What is lumber and its varieties for construction and household use. Wood. Lumber and wood materials I. Organizational moment

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Lumber and wood materials

At longitudinal sawing tree trunks on sawmill frames receive different lumber (see figure): beams, whetstones, boards, plates, quarters and slabs.

timber - lumber with a thickness and width of more than 100 mm. If the beam is sawn on both sides, then it is called two-edged, and if on four sides, then four-edged.

Bruschi - lumber having a thickness of 50-100 mm and a width of no more than double the thickness, i.e. 100-200 mm.

Boards - these are lumber 13-100 mm thick and 80-250 mm wide, i.e. more than double thickness.

Plates obtained by longitudinally sawing a log in half, and quarters - into four parts.

A board differs from a block in that its width is more than 2 times the thickness.
Gorbyl , or both sexes , called the sawn side part of a log

Lumber:
A– four-edged beam; b– double-edged beam; V– bars; G– edged boards; d– unedged boards; e- plate; and- quarter; h– croaker ( 1 – layer; 2 - edge; 3 - end; 4 – rib).

Lagging- side parts of the log, cut off during longitudinal sawing.
Planks and planks- thin and short lumber rectangular section, A slats- flat bars and thin narrow boards.
According to the nature of processing, lumber is divided into unedged and edged . U edged materials all four sides are sawn, and the dimensions of the wane do not exceed the permissible limits; at unedged The sides are sawn, but the edges are not sawn at all or are partially sawn.

Blanks. These are boards and bars, cut to the overall dimensions of the parts with appropriate allowances for shrinkage and subsequent processing. Blanks used in the construction of joinery and furniture products can be either solid or glued, and have various cross-sectional shapes.

Modern methods of wood extraction are shown in the video -

And this video shows another version of the wood harvester -

Lumber have the following elements: faces, edges, ribs and ends.
Plasyu called a wide plane of lumber, and edge - narrow plane.
Edge is the line of intersection of these two planes.
end - transverse (end) plane of lumber.

Lumber can be obtained from a log by sawing it into beams and boards, turning it over and changing the distances between saws. Several cutting options are shown below.

Widely used as a construction material plywood . Plywood is made by gluing three (or more) thin sheets of wood on top of each other - veneer . “Veneer” translated from German means “sliver” (shavings)
Veneer. It has been known since ancient times, and mechanical method obtaining (on a machine) veneer was invented at the beginning of the 16th century. Currently widely used in woodworking peeled and sliced ​​veneers.
Veneering is the process of attaching thin layers of wood High Quality to the wood panel. This is an old process that was first used around 1300 AD. Modern method Veneering is used to improve the surface of products, mainly for high-quality furniture, table tops, decorative wood panels and doors. Veneering can also be used in the production of parquet. When veneering, glue is usually applied to the backing. The veneer is then placed on top of the adhesive film and the product is pressed in a hot press.
Veneer used for decorative finishing of furniture and other wood products. Veneer gave craftsmen the ability to make lighter, less expensive furniture by dramatically reducing the amount of wood needed to make it.
Veneer- this means gluing the veneer onto a stable base (MDF, chipboard, plywood, etc.). This made it possible to produce finished products made of wood that is not subject to deformation and cracks, so characteristic of solid wood. In addition, the use of sliced ​​veneer made it possible to use wood species that are usually unsuitable for use in solid wood due to their unequal sizes, such as root and exotic wood, aesthetically very beautiful and in demand. Veneer production has decided a number of environmental problems, significantly reducing wood costs in the production of furniture and doors.
Peeled veneer- these are single-layer sheets of wood obtained by peeling birch, alder, maple, beech, pine, spruce, and larch wood on machines.
Peeled veneer cut (peeled) sharp knife a special peeling machine when rotating a log, previously steamed in hot water, about 2.0 m long (see figure). In this case, the log, like a roll, is rolled out into a veneer strip. The veneer strip is cut into square sheets, which are dried in dryers, coated with glue and laid on top of each other so that the direction of the fibers in them is perpendicular to each other. The sheets are glued together under a press. This is how plywood with a thickness of 2 to 20 mm is obtained.
Veneer is used for veneering wood products and making plywood, glued and bent-glued products, and furniture is also made from plywood, Sports Equipment and other products.
Veneer dimensions at a humidity of 8±2% should have a length of 800-2500 mm (with gradations of 100 mm), a width of 150-2500 mm and a thickness of 0.35-4.0 mm.
Sliced ​​veneer represents thin sheets, obtained by planing beams from wood species with beautiful texture(oak, beech, walnut, maple, ash, mahogany) on veneer-planing machines.
When planing, the log is stationary, and the knife moves back and forth and cuts the wood layer by layer (sliced ​​veneer).
Depending on the texture of the wood, sliced ​​veneer is divided into tangential, radial, semi-radial and tangential-end. Sliced ​​veneer can have a length of over 300 mm with a gradation of 100 mm and a thickness of 0.4-1.0 mm. The width of the veneer, depending on the type and texture of the wood, must be at least 60 mm. The moisture content of veneer varies between 8 + 2% Veneer sheets are placed in bundles in the order in which the sheets were released when planing wood.
Sliced ​​veneer is used for lining wood products and semi-finished wood products in the manufacture of furniture. From it you can type various geometric and other ornaments.

