The www.archdaily.com featured this informative article about Brazilian vernacular architecture.
The regional expressions of a country’s culture are vital in helping us understand the relation between context and specific conditions of social manifestations. These nuances and singularities inside the realm of construction are translated into what can be called vernacular architecture. Although it has always existed, this universe of local exemplars of architecture with their particular materials, techniques and regional constructive solutions came to be well studied in the second half of the twentieth century in Brazil, in a project that traced national architecture history, headed by Lucio Costa.
It is a type of architecture that, besides being an undeniable knowledge that is passed down through generations, it is usually highly sustainable as it incorporates low energy materials and local techniques with solutions made to be passively adapted to the local climate and conditions.
Just as in most countries, vernacular architecture in Brazil is predominantly residential. Learn more about the different residential typologies, from North to South, that have contributed to forming regional identities in the country.
A well-known indigenous residential typology, the oca (in Tupi) or oga (in Guarani) is one of the forming units of villages. Usually built with straw and timber, without interior separations, it is a collective living space and also used for daily activities such as cooking and making artisanal objects.
Another example of indigenous living spaces are the malocas, mainly found in the Brazilian and Colombian Amazon. They are also known as “big houses” and are larger than the ocas, besides having interior partings in which different family groups live. Each tribe bestows specific features to the architecture and space organization.
The quilombos emerged as resistance settlements for African slaves and descendants through all American territories. Having occurred in all Brazilian states, quilombos are a consolidated form of settlements in Brazil, from North to South.
Stilt houses are houses raised on piles over swampy soil or bodies of water, recurring in areas of high rainfall. It is common to find exemplars of this typology in Brazil, particularly in the North region.
The construction present in slums all around the world are commonly known as “shacks.” In Brazil, they are typically built in masonry without plaster. This type of building represents the reality of a significant part of the Brazilian urban population as, according to an IBGE survey (Brazilian Institute of Geography and Statistics), the country had more than 6300 slums in 2010.
Commonly present in the 17th and 18th centuries, the Bandeirista House is an exemplar of colonial architecture in the hinterland of São Paulo. Although it was built in rammed earth, like many other typologies in that time, it is mainly characterized by its floor plan, almost always rectangular or square, and a simple distribution of rooms and typical windows.
This vernacular architecture typology was highly employed in the colonial era. It is a wall building technique based on interwoven vines with wood or bamboo sticks which are fixed to the floor, and then manually filled into the empty spaces with clay.
Just like the wattle and daub technique, rammed earth was introduced in the colonial era due to its durability and constructive ease, compared to masonry and stone building. In the rammed earth case, the wood frame is removed after the mixture of clay, lime and gravel, which fills it, is mechanically compacted.
The technique came to Brazil with German immigrants in the South during Dom Pedro II of Brazil’s rule in the 19th century. The exemplars are limited to that region, with some occurrences in the Southeast. This technique consists of fitted and joined timbers, making a framework comprised of horizontal, vertical and diagonal elements. The empty spaces are then filled with masonry, stones or, in some cases, clay.
Thanks Rob, I really appreciate you educated imput
Hello. I love the idea of building a home with cordwood in Brazil.
What would be the proper local wood to use and proper cement mixture etc.. Considering bugs hot humid the weather,and it could also get very chilly in the winter. any feed back will be very much appreciated
Thanks
Rob Roy, an expert in cordwood building writes:
The characteristics that you should be looking for in a good log-end are
1. Stability. Shrinkage and expansion are two sides of the same coin. Wood that shrinks a lot can expand a lot, and vice-versa. In general, dense, hard, heavy woods (usually characterized by small annual growth rings), will shrink more than light, softer, airy species. This may seem counter-intuitive, but, with few exceptions (such as hemlock), this is the case. Shrinkage is a cosmetic problem that can be addressed a year or two after construction, by a variety of methods described in the literature (and some of my other replies in this column.)
2. Insulation (R-value). Once again, the lighter airier softwoods perform better as insulation. Dense heavy woods are more like stone: they are good heat storage capacitors (thermal mass), but also transfer heat rapidly (poor R-value.)
3. Consistent dimension. By this, I refer to a log-end maintaining a consistency of size and shape from one end of it to the other. If there is a severe twist or taper to a majority of your log-ends, this will be a very difficult wall to build. Further, because there is no chemical bond (and very little “paste bond”) between wood and mortar, a wall built of irregular log-ends will be inherently unstable. Cordwood is strong on compression, but not on tension, even worse than other masonry units such as brick, block, or stone. So, log-ends cut from “bushy” or severely twisted or tapered species are a pain to work with and will not yield as stable a wall.
4. Rot resistance . Oddly, wood rot is hardly ever a species-related problem, if you pay attention to basic building principles: (A) Do not use punky or insect-infested log-ends, (B) Get the bark off, (C) Don’t have log-ends resting against each other, which traps moisture, (D) Keep the first course of cordwood masonry well clear of the ground, and (E) Use a good overhang on the building, at least 16 inches. With regard to “D”, I like to keep the wood two to four inches off the ground in dry or “normal” areas like where I live in northern New York, 8″ to 12″ in wet areas. In Mountain View, Big Island Hawaii (with 190 inches of rain per year), we kept the wood a full eight-inches off the footings (on a course of blocks) and there has been no ill effects to the cordwood.
5. Aroma. This one rarely comes into play, but some woods do stink, like the so-called “piss elm.” I’d avoid ’em. Some aromatic cedars may seem like a nice smell in small doses, but I know of one lady who had a sauna built for her of strong incense cedar and she could not go into the stove room at temperature. There is a reason that moths do not attack woolens in a cedar closet!
So, readers with rare woods please cut a log-end sample of the wood you have in mind and evaluate it yourself, keeping the five criteria above in mind.
Here are two different non-shrink mortars (not concrete, which contains stone aggregate):
Mix A: 9 sand, 3 soaked softwood sawdust, 3 hydrated (Type s or “Builder’s”) lime, 2 Portland cement. The sawdust should be passed through a half-inch mesh screen and soaked at least overnight.
Mix B: 9 sand, 3 masonry cement, 3 ounces of W.R. Grace Daratard 17 cement retarder.
All mixes are equal parts by volume. Medium shovelsfulls will yield one wheelbarrow load in either case.