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. Edged boards made using new technologies on 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.
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Grape
In gardens and household plots, 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 from 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 layer at best reaches 30 cm 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
Sections: Technology
Goals: to acquaint students with wood as a structural material, with types of lumber.
Tasks:
- educational: to teach to determine the appearance of samples of wood species.
- educational: cultivate a respect for wood and wood.
Means of education:
- Presentation for the lesson.
- Collection of samples of tree species.
- A set of wood lumber.
- Samples of veneer, plywood, chipboard, fiberboard.
Lesson progress
I. Organizational moment
Check readiness for the lesson.
II. Lesson topic message
Wood is a natural structural material. Lumber.
III. Motivation for learning activities
Wood is one of the most important and widespread material. The ease of processing and the variety of species made it possible to use wood for a wide variety of jobs. Each wood product has its own requirements. To correctly determine which wood to use for a product, you need to know the characteristics of each species.
IV. Formation of knowledge and skills
History reference.(slide number 1)
It is difficult to name an area of human activity where wood was not involved. Already in the early stages of development, man began to use this material. A little later, wood was used for construction (houses, bridges, ships), various household equipment, furniture, dishes, musical instruments, and much more. With the advent of crafts, wood became one of the first structural materials for the manufacture of spinning, weaving, milling, pottery and other machines. It was widely used in the car, ship, auto and aircraft industries. Currently, products of thousands of names and purposes are manufactured.
wood structure(slide number 2)
The structure of wood can be seen in its cross section, which clearly shows pith, bark and annual layers. For a more complete picture of the structure of wood, you need to consider three main sections of the trunk - transverse, radial and tangential. On the transverse section, the annual layers look like concentric circles, on the radial - longitudinal stripes, on the tangential - winding cone-shaped lines. In addition, on the transverse section, you can see light lines directed from the core to the cortex, core rays. The dark-colored part of the trunk is called the core, and the light peripheral part is called sapwood.
Wood species(slide number 3)
Coniferous breeds. Coniferous wood has a lower density, and therefore, it is easier to process and its heat-saving properties are higher.
The group of conifers includes the following species:
- Pine - the most common coniferous tree. The color of its wood can be brown, reddish, yellowish and almost white with slight stains of red. When dry, pine is light and pliable for joinery work. Furniture, windows, doors, etc. are made from it. Wood is well processed by dyes and varnishes.
- Spruce - softer than pine, but it has a large number of small and medium knots, which makes it difficult to use it in critical carpentry structures. The texture is inexpressive, it is less moisture resistant, more likely to rot. In carpentry, it is used for non-responsible furniture designs.
- Fir - It is used on a par with spruce, although it has reduced physical and mechanical properties.
- Larch - occupies a special place among other conifers. Its wood has a red-brown, sometimes brown tint and is highly durable (stronger than oak) and moisture resistant. It is used in building structures where high strength and resistance to decay are required, it is used for the manufacture of parquet.
- Cedar - has a whitish-yellow wood with different color shades depending on the place of growth. Wood does not differ in high strength and density. Cedar is a good material for carving. It is trimmed mainly with wax.
- Juniper - coniferous shrub, trunk diameter is up to 10-15 centimeters. Strong thin-layer wood is well processed and polished, has a specific smell. It is used for the manufacture of small parts, when turning, for carving and mosaic work.
- Cypress and thuja similar in properties to juniper, but their wood is broader and darker in tone. Used for small carvings.
Hardwoods:
- Oak - It is characterized by high strength, hardness, resistance to decay, bending ability, beautiful texture and color. Wood is widely used for the manufacture of furniture, parquet. Oak veneer is used for facing plywood, chipboard.
- Beech - has a strong and solid wood, it is not inferior in strength to oak. Beautiful texture on cuts, these decorative qualities are used when facing furniture with sliced veneer.
- Birch - It is characterized by high strength, uniform structure and color, medium density and hardness. It is mainly used for the manufacture of plywood, peeled chipboard veneer. Easily processed and finished, when etching under more valuable breeds. In the steamed state, it bends well.