Veneer is obtained in several ways: planing, peeling or sawing

Sliced ​​veneer used for covering furniture, peeled - for the production of multilayer plywood.

Veneer can be used to cover not only smooth surfaces, but also of a complex curved shape. To cover such surfaces with veneer, special “beds” are most often used, which cover sheets of veneer or in which they lay it, pressing it with clamps or a press.

Plywood. It is obtained by gluing three or more sheets of peeled veneer. The joined sheets are positioned so that the direction of the fibers in them is mutually perpendicular. The type of plywood is determined by the type of wood from which its outer layers are made. The dimensions of plywood sheets are as follows: length (width) 1220-2440 mm, width (length) 725-1525 mm, thickness 1.5-18 mm.

Plywood differs from other sheet materials in the comparative sameness of physical and mechanical properties due to the cross direction of wood fibers in adjacent layers, less warping and cracking in different conditions applications. Plywood stronger than wood, almost does not dry out or crack, bends and is processed well. In house construction it is used for cladding. panel doors and panels, manufacturing attic floors and etc.; in car and shipbuilding it is used as a front finish; in furniture production, the back walls of cabinets are made from plywood, bookshelves, chairs, tabletops and other products.
Plywood is made mainly from birch wood.

Particle boards (chipboards) obtained by pressing and gluing crushed wood in the form of shavings, sawdust, and wood dust. For production particle boards They mainly use wood waste and even bark.
According to manufacturing technology, slabs are distinguished flat pressing(with the arrangement of wood particles parallel to the surface); continuous pressing(with the arrangement of wood particles perpendicular to the surface. Depending on chipboard designs divided into one-, three- and multi-layer. The slabs are produced uncoated(unsanded and polished), lined with peeled or sliced ​​veneer, paper. In addition, lined slabs can be finished and unfinished(With paint coating or without). Chipboards have the following dimensions: length 2400-5500 mm, width 1220-2440 mm, thickness 10-26 mm.
Flat pressing slabs are used for the production of furniture and critical parts in construction, and continuous pressing slabs are used for the production of non-critical building parts.
They are durable, almost do not warp, and are well processed cutting tools. They are used to make furniture, doors, partitions, walls, and floors. However, over time, they release substances harmful to health, so they are undesirable for use in residential areas.

For furniture production the surface of the slabs is improved by lamination (slabs laminated chipboard, melamine faced particle board). The production volumes of chipboards in the world can be considered stable - the annual increase in capacity does not exceed 2-3%, mainly due to the rapid development of boards MDF And OSB.

You can watch a fragment of a film about the production of chipboards and furniture, and the entire film can be downloaded .

Fiberboards (Fiberboard). This is a sheet material made from wood fibers compressed into a homogeneous material under high pressure and high temperature. Based on their bending strength, slabs are divided into super-hard, hard, semi-hard and soft. The length of the slabs is in the range of 1200-6100 mm, width 1000-2140 mm, and thickness 10-25 mm.
Fiberboard used along with plywood in the manufacture of joinery and furniture and joinery and construction products, for interior decoration: cladding walls, ceilings, floors, in the production of furniture and doors.
They have a nice gray or Brown color, smooth surfaces, bend, like plywood.

Since the 1960s, plate production technology began to develop MDF. Abbreviation MDF comes from English (Medium Density Fiberboard, medium density fiberboard ). The base of the slabs is ground to a fibrous cotton wool-like state wood pulp, but there are a number of technological features that provide MDF boards with much higher consumer properties: during the production of MDF, dry fiber is pressed, and the fibrous mass does not just “glue together”, but forms an inextricable connection through physical and chemical reactions. This, in particular, makes it possible to process MDF boards with deep milling. MDF production volumes in the world increase annually by 10-15%. MDF boards are used in construction, furniture, wall panels and laminated flooring ( HDF).

