What is lumber. What types of lumber there are Types of lumber and how to obtain them

In turn, from ka-san-tva pi-lo-ma-te-ri-alov, it is the strength and long-eternity of the future structure. Therefore, it is very important, but for the second time, to notice and to select not-ka-ches-tven-ny ma-te-ri-al.

Lumber should be made from coniferous pine, spruce, fir, larch and cedar.

About-cut pi-lo-ma-te-ri-al- this is pi-lo-ma-te-ri-al having a rect-coal-see-cess with a possible up-start ob-zo-la (ob-zol - de -defect with ras-pi-lov-ki dre-vi-si-ny, saving-ra-nya-sya along the edge of the board, for example, co-ra de-re-va) , if he does not exceed the given norm-ma-ti-va-mi knowledge.

So-s-shes-tvu-em group-pa not-about-cut pi-lo-ma-te-ri-alov, at some-ryh edge-ki may be not-described, or partially described. An hour-something-pa-de-xia-cut pi-lo-ma-te-ri-al with poorly opi-ed chrome-ka-mi, this goes-rit about the fact that the pre-acceptance is that-that-winking-cut pi-lo-ma-te-ri-al py-ta-et-sy to-get-to-half-no-tel -new profit due to the eco-no-mi of dre-vi-si-ny, py-ta-yas from not-about-ra-bo-tan-no-go ma-te-ri-ala na-re- to name as many products as possible.

Need-but-no-mother, that such pi-lo-ma-te-ri-al ob-la-da-et is not very good-ro-shi-mi-ka-te-la- and it is better to use it in ka-san-tva flow-rate-no-ma-te-ri-al in the construction of an object. For the inner and outer from-de-li, pi-lo-ma-te-ri-ala must look-la-do ide-al-no.

Lumber classification

The main types of pi-lo-ma-te-ri-als:

1. Pi-lo-voch-nick(circle-lyak) - round wood, log-na.

2. La fet- a log, passed once on pi-lo-ra-me and having a plane on both sides. "By-way-ny" product-tom on-th-niya la-fe-tov yav-la-et-sya:

• grief
• not-about-cut board

3. About-rez-noy ma-te-ri-al(when all four-you-re sides are pro-pi-le-ny). Po-lu-cha-et-sya po-tem ras-pi-lov-ki la-fe-ta. Divided by:

• timber,
• revised board
• small bru-juice

4. Stro-g-ny po-go-naz... It can be su-hoi and es-tes-twen-noy wet-nos-ty. To no-mu-no-sit-Xia:

• dos-ka-la,
• ob-shi-voch-naya dos-ka (va-gon-ka and ev-ro-va-gon-ka),
• folding,
• small-k-go-ny-nye from-de-lia (plin-tus, n-personal-nick, sht-peak, etc.).

5. Glued from de lia... They include glued beams, etc.

Pi-lo-ma-te-ri-aly yav-la-yut-sya very much to-ro-gos-to-yaschim pro-duc-tom de-re-in-work-bot-ki, so how the output of the product is only 65%, and the remaining 35% is from the output in the form of mountains (14%), described lok (12%), cut-off, small-chi (9%).

Ka-chas-thy ma-teri-ala

From the speed of growth of the ras-pi-li-va-niya pi-lo-ma-te-ri-alov and from us-three-ki the equipment-to-va-niya za-vi-sit raz-throw the size of the party pi-lo-ma-te-ri-alov, both in thickness, and in length. Throw-away in size ska-zy-wa-th-Xia on the complexity of the pod-gon-ki do-juice to each other, in the re-zul-ta-te th-go -yav-la-yut-sya for-zo-ry and not-co-answers in length-not.

Exists stan-dar-you, ha-rak-te-ri-zu-yi-ka-tch-ty pi-lo-ma-te-ri-ala, its dimension. This includes GOSTs, for example, GOST 8486-86, GOST 10950-78, and many others.

Pi-lo-ma-te-ri-ala variety op-re-de-la-et the number of knots per unit length, as well as their number of knots. When you choose a ma-te-ri-ala for non-existent structures, for example, an inter-zhe-tazh-noy, the grade pi-lo-ma-te- ri-ala is more important for-for-body, is not her appearance.

For ka-san-tvu dre-ve-si-ny and processing-bot-ki boards and bars-ki raz-de-la-yut for five varieties(selected 1, 2, 3, 5th), and the bars - on the fourth grade (1, 2, 3, 4) and should be co-from-vets- create certain requirements.