- Disadvantages - dries for a long time, easily pricks, cracks and warps a lot. Wood Karelian birch viscous and hard, easily amenable to carpentry. It is highly valued in mosaic work and as an ornamental material.
- Ash - wood similar to oak. It bends well after steaming.
Wood defects(slide number 4)
Curl - it is an undulating arrangement of fibers, especially at the root of the tree. Most often observed in maple, oak, Karelian birch, walnut. Such wood is difficult to process, but is valued in the manufacture of sliced veneer.
Curl characteristic of local curvature of the annual layers due to the influence of progrowth or trunk knots.
- Sprout - a defect in the area of \u200b\u200bthe tree that arose as a result of mechanical damage to the fiber. Such a defect most often occurs due to the growth of dead wood or bark into the sapwood.
- Oblique - a defect expressed in the fact that the wood fibers are placed obliquely. Slanted wood is not used for crafting.
Wood color (slide number 5)
The color of wood is one of the signs by which one type of wood differs from another.
Wood linden, pine, birch, maple, aspen- light, oak and ash- brown, walnut, teak - brownish.
Color shades of different species can be classified into main groups, where one color of wood will prevail.
- Yellow - birch, spruce, linden, aspen, hornbeam, maple, fir, ash, barberry, Karelian birch.
- Brown - cedar, poplar, beech, larch, alder, pear, plum, chestnut.
- Brown - cherry, apple, apricot, walnut.
- Red - yew, mahogany.
- Pink - laurel cherry, plane tree.
- Orange - buckthorn.
- Violet - lilac, privet.
- Black - bog oak, ebony.
- Greenish - persimmon, pistachio.
Physical and mechanical properties of wood(slide number 6)
- Hardness - ability to resist machining with cutting tools. The bottom of the barrel is harder than the top.
- Strength - the ability of wood to resist forces acting on it.
- Elasticity - the ability of wood to change its shape under the influence of external forces and to take its former shape after the termination of this influence.
- Plasticity - the ability of wood to change (without destruction) its shape under pressure and retain it after the load is removed.
Conditional density wood is the ratio of the minimum mass to the maximum volume of the sample. By density at a moisture content of 12%, tree species are divided into groups:
- low density
- medium density
- high density
Humidity - physical property of wood, characterized by the amount of moisture contained in it.
Hygroscopicity - is the ability of wood to absorb or release moisture.
Thermal conductivity - the ability of wood to conduct heat from one surface to the opposite. Conifers have a lower density and, consequently, lower thermal conductivity.
Sound conductivity - the ability of wood to conduct sound. Sound travels in different directions with different force. So, the sound conductivity along the fibers is 4-5 times higher than across.
high flammability wood reduces the fire resistance of the building.
lumber(slide number 7)
- bars- these are sawn timber with a thickness and width of more than 100 mm (up to 400x400 mm). According to the number of sawn sides, the bars can be two-edged, three-edged and four-edged.
- Boards- these are lumber with a thickness and width from 16 to 100 mm., The width of which exceeds the thickness by at least 2 times. By the nature of processing, they are unedged, single-edged and edged. The width of the boards is from 275 mm, the length is up to 6.5 m. The wide side in the boards is called the face, and the narrow side is called the edge.
- bars- these are lumber with a thickness of 50 to 100 mm, and a width of no more than double the thickness.
- Sliced and peeled veneer serves as material for facing and mosaic works. Obtained by planing or peeling wood:
- shelled- birch, alder, spruce, pine, beech-linden.
- planed- walnut, ash, beech.
- Plywood consists of several (three, five or more) glued layers of peeled veneer.
- Practical work.
To acquaint students with the appearance of the most common types of wood, samples of lumber, veneer, plywood. To teach students to determine the type of wood and the type of lumber by the appearance of the samples.
V. Summing up the lessons
Today you got acquainted with wood as a structural material. We learned about the structure of wood, remembered various species. Familiarize yourself with the various properties of wood. We knew what lumber is and where they are used. This knowledge will be useful to you in the further study of wood processing technology, and some may be useful in everyday life.
ADVICE. If possible, these slides can be printed as posters or as student handouts.
