A modern brick by and large is not a very exciting thing. And a pile of bricks are probably a nuisance; an obstruction or at the very least an eyesore. And in the developed west, brick is ignored or maybe in some minor way still appreciated by a few for the beauty that they bring to the façade of mostly older homes, schools, churches, and libraries. Brick used in this nonstructural way is an attractive but costly alternative to less expensive options like PVC siding and as such must be amortized over many years to realize the financial benefit.
A Mexican brickmaker gave me the cost lowdown on locally made brick. He told me that 20 years ago a brick cost 2 pesos and a kilo of tortillas cost 2 pesos. Now, tortillas cost 18 pesos per kilo while a brick still costs 2 pesos.
The fundamentals of brickmaking here in Mexico is this: mix clay mud with cheap binder like sand, shovel the wet muck in 8 brick molds, let dry in the sun, then stack them over a some burnable energy source, then torch it and then keep the fire going for the better part of a day. And all that work for a measly 2 pesos per brick. I don’t know what it costs to make an adobe brick these days because nobody builds with adobe anymore at least not here where the fired bricks are so cheap and plentiful.
In 2000 BC, 14,400 mud bricks cost the equivalent of just 504 fired bricks. The cost ratio gradually improved to where, by 600 BC the cost difference was down to a factor of 2X – 5X. But those were building bricks – structural – and the added strength that came from firing the brick was a justifiable cost given the improvement in compressive strength. Quite probably unbeknownst to the builder, but viewed historically, this improvement was important for the advancement of civilization. And the co-development of architectural structures with more complex shapes and larger sizes were in large part due to the bootstrap of ancillary technologies like science and engineering but still predicated on advances in the [material] sciences of mortar and concrete. For example, the Pantheon in Rome constructed in the 2nd century AD stood with the largest dome for 13 centuries. That is singularly very important architecturally. To support a dome of that diameter (43 meters) speaks volumes about the technological prowess of the Romans.
The modern use of brick as a true building material isn’t realized until one steps into the developing world. Here in places like Mexico one can still see the full spectrum of its true use as a structural material. In Mexico (and Peru and others) architecturally speaking, the 16th century sits along side both the modern as well as the ancient. The structures broken down to their least common denominators; no matter the historical index point – be it 3500 BC, 1600 AD, or the present – are those ever present commonalities of brick, mortar, and concrete. The only differences are that the specific material compositions are dependant on where the building happens to be on the historical timeline. But make no mistake; these simple [yet improvingly more complex] materials were the instrumental technologies that enabled the building of every single civilization on the planet.
And there is both an art and science to bricklaying and a skilled mason can make walls with wonderfully pleasing geometries that contain great strength. Brick is beautiful. They are texturally pleasing and possess warm earthy color components. And believe it or not, a bucket of wet mortar smells good: earthy with middle notes of chalk and lime.
Bricks are practical. They are the real world version of the Lego’s toys; except formless. If you can imagine it; you can build it.
A brick is satisfying. It’s nice to hold a brick in your hand. They’re heavy which somehow maps to trustworthy in another part of our brain. Some get that patina over time that makes us temporarily forget about the scarier side of aging like entropy, decay and death.
And they’re versatile in non-building ways too. You can stack them and put things on them like books or rusted out old cars. I used the one in the picture to break into my house by smashing the 3rd floor glass in the otherwise securely locked iron door (the key was on the other side of the glass).
When I was nineteen I worked for a blocklayer and my job consisted of moving tons and tons of concrete blocks from one pile to another; all by hand of course. Another summer I helped pour concrete slabs and driveways. In ’99 I built a house where I did a lot of the foundation work myself. So I have some proverbial skin in the game when it comes to the use of these materials.
Over time my appreciation has widened as I traveled and was privileged to marvel over some of the great buildings and monuments of antiquity. I began to ask questions and look for the answers to things like how are those things put together? What makes them stand up? And just what is the history of mortar, concrete and brick?
A beautiful and interestingly comprehensive book on the use of these and other indigenous building materials can be found in ‘Built by Hand’ by Eiko Komatsu. It is picture book that shows the world wide use of brick and some wonderful examples of the creative architecture that has been wrested from such an amorphous material. One doesn’t need to be a student of art history or architecture to see what modern thinking reaffirms; that these building materials are inexpensive, widely available and highly adaptive. So, at one level – from the reasoning to the diverse applications and practices; little has changed in six thousand years.
I see exposed brick almost every waking minute of every day and most of it isn’t pretty but damned if I haven’t fallen in love with it’s most splendid utilitarian nature. The lead character for my second novel (same as my first) is a master structural engineer who for reasons developed in my first story bails out of his career in his ‘40s to explore alternatives, eventually moving to Ecuador where he among other things builds an adobe house.