Pi-lo-ma-te-ri-aly selection-bor-no-go, 1, 2, 3-rd grades from-go-to-la-yut su-khi-mi (with a moisture content not more than 22%) and cheese-mi anti-ti-sep-ti-ro-van-ny-mi. In the period from May 1 to October 1, from-go-to-le-ies of raw anti-sept-ti-ro-van and raw pi-lo-ma -ter-ri-alov do-start-ka-em-Xia on co-la-co-va-nii with pot-re-bi-te-lem (for-kaz-chi-com). Humidity pi-lo-ma-te-ri-als of the 4th grade is not normal-mi-ru-et-Xia.

Ots-ka-tch-tva pi-lo-ma-te-ri-alov, for the is-key-no-it-p-lub-nyh, must be pro-out-of-the-go-on on the surface or the edge, the worst for this board, and beams and beams of square-rat-no-th se-ch-niya - at the worst a hundred-ro-not.

Para-ra-meter she-ro-ho-va-tos-ti-ver-hnos-ty pi-lo-ma-te-ri-alovyou should not take 1250 microns for selection, 1,2, and 3rd grades, and for the 4th grade - 1600 microns.

Defects of wood in lumber

Norm-we og-ra-no-che-nia-ro-cov

Notes:

1. Bitches of a size less than lo-wines-mak-si-mal-but do not learn-you-wa-yut.

2.In pi-lo-ma-te-ri-alah thickness 40 mm and more (for is-key-no-selection), do-go-ka-go-go pro -th and stitched knots in size along the small axis up to 6 mm and depth-bi-noy up to 3 mm without limiting the size a measure along the major axis.

3. Pa-son-nok do-start-ka-em-Xia according to the norms of the growing-shih knots. In the out-of-the-way sor-those are not allowed.

4. The size of the bitch is op-re-de-la-yut with the distance between the ka-sa-tel-ny to the cont-ru of the bitch, pro-ve- den-ny-mi pa-ral-lel-but pro-long axis pi-lo-ma-te-ri-ala. For the size-measure of pro-long-go-va-that-go and sew-no-go bitches on the pillars of pi-lo-ma-te-ri-alov and on all the sto-ro-nah of the bars and the bars-eu-ni-ma-yut by-lo-vi-well the distance between ka-sa-tel-ny-mi, pro-ve-den-mi pa-ral-lel -but about the long axis pi-lo-ma-te-ri-ala:

5.In pi-lo-ma-te-ri-alah with a length of more than 3 m to-start-up-to-if there is one bitch-by-size, pre-dus-mot-ren-ny in the norm, adjacent -go more low-grade.

6. At the site pi-lo-ma-te-ri-alov length equal to its shiri-no, na-ibol-shaya sum-ma of sizes of knots, lying on a straight line, pe-re-se- ka-th bitches in any direction, should not exceed the pre-del-no-th size of the up-to-ka-th knots.

Continuation

Note-cha-tion. Allowable sizes of cracks us-ta-nov-le-ny for pi-lo-ma-te-ri-als with the moisture of wood-ve-si-ny are not more than 22%, with more moisture, these cracks are halved.

Continuation

Continuation

Continuation

Notes:

1. Ko-ra on ob-zo-lakh of ek-sports pi-lo-ma-te-ri-als is not allowed

2. About-re-cut pi-lo-ma-te-ri-aly, co-replies-vets-tvu-ya-ya-ry-ka-za-te-lyam tre-bo-va-ni-yam op-re-de-len-no-go sor-ta, but with ob-zo -lom, pre-v-sha-ying us-ta-new-flax-mu for this sort-that, do-let-ka-e-xia pe-re-enter-dit in not-about -rez-nye with saving-ra-no-it-s-tness.

Continuation

Notes:

1. Norm-we in-co-rob-len-nos-ty us-ta-nov-le-ny for pi-lo-ma-te-ri-als with a moisture content of no more than 22%. With more moisture, these norms are halved.