>>Technology: Lumber and wood-based materials
During longitudinal sawing of tree trunks at sawmills, various lumber is obtained (Fig. 11): 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- sawn timber with a thickness of less than 100 mm and a width of less than twice the thickness.
Boards- sawn timber with a thickness of up to 100 mm and a width of more than double thickness.
plates obtained by longitudinal sawing of a log in half, and quarters - into four parts.
croaker, or obopolom, called the sawn side of the log.
Lumber has the following elements: face, edges, ribs and ends.
plastic called the wide plane of the lumber, and the edge - the narrow plane.
edge is the line of intersection of these two planes.
Butt- transverse (end) plane of lumber.
Plywood is widely used as a structural material. Plywood is obtained by gluing three (or more) thin sheets of wood - veneer onto each other. "Veneer" in translation from German - "sliver" (shavings). The veneer is cut (peeled) with a sharp knife of a special peeling machine while rotating a log about 2.0 m long (Fig. 12). In this case, the log, like a roll, is rolled into a veneer tape.
The veneer tape 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 (Fig. 13). Sheets are glued together under pressure. So get plywood with a thickness of 2 to 20 mm. 
Plywood is stronger than wood, almost does not dry out and does not crack, bends well and is processed. Plywood is used in construction, furniture manufacturing, mechanical engineering and aircraft construction.
Peeled veneer is used to make curved wood, which is used to make furniture, sports equipment and other products.
Chipboards (chipboards) are obtained by pressing and gluing chopped wood in the form of shavings, sawdust, wood dust. For the production of particle boards, mainly wood waste and even bark are used.
Plates are made with a thickness of about 10 ... 26 mm. They are durable, almost do not warp, are well processed by cutting tools. Furniture, doors, partitions, walls, saws are made from them. However, over time, they release substances harmful to health, so they are undesirable for use in residential areas.
Fibreboards (MDF) are pressed in the form of sheets from steamed and crushed to individual fibers of wood pulp. They have a pleasant gray color, smooth surfaces, dull, like plywood. They are used for interior decoration of premises: facing walls, ceilings, floors, in production
furniture, doors.
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.
PRACTICAL WORK
Examination of samples of lumber and wood-based materials
1. Consider samples of lumber and determine their type (bars, boards, slabs, etc.). Determine the types of wood.
2. Find the face, edge, edge, butt in the lumber samples.
3. Consider samples of plywood, chipboard and fiberboard, measure their thickness. Count the number of layers in the plywood samples.
4.Check whether the samples are easily processed with any tool (file, hacksaw, etc.).
- Lumber (beam, board, bar, slab), lumber elements (face, edge, edge, butt), veneer, wood-based materials (plywood, chipboard and fiberboard).
1. What types of lumber do you know?
2. Name the main elements of lumber.
3. What is veneer?
4. What is plywood made of and how? Chipboard? Fiberboard?
5. How are wood-based materials different from wood?
6. What are their advantages, disadvantages?
A.T. Tishchenko, P.S. Samorodsky, V.D. Simonenko, N.P. Shchipitsyn, Technology Grade 5
Submitted by readers from the website
Obtained by cutting logs(blanks). In fact lumber- this is a sawn product of a certain size with two plane-parallel sides ( layers). Sawing can be both radial and tangential. (Fig. 1) are subdivided into plates, bars, boards, bars, croaker.
plates receive at sawing logs along the axis into two equal parts.
bars- this is lumber thickness and width of more than 100 mm; there are two-, three- and four-edged.
Boards are no more than 100 mm thick, with a width of more than double the thickness.
bars have a thickness of less than 100 mm, a width of less than twice the thickness.
croaker- the side parts of the log remaining during sawing.
lumber elements
AT lumber highlight the following elements: plasti, edges, ribs, ends.
Plast- longitudinal wide side lumber, as well as any side lumber square section. In the best plasti lumber the smallest number of defects, the best quality of processing. Plast lumber, facing the core, is called internal, and facing the sapwood - external.
Edge- longitudinal narrow side lumber
Edge- line of intersection of two adjacent sides lumber.