Most of the story line for the first novel takes placer in Peru and over the course of several trips to country I became slightly obsessed with the pre-conquest architecture; as in, how did they do what they did. I actually read an entire book just on the civil engineering works at Macho Picchu. Some US university civil engineering program sponsored a field study trip then published the book. And I read it without yawning [even once] because to truly understand what the Inca engineers did was mind-blowing in its absolute thoroughness. Impeccable work. Without the underlying civil infrastructure: maintaining slope for drainage, creating deep gravel foundations for water management, and all the other cool things that they did, there probably wouldn’t exist the pristinely preserved UNESCO World Heritage site as we know it today.
I read somewhere along the way that the Incas were the Romans of South America. And the Roman’s were the master builders of the world for 600 years. Roman Legion’s were composed not just of soldiers but engineers as well. If you were conquered by the Roman’s then chances are you got new plumbing in the way of a better water system, new roads and other technological accoutrements that served to turn front line barbarians into citizens of the empire. A great example that is largely unknown is that the Romans’ teraformed a vast portion of the northern Sahara Desert which they did through a series of wells and aqueducts with secondary and tertiary water distribution systems. And they maintained those reclaimed desert areas until something like 300 AD.
So when I started writing my second novel I felt that the story had to have some component of building construction as a character. As Ridley Scott said, ‘The landscape in a western is one of the most important characters that the film has. The best western is about a man against his own landscape’. And I liked that and decided to apply it. Paul starts building with no more than a shovel. He has the experience of designing the supportive cores of skyscrapers but he quickly discovers that those skills are just as useless as the availability of modern tools are scarce.
He’s 5 miles from town and there are only 4 miles of road. The terrain is harsh: rock, river, dense vegetation and steep mountains. At some point out of frustration he makes fun of himself and says, ‘One man, one shovel, one wheelbarrow doesn’t amount to more than 10 or 12 hours of labor for any given day no matter how skillfully they’re applied’.
So I decided part of my story was to parachute this modern character into a technological primitive world. I also wanted to create a character with all of those admirable DIY characteristics; a refresh if you will on Heinlein’s legacy of man as a most capable and multi-disciplined life-form‘where specialization is for insects’. I wanted a tool-wielding man-of-action, who was at heart a problem solver. Not some stupid McGyver bullshit thing but instead taking a more composite view of the single biggest takeway skill of engineering; namely that of problem solving. The most rudimentary form being, break a single big problem up into several smaller problems.
In my humble opinion, structural engineers are the ‘Guys’. You can’t get an undergraduate degree in structural engineering; it’s master’s program only because of the specialization. Life or death kind of stuff. Big liability stuff; f***up once big time and your career is over kind of thing. Structural engineering is one of those professions that still has integrity. Where there is still accountability. A structural engineer can’t hide behind things like bad numbers because numbers don’t lie. And where making things that prematurely break still means something.
And so, because I know even less about structural engineering than I do about civil engineering – or adobe for that matter – I was forced to do some research into the area if for no other reason but to learn the principles and history of building with brick, with adobe being the most ancient.
The rest to follow are my notes from handwritten paper. I thought it might be useful to see this summary of the history of bricks against a back drop of some of the other related information that I am also currently writing about. Like the recent post I did called ‘Anatomy of a wall’ where the photo showed exposed adobe bricks where the concrete stucco wore away due to combined forces of weather and neglect. The ‘5 Heads in a Sack’ post had a long paragraph or two on brick-making as it is done in this Mexican valley in the present age with the observation that it hasn’t changed locally in millennia with one possible exception. The fuel sources that the brickmakers use to fire the brick are inventive and extremely cost conscious. It is not unusual for local brickmakers to reclaim the energy from the unused hydrocarbons locked in old tires. After witnessing an example of such I remind myself that ‘in Mexico you are free’; my mantra for when witnessing extreme environmentally or sentient-being unfriendly shit. I further remind myself, ‘you take the good with the bad’. And you can’t change world by shouting at people or throwing your body on a heap of burning tires. Or maybe you can, but I leave that for majorly more eco-sensitive persons than myself.
I also did a post called ‘Architecture of the Inca’, which followed on after the one called ‘House Building’ where I recollected the filled cinder block chimney that I built back in ’99. I didn’t mention in that particular post about all the design and other work that went into structurally supporting that 60 ton/45 foot tall chunk of concrete that stuck up through the center of my house. Just a note: the foundations for the interior load-bearing walls were poured as the same time as the slab and the chimney foundation. Re-enforcing steel bars (rebar) tied everything together. I dug the foundations and both designed and personally placed and tied all the rebar together by myself. The rebar and the single concrete pour insured that the respective foundations were made monolith and integrated with the immense surface area of the slab. This design foreshortened the possibilities of the walls settling or the chimney tipping over or sinking towards the center of the earth. You only have to see something like that grand 16th century Metropolitan Cathedral that is/was sinking on the edge of the main plaza (zocalo) in Mexico City to realize just how important it is to get the civil/structural engineering pieces right. Foundations are one-shot propositions and there are no do-overs, giant erasers, or delete keys.