2. Po-ro-ki dre-ve-si-ny, do not mention-me-well-tied in us-that-that-dar-dar-those, do-let-ka-yut-sya.

Pay attention to the quality of lumber

When-about-re-ta-e pi-lo-ma-te-ri-aly, with which-ry-mi you co-bi-ra-e to work, must be not only solid, and "good-ro-you-mi" - one no-ro-ny-mi in color, without a trace of-ra-ze-niya dre-ves-ny-mi-di-te-la-mi. It is not necessary to use-use-for-work for the tree-wi-si-well, the mushroom-lump. It is easy-to-op-re-de-pour according to the color of the tree-vi-si-ny and according to the splitting-off in-lo-con in the place of the ra -generation. The color of the feminine pi-lo-ma-te-ri-als can vary from cream-mo-in-go and bu-ro-go to si-not-va- so and ze-le-no-va-so.

Play-shah-ra-zha-em dre-ve-si-well, only sleep-si-well, for this-mu-tree-ve-si-well, you can still save it, if it is -ev-re-men-but clean it from ple-se-ni ru-ban-com and ho-ro-sho pro-su-sew. Rot, especially-ben-but poison-ro-vaya in-ra-zha-em dre-vi-si-well from the inside-ri, destroy-ru-sha-et its structure and de-la-et it unsuitable for use.

When-about-re-thawing pi-lo-ma-te-ri-aly es-tes-twen-noy wet-ness, be-those go-then-you to the pre-standing complex-nos-ty: post-le mon-ta-zha ma-te-ri-al start- no pod-si-haat, change the form (ko-ro-beat-Xia), decrease-shake-Xia, tres-caste-Xia.

If you want to avoid the above-mentioned problems, you must choose one of the following solutions. niy: buy-drink already you-sous-shen-ny according to GOS-Tu on the special-tsi-al-nom-ru-do-va-nii pi-lo-ma-te-ri-al-li-bo pro su-sew already purchased. You can pro-su-sew pi-lo-ma-te-ri-al in the EU-tes-tven-conditions-vi-y. For this, pi-lo-ma-te-ri-al uk-la-dy-va-e-Xia under the open from the sides on-ve-som on the through-nya-ke, in -te-n-nn-nom-those. Each layer of pi-lo-ma-te-ri-al, laid down for the eu-tes-twen-dry-ki, pro-la-dy-va-et-sya in-speech us-mi narrow-ki-mi bars-ka-mi.

In the process-se-es-test-twen-noy-ki, not-about-ho-di-mo, to follow, so that pi-lo-ma-te-ri-al does not zap-forest-no- led under the pro-lo-wives-us a bar-ka-mi. In such a view, he must-wife su-sew-Xia for about 20-30 days

For something that would be right, but choose a supplier about-cut pi-lo-ma-te-ri-alov carefully-but-chi-chi-chi-chi-shchess-stan-dar-you and you-take-ri-those on-for-more suitable for you a class, as for chas-tvu, and for the price. In some cases, perhaps, you will have a year-to-go to another way of the dre-ve-si-ny , and not to look for op-re-de-len-nyu in-ro-du with more you-so-kim class ka-ch-tva.

Pop-ro-bui-te estimate-thread, in how much prob-le-we with ka-tch-tv of cut-out pi-lo-ma-te-ri-als will be used for you. About-calls-no-those different-personal-suppliers. Sometimes you will buy different elements of the structure from different suppliers for a year. If you are exactly op-re-de-li-te pa-ra-meters not-about-ho-di-mo-go you about-re-de-no-go pi-lo-ma-te- ri-ala, then you will be able to find that-var from a person-but-go ka-san-tva, moreover, on-for-lee lower prices!

Lumber is produced by sawing wood into separate parts - plates, quarters, bars and beams, boards, slabs. The types of lumber are very diverse.

The thickness of the boards manufactured in a production environment can be no more than 100 mm, the width is greater than the thickness value multiplied by two. The beams have a thickness of no more than 100 mm, the width should be less than twice the thickness.

How lumber is subdivided depending on processing

According to the method chosen for the processing of raw materials, lumber is divided into unedged and edged. For the latter, processing from four sides is characteristic, on the faces and edges, while the values ​​\ u200b \ u200bwane should be allowed only those determined in accordance with the type of product. Scab is the part of the log surface that is preserved on the part after mechanical trimming. It turns out a piece of board that is not finished around the edges, which can be used in architectural structures or in carpentry finishing of buildings.

Uncut lumber has edges that are partly sawn or not at all. One-sided products have one edge and sawn edges, while on the sawn lump, wane is not allowed that is larger in magnitude than the parameters permissible for a particular product. This type is used in construction a little less often. It can be used for sheathing various parts of the structure, for making flooring, other options are also possible.