Butt- end transverse side lumber.
wane is optional lumber element, this, so to speak, is an element of marriage edged board due to the substandard source material ( logs or blanks).
Planed with giving them curly sectional shapes, they are called planed moldings (architraves, skirting boards, grooved boards for flooring etc.).
Wood sheet materials and various additives plywood, wood fiber (DVP) and chipboard (chipboard).
Lumber production
Manufactured according to GOST 8486-86E:
1) From coniferous wood - pines, ate, larches, firs
2) From hardwood - beech, birches, alder, lindens, aspens and poplars.
Softwood
Coniferous wood usually softer and lighter than wood majority hardwood; however, this is not always the case yew wood heavier and denser than wood some deciduous trees. For processing usually go spruce trees growing in cool or cold climates. Wood they are light yellow, with resin passages and numerous knots. She's cheaper than hardwood and easier to process. spruce wood used for almost all basic carpentry and construction work. Usually on sale lumber as planed or unplaned boards different thicknesses and widths red and canadian spruce. For outdoor use, you will need either a rot-resistant view wood, or spruce wood pre-treated with a special protective compound. It is not enough just to apply this substance to the surface of the wood with a brush - if possible, buy a tree impregnated with an antiseptic under pressure: in this case, the protective composition penetrates deep into wood.
Table 1. conifers
| wood species | Description |
| Thuja western | The wood is reddish brown with a silky surface. Resistant to rot and insect attack. Used for sheathing, building fences and greenhouse frames. Flaws: the color fades over time, the surface is easily damaged, and the nails in such wood do not hold firmly |
| Larch | The wood is hard and difficult to work with. Advantages: resists decay well, holds nails well. Used for poles and building fences |
| Spruce red | Used for outdoor work. The wood is durable, easy to process, suitable for etching stain and painting. Color varies from light yellow to reddish brown. Rotting quickly, requires antiseptic treatment |
| Canadian spruce | The wood is softer and finer textured than red spruce. Light yellow color does not fade over time. Used for interior decoration. Not impregnated with an antiseptic, therefore unsuitable for outdoor use |
hardwood
Trees such as oak, mahogany, or red, wood and teak. Wood these breeds denser and harder than coniferous wood; it is heavy, resistant to decay, with a denser structure and more decorative than coniferous wood. At the same time, it is more expensive and more difficult to process.
On the transverse cut of the trunk of hardwood deciduous trees grown in Europe or other regions with cool or frosty winters are clearly visible growth rings. Wood these breeds usually light and difficult to process. Coming to market tropical tree wood almost always darker, less textured and easier to work with. Important:
- Allowed
application lumber from hardwood for details of rafters, internal stairs, internal wall and partition linings, filing of ceilings, rolls, pediments, internal architectural details, joinery and fine wood.
- Not allowed
application wood birches, lindens and poplars for rafters; lindens, alder, aspens and poplars for treads of wooden stairs; lindens and poplars for clean floors.
Table 2. hardwood
| wood species | Description |
| Iroko | Grows in West Africa. The cheap wood of this plant is used instead teak for the manufacture of garden furniture. The color is rich brown, the texture is rather rough |
| mahogany (red) wood | Wonderful, but too expensive for outdoor decoration with wood unit. African mahogany has a rich orange-brown color, American has a stronger gloss and is more expensive. |
| Meranti (Shorea) | A cheaper substitute mahogany from Malaysia. The coloration of pronounced red tones is easier to process than the Red tree. Used for making garden furniture |
| Oak | The strongest and most durable sessile oak, but it is expensive, difficult to work with, and splits when nails are driven into it. Oak ordinary is slightly softer |
| Teak | Traditional garden furniture material: rot-resistant, water-resistant, flame-retardant. Color light brown with darker stripes |
lumber dimensions
lumber length: conifers no more than 6.5 m, deciduous- no more than 5 m. For special structures can be used lumber length up to 9 m, made by special order. Thickness and width of lumber determined assortment(Table 3, 4, 5, 6).
