THE METHOD OF CONSTRUCTION WITH WOODEN STRUCTURES
We propose building the exterior walls – sandwich type, the heat comfort way, in the next formula: a thermal – system on the exterior with a decorative daub, a resinous wood structure, mineral wadding in the thickness of the walls, foil, and gypsum board. The prefabrication, in the workshop, of the components of the future construction, in the panel way – for the ground-floor and floor walls, and the dimension cutting of the floor and roof framing elements to the designed dimensions, assures a small period of time when assembling and also when operating. The panels will be built on professional tables with pneumatic grip.
Specialized pegs are used with a chemical interlocking system, for this type of works.
WHAT DOES THIS METHOD OF CONSTRUCTION BRING THAT IS NEW OR DIFFERENT
Due to the superior physical-mechanical characteristics, and to the multiple technical and constructive advantages it features, wood represents one of the main building materials.
The wood frame system, suggested by our company, has the best behavior when dealing with earthquakes.
An essential role in the good behavior it has on earthquakes is played by the elasticity of the wood material, which fades out the vibrations and absorbs the seismic waves.
The carrying panels of the walls have and important role in taking over the horizontal forces from the earthquake and wind;
The floor panels – impossible to deform when placed horizontally, have the role to assume and convey the horizontal forces to the elements of the vertical structure and to the metallic connectors – for the adjustment and stiffening of the elements of the structure.
To assume the horizontal forces in the earthquake, the wood frames of the exterior walls are stiffened with OSB – wooden fiber slabs, with an anti-wind role.
THE ADVANTAGES OF THIS METHOD
- - own weight reduced versus the mechanical characteristics it presents, thus leading to a high quality coefficient accountable to the other construction materials,
- - Time of execution reduced, due to the dispatch of the assemblage, whatever the climate conditions,
- - The possibility of prefabricated elements and constructive unit,
- - Low incorporated power demand – needed for producing and operating,
- - Thermal isolation and high interior comfort,
- - Low power demand when exploiting,
- - Low maintenance costs,
- - Ecological materials,
- - Healthy interior climate,
- - Subsequent re-sectioning.
ARGUMENT FOR THE HOUSES MADE OUT OF WOOD
- The wood and the superior products that are made out of wood have surpassed, on a worldwide level, the period of their utilization as roof structures and auxiliary buildings, being more and more used in important constructions, some of them belonging to the luxury class buildings.
- The usage of wood in construction, after a period in which it has been thought as definite its replacement in the resistance structure, has had a come-back due to its certain qualities that make it the ideal material for building a healthy microclimate in dwellings.
- Besides the very low coefficient of thermic conductivity, 7-10 times better than that of concrete and 3-4 times better than that of bricks, the easiness of the assemblage, reduced weight and the possibility to modify and extend in time, have had an impact in option stimulation.
- It is important to delimit the modern houses with wood structures from the traditional houses with casing swedges more or less finished or the little camping houses.
- 82% of Americans live in this kind of houses, they have only the resistance structure out of wood, and the exterior and interior details incorporate only the most refined construction materials.
- It is true that they can also be vacation houses, but the main porpoise is building a family house with a permanent characteristic which will realize a healthy microclimate and favorable investment and maintenance costs.
- In the European Union this building system has hardly earned its status of an alternative to brick houses but now three out of five houses are done using this system, although their cost is 8-10% higher than in other construction systems.
- How come in Romania, a country so rich in wood and where the investment costs for a family house would lower 30-40%, this system is almost unknown? As in many other cases, the answer is found in prejudice and lack of information.
- It is a house with a temporary character, with a short life span? – By no means!
- The modern treatment of wood is efficient and ecological. The life span of the houses with a wooden structure is similar to that of a brick house and the producers offer a 10 year guarantee for the structure, five times more than those specialized in brick houses.
- Resistant to fire?
- Again, the present treatment of the wood allows the accomplishment of a true performance: a house with a wooden structure has now reached the same performance class (F 30 B) as the brick houses but through special treatments it includes itself in F 90 (the indicative represents the number of minutes in which the house does not burn), the top class in this domain.
- Fragile to earthquakes? – By no means!
- Being made out of slender elements uniformly organized in the structure, the house acts elastic when dealing with seismic charges, does not have effort concentration and dissipates the energy without major damages. It is an example of proper behavior when having to do with this kind of solicitations.
- Does it assure thermal comfort; are there necessary high expenses for heating?
- The walls of this kind of house include a layer of mineral wadding, very efficient, the closing of the intimate part of the wall being made with OSB (Oriented Strand Board) – boards that are orientated out of wood chips, a material which is also a good thermal isolated.
- It is enough to remind that 3 cm of mineral wadding has the same thermic resistance as a daubed brick wall of 24 cm and the layer of wadding of 15 cm thickness that we normally find in the walls, assures the ensemble of approximately 25 cm thickness a thermic equivalent with a brick wall thick as 1,66 m!
- Being that we are in the numbers domain, the German norms WschO, considered to be the most exigent in Europe, foresee for the new houses a maximum annual consumption of fuel for heating of 100 kWh for every square meter of inhabited area. In other, more accessible, units of measuring – maximum 10 mc of gas consumed per year for every square meter of inhabited rooms. And the houses that permit a consumption of no more than 70 kWk/sm are considered “houses with very low consumption” and are included by that Banks that offer loans as having a notable performance and the clients that wish to own such houses are encouraged with the lowest interests in loans.
- The problem stands :
- Since when such care for the client’s pocket? Economic recession?
- Again, the answer is negative: the German legislation imposes the encouragement of actions that lead to reducing the CO2 discharge in the atmosphere, one of the obsessions of the super-industrialized countries in the modern world.
- How do the houses with wood structures border in this “modern” expectancy?
- According to the HAUS TEST 2002 magazine, from the 46 houses representative for the big companies on the German market, the most sophisticated solutions with bricks, Hebel and Renolit but also layers of mineral wadding and polystyrene hardly manage to go under the 70kWh limit and none under 62 kWh. All the models of houses with wooden structure go under 60 kWh and some even less than 50 kWh!
- Coming back to the new legislation proposals, we consider that the solution that we are suggesting is perfectly bordered in the actions that need to be encouraged. Besides the reducing the CO2 discharge, the microclimate in the house is healthy, the walls are breathing, the formation of mildew and fungus. It is the only system that offers constructive solutions for the protection of the rooms on the ground floor from the discharge of radon, responsible for most of the cases of cancer in the zones with soils that origin from rocks of a volcanic nature.
- The current maintenance and mending works will be efficiently programmed, the draftsman will draw up a chart with the optimum intervals for intervention. Accidental interventions (break down of the input installation with water or sewage – for example) will be done easily, with low costs and minimum trouble. Also, later modifications (room extensions, moving the walls, etc), the system permits the rethinking of the interior space and the change of the repartition.
- The only real danger that lurks those who wish to have such homes – the lack of professionalism on behalf of the doer or the breaching of the correct technology for executing!