How to Destroy Your Adobe Home

A customer, who I will call “Bob,” called me the other day (today is November 20, 2025). He said he lives in a small town in Arizona whose family owns an adobe building—built in 1923—that has been in the family for decades; it was once a pool hall and barbershop but now exists as a visitor center, gift shop, and museum.

(Need adobe repair on your adobe home? Click here or call/text Adobe Masters: 520-331-4004. Email: adobemastr@gmail.com)

The building is constructed out of the old style, sun-dried mud adobe. It was stuccoed sometime in the early part of the 20th century, probably before WW2. Then, just recently, this building was re-stuccoed, the old stucco was removed, and 2″ of insulating EPS foam was attached to it, then covered with chicken wire and/or lath, and stuccoed with what I believe is a modern day, Portland cement based stucco.

There is a small “window” which was left in one wall of this adobe building which is basically a small, window type opening where people can see the original adobe. This small window has a piece of plexiglass over it so people cannot actually touch the raw adobe and potentially scrape, claw at, or carve into the adobe, as unfortunately some people might be inclined to do. Bob wanted to inquire about the Silox Adobe and Rammed Earth Water Repellent to see if it would be appropriate to protect and preserve this small adobe area.

A couple of red flags were immediately raised in my mind as Bob described the situation and I began to ask him some questions. What prompted these red flags was this new stucco which the building was recently covered in.

For readers of this website, I have made it clear that one of the worst decisions someone can do to their old (or new) mud adobe home whose bricks were made in the old-fashioned way (a pit was dug somewhere and out of this pit adobe soil was extracted, water and straw was added to this mixture, then the material was dropped or scooped into wooden forms laid on the ground and allowed to dry for a short amount of time. The wood forms were shortly and carefully lifted off of the hardening/drying adobes and they are allowed to lie out in the sun for weeks or even months after carefully being turned on their sides and stacked for better drying) is to cover it with a modern, Portland cement based stucco.

Why do I write this? In a nutshell: breathability. Adobe must be able to breathe. I have written a chapter on this elsewhere on this site you can access here. Modern, Portland cement based stuccos do not allow the adobes to adequately breathe, especially when covered with a 2″ layer of EPS foam.

Stucco is like concrete: both crack; it is simply the nature of the material. But a significant enough crack formed in the stucco covering your adobe, if that portion of the wall receives moisture from the rain, may certainly allow the rainwater to enter this protective “skin” provided by the cement based stucco and percolate into the adobe, dampening it.

And now, the same stucco that initially protects the adobe from being damaged becomes a tomb for the adobe because the water is now trapped inside these cement based walls and the sun and air cannot warm up and freely circulate around those walls and allow them to quickly dry out. In other words, the very material thought to protect the fragile adobe from being damaged by the elements becomes the very cause of one of the most damaging effects on the adobe: water that enters into the adobe now cannot easily escape and the adobe begins its slow death from moisture saturation.

This was the situation with Bob’s adobe building. A 100 year old building constructed in “the old fashioned way” and now requiring major maintenance was now being subjected to the “new way” of addressing this century old problem: how do we protect, preserve, and maintain ancient adobe buildings? For the vast majority of people, the answer seems to be a self-evident one: utilize the benefits of modern day technology, knowledge, and materials to address old problems. Makes sense, but nothing could be further than the truth. If someone follows this “new advice,” there is a great chance they will be putting that old building on a path of quiet, incremental destruction.

The late legendary investment guru Charlie Munger of Berkshire Hathaway was a fan of the principle of “inversion”: the practice of solving problems by approaching them backwards. This is a counter intuitive way of looking at problems but one that can provide us with some interesting perspectives we might not have otherwise seen from approaching problems in the traditional manners.

Inversion has a definite place in the study of preserving, repairing, and maintaining adobe homes. The typical way we address this issue is by asking, “What is the best way for me to preserve my adobe home and keep it from melting away or falling apart?”

Let’s try inversion and ask the question in this way: What is one way I might be able to help destroy my old, mud adobe building built in the early 1900’s? Answer: Stucco it with a modern, Portland cement based product which will prevent it from being able to effectively breathe.

The understanding this provides us is a bit more nuanced and subtle than looking at the situation from the normal perspective. It causes us to shift our thinking in a different way and directs our brains to look at the problem from a slightly different angle. To me, in fact, this “inverted question” is somewhat jarring, for who would intentionally seek out answers to ruin their adobe home? But this is part of the beauty of inversion as it can shock us to see things in the opposite way we normally would look at in solving problems.

I believe a great many adobe homeowners need to be shocked into some realities simply because they own such unique homes. Adobe homes, and in particular those adobe homes that were built in the old-fashioned way as described above, are in a different league than modern day frame or brick built homes. In fact, they are, in my opinion, two different species that just happens to share some of the same characteristics: walls, roofs, doors, windows, kitchen, baths, bedrooms, etc. But would we consider a lion to be the same animal as, say, a hippopotamus? Both have four legs, two eyes, two ears, a tail and a mouth, don’t they? Yes, of course, but, well, you get where I’m going with this analogy. Just because two things share some characteristics does not mean they are the same animal and require the same diet, food source, habitat, and living space. To feed both the exact same food would end up starving one of them.

Shocking, isn’t it, to look at things that are similar and believing both require the same things to survive and thrive? Just as you would not throw a steaming pile of swamp grass into the pen of a lion and expect it to devour it is the same way of thinking about how you maintain a brick home and an adobe home: what works for the one might end up destroying the other.

Throughout my website, I try to educate my adobe home readers to stop thinking they are living in a brick home. They are not. They are living in a dirt home. The two materials could not be more different in care and feeding, exactly like the dietary and living conditions of the lion and the hippo.