In 1981, another mini-revolution took place in the production of wood boards - boards appeared OSB (Oriented Strand Board , oriented strand board ). By analogy with slabs MDF, which can be called today “ideal furniture boards”, boards OSB can be called "ideal building slabs". In terms of their properties, OSB boards are similar to solid wood, but “cleared of defects” - such as disordered anisotropy of properties and local defects (knots, delamination). OSB cuts well and holds screws well. If necessary, slabs OSB can be sanded, varnished (including tinting), painted and even laminated. Moisture resistance and resistance to the formation of fungi and mold in slabs OSB also significantly higher than that of solid wood. Production volumes OSB in the world annually increase by 10-15%. In 2000 OSB application V frame housing construction has already exceeded the volume of plywood use. The use of OSB is also growing in furniture production.

The disadvantage of plywood, particle boards and fibreboards is that they are susceptible to dampness. Under the influence of water and moisture, plywood delaminates, and the boards swell, lose strength and crumble.

If you want to purchase material from exotic tree species with an original natural pattern, you will have to overpay in comparison with lumber from ordinary trees. Durability is also of great importance when choosing wood. There is a distinction between hard rock, which is used in the construction of building frames or installations load-bearing elements. Medium strength lumber is often used in furniture production. With the help of soft rocks, you can try to reduce the cost of construction by using them in the production of non-load-bearing elements of buildings. Durable species include cherry, hornbeam, maple, ash, oak, and beech. Alder, linden and conifers are used to make furniture. Poplar and birch are softwoods.

Today, lumber manufacturers offer processed and freshly cut products from the highest to third grade. The highest is the most valuable. Materials on sale different sizes. Edged boards made using new technologies using high-quality equipment from environmentally friendly raw materials are popular. When choosing lumber, you should pay attention to their quality and then the manufactured products will delight you and your family.

Grape

In gardens and personal plots, you can choose a warmer place for planting grapes, for example, on the sunny side of the house, garden pavilion, or veranda. It is recommended to plant grapes along the border of the site. The vines formed in one line will not take up much space and at the same time will be well lit from all sides. Near buildings, grapes must be placed so that they are not exposed to water flowing from the roofs. On level areas it is necessary to make ridges with good drainage due to drainage furrows. Some gardeners, following the experience of their colleagues from the western regions of the country, dig deep planting holes and fill them with organic fertilizers and fertilized soil. The holes, dug in waterproof clay, are a kind of closed vessel that is filled with water during the monsoon rains. In fertile soil, the root system of grapes develops well at first, but as soon as waterlogging begins, it suffocates. Deep holes can play a positive role on soils where good natural drainage, permeable subsoil is provided, or reclamation artificial drainage is possible. Planting grapes

You can quickly restore an outdated grape bush using the layering method (“katavlak”). For this purpose, healthy vines of a neighboring bush are placed in grooves dug to the place where the plant used to grow. dead bush, and sprinkled with earth. The tip is brought to the surface, from which it then grows new bush. Lignified vines are laid on layering in the spring, and green ones - in July. They are not separated from the mother bush for two to three years. Frozen or very old bush can be restored by short pruning to healthy above-ground parts or pruning to the “black head” of an underground trunk. In the latter case, the underground trunk is freed from the ground and completely cut down. Not far from the surface, new shoots grow from dormant buds, due to which a new bush is formed. Neglected and severely frost-damaged grape bushes are restored due to stronger fatty shoots formed in the lower part old wood, and removal of weakened sleeves. But before removing the sleeve, a replacement is formed. Grape care

A gardener starting to grow grapes needs to thoroughly study the structure grapevine and the biology of this most interesting plant. Grapes are vine (climbing) plants and require support. But it can spread along the ground and take root, as is observed with Amur grapes in a wild state. The roots and aboveground part of the stem grow quickly, branch strongly and reach large sizes. IN natural conditions without human intervention, a branched grape bush grows with many vines of different orders, which begins to bear fruit late and produces crops irregularly. In cultivation, grapes are shaped and the bushes are given a shape that is easy to care for, ensuring a high yield of high-quality bunches. Vine

Schisandra

In the literature devoted to climbing lianas, the methods of preparing planting holes and the planting itself are unnecessarily complicated. It is proposed to dig trenches and holes up to 80 cm deep, lay drainage from broken bricks, shards, install a pipe to the drainage for feeding, cover it with special soil, etc. When planting several bushes in collective gardens, such preparation is still possible; but the recommended pit depth is not suitable for Far East, where the thickness of the root layer at best reaches 30 cm and it is most often underlain by waterproof subsoil. Whatever drainage is laid, but deep hole It will inevitably turn out to be a closed vessel where water will accumulate during the monsoon rains, and this will entail damping off and rotting of the roots from lack of air. And the roots of actinidia and lemongrass vines, as already noted, spread in the taiga in the surface layer of soil. Planting lemongrass

Schisandra chinensis, or schisandra, has several names - lemon tree, red grapes, gomisha (Japanese), cochinta, kozyanta (Nanai), kolchita (Ulch), usimtya (Udege), uchampu (Oroch). In terms of structure, systemic relationship, center of origin and distribution, Schisandra chinensis has nothing in common with the real citrus plant lemon, but all its organs (roots, shoots, leaves, flowers, berries) exude the aroma of lemon, hence the name Schisandra. Schisandra vine clinging or entwining around a support along with Amur grapes, three species of actinidia are original plant Far Eastern taiga. Its fruits, like real lemons, are too sour for consumption in fresh, but they have medicinal properties, pleasant aroma, and this brought him a lot of attention. The taste of Schisandra chinensis berries improves somewhat after frost. Local hunters who consume such fruits claim that they relieve fatigue, invigorate the body and improve vision. The consolidated Chinese pharmacopoeia, compiled back in 1596, states: “the fruit of Chinese lemongrass has five tastes, classified as the first category of medicinal substances. The pulp of lemongrass is sour and sweet, the seeds are bitter and astringent, and in general the taste of the fruit is salty. Thus, All five tastes are present in it." Grow lemongrass

The unique properties of wood - strength, long service life, environmental friendliness, pleasant aesthetic appearance, have made it a popular building material, raw material for the production of furniture, decorative coatings, folk art. People who work with wooden blanks after sawing them are called upon to have a good understanding of the types of lumber and know their technical characteristics.

Type of raw material and its preparation for cutting

When classifying wood according to the degree of preparation, the moisture content of the material is taken into account. Absolute humidity is determined by the ratio of mass - moisture and dry wood per unit volume.

There are several types of lumber

Exterior lumber with an air-dry or natural humidity more than 18–20%, obtained after prolonged exposure to air. Used in construction and for the construction of wooden structures.

A universal lumber with a moisture content of up to 15%, it is used for arranging skirting boards, platbands, and beams.

– in a special box with high temperature. Humidity – within 8–10%. Absolutely dry wood is processed protective composition to protect against moisture absorption from the atmosphere.

Insufficiently dried or improperly stored wood is susceptible to deformation, rotting or destruction. To prevent this from happening, lumber needs additional processing in steam chambers.

All wood is divided into several types:

• trimming material, when the workpiece is processed from all sides;
• unedged pieces – processing on one side only.

By processing method:

• unmilled lumber;
• milled or planed.

There are different cutting methods in relation to the annual rings of wood:

• The radial cut is oriented towards the center of the rings. Blanks – with various sizes, width limited cross section logs
• Tangential - the cut is directed tangentially to these rings and helps to obtain long boards with the same dimensions and cross-sectional shape.

Each type of cutting lumber serves to create various forms products. It is the variety of sizes and shapes that allows processed wood to be used in all areas of human activity.

Classification of processed lumber

There are several types of lumber, depending on the degree of processing.

Plate- half a log obtained by cutting a tree down the center. It is used for the manufacture of sleepers, timber, and solid boards.

timber– a common result of woodworking. They are used when arranging cladding and as an independent structure in buildings. The timber has a thickness not exceeding 100 mm, and a width less than twice the thickness.

Depending on the number of processed sides, there are two-, three- and four-edged timber. There are its varieties:

• simple timber;
• rounded timber.

The influence of part size on its classification

Bar– the same timber, but with smaller dimensions, the standard section size is 40×40 or 50×50 mm. Used in furniture industry and for the production of joinery products.

Rail- a type of bar, flatter and narrower, available in different sizes. Often such a product is sawn directly at the construction site, its width and height are adjusted to the required dimensions.

Board– edged products whose width ranges from 85 to 140 mm, and thickness ranging from 27 to 45 mm. Products are needed in capital construction, for interior decoration, in furniture production.

The board is divided into 5 grades:

• Selective - applicable in shipbuilding, car side sheathing and creating luxury class interiors.
• First and second grade lumber is suitable for the production of furniture facades.
• The use of third-grade boards is construction projects.
• For fourth grade boards – production of boxes. They are used to pack large mechanisms for shipment.

Popular types of boards:

• Parquet - its bottom layer is made of roughly processed wood, and elite species are used for the top.
• – durable and light, it is made from the best wood.
• Window sill - well dried, with special impregnation.
• Engineering - with a top made of wood and a bottom layer of plywood.

Additional classification of materials by purpose

Lining is lumber used for interior and external cladding. IN technical documentation it is called cladding board. Street cladding is made exclusively from solid lumber.

Sleepers are made from valuable wood, with excellent wood condition, as they are susceptible to adverse effects external environment and heavy loads from heavy trains.

Lumber is selected that can reliably hold the rails and dampen the vibration of trains. Pine is often used to make railroad ties, and they are sometimes made from spruce, fir, red maple and Siberian cedar. To prevent rotting and rapid destruction, they are impregnated with a special substance.

Small moldings - these products include corners, skirting boards, platbands, glazing beads - various dimensions to satisfy the need for selecting optimal options.

Croaker – waste from sawing logs into boards, its side part. It is used for the construction of temporary buildings, as sheathing under the roof. Some designers advise customers to make decorative finishing using this lumber. Low cost Such wood made the croaker in demand.

Obapol (quarter) is an unfinished version of the board, only one side is flat, the width along the entire length is unequal, so the longitudinal section has an irregular shape.

A wide range of wood and an abundance of lumber, differing in - real opportunity choose all the interior details to your advantage.

Tree species for lumber

Known types of lumber from various breeds trees, they can refer to two types of wood:

• coniferous;
• deciduous.

Almost all hardwood lumber that has an aesthetic appearance and operational properties, suitable for interior decoration.

Both coniferous and deciduous wood of different price groups are environmentally friendly materials. They are now popular for interior finishing and exterior work in the construction of private houses.

But it is necessary to select the right wood and take into account performance qualities various types lumber.

Features of coniferous materials

Larch– resistant to water, not damaged by insects and fungi, rotting rarely occurs.

Pine– less durable, more prone to fire than other types of wood, due to the resins protruding on its surface.

Cedar– close in quality characteristics to pine and has a pronounced and rich wood texture, is resistant to decay and is able to disinfect the air in rooms where there are products made from it. Lumber is rarely used due to its high price.

Yew– the wood is red-brown in color with veins, is durable and hard, and has many knots. The material is not susceptible to wormholes and is insensitive to precipitation. Yew bars are good for carving, and veneer is good for mosaic work.

Fir– light and not too elastic wood, convenient for woodworking. It is made from roofing materials, lining for building cladding. The absence of the characteristic smell of resin allows the material to be used for the manufacture of food containers (barrels and boxes).

Deciduous range of materials

Acacia– hard wood yellow color with pronounced growth rings. It does not crack or warp, has elasticity, high friction resistance, and can be easily polished. It is used to make parts for woodworking tools and carpentry workbenches, and veneer is good for mosaic work.

Oak– demanded wood in the construction of houses and buildings. It has a beautiful texture, high strength, rot resistance, bendability and durability. Oak blanks are used for the production of furniture and parquet, arts and crafts.

Ash– with mechanical properties close to oak. High bending ability and strength are the advantages of wood. But it is easily damaged by a wormhole and needs antiseptic treatment. Ash lumber is used to make furniture and gymnastic walls.

Aspen– made from deciduous lumber, it is easy to process and is used for various works. Most often, its wood is used for making plywood or chipboard.

Alder– soft wood does not rot, it is used for making furniture, building houses, storerooms and well log houses, the material does not smell and does not absorb third-party aromas.

Birch is a durable wood with a beautiful texture, easy to process, but not resistant to rotting. It is used to make plywood, chipboard and peel-cut veneer used for furniture production.

Hornbeam or white beech belongs to a tree species with strong and hard wood. After drying, this indicator increases, exceeding the quality of oak. Difficult to process with cutting tools, but finishes well.

Maple - with hard light yellow wood, it can be processed and polished, does not warp, and is easy to cut. Wood is in demand for arts and crafts, and carved items made from it are especially successful.

Video: Types of lumber

Types of wood and characteristics of lumber in photographs.

Lumber made from natural wood is often used for construction. They can be classified according to the type of wood, the shape of the workpiece and other parameters. The characteristics of lumber depend on a number of properties of a particular type of tree.

Table of lumber characteristics.

Classification of lumber

Each type of wood has its own properties. That is why it is customary to follow a convenient and understandable classification. All natural wood materials can be divided into several groups:

Classification of lumber and characteristics:

Diagram of types of lumber.

Before purchasing one or another type of lumber, it is necessary to study their characteristics and areas of use. In this case, the selection will be correct, and the wood itself will last a long time.

Wood options

Lumber classification scheme.

Lumber used for construction can be made from various types of wood. The most popular material is pine needles; most beams and boards are made from pine and spruce, but there are other options.

Pine, unlike other types of wood, is lightweight; during construction, minimal loads are placed on the foundation. For example, aspen or birch are very heavy, but their strength characteristics are not so good. The boards are usually made of pine; this material is very durable, easy to process, and has numerous advantages.

Pine contains natural resin, which acts as an excellent antiseptic.

This ensures the absence of traces of rot and mold for a long time. Pine has a soft and delicate structure, which makes processing simple, pleasant and quick. The smell and color of pine add attractiveness to the material not only as a standard building material, but also as an option for decorative cladding walls, log structures.

The characteristics of lumber are not complete without such parameters as the number and presence of branches. Here you need to pay attention to the spruce.

This coniferous species is distinguished by numerous positive characteristics, but its processing is complicated. The problem is that the trunk contains many branches, and this is an obstacle to processing. .

Scheme of wood cutting options.

Wood such as cedar can also be used for boards. This option is not common, but is still used.

Cedar wood is strong and reliable, like spruce, but easier and more convenient to process. Fir can also be used to make lumber. It is rot-resistant, easily processed, and has numerous advantages.

Types of lumber

Lumber is available in a variety of varieties, it is possible to choose suitable option. Products differ in shape, size, characteristics, and areas of use. Common materials include edged and unedged boards, which are suitable for almost any job, but there are other options that act as auxiliary materials.

Most often for construction work edged and unedged boards, they differ in a number of parameters. These lumber are very popular; they are used for the construction of house frames, for the construction of strips, walls, partitions, for installation rafter systems, formwork and other works.

An edged board is a material obtained by cutting a log. In this case, all its edges are smooth, but a small amount of bark, that is, wane, may remain. Indicators of moisture resistance, strength, and mechanical stability vary greatly, as does the cost.

Edged board calculation table.

This makes it possible to choose exactly the material that is more suitable for the job than others, without overpaying. Pine or spruce are most often used to make edged boards. The cost of such boards is not so high, but strength and durability meet all parameters.

From such boards you can safely build not only outbuildings, but also perform interior decoration. Lumber has a standard size of 6 m, but the thickness and width vary. The width of the boards can be 100 mm, 150 mm, 200 mm, for thickness - 25 mm, 40 mm, 50 mm.

The scope of application of edged boards is quite wide:

Unedged boards have bark edges and are used quite often in construction. The appearance of these lumber is attractive, as close as possible to natural, which makes them excellent option for wall covering.

Unedged boards have less high density, therefore easily amenable to any processing. Finishing with such boards does not take much time. But if there are many cracks on the surface, this will significantly reduce the service life of the lumber.

Lumber can vary in price and quality. The cheapest include four-edged timber, which is produced in large quantities without requiring large, costly capacities.

The production of timber is carried out by sawing or hewing solid wood, but the quality of the surface will differ significantly. For example, when hewing, the sides end up torn, which is not always acceptable. When sawing, the edges and ends are more accurate; such timber is suitable for work where it is important appearance materials.

Clean-edged timber is a square-section material, planed on all sides. Its length is usually 4 m, thickness - from 100 mm, depending on the purpose. Such timber is usually made from pine.

It is processed from all sides, including the end parts. It is most often used for the construction of house walls, beams, ceilings, and subfloors. It has high strength properties.

Semi-edged board and slab

The semi-edged board has uneven planes; traces of bark may remain on the ends. This board is used for technical work. Walkways are made from it; it can be used for technical and subfloors, as a basis for other products.

In appearance, the slab is very similar to the side of a log; part of it is sawn on one side, but not on the other. Such lumber is considered lump-type waste; it remains after cutting the base material.

But the dimensions of the slab are standardized; it has the same width at the ends and along the entire length. Today, two types of croaker are used - wood and business material. It is used for various purposes, as blanks for other products and building elements.

Lumber is blanks made from natural wood.

They all differ in shape, individual characteristics, size, appearance, and degree of processing. Lumber is used for construction and repair work various types, are often used in assembling furniture, fencing, and in the construction of subfloors. When choosing, you should focus on those properties that are necessary for specific conditions.

Overview Types of wood and characteristics of lumber.

None of the building materials available on the market today have such unique qualities like natural wood.

It is very convenient and easy to process, so that you can make anything, even a spoon, even an airplane fuselage. The wood has excellent strength, it is light and has a pleasant smell. Working with wood brings true pleasure, if you understand what types of wood are and the characteristics of lumber.

Wood building materials

If you look closely at any block of wood, you can see on it a textured pattern formed by growth rings. Its appearance depends on the direction in which the tree trunk was sawn. It is customary to saw it in three directions: along and across the grain, as well as at an angle of 45 degrees. If the cut is made at an angle, then it is called tangential.

It forms a texture similar to cone-shaped lines. Three different types of cuts depending on the direction. If the cut is made along the fibers, then it is called radial. The parallel lines formed by the fibers are clearly visible on it. A cross section shows us the annual rings of a tree trunk in all its glory. The drawing has important for the external beauty of wood products, so before making wooden blank We need to be clear about ourselves in which direction we want the patterns to go.

Internal structure of wood

In order to understand the structure of a tree trunk, it is necessary to make a complete cross-section.

The top layer is called the bark. It is of no interest, so it is removed. Next thin layer- this is the so-called growth zone.

It is difficult to see, but if the tree is young, then after removing the bark you can see green fibers that are damp to the touch. They are also called cambium. After it, the wood itself begins with pronounced annual rings.

Professionals call it sapwood. In the center of the trunk there is a darker core or one that merges with the sapwood. It depends on the type of wood, which can be sapwood or heartwood.

Sound tree species are represented by all conifers (cedar, pine, spruce, larch, yew) and some common deciduous species such as oak, poplar, ash. The vast majority of deciduous trees are sapwood: birch, alder, hornbeam, maple.

Wood cell density affects strength and other physical qualities wood, but to create artistic compositions and the possibility of using this or that raw material in the work is influenced by the pattern of growth rings and heart-shaped vessels. These are macrostructural elements, and they also include knots, growths, undeveloped shoots that deflect growth rings and form various curls.

Wood with a pronounced macrostructure is the most interesting for processing, therefore, without exception, all conifers are used for crafts

Physical characteristics of wood

Like any building material, wood has a number of physical properties:

Density is measured in g/cm3 and depends on the type of wood and its moisture content. The higher this indicator, the stronger and heavier the material, it is more durable and less susceptible to rotting.

The most dense wood is considered to be oak, ash, maple and larch, and the least dense is aspen, spruce and fir. The moisture content of the wood indicates the degree of its quality and durability. Room-dry has 8 - 12% moisture, air-dry from 12 to 18%, and atmospheric-dry 18 - 23%. If the humidity is even higher, then such wood is called damp. Acoustic conductivity and thermal conductivity are important qualities.

High-quality dry wood perfectly retains heat and sound in the transverse direction. Thermal conductivity along the fibers is reduced, but sound travels perfectly along the trunk. This is even an indicator of quality and dryness. Corrosion resistance, which is higher than coniferous wood, due to the presence of resin in it. Texture, color, smell and shine make it possible to determine the type of wood and determine its decorative value.

All listed physical properties are very important for the use of a particular tree species.

Mechanical characteristics of wood

The mechanical properties of different types of wood are more important. After all, they influence the strength and durability of buildings or wood products. Mechanical strength is the ability to resist various static and dynamic influences from the outside.

The strength of a material depends on the direction of the load. In this regard, it is customary to distinguish between shear or shear strength, bending strength and compression strength. Any wood has greater strength along the grain than across it.

Testing the strength of a wooden block in the direction of load

It is worth noting that damp wood becomes less durable. The same is observed in light and loose breeds.

Plasticity is the property that allows you to create bent parts from wood. More plastic rocks retain the shape obtained under a certain long-term exposure.

Humidity and temperature greatly increase this indicator, so to make curved parts, wood is exposed to hot water or steam. Beech, elm, oak, and ash boast high plasticity. This cannot be said about conifers, since the structure of their fibers is too linear.

The hardness of wood is the ability to resist various penetrations into it. foreign bodies. There are hard tree species, such as: beech, maple, larch, oak, ash, elm (the hardest are boxwood and acacia) and soft ones, such as: linden, alder, spruce, pine. The level of wear resistance of wood directly depends on its hardness.

Characteristics of various types of wood

One type of wood or another is used for different purposes.

All of them are divided into coniferous and deciduous. The former have a sharp resinous odor and a pronounced macrostructure. The most common coniferous species are: cedar, pine, fir, spruce and larch.

Pine is the most common building material. Its color varies from pale yellow to reddish yellow. The wood is quite light and durable.

