Properties and applications of timber

To build the most extensive use of coniferous trees, pine, fir, larch. The most widely used is pine. Fir wood contains less tar than a pine tree, and therefore easier to rotting in a high and variable humidity. Spruce are produced predominantly bearing wooden structures. Hardwoods have less stability and uniformity, with the exception of oak, the wood is solid and durable. The density of wood ranges from 400 to 1100 kg/m3 and porosity - 30 to 80%. Properties and applications of wood Wood moisture affects all of its major properties, and varies depending on the humidity and temperature. Depending on the humidity of the wood are distinguished: completely dry - humidity of 0%; room-dry - humidity of 8-14% air-dry - humidity of 15-20% wet - wet more than 20% freshly cut - more than 35% humidity. Apply the wood for the device and partition walls, roofs and ceilings, making moldings and millwork are also used wood waste (sawdust and chips are made Pressed plates, etc.). Pine Pine is of two kinds: Rudova growing on elevated sandy ground, and myandovaya, growing in lowland areas. Rudova melkosloynuyu pine has a dense resinous wood myandovaya - a loose, coarse-grained wood. Used for cutting pine walls of houses, manufacture window frames, doors, floors, millwork, plywood, etc. Spruce fir is of two kinds - the European and Siberian. Fir wood a uniform white color with a faint yellowish tinge, it is soft, like pine, but with less tar, which reduces resistance to decay. Used spruce for the same purpose as the pine. Larch strength, density and hardness of larch is about 30% higher than that of pine. Larch is very resistant to decay, has a high hardness. The disadvantages include larch its cracking during drying. Larch handled with difficulty and zasmalivaet sole instrument. Larch used for the manufacture of pillars and beams, mainly in hydraulic engineering. Roundwood logs construction softwood and hardwood must have a thickness on the upper end of at least 14 cm and a length 4-6,5 m for structural round timber houses humidity should not exceed 25%. The logs should be cleared of branches flush with the surface, the ends - sawdust at right angles to the longitudinal axis. Logs intended for antiseptirovaniya must be cleaned of bark and bast. In addition to applying a thin round wood logs: podtovarnik (diameter 8-13 cm) and poles (3-7 cm). Apply round timber, depending on the quality of timber or processing defects. Round material is divided into four grades. In construction logs are used primarily 2 nd and third grades. Round wood is also used to produce lumber that receive sawing logs on the plate, quart, rods, sticks, boards, slabs. Bars have a thickness of 15 cm and a width of no more than twice the thickness, the board - a depth of 10 cm and a width of more than twice the thickness. Lumber is divided into edging and edging on the milled (sliced) and nefrezerovannye. Thin timber have a thickness of up to 3,2 cm thick - more than 3 cm boards and beams are divided into five grades (choice, 1 st, 2 nd, 3 rd and 4 th), the boards do not have a perfect grade. Used lumber in almost all areas of construction. From sawn semi-finished building materials are made and products: board (planed on the edges in the quarter, tongue and groove), sexual rake, rake for lining, specially processed bars, rods, profiles (molded) products - frames, baseboards, handrails for stairs and railings etc. For molded products include frames, layout, skirting boards, boards for floors, handrails, banisters, parapet boards, siding, moldings humidity planed products must not exceed 15%. Materials for flooring materials for the floors are of the following types: block parquet, parquet boards, planks for the flooring clean floors, stoves, chipboard, fibreboard panels, planks for the flooring clean floors are made of pine, fir, larch. Humidity of wood for clean floor should not exceed 12% for wood flooring - no more than 6-10%. Materials used for floors, depending on destination and class room building. In the living room is best to arrange the floors of the tongued antiseptirovannyh planks or parquet, parquet is more expensive but more durable material.