Lumber and wood products. Wood is a natural structural material. Lumber and wood-based materials Features of coniferous materials

Types of wood and characteristics of lumber in photographs.

For construction, lumber made from natural wood is often used. They can be classified according to the type of wood, forms of workpiece and other parameters. The characteristic of lumber depends on a number of properties of a particular type of tree.

Table of lumber characteristics.

Timber classification

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

Timber classification and characteristics:

Scheme of lumber types.

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

Wood options

Timber classification scheme.

Pine, unlike other types of wood, is light in weight; during construction, minimal loads are placed on the foundation. For example, aspen or birch have a very large weight, but their strength characteristics are not so good. Planks are usually made from pine, a material that is very durable, easy to work with, and has many advantages.

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

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

The characteristics of lumber are not complete without such a parameter as the number and presence of branches. Here it is necessary to pay attention to spruce.

This coniferous breed has numerous positive characteristics, but its processing is complicated. The problem is that the trunk contains a lot of branches, and this is an obstacle to processing. .

Scheme of options for sawing wood.

For boards, wood such as cedar can also be used. This option is rare, but still used.

Cedar wood is durable, reliable, like spruce, but easier and more convenient to process. Fir can also be used for the manufacture of lumber. It is resistant to decay, perfectly processed, has numerous advantages.

Types of lumber

Lumber is available in a variety of sizes, so you can choose the one that suits you best. Products differ in shape, size, their characteristics, areas of use. Among the common materials are edged and unedged boards, which are acceptable for almost any job, but there are other options that act as auxiliary materials.

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

Edged board is a material obtained by sawing a log. At the same time, all its edges are smooth, but a small amount of bark may remain, that is, a wane. Indicators of moisture resistance, strength, mechanical stability are very different, as well as the cost.

Edged board calculation table.

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

The scope of the edged board is quite wide:

Unedged board has a not so high density, so it can be easily processed in any way. Finishing such boards does not take much time. But if there are many cracks on the surface, then this will significantly reduce the life of the lumber.

Lumber can vary in price and quality. The cheapest can be attributed to the four-edged timber, which is manufactured in large quantities, without requiring large costly capacities.

The production of a bar is carried out by sawing or hewing an array of wood, but the surface quality will differ significantly. For example, when hewing, the sides turn out to be torn, which is not always acceptable. When sawing, the edges and ends are more accurate, such a beam is already suitable for work where the appearance of materials is important.

A clean cut 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 a bar is made, as a rule, from pine.

It is processed from all sides, including the end parts. It is used most often for the construction of the walls of the house, beams, ceilings, subfloor. Differs in 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. Bridges are made from it, it can be used for technical and subfloors, as a basis for other products.

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

Lumber is made from natural wood.

All of them differ in shape, individual characteristics, size, appearance, degree of processing. Lumber is used for various types of construction and repair work, often used in the assembly of furniture, fences, 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 lumber characteristics.

None of the building materials on the market today has such unique qualities as natural wood.

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

Building materials from wood

If you look closely at any wood bar, you can see on it a texture pattern formed by growth rings. Its appearance depends on the direction in which the tree trunk was sawn. It is customary to cut it in three directions: along and across the fibers, 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. It clearly shows the parallel lines formed by the fibers. A cross section in all its glory shows us the growth rings of a tree trunk. Drawing is important for the external beauty of wood products, therefore, before making a wooden blank, it is necessary to clearly understand in which direction we want to have patterns.

The 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. The next thin layer 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 moist to the touch. They are also called cambium. After it, the wood itself begins with pronounced growth rings.

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

Heartwood 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.

The density of wood cells affects the strength and other physical qualities of wood, but the pattern of growth rings and heart-shaped vessels affects the creation of artistic compositions and the possibility of using one or another raw material in work. These are macrostructural elements, and they can also include knots, growths, undeveloped shoots that deviate annual rings and form various twists.

Wood with a pronounced macrostructure is 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 prone to decay.

The most dense wood is oak, ash, maple and larch, while aspen, spruce and fir have the lowest density. The moisture content of 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 raw. Sound and thermal conductivity are important qualities.

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

All of these 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 affect the strength and durability of buildings or wood products. Mechanical strength is the ability to resist various static and dynamic influences from 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 and compression. Any wood has greater strength along the fibers than across them.