The main thing is that it is very convenient for processing. It contains a lot of resin, so it rots poorly and is not particularly afraid of precipitation. Because of its softness, it easily accepts various coloring matter and varnishes.

Warping during drying almost does not occur in pine. The disadvantage is the inability high-quality finishing and coloring. However, it is successfully used for the production of furniture and plywood. Spruce can be placed in second place after pine in terms of use.

There is not much resin in it, so it is more susceptible to rotting and exposure to precipitation. Spruce wood is strong and light, but at the same time it has a large number of knots, which significantly reduces its consumer qualities. The advantages include White color wood and low resin content.

It holds various fasteners well. In construction, not the most important parts are made from it. Cedar, or correctly Siberian pine, is in no way inferior to spruce in its construction qualities, and is far superior to it in terms of resistance to rotting. Despite the softness of cedar wood, it has good density and strength, and is easy to process. Fir is no different from spruce: it can easily be processed and does not tolerate caustic chemicals.

It contains quite a bit of resin, which is why the wood rots too quickly without the use of special treatment. Larch is valued for its hardness and strength. Its density is such that the trunk of this tree sinks in water. But larch wood practically does not rot.

Hardwoods are usually divided into soft and hard.

Their wood is odorless. It is only found on fresh saw cuts. Hardwood species include oak, ash and birch, and softwood trees include aspen and alder.

Oak has very high strength and resistance to rotting. Its wood has beautiful color and texture. It does not crack or warp, which is why furniture, luxury items and art are made from oak.

Tannins have powerful antiseptic properties. The most durable and beautiful oak wood is obtained when it is kept in a flowing water for 1.5 years. cold water. Her color turns black.

Expensive furniture is made from such stained wood. This is an ideal material for furniture production, but it is very inconvenient to process due to its density and strength. Birch wood has average density and hardness. It is durable and quite viscous, does not have a very bright pronounced texture, but homogeneous.

The disadvantages of this material are susceptibility to severe cracking and warping, too much shrinkage, low resistance to rotting, and quite frequent damage to diseases such as wormholes. However, it lends itself well to processing hand tools, glued in plywood, easily polished and painted, makes it possible to produce very fine relief carvings. Aspen has fairly soft wood, which has so few knots that it lends itself well to any processing. However, her porous structure does not allow making small details. Linden is very valuable in the manufacture of various carved parts for furniture production.

It does not warp and does not crack at all when dried. Linden wood has a fairly strong structure, which is very resistant to rotting. Maple has a strong, dense and low-drying wood. It hardly warps, but rots quickly and is highly susceptible to wormholes.

This wood is well processed, glued, finished and painted. It is used in carvings and the manufacture of solid wood parts. Mahogany, growing in evergreen tropical forests, has red wood. This is not just one species, but many with similar properties.

Mahogany wood is very soft and lends itself well to processing, is easy to polish, and also absorbs varnish. Some pieces of furniture are made from such wood. Her high price does not allow making the entire product out of it.

Rare wood species

Rare wood species

Lumber and its varieties

Mostly dry wood is sold at the lumberyard and in the store. Raw is rarely sold. If you decide to build something or make a piece of furniture, then you will come across the names of types of lumber, the meaning of which is worth understanding:

The ridge is essentially solid tree trunks without bark or pieces of them of sufficiently long length. It is important that their diameter exceeds 25 cm. A ridge is the same ridge, but with a diameter less than 25 cm. A pole is a solid trunk without bark with a diameter of less than 9 cm. A plate is half a ridge, which is sawn along the fibers. A quarter is half a plate, sawed along fibres. A log, or in other words a timber with a wane, is a log hewn on both sides, which can be placed on one of two planes. A beam is a log that is hewn on four sides with a cross-section of at least 100x100 mm. If it is smaller, then the product is called a block. The board can be very different depending on the method of its processing and size: unedged, edged, slab, planed on four sides, tongue-and-groove, folded.

Cross sections of boards depending on processing.

All lumber that is commonly used in construction has its own specific name. They differ in the thickness of the product, as well as the ratio of width to this thickness.

For boards, this ratio should never be more than 2. The maximum permissible board thickness is 100 mm. Length of any material hardwood does not exceed 5 m, and from conifers 6.5 m.

Main types of lumber

After reading this article, you have become familiar with the basic concepts and characteristics of wood. Therefore, with such knowledge, you can safely purchase lumber, using terms no worse than sellers. Today, almost no major construction or renovation can be done without the use of wood to one degree or another, so such knowledge will be very useful.