation in performance of materials based on humidity level and the starting humidity content in the material). I don't know how the situation is in US, but now Europe moved to a more accurate method, that involves complex calculations made only by computers. a good software to have a pretty accurate analysis is Wufi plus: http://www.wufi.de/index_e.html the bad news is it costs a lot!
The rule of thumb, however, is to use layers with diffusion values that increases as you go outside of the wall.
To sum up, I think the term "Breathing" is very misleading, and should be changed with "Transpirant", to avoid misconceptions.
just my 2 cents

I think what separates this book from the rest including online forums and videos, word of mouth, or experience others may have by the data it presents, material property data that supports the book. We can easily find lots of info and opinion (many inaccurate and misleading) without data, and people that say it does not exist, ignore it, or say it is not measurable. The book diffused the myths that manufactured products are better and well know. The truth is, and most that have been around a while know this, that natural materials date back farther than manufactured. There is more money to be made in manufacturing. The book as the title states, promotes fully breathable walls in all directions, no barrier’s, but also acknowledges that barriers may be needed in some cases.

The main reason data is important is it is probably one of the biggest bottle necks in the growth or replacement of natural building materials with conventional or mainstream. If you look at code, or any material that is not approved by it, you need data to satisfy it and inspections, or a Professional Engineer (PE). You can find the guidelines for data in code too, it just cannot originate from people’s experience with materials or history, there are ASTM test procedures that must be met even though some are limited like those related to moisture in building’s this book address and manufacture’s use it to their advantage. The book proves for one example that there is more to it than vapor permeance, or r-value, the majority of building and manufacturing industry uses to design. This topic of code is one that is real almost deserving a forum section of it’ own. Often I see permies heading down some natural material path only to be stopped dead in their tracts when they learn permit requirements. In America, another bottle neck is Architectural Control Committees (ACC), or cookie cutter controlling sub-divisions. If you are in a rural area with no codes or ACC no problem, but that is the minority.

I want to keep the other thread technical content, but the other deterrence for the natural builder along with code is financing and comparable (comps). Banks really struggle with lending for natural building methods that are not known or conventional, the minimum requirement for financing is three comparable must be in the proximity of the building requesting financing. Fannie May and Freddie Mac have strict lending guidelines. Sure it is everyone dream to stay out of debt or reduce it, but for many that is not reality, and when you factor in costly code requirement’s it makes it more difficult. Add to that the cost to get insurance, training agents, etc. Natural Building Finance would be another forum section I would suggest. We can discuss natural building materials all we want but if we cannot make them reality what good is it.

The book was published in 2008 so it is about seven years old but, the data it references, although a little old too, is still good. I talked to George personally about the hurdles the Natural Builder has to overcome and he has since developed some materials and building methods that are not too far out in left field and costly. I see other natural builders do the same thing, for example, combing straw and blown in insulation with conventional wood studs. He has been a natural builder a long time and done it all. I asked how well he profited compared to the mainstream builders and he said not as much, often taking a loss for what he believes in. That’s great, but like all we builders have to bring the bread and butter home and overcome the obstacles like others finding value in our building’s and their own health. I’m amazed how some do not care about their own health and sick building’s or are just completely unaware.

This is an excellent video on clay slip since it quantifies it by a chemist. Authors of the book, Wayne is a Master chemist, George an Engineer, Oram a biologist: https://www.youtube.com/watch?v=5IVoSR5kLyc

This is an excellent document I have been using in the thread since it provides material properties based on lab and field test for design purposes: http://www.ecobuildnetwork.org/images/PDFfiles/Straw_Bale_Test_Downloads/moisture-properties_of_plaster_and_stucco_for_strawbale_buildings_straube_2003.pdf

Terry, I've embedded the video here. Could you rate the book with permie's 0-10 'acorn' rating for us? Thanks!

Andrea Ghensi wrote:Hi all, first post here, please let me share my thoughts.
I live in Italy and just graduated from Architecture and Building Engineering, and took a couple of courses on timber constructions and and architecture, in which we talked a bit about energy efficiency/passive houses.
Eager to know more about sustainable architecture and permaculture, I started reading Paul Wheaton site and this forum, then came across this thread. It really confused me.
I was taught homes need to be airtight in order to prevent heat losses, and a proper layered walls avoids the moisture to be trapped between layers and mould to develops on the surface.
Then I took a look at chapter 7 of the book, and found that the author addresses what the real problem is: vapor retarders are misused in a conventional building. It has nothing to do with air. In fact, if air could be the main vector of vapor if you don't pay attention at the connections.
The incorrect use of the vapor barriers are the product of relying on the old Glaser model, a method that doesn't take account of the many variables of the heat and moisture "transmission" (i.e. variation in performance of materials based on humidity level and the starting humidity content in the material). I don't know how the situation is in US, but now Europe moved to a more accurate method, that involves complex calculations made only by computers. a good software to have a pretty accurate analysis is Wufi plus: http://www.wufi.de/index_e.html the bad news is it costs a lot!
The rule of thumb, however, is to use layers with diffusion values that increases as you go outside of the wall.
To sum up, I think the term "Breathing" is very misleading, and should be changed with "Transpirant", to avoid misconceptions.
just my 2 cents