Strength test of a wooden bar in the direction of load

It is worth noting that wet 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 breeds keep the form received at certain long influence.

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

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

Characteristics of various types of wood

For various purposes, one or another type of wood is used.

All of them are divided into coniferous and deciduous. The former have a sharp resinous odor and a pronounced macrostructure. The most common conifers 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 strong.

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. Due to its softness, it easily accepts various dyes and varnishes.

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

There is not much resin in it, so it is more susceptible to decay and 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 the white color of wood and low resin content.

It holds various fasteners well. In construction, not the most important details are made from it. Cedar, or correctly Siberian pine, is in no way inferior to spruce in its building qualities, and far surpasses it in resistance to decay. Despite the softness of cedar wood, it has a good density and strength, while being perfectly processed. Fir is no different from spruce: it easily lends itself to any processing and does not perceive caustic chemicals.

It does not contain enough 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 available fresh. Hardwood species include oak, ash and birch, and softwood aspen and alder.

Oak has very high strength and resistance to decay. Its wood has a 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 strongest and most beautiful oak wood is obtained when it is kept for 1.5 years in running cold water. Its color turns black.

Expensive furniture items are made from such stained wood. It is an ideal material for the production of furniture, but it is very inconvenient to process due to its density and strength. Birch wood has an average density and hardness. It is strong and quite viscous, has a not very pronounced texture, but is homogeneous.

The disadvantages of this material are susceptibility to severe cracking and warping, too much shrinkage, low resistance to decay, and a fairly frequent lesion with such an ailment as a wormhole. However, it lends itself well to processing with a hand tool, sticks together in plywood, is easily polished and stained, and makes it possible to produce very fine relief carvings. Aspen has a fairly soft wood, in which there are so few knots that it lends itself well to any processing. However, its porous structure does not allow making small details. Linden is highly valued in the manufacture of various carved parts for furniture production.

It does not warp and does not crack at all during shrinkage. Linden wood has a fairly strong structure, which is very little susceptible to decay. Maple has a strong, dense and slightly drying wood. It almost does not warp, but quickly rots and is highly susceptible to wormholes.

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

Mahogany wood is very soft and perfectly workable, easy to polish, and also absorbs varnish. Some pieces of furniture are made from such wood. Its high cost does not allow making the entire product out of it.

Rare wood species

Lumber and its varieties

Mostly at the timber base and in the store they sell dry wood. 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 their pieces of a sufficiently large length. It is important that their diameter exceeds 25 cm. The garter is the same ridge, but less than 25 cm in diameter. The pole is a solid trunk without bark with a diameter of less than 9 cm. The plate is half of the ridge, which is sawn along the fibers. fibers. Lezhen, or in another way a beam with a wane, is a log hewn on both sides that can be placed on one of two planes. I call a beam 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 bar. The board can be very different depending on the method of its processing and size: unedged, edged, slab, planed on four sides, grooved, folded.

Cross sections of boards depending on processing.

All lumber that is commonly used in construction has its own specific names. 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 allowable board thickness is 100 mm. The length of any material from hardwood does not exceed 5 m, and from coniferous 6.5 m.

The 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, in terms of terms, no worse than sellers. Today, almost no major construction or renovation can do without the use of wood to one degree or another, so such knowledge will be very useful.

Wood is a versatile material used in capital construction, the manufacture of decorative coatings and the production of furniture. There are various forms of wood, differing in structure and method of obtaining. The most durable and aesthetic material, which was used long before the advent of glued and pressed wood masses, are the sawn products of a solid tree trunk.

By longitudinal unraveling of the log into long component parts having at least one flat side (face). Most lumber has two flat edges that are parallel to each other.

Two methods of sawing logs are used - radial and tangential. With a radial approach, the cutting directions are oriented towards the center of the growth rings. The resulting boards or beams have different sizes, and their width is limited by the diameter of the tree to be blossomed.

Tangential sawing is designed to obtain long boards and is directed tangentially to the growth rings. Thus, a large number of fragments with the same size and sectional shape are obtained.

Further processing and giving the appearance depends on. The more work will be carried out to improve the surface and protect it from external influences, the higher the cost of the final product will be.

It is very important to choose high-quality lumber, which you should not buy, you can see on the video:

What are

There are several approaches to the classification of lumber. Allocate directions according to the method of obtaining (preparation), the degree of processing and purpose.

