Advantages of wood over other materials and comparative characteristics of wood
Everyone who decided to build a wooden house, I want him to long standing and well served. It is unlikely that someone wants each year to build a new home: lots of time, hassle lot of money too much. There is no peace.
Traditional material for walls of low-rise buildings is a tree. Wood as a material has many important advantages. Wood is fairly easy to stick together, easily connects with nails, screws, etc. She is well handled, and amenable to finish. In terms of the ratio of the density and strength of wood can be compared with metals. Walls of the house should be durable, have good sound insulation qualities to have, perhaps, less weight, to provide a permanent indoor temperature needed for the building.
Its disadvantages are the only sedimentary deformation in the first 1,5-2 years and a low fire. However, now with the two drawbacks can be overcome. To improve the fire resistance using special equipment, which is impregnated wood. This allows us to improve the fire resistance to such an extent that even at high temperatures, the tree will smolder, not burn.
Most comfortable for the sanitary-hygienic requirements (including having a low thermal conductivity) are bruschatye and chopped walls of coniferous trees.
Conifers is more appropriate than deciduous for the reason that there are more correct form of the trunk and less susceptible to decay.
The main parameters that determine the longevity of the tree are:
- strength
- density
- resistance to cracking
- resistance against rotting
- durability
- poor knotty
- low hardness
- high barb
- ease
Humidity is the free and bound. Feature of the free moisture is that it evaporates from the tree very easily. To test this, it suffices to recall that the rain soaked wood dries fairly quickly, within a few hours. Bound moisture, by contrast, evaporates slowly, and in order to dry the wood, without resorting to the aid of special technology, can take a few years. As the number of bound moisture resistance of wood is getting smaller.When moisture enters a limit of hygroscopicity (30%), moisture will cease to exert influence on the strength of wood. In addition, the practical value of the difference between free and bound moisture is that during evaporation the first changes only the severity of the tree, while the second varies the amount of evaporation, ie, shrinkage occurs. Reducing the amount of wood in its drying unequally in different directions. At thickness greater than the length. The table tree species are divided into 3 groups according to the value of the coefficient of volumetric shrinkage.
With reasonable drying shrinkage: oak, elm, beech, aspen, ash, black poplar, small-leaved lime, etc.
With a strong drying shrinkage: Norway maple, hornbeam, larch and birch.
When drying wood moisture evaporates evenly. First, moisture evaporates from the outer layers, and then from the interior. This uneven evaporation of moisture causes the wood that occurs internal tension, stretching it to the surface and compressive inside, resulting in the tree may show cracks.
With the density and moisture content is closely related to its ability to hold a metal mount. The greater the density of wood, the higher the resistance to pulling nails or screws. Humidity makes driving nails into wood.
Hardness - is the ability of wood to resist the ingress of solids. According to the degree of hardness tree species can be divided into 3 groups:
Soft: pine, spruce, cedar, fir, aspen, basswood, alder, poplar.
Solid: Birch, beech, elm, larch, ash, elm, elm, maple, apple.
Very solid: Grub, dogwood, boxwood, locust, birch.
Wear resistance of timber - is its ability to resist degradation in the process of friction.Here there is a pattern: the greater hardness and density of wood, the less wear.
Rot is the result of different life fungi that destroy wood and in most cases make it unfit for work.
Knotty - there was a case of branches (knots) alive or dead during growth. Knotty breaks the homogeneity of the structure of wood, reduces its strength, difficulties in processing.
Lightness - the property of wood, which is beneficial for construction in conjunction with other qualities.
(Article from the site "Wooden Houses")
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Last Updated (Thursday, 03 January 2013 13:07)