So for me the study of the history of brick was about tying together all the incomplete information that had been bouncing around in my head into some sort of historical summary that captured the major milestones where the technology got an uptick. And yes, bricks, brick-making, mortar, and cement are all technologies. Understanding them historically is a peek through yet another window into understanding the rise and development of civilization.
Another side note: I did all of my reading and research in two of my most favorite places in the world; the Reading Room in The Library of Congress and the second floor of the Martin Luther King, Jr. Library, both in Washington, DC. If you are interested in the subject of brick I heartily recommend ‘Brick: A World History’ by Campbell and Price.
My brick notes: The technology of fired brick first appeared on the historical scene in 3500 BC. In order for a brick to vitrify (a chemical reaction that makes the brick harder and stronger) it must be heated to a temperature of 900 – 1150°C for 8 – 15 hours.
All bricks are made from clay and the chemistry of clay is very complex and because the composition of clay varies by geography it made the understanding of clay even more complicated. Clays contain traces of oxidized metals that respond well with silica’s and other compounds to long firing times and in the doing create chemically strong bonds that makes for a better load bearing brick.
The predecessor to fired-brick was air-dried brick generally known by many as adobe. The percentage of clay determines the properties for both air-dried and fired-brick. Air-dried bricks are made from a clay containing mud and mixed with straw and other locally available material to give it strength.
Ancient walls were immensely thick due in part to the fact walls of half a brick in thickness were not sufficiently strong enough to support more than their own weight. Bricklayers strove to lay their bricks in such a way to create the strongest wall possible. The modern term ‘bonding’ speaks to the various patterns to which walls are constructed by way of alternating what bricklayers call headers and stretchers. Header bricks lie perpendicular to the face of the wall while stretchers are laid parallel.
Mortar, like brick, is another technology that has evolved over time. The earliest mortars were no more than mud daubs. But as the Stone Age was overtaken by the Bronze Age and technology of hotter fires evolved so did the chemistry of creating stronger and more resilient and binding building materials.
The first evidence of a mortar of any sophistication was found in the ziggurat of Sialk built in Iran in 2900 BC. The technology of mortar had improved by the time the oldest of the Egyptian pyramids were built 300 years later. Those early Egyptian architects and engineers used a combination of mud and clay or clay and sand for their limestone constructions. Later pyramids were mortared with combinations of gypsum, clays, or lime and sand.
The next evidence of the technology improving again was with the Greeks in 500 BC when they began adding volcanic ash to a purer form of lime then after which adding sand thus creating the first hydraulic cement. A hydraulic cement is one that can cure underwater just like today’s Portland cement. So with the Greeks came both the earliest use of concrete – where concrete was made from a slurry of cement, aggregate, and water – and the related use of creating stronger mortars by way of cement mixed with sand.
The Romans built from the work of the earlier Greeks by using an improved chemistry which added crushed terra cotta, aluminum oxide and silicon dioxide into the mix.
It’s interesting to note that the technology of cement, so widely used in the Greek and Roman worlds was then lost for the better part of 2 millennia where even as late as the Middle Ages, Gothic cathedrals were being constructed with only lime based mortars.
The technology was eventually reclaimed but it wasn’t until the early 19th century that modern day Portland cement was invented and patented. Ordinary Portland Cement (OPC) as it’s known today is the result of a closely controlled formulation of calcium, silicon, aluminum, and iron and trace amounts of other elements crushed and then heated together before gypsum is added in the final grinding process to regulate the setting time of the concrete.
Concrete doesn’t dry; it cures. Curing involves an exothermic reaction called hydration where water is subsumed in the reaction. Hydration is the combination of several complex reactions with some occurring concurrently.
So, for me to write from the knowledgeable perspective of my lead character I needed to have some historical basis of understanding of the underlying technology of the adobe he was using in his house building. Why did Paul use air-dried brick rather than the more superior fired-brick? And contrast that answer with why adobe, generally speaking, is with more expensive to build with these days in a place like Mexico? Fortunately I can now comfortably answer those questions and in the doing write a more credible story where building and problem solving are in themselves a minor character in the story that I want to tell.
Forensic technicians search for human remains in a mass grave on the banks of the Lerma river in La Barca. Photograph: Alejandro Acosta/Reuters
MEXICO CITY – Authorities found the remains of 20 people distributed among eight clandestine graves while they were searching for two federal police who went missing earlier this month in the western state of Michoacan, sources in the Mexican Attorney General’s Office told Efe.
mexsandalguy 