By way of preparation

This approach takes into account the final moisture content of the material. The most common concept is absolute humidity, which is the ratio of the mass of moisture to the mass of dry wood (per unit volume).

According to the magnitude of the absolute water content, there are:

dry lumber(air-dry or natural humidity) - contain no more than 20% water and are widely used in construction and construction of structures. Obtaining the air-dry state of the tree is preceded by its long stay in the air;
kiln-dried wood- obtained by drying in a closed box at elevated temperature. The moisture content of the material can be 10-14% or less, depending on the requirements of the consumer. Absolutely dry wood must be treated with protective compounds to prevent moisture absorption.

When stored for a long time in a humid environment, the wood becomes wet (contains 100% or more moisture). Boards made from freshly cut wood have a moisture content of about 50-100%.

By appointment

The following types of lumber are distinguished by size and shape, as well as mechanical properties:

timber- characterized by a thickness and width of more than 100 mm, is the main load-bearing element of many building structures and is used in the assembly of the base;
boards– have a thickness of less than 100 mm and their width is more than twice the thickness. Along with beams, boards are the most common lumber and are widely used for industrial, domestic and other purposes. Boards are made by longitudinal sawing of logs and beams;
bar- It is made of boards, which is the reason for its small size. The thickness of the bar should be no more than 100 mm, and the width should be less than twice the thickness;
sleepers- short bars used for railway purposes as supports for rails. The sleepers are usually treated with a strong mixture of petroleum or coke-chemical antiseptic, which is highly toxic. The use of impregnated sleepers in everyday life is highly discouraged;
lagging- is an "unfinished" version of the board, in which only one face is flat. The width of both fields can vary along its length, due to which the longitudinal cut along the sawn plate has a pronounced irregular shape;
croaker- refers to an intermediate variant between the board and the floor, which has one even surface. The raw surface on the opposite side has a regular cylindrical shape (truncated), therefore, in a longitudinal section, the slab is a rectangle.

Photo of various types of lumber

Beam Boards Bar Sleepers Obapol Slab

According to the degree of processing

The simplest version of lumber has two parallel faces and two raw wane (side faces) of a semicircular shape (external roundness of the tree). Two layers are often not enough to implement a number of construction and design tasks. Wane processing increases the aesthetics of wood and increases its cost.

According to the degree of processing, the following types of lumber are distinguished:

unedged- have untreated wane, freed from bark and coarse knots;
edged– wane sawn parallel to each other, giving the transverse profile a rectangular shape;
planed– the surface of at least one of the faces (plast or wane) is planed to reduce roughness. Such boards or beams are used to create floor and wall surfaces, seats and other outdoor structures.

What trees are lumber made from?

For the production of lumber, coniferous and deciduous wood, including their valuable varieties, is used.

The most common species, the trunks of which are used to obtain boards and beams, are:

larch– resistant to water and practically not damaged by insects and fungi. Even without the additional processing that is required for most other woods, hardwood is resistant to rot and is widely used in wet areas;
beech- used in the manufacture of furniture, stairs and wooden floors. Due to its high wear resistance, seating for benches in public places is often made from beech lumber;
Pine– differs in the high environmental friendliness supported by the pitches which are its part. Pine wood is less durable than hardwood and is more prone to catching fire and emitting acrid tar smoke. They try not to make benches from pine lumber, so as not to spoil clothes with protruding resins;
oak- is one of the most popular trees for the construction of houses and structures, has high strength and beautiful texture. Oak products swell slightly with increasing humidity, but are less common due to their high cost;
ash– has mechanical properties close to oak. The shades of its wood are not always attractive, which is caused by a violation of the integrity of the cellulose fibers as a result of diseases. A high bending tendency and impact resistance are among the main advantages of ash;
cedar- it is used much less often than other pine species due to its high cost, however, it is distinguished by aesthetics, resistance to decay and the ability to disinfect the air of the room in which it is located. In terms of mechanical properties, cedar is close to pine and has a more pronounced and rich texture;
deadwood- used to obtain the least quality material from naturally dried wood. Dead wood lumber is usually broken down into small bars and used as ancillary material;
Linden- has become widespread in the manufacture of quiet and warm floors, as well as walls of warehouse and industrial utility rooms (not damaged by rodents). The relative softness of linden lumber simplifies its processing when assembling composite structures;
aspen- Most often, aspen lumber is used for the construction of baths and saunas. Low performance reduces the value of solid aspen, a significant part of which is sent to the production of plywood or chipboard;
Birch tree- It is used to obtain light and durable lumber. Birch wood is almost free of resin, and its sawn timber has found the greatest use in furniture production due to its beautiful texture and ease of processing.

