- Lumber – general information
- Classification of lumber depending on the cross section
- Separation of lumber depending on their processing
- The placement of products in the log and the level of processing are important indicators of lumber
- The parameters of the correct choice and features of lumber storage
- Properties of various tree species
Lumber – general information
Lumber is usually called sawn products of special quality and dimensions, which have two flat parallel surfaces. Such products are made by dividing the log into a certain number of parts with further cutting along and across. All sawn timber is classified directly into lumber, wood parts and blanks, depending on the degree of suitability for future use. All woodworking products are relatively expensive goods, since only about sixty-five percent of the timber taken becomes quality sawn timber. The remaining thirty-five percent goes in the form of sawdust and wood fines..
Classification of lumber depending on the cross section
Transverse section– this is a special indicator, depending on the form of which all lumber is divided into bars, boards, obapol, sleepers, beams. Various types of lumber are formed depending on the type of wood sawing. For example, if we pass a round log once through circular saws, we get a carriage with planes on all sides. When processing wood by planing, at the exit we get planed moldings, for example, platbands, lining, skirting boards belong to it. The list of glued sawn timber includes glued logs, beams, as well as furniture boards.
Barscharacterized by a thickness not exceeding 100 millimeters, as well as a width smaller in size than the double thickness of the product. These rules do not only apply to aircraft lumber. Bars are used in all types of construction, from civil to industrial, they are used to make crossbars, frames for doors, with the help of which they level surfaces.
Boardson the contrary, they have a width exceeding twice the thickness of the product, which varies in the range from 16 to 100 millimeters. Boards are used in the production of floors, various furniture, they are an irreplaceable material in the construction of fences, in the process of decorative carving.
LaggingIs a sawn timber that has two surfaces, only one of which is sawn. Slats are called thin flat blocks, and slats and planks are short and thin lumber with a rectangular section..
Lumber intended for laying under railway rails, having the form of a bar, is called sleepers.
Provided that lumber has a width exceeding 100 millimeters, they are called beams. Barsclassified according to the number of sawn sides into two-, three- and four-edged. Most often, beams are used to create load-bearing structures, as they can withstand a huge load over a long period of time. Also, timber is used in the process of creating stairs, for the construction of wooden cottages and houses. Most often, the beams are made from pine or spruce of the highest grades..
All lumber has the following components: ribs, ends, edges, faces. The face is called the wide longitudinal side of the product, as well as all sides of the lumber with a square section. The highest purity of the quality of the wood itself and its processing is an indicator of the best face, respectively, the opposite face is called the worst. The edge is called the narrow longitudinal side of the product, and the edge is a special line of intersection of the edge of the product and the face. The cross-section is called the butt.
Separation of lumber depending on their processing
All lumber is classified, depending on their processing, into edged, unedged, and one-sided edged. Unedged timber is those that have a side surface of the log itself instead of edges. Such materials with a bark along the edge are used in those industries where the ideal appearance of products is not required. By analogy, sawn timber cut from four sides is called edged, and the surface of the log that remains in the product should not exceed the established dimensions. One-sided edged timber has one edge and sawn edges. Of course, edged lumber is more in demand and expensive, since it can be used for external construction work and for finishing.
The placement of products in the log and the level of processing are important indicators of lumber
There is another type of classification of lumber – according to the level of processing. In accordance with this division, lumber is divided into planed and non-planed. Sliced lumber has a variety of cross-sectional shapes depending on the purpose.
Depending on the location of the sawn products in the log, all sawn timber is classified into side, center and core boards. Side boards are made in the process of cutting the area of the log, which is located between the slab and the central boards. Such products have practically no knots, they are quite easy to process, and are also characterized by a clean surface. These products are of the highest quality, defects and flaws are much less common in them. Central boards are those products that have a central cut along the axis of the core. In the process of sawing such products, you can ideally see all the defects of the inner layers of the board. The central boards are of inferior quality compared to the side boards, however, due to the cutting of all annual layers, these products crack less than the core boards of the lowest quality of the three listed types. Core boards have a large number of various knots that reduce the quality of the wood parameters, as well as the core of the tree. A fairly common occurrence in such boards are flawless and metic cracks. These products often crack. Most often, core boards are more than forty millimeters thick. Sometimes, in the process of sawing these boards, the core comes out to the very face, it is for this reason that the highest grades of core boards are not made.
The parameters of the correct choice and features of lumber storage
High-quality lumber is considered the most environmentally friendly, as well as sound building material. In order to choose the right one from the variety of lumber on the market, you need to compare many parameters, such as the type of wood, the appearance of the lumber, as well as the quality of wood processing. Depending on these indicators, lumber varies significantly in price. After the lumber is selected, it is transported to the site of future construction. Lumber is stored on a flat surface, raised above the ground. They must be laid loosely, and the layers must be laid with slats. After stacking, the cover is laid on top. These simple rules will keep the materials dry. Planks purchased for external cladding, as well as other lumber that are planned to be used in important places and structures, should be stored in those places, the atmosphere of which is similar in humidity to the atmosphere in the place of the future installation. If the lumber is packed in polyethylene, it should not be removed prior to construction work. Do not seek to buy lumber in advance, for example, boards intended for indoor decoration are bought right before use or are necessarily stored only indoors. This, firstly, will reduce the likelihood of mechanical damage, and secondly, it will maintain the moisture level of the tree. Long-term storage of lumber adds unnecessary hassle, such as building a canopy that needs to be ventilated, since moisture that collects under the awning will definitely have a negative effect on the wood of the outer layers.
Properties of various tree species
What kind of wood material should you choose? Pine is ideal for building a house, which is characterized by density and strength, pine practically does not crack, does not rot or dry out. Pinehas a small number of knots, it is a fairly light material, and also relatively inexpensive. Compared to cedar, pine is less susceptible to decay, compared to oak and larch, it is more durable, despite the fact that oak, cedar and larch are much more expensive than pine.
Softwoods are most commonly used for supporting structures, but hardwoods are ideal for small critical parts such as pillows, dowels and dowels, and for finishing work. Linden, alder, aspen and poplar are considered soft deciduous trees, which is why they can become an alternative to conifers only in the creation of temporary structures.
Each wood species is unique in its own way, has both positive and negative properties. The disadvantages of spruce include susceptibility to decomposition, since the wood of this tree contains a small amount of resinous substances that prevent the tree from decay. Spruceordinary is used in the construction of load-bearing structures, sleepers, piles, poles, joinery.
MapleIs a solid tree species with a beautiful pattern on a radial cut. Maple is durable even in conditions of changeable humidity. Maple lumber is used to make veneer plywood as well as raw material for finishing.
Larchit is most often used in the construction of bridges, for the production of sleepers and piles, as well as in hydraulic engineering, as it is distinguished by its strength and hardness, as well as resistance to moisture. Larch, however, cannot be used for the production of nail support structures..
The oak kernel can be light or even dark brown. A feature of this wood is the property of oak to become stronger under water. Oakused in the furniture industry, in car building and ship construction, for the processing of parquet, parts of supporting devices, various joinery.
Thus, the variety of lumber presented will allow you to choose the right products in accordance with the requirements presented, the price and the required indicators of materials.