Hi Andrea, welcome! The problem with WUFI is it lacks natural materials properties the book and we have been discussing here: https://permies.com/t/43637/natural-building/Breathable-Walls . Permeability and Diffusion, Hygroscopic Adsorption/Desorption, Capillary Absortion/Desorption, to name a few. It fails to fully define alot of mainstream conventional materials, and mating of materials as well along with fungi production which is the underlying reason we want to limit moisture in walls to begin with for health reasons, and rot. If you search the internet you'll find alot of end user anomalies. Relatively speaking it is not the best computational fluid dynamics (CFD) software out there, and if you add in the cost for an Engineer that may or may not understand it, it can be expensive.

"I was taught homes need to be airtight in order to prevent heat losses"

The book agrees with this concept, just in a different way than you will find in highly insulated walls we are more familiar with by quantitative analysis and data (some incorrect and misleading, or limited), the author's promote mass often found in natural building and walls that transport heat/cool through them slowly, to dry or cool before they reach the interior/exterior air yielding no heating or cooling additional load, but rather a time lag and storage benefit especially solar passive high insulation one dimensional steady state r-value walls lack. The massive walls also act to store humidity based on the difference between the wall and outside wall air RH, that can also dry out moisture and provide a small air change per hour (.02-.03/hr), that along with a holistic approach of combining natural ventilation to replace active or mechanical devices. Most of mainstream is failing at all this and continues to add HRV/ERVs, now large capacity dehumidifiers that are not smart enough ( like WUFI) to understand the wall, EG: all material properties and RH, vapor drive, and air dynamics.

"chapter 7 of the book, and found that the author addresses what the real problem is: vapor retarders are misused in a conventional building. It has nothing to do with air. In fact, if air could be the main vector of vapor if you don't pay attention at the connections."

Chapter 7 "Water Intrusion and Condensation Problems in Conventional Energy-Efficent wood frame Construction " I have not got to yet, but we did touch on some of it already in a review of CH 1, part two. If you have not read this section the rest of the book will confuse you. Air and moisture vectors as the book points out are often opposing each other, not one and the same. If they were in the same direction we would still focus on the connection of materials that are food for fungi often found in manufactured products in the form of blowing agents, fire retardants, etc. Barrier's can be more problematic and a breeding ground than retarders, depending. Please join in on the quoted thread with any comments or questions, Bill and I are having fun with it. None of this book is set in stone, the book acknowledges that, there are many ways to go about this, we just looked at the four main ones. Don't let the book confuse you without reading it from the beginning nor the title which is used loosely.

Judiith, I've only read 1/3 of the book so far and I give it a 10. I value data and proof so that is why.

I just put an explanation of how "Air Tight and Ventilate right " of highly insulated conventional studded walls differs with massive and Breathable Walls along with proof of concept on the review thread.

I don't know how to embed the video but there is an excellent one along with a data graph on Brick "Thermal Mass" and bridging on this blog. http://hopeforarchitecture.com/blog/

Thanks Terry for your explanation.
I've read the free materials of the book and I'll dig the other thread soon.
I guess I have to surrender to the misuse of the word "breathing" I know that the term is explained earlier in the book, but I'm still thinking about the man next door that wants to drill holes in the wall to let it breathe

Forgive me about WUFI, I was certain that it took in account some (if not all) of the properties of a material, but evidently my memory failed me
I never used it, but I saw it used by a professor to perform analysis to choose the right insulation material for a building renovation. And It does a pretty good job by telling you that vapour barriers/retarders are not so good, and that moisture permeable insulation in the inside of the house (the only one permitted in a listed historical building) can help drying the existing walls!

Thanks again,
Cheers from Italy

I'm ashamed, I just realized that the term breathable is not what I believed (in Italy we use the term "traspirante")! not it all makes sense!
I've read all the other thread, thanks so much for providing all those informations!