Table 3 The standard for the output of edged lumber per cubic meter. logs
| Type of wood | Log diameter, mm | Variety | Output from 1 m³ | ||
| lumber, m³ | wood waste, m³ | sawdust, m³ | |||
| conifers | 140-240 | 2 | 0,591 | 0,269 | 0,14 |
| Same | Over 260 | 2 | 0,637 | 0,223 | 0,14 |
| hardwood (including birch) |
140-240 | 2 | 0,533 | 0,307 | 0,14 |
| Same | Over 260 | 2 | 0,565 | 0,295 | 0,14 |
| Aspen | 140-240 | 2 | 0,481 | 0,379 | 0,14 |
| Same | Over 260 | 2 | 0,512 | 0,348 | 0,14 |
Table 4 Thickness and width of sawn softwood in mm.
| Name | Thickness | Width | |
| Least | The largest | ||
| Boards | 16 | 70 | 180 |
| 19 | 70 | 180 | |
| 25 | 70 | 180 | |
| 30 | 100 | 180 | |
| 40 | 50 | 180 | |
| 50 | 50 | 220 | |
| 60 | 60 | 220 | |
| 70 | 80 | 220 | |
| 80 | 100 | 240 | |
| 100 | 100 | 240 | |
| bars | 120 | 120 | --- |
| 150 | 150 | 200 | |
| 180 | 180 | 220 | |
| 200 | 200 | 260 | |
| 220 | 280 | 280 | |
Table 5 Thickness and Width of Hardwood Lumber in mm.
| Name | Thickness | Width | |
| Least | The largest | ||
| Boards | 16 | 50 | 160 |
| 19 | 50 | 200 | |
| 25 | 50 | 220 | |
| 30 | 50 | 220 | |
| 40 | 50 | 200 | |
| 50 | 50 | 260 | |
| 60 | 60 | 220 | |
| 70 | 70 | 220 | |
| 80 | 80 | 260 | |
| 100 | 100 | 260 | |
| bars | 120 | 120 | --- |
| 150 | 150 | 200 | |
| 180 | 180 | 220 | |
| 200 | 200 | 260 | |
| 220 | 220 | 260 | |
Table 6 The volume of one log, cubic meters
| Log diameter, cm | log length, m | |||||
| 4,0 | 4,5 | 5,0 | 5,5 | 6,0 | 6,5 | |
| 12,0 | 0,053 | 0,063 | 0,073 | 0,083 | 0,093 | 0,103 |
| 13,0 | 0,062 | 0,074 | 0,085 | 0,097 | 0,108 | 0,120 |
| 14,0 | 0,073 | 0,084 | 0,097 | 0,110 | 0,123 | 0,135 |
| 15,0 | 0,084 | 0,097 | 0,110 | 0,125 | 0,140 | 0,154 |
| 16,0 | 0,095 | 0,110 | 0,124 | 0,140 | 0,155 | 0,172 |
| 18,0 | 0,120 | 0,138 | 0,156 | 0,175 | 0,194 | 0,210 |
| 20,0 | 0,147 | 0,170 | 0,190 | 0,210 | 0,230 | 0,260 |
| 22,0 | 0,178 | 0,200 | 0,230 | 0,250 | 0,280 | 0,310 |
| 24,0 | 0,210 | 0,240 | 0,270 | 0,300 | 0,330 | 0,360 |
| 26,0 | 0,250 | 0,280 | 0,320 | 0,350 | 0,390 | 0,430 |
| 28,0 | 0,290 | 0,330 | 0,370 | 0,410 | 0,450 | 0,490 |
| 30,0 | 0,330 | 0,380 | 0,420 | 0,470 | 0,520 | 0,560 |
Characteristics of lumber
Lumber ends and draft blanks should be sawdust at right angles to the longitudinal axis. Wane bars(with a partial absence of a cut in the edge) with a section of 120 x 120 mm or more must have a cut width at the thin end of at least one third of the side of the beam.
Maximum allowable lumber moisture for load-bearing structures - 25%, for glued structures - 15%.
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.
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 shape, 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 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.
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.
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 manufacture of timber is carried out by sawing or hewing solid wood, but the surface quality will vary 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.
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.
