wooden structure

The wood is one of the materials of older use in the constructions, was used to put the whole world, wants in the primitive civilizations, wants in the developed ones, the east or ocidente. With the advent of the industrial revolution England, as great power imposes the architecture in metal. With the invention of the armed concrete the technician of superior level had concentrated its studies in the new material. The masters of workmanships, had still kept to put some time the knowledge practise on structures wooden.

This knowledge if lost with the time, being restricted the structures of roofs.
In Brazil, currently, the architecture facultieses offer in its resumes horária load of only one period to the study of the wooden structure, the offered free courses are rare, and the literature specialized existing on the subject is sufficiently scarce. The Institute of Technological Research of the University of São Paulo offers to publications and periodic courses. The use of the wood in structure of constructions, despite surrounded of “preconceptions”, in relation to the armed concrete and the metal, if it has shown advantageous, mainly with regard to the following factors:

1. On to the expontâneas popular constructions
In Canada building of up to 17 floors with wooden structure exist. In esportivos Germany, gymnasia, stadiums, etc… with space coverings in wooden structure. The sophisticated residences more of U.S.A. are constructed using wooden structure.

2. Durability
The archaeologists are always searching existing old parts still in wood such as: domestic sarcófagos, boats, sculptures, utensils, weapons, musical instruments, elements of constructions, etc. In Kyoto in Japan we can find constructed millenarian temples with wooden structure. In the end of century 19 in Salvador, some sobrados had been constructed on props wooden in next zone to the sea. In 1978 its demolition was possible to be observed some of these parts removed after, in perfect state. We still detach constructions with more than 200 years in Salvador, Parati, Rio De Janeiro, Ouro Preto, Olinda, at last to put all Brazil constructed with wooden structure.

3. Resistance to the attack of xilófagos (Cupins, Drills)
The used Brazilian wood in structures (Ipê, Maçaranduba, Jatobá) had demonstrated in assays of laboratory and practical the high resistance to the attack of xilófagos organisms. These only attack it, when the wood show apodrecimento signals.

4. Maintenance
It can be prevented the precocious apodrecimento of the wood with some details of project, such as:
- To prevent points of water condensation.
- To apply waterproof in rabbets and the supports.
- To always use the wood 20 cm or higher up of the ground.
- The roofs must have bigger beirais that 1 meter. - The sidewalk lateral always they will be inclined to prevent I accumulate of together water the walls or foundations. - To leave free space between the wooden floor and the ground for ventilation.
- To leave free space between the lining and the covering, also for ventilation.
- Joined products in the market of materials Exist easily that fight and prevent humidity, fungo, cupim, drill, etc.

5. Security
The wood does not oxidate. The metal when it is led to the high temperatures for the deformed fire occurrence, losing the structural function. Of course, if the iron of the armed concrete will not be with the adjusted covering, it also loses the structural function when submitted the high temperature for the fire. The wood in the nature already plays a structural function. After sawed, when used as structure of a construction it functions as a daily pay-molded element, of easy assembly (she has led, soft), that she did not pass to put manufacture processes that determine its resistance. What it determines its resistance is only its species. In unifamiliares residential workmanships, the control in the manufacture of the armed concrete is defective. The concrete is manufactured to put professional without technological qualification, what it represents a danger for the structures of armed concrete although I calculate to foresee it great safety margins.

6. Economy of energy
In experience carried through in Switzerland, the structure of one exactly shed was constructed in wood, concrete, iron and aluminum. A comparison of the energy expended since the manufacture of the materials until the end of the workmanship presented the following picture:
Wood - 1 unit
Concrete - 6 units
Iron - 16 units
Aluminum - 160 units

7. Comparison between armed concrete and wood in the workmanship
Armed concrete
Materials - diverse cement, wood (dismissable), pregos, screws, wire, vergalhões, sand, brita, water, additives, finishings.
Hand of workmanship - carpenters, shipowners of iron, masons, assistant.
Equipment - buzz saw, wimble, shears to cut iron, key to fold iron, concrete truck mixer, vibrator, sergeants.
Madeira
Materials - wood, pregos, screws.
Hand of workmanship - carpenters, assistant.
Equipment - Buzz saw, wimble, sergeants

Tips of the Greenpeace

To enter in contact with professionals specialized in structures wooden, it orders email stops: vladimir@brazilianarchitects.com

The photos are of projects of the architect to vladimir larin - tel: (21) 99730019