The video will tell about the varieties of larch lumber:

Let's evaluate lumber, comparing them with stronger and more durable stone materials for construction:

price - 5. A wide range of wood allows you to choose lumber for any financial opportunity. In addition to expensive wood species, there are their cheaper counterparts. They are inferior in terms of texture, but not performance;
practicality - 4. Wood is easier to damage than stone building material, so wooden coatings require care and additional processing;
appearance - 5. The wood surface is considered the most aesthetic. Even artificial surfaces are often disguised as wood to give the room more flavor;
ease of manufacture - 3. Although the tree is not very difficult to process, its finishing is quite difficult;
laboriousness when using - 4. It is better to work with wood in pairs to hold structural elements when marking, trimming or fixing;
environmental friendliness - 5. Wood is one of the most environmentally friendly materials. To increase the safety and durability of wood, treatment with special antiseptic compounds is used.

" onclick="window.open(this.href," win2 return false >Print
Email

Details Category: Wood and timber

Lumber and wood products

When sawing tree trunks longitudinally on sawmill frames, various lumber (see pic.): beams, bars, boards, plates, quarters and slabs.

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

bars - lumber having a thickness of 50-100 mm and a width of not more than double the thickness, i.e. 100-200 mm.

Boards - these are lumber with a thickness of 13-100 mm and a width of 80-250 mm, i.e. more than double the thickness.

plates obtained by longitudinal sawing of a log in half, and quarters - into four parts.

The board differs from the bar in that its width is more than 2 times the thickness..
croaker , or both sexes , called the sawn side of the log

Lumber:
but- four-edged beam; b- two-edged timber; in- bars; G- edged boards; d- unedged boards; e- plate; well- a quarter; h- croaker ( 1 - layer; 2 - edge; 3 - butt; 4 - rib).

Lagging- the side parts of the log, cut off during longitudinal sawing.
Planks and planks- these are thin and short lumber of rectangular section, and reiki- flat bars and thin narrow boards.
According to the nature of processing, sawn timber is divided into unedged and cut . At edged materials all four sides are propylene, and the dimensions of the wane do not exceed the allowable ones; at unedged The faces are propylene, and the edges are not propylene at all or partially propylene.

blanks. These are boards and bars cut to the overall dimensions of the parts with appropriate allowances for shrinkage and subsequent processing. The blanks used in the construction of joinery and furniture products can be both solid and glued, 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: face, edges, ribs and ends.
plastic called the wide plane of the lumber, and edge - narrow plane.
edge is the line of intersection of these two planes.
Butt - transverse (end) plane of lumber.

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

Widely used as a structural material plywood . Plywood is obtained by gluing three (or more) thin sheets of wood onto each other - veneer . "Veneer" in German - "sliver" (shavings)
Veneer. It has been known since ancient times, and the mechanical method of 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 high quality wood to a wood panel. This is an old process that was first applied around 1300 AD. The modern veneering method is used to improve the surface of products, mainly for high-quality furniture, table surfaces, decorative wood panels and doors. Veneering can also be used in the production of parquet. When veneering, the adhesive is usually applied to the substrate. The veneer is then applied over the adhesive film and the product is pressed in a hot press
Veneer It is used for decorative finishing of furniture and other wood products. The veneer gave artisans the ability to make lighter and less expensive furniture by drastically reducing the amount of wood needed to make it.
Veneering- this means gluing the veneer onto a stable base (MDF, chipboard, plywood, etc.). This made it possible to produce finished products from wood that is not subject to deformation and cracks, which are 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. The production of veneer has solved a number of environmental problems by significantly reducing the use of wood in the production of furniture and doors.
Rotary cut veneer- these are single-layer sheets of wood obtained by peeling birch, alder, maple, beech, pine, spruce, larch wood on machine tools.
Rotary cut veneer cut (peeled) with a sharp knife of a special peeling machine while rotating a log, previously steamed in hot water, about 2.0 m long (see Fig.). In this case, the log, like a roll, is rolled into a veneer tape. The veneer strip is cut into square sheets, which are dried in dryers, smeared with glue and stacked on top of each other so that the direction of the fibers in them is perpendicular to each other. Sheets are glued together under pressure. So get plywood with a thickness of 2 to 20 mm.
The veneer is used for veneering wood products and for the manufacture of plywood, glued and bent-glued products, as well as furniture, sports equipment and other products from plywood.
The dimensions of the veneer at a moisture content of 8±2% should be 800-2500 mm long (with 100 mm gradation), 150-2500 mm wide and 0.35-4.0 mm thick.
Sliced veneer is a thin sheet obtained by planing beams from wood species with a 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 wood, must be at least 60 mm. Humidity of veneer fluctuates within 8 + 2%. Veneer sheets are stacked in packs in the order of sheets output during planing of wood.
Sliced veneer is used for facing wood products and wood semi-finished 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 furniture upholstery shelled - for the manufacture of multilayer plywood.

