Use of wood in the construction of housing
The Italians love less brick. Do not talk about the housing crisis that is unfolding well, but the growth of attention to a building material that did not seem to belong more to our culture until recently. The wood.
In Northern Europe, in fact, the wood carvings are part of the building culture both for historical reasons and because of supply. In past centuries, in fact, in those areas the primary requirement compared to houses was to encourage the mobility of populations living mainly dedicated to hunting, which was allowed by the wood, while in the Mediterranean regions, more sedentary as devoted to agriculture , the choice was that of brick.
In the last century, moreover, the improvement and industrialization of construction techniques led to the abandonment and decline of the wood even for those parts of buildings, such as roof trusses, floors and ceilings, and only in the last decade there has been "rediscovered "wood as a key element in the construction world, thanks to the growing demand for materials that allow for greater energy efficiency in buildings. And the wood from this point of view it is a real star.
This material allows for the creation of cavities which allow to limit the overall dimensions of the walls, thus freeing useful surfaces, but also to constructive solutions which allow a greater rationalization both of equipment, both of the insulation. The solution of the systems to the substructure, for example, allows the realization of cavities useful for the steps of the installations that are always inspected and possibly modified, which makes these solutions also optimal for use in the service sector.
It is a solution that significantly reduces the times of worksite seen that thanks to the lightness of the constructive elements these can be prefabricated in a partial and then assembled on site. Another system used is that of the prefabrication of the bearing panels which in this case possess the thermal insulation as an integral part and allow to overcome the rigidity of the systems based on the concrete.
Wooden Vs Steel
Regarding the performance of the wood with respect to building materials with "traditional" the comparison is to fail to the advantage of the latter. The thermal transmittance, for example, which is of 5.88 W / (m2K) for an external wall of normal cement of 10 centimeters, that value drops to 1.06 W / (m2K) with regard to a wall of solid wood of same thickness, while for the thermal conductivity of the wood takes the concrete with 0,040 W (m K) for the wood and 2,000 W (m K) for the latter.
Another common place to dispel is that of the "poor" mechanical characteristics of wood used as a structural element. In view of its greater lightness, has a specific weight of 500 kg/m3, against 2.000 kg/m3 and 7.800 kg/m3 of concrete steel, wood possesses efficiency performance (E / f) for the structures, equal to that of steel.
The laminated wood, in fact, an E / f of 470, compared with 480 steel and 1,250 concrete. This explains why Renzo Piano has used the wood in the construction of the roof of the Parco della Musica in Rome and also because this material has been used in other innovative projects such as the new cruise terminal in Brindisi and the Nuova Fiera di Rimini.
In terms of fire wood used as a structural element belies more than a cliché. During a test carried out in 2007 in Japan at the Building Research Institute in Tsukuba, the project carried out by the National Research Council SOFIE Ivalsa, (Institute for the Development of Wood and tree species) was carried out a test fire on a building three-storey made of solid wood panels cross-laminated. The fire started from a room with a fire load twice as high as possible in a shared hotel room, after an hour not only had affected the structural elements of the building but had not propagated to other local and it was easy to extinguish with fire hydrants, while for the damage it was easily repairable deterioration.
About the potential of the wood on the market must be taken into account that, according to research carried out by Promolegno, an association for the promotion of wood culture in Italy desired by business associations in the industry, every twelve buildings constructed in Italy one is made of wood and it is a growing trend. In 2005, in fact, new wooden houses were 1,000, 5,000 and is expected to rise in 2010, estimated at 7,500 in 2015.
And potentially it is not building "small" as that of the individual homes. "Today, 82% of the wooden buildings are single family homes, but thanks to technological developments this material can conquer cities, where you build more and more vertically: at the time you can build wooden buildings of up to nine stories» .
25/11/2012
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Translated via software
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Source:
Italian version of ReteArchitetti.it