Veneer can cover not only flat surfaces, but also complex curved shapes. To cover such surfaces with veneer, special "beds" are most often used, which cover sheets of veneer or in which they spread it, pressing it with clamps or a press.

Plywood. It is obtained by gluing three or more sheets of peeled veneer. The connected sheets are arranged so that the direction of the fibers in them is mutually perpendicular. The species of plywood is determined by the species 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 by the comparative similarity of physical and mechanical properties due to the cross direction of wood fibers in adjacent layers, less warping and cracking in various conditions of use. Plywood stronger than wood, almost does not dry out and does not crack, bends well and is processed. In housing construction, it is used for cladding panel doors and panels, for the manufacture of attic floors, etc .; in car and shipbuilding, it is used as a front finish; in the furniture industry, plywood is used to make the back walls of cabinets, bookshelves, chairs, countertops and other products.
Plywood is mainly made from birch wood.

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

For furniture production, the surface of the plates is ennobled by lamination (plates chipboard, melamine faced particle board). The volumes of chipboard production 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 chipboard and furniture, and the entire film can be downloaded .

Wood fiber boards (MDF). This is a sheet material made from wood fibers pressed into a homogeneous material under high pressure and high temperature. According to the bending strength, the plates are divided into superhard, hard, semi-hard and soft. The length of the plates is in the range of 1200-6100 mm, the width is 1000-2140 mm, and the thickness is 10-25 mm.
fiberboard used along with plywood in the manufacture of joinery and furniture and joinery and building products, for interior decoration: facing walls, ceilings, floors, in the manufacture of furniture, doors.
They have a pleasant gray or brown color, smooth surfaces, bend like plywood.

From the 1960s, plate production technology began to develop MDF. Abbreviation MDF comes from English (Medium Density Fiberboard, medium density fibreboard ). The basis of the boards is wood pulp milled to a fibrous cotton-like state, but there are a number of technological features that provide MDF boards with much higher consumer properties: in the production of MDF, dry fiber is pressed, and the fibrous mass is not just "glued", but forms an inseparable connection by physical chemical reactions. This, in particular, allows deep milling of MDF boards. MDF production volumes in the world increase by 10-15% annually. MDF boards are used in construction, furniture, wall panels and laminate flooring ( HDF).

In 1981, another mini-revolution took place in the field of wood-based panel production - boards appeared OSB (Oriented Strand Board , oriented strand board ). By analogy with plates 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 imperfections" - such as disordered anisotropy of properties and local defects (knots, delamination). OSB cuts well and holds screws well. Plates if required OSB can be sanded, varnished (including tinted), painted and even laminated. Moisture resistance and resistance to the formation of fungi and mold in plates OSB also significantly higher than that of solid wood. Production volumes OSB in the world annually increase by 10-15%. In 2000, the use of OSB in frame housing already exceeded the use of plywood. The use of OSB in furniture production is also growing.

The disadvantage of plywood, chipboard and fiberboard is that they are afraid of moisture. Under the action 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. Distinguish between hard rock, which is used in the construction of building frames or the installation of load-bearing elements. Lumber with medium strength is often used in the manufacture of furniture. With the help of soft rocks, one can try to reduce the cost of the structure by using them in the production of non-load-bearing building elements. Durable species include cherry, hornbeam, maple, ash, oak, beech. For the production of furniture, alder, linden and coniferous trees are used. Poplar and birch are soft woods.

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

Read also

Grape

In gardens and home gardens, you can choose a warmer place for planting grapes, for example, on the sunny side of the house, garden pavilion, 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 should be placed so that water flowing from the roofs does not fall on it. On level ground, it is necessary to make ridges with good drainage due to drainage furrows. Some gardeners, following the experience of their colleagues in the western regions of the country, dig deep planting holes and fill them with organic fertilizers and fertilized soil. Pits dug in waterproof clay are a kind of closed vessel that fills with water during the monsoon rains. In fertile land, the root system of grapes develops well at first, but as soon as waterlogging begins, it suffocates. Deep pits can play a positive role in soils where good natural drainage is provided, the subsoil is permeable, or reclamation artificial drainage is possible. planting grapes

You can quickly restore an obsolete grape bush by layering (“katavlak”). To this end, healthy vines of a neighboring bush are placed in grooves dug to the place where the dead bush used to grow, and sprinkled with earth. The top is brought to the surface, from which a new bush then grows. Lignified vines are laid on layering in spring, and green ones in July. They are not separated from the mother bush for two to three years. A 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. Grape bushes that have been neglected and severely damaged by frost are restored due to stronger fatty shoots formed in the lower part of the old wood and the removal of weakened sleeves. But before removing the sleeve, they form a replacement for it. Grape care

A gardener starting to grow grapes needs to study well the structure of the vine and the biology of this most interesting plant. Grapes belong to liana (climbing) plants, it needs support. But it can creep along the ground and take root, as is observed in Amur grapes in a wild state. The roots and the aerial part of the stem grow rapidly, branch strongly and reach large sizes. Under natural conditions, without human intervention, a branched grape bush grows with many vines of various orders, which comes into fruiting late and yields irregularly. In culture, the grapes are formed, give the bushes a form that is convenient for care, providing a high yield of high-quality clusters. Vine

Lemongrass

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

Chinese lemongrass, or schizandra, has several names - lemon tree, red grape, gomisha (Japanese), cochinta, kojianta (Nanai), kolchita (Ulchi), usimtya (Udege), uchampu (Oroch). In terms of structure, systemic relationship, center of origin and distribution, Schisandra chinensis has nothing to do with the real citrus plant lemon, but all its organs (roots, shoots, leaves, flowers, berries) exude the aroma of lemon, hence the name Schisandra. Lemongrass clinging or wrapping around a support, along with Amur grapes, three types of actinidia, is an original plant of the Far Eastern taiga. Its fruits, like real lemons, are too acidic for fresh consumption, but they have medicinal properties, a pleasant aroma, and this attracted a lot of attention to him. 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 eyesight. In the consolidated Chinese pharmacopoeia, compiled back in 1596, it says: "Chinese lemongrass fruit has five tastes, classified in the first category of medicinal substances. The pulp of lemongrass is sour and sweet, the seeds are bitter-astringent, and in general the taste of the fruit is salty. Thus, It contains all five tastes. Grow lemongrass

Timber classification

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

The bars are mostly rectangular in shape. The characteristic of such materials implies that the division in the group is carried out according to the form, method of manufacture, and the size of the section. The cross section is usually made from 100 mm or more.
Boards can be divided into edged / unedged, sawn. The last group is divided into clean-edged, with a blunt wane (blunt and sharp).
Staves are used for barrels. The group is limited, includes rivets with a cylindrical or blunt section.
Planks and planks, sleepers are materials that are small in size, rectangular in cross section. Their thickness and shape may vary slightly.
Reiki is an unedged board, the edges of which are processed. Three sides of the board are unsawn and one side is sawn.

Timber classification and characteristics:

By type of surface treatment. Lumber can have wide surfaces (plasti), narrow (edges), end (ends). In turn, wide can be divided into external and internal.
Like sawing wood. Regarding annual rings, lumber is classified into radial, tangential, mixed.
By type of wood. All lumber can be made from different types of wood, each of which is best suited for specific purposes. Pine is the leading one in this area; various types of products can be made from it, including for wall and roof cladding. Spruce, larch, cedar, fir are used in construction. All of them are great for boards. But ash, oak, mahogany are applicable for the manufacture of finishing materials, as joinery, where they fully reveal their qualities. Aspen is great for finishing the interior walls of saunas or steam rooms, it perfectly resists the negative effects of moisture, sudden changes in temperature. For parquet boards and natural parquet, experts recommend using birch. Here she fully reveals her potential.

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

Wood options

Lumber that is used for construction can be made from various types of wood. The most popular material is needles, most of the bars and boards are made from pine and spruce, but there are other options. Pine, unlike other types of wood, is light in weight; during construction, minimal loads are placed on the foundation. For example, aspen or birch have a very large weight, but their strength characteristics are not so good. Planks are usually made from pine, a material that is very durable, easy to work with, and has many advantages.

Pine in the composition contains natural resin, which acts as an excellent antiseptic. This ensures the absence of traces of rot, mold for a long time. Pine has a soft and delicate structure, which makes processing simple, pleasant and fast. Smell, pine color add attractiveness to the material not only as a standard building material, but also as an option for decorative wall cladding, construction of log cabins.

The characteristics of lumber are not complete without such a parameter as the number and presence of branches. Here it is necessary to pay attention to spruce. This coniferous breed has numerous positive characteristics, but its processing is complicated. The problem is that the trunk contains a lot of branches, and this is an obstacle to processing. Spruce is not as resistant to decay as pine, but its price is much lower..

For boards, wood such as cedar can also be used. This option is rare, but still used.

Types of lumber

This makes it possible to choose exactly the material that is more suitable for the work than others, without overpaying. For the manufacture of edged boards, pine or spruce are most often used. The cost of such boards is not so great, but the strength and durability correspond to all parameters. From such boards, you can safely build not only outbuildings, but also carry out interior decoration. Lumber has a standard size of 6 m, but the thickness and width are different. The width of the boards can be equal to 100 mm, 150 mm, 200 mm, for thickness - 25 mm, 40 mm, 50 mm.

The scope of the edged board is quite wide:

for the manufacture of frames, walls, partitions;
for flooring of draft, finishing floors;
for the manufacture of various load-bearing structures;
for the manufacture of formwork;
in the manufacture of furniture;
in the manufacture of carved furniture;
at construction of arbors, garages, canopies, protections.

Unedged board has edges with bark, it is used quite often in construction. The appearance of these lumber is attractive, as close to natural as possible, which makes them an excellent option for wall cladding. Unedged board has a not so high density, so it can be easily processed in any way. Finishing such boards does not take much time. But if there are many cracks on the surface, then this will significantly reduce the life of the lumber.

Four-edged and clean-edged timber

Lumber can vary in price and quality. The cheapest can be attributed to the four-edged timber, which is manufactured in large quantities, without requiring large costly capacities. The production of a bar is carried out by sawing or hewing an array of wood, but the surface quality will differ significantly. For example, when hewing, the sides turn out to be torn, which is not always acceptable. When sawing, the edges and ends are more accurate, such a beam is already suitable for work where the appearance of materials is important.

A clean-cut 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 a bar is made, as a rule, from pine. It is processed from all sides, including the end parts. It is used most often for the construction of the walls of the house, beams, ceilings, subfloor. Differs in high strength properties.

Semi-edged board and slab

Slab is a fairly cheap lumber, which, when properly processed, perfectly replaces other wood products.

In appearance, the slab is very similar to the sidewall of a log, part of it is propylene on one side, and not on the other. Such lumber is considered lump type waste, they remain after cutting the base material. But the dimensions of the slab are normalized, it has the same width from the ends and along the entire length. Today, two types of slab are used - wood and business material. It is used for various purposes, as blanks for other products and building elements.

Lumber is made from natural wood. All of them differ in shape, individual characteristics, size, appearance, degree of processing. Lumber is used for various types of construction and repair work, often used in the assembly of furniture, fences, and in the construction of subfloors. When choosing, you should focus on those properties that are necessary for specific conditions.

Semi-edged board and slab

The internal structure of wood

Physical characteristics of wood

Mechanical characteristics of wood

Characteristics of various types of wood

Lumber and its varieties

What are

By way of preparation

By appointment

According to the degree of processing

What trees are lumber made from?

Grape

Lemongrass

Timber classification

Wood options

Types of lumber

Four-edged and clean-edged timber

Semi-edged board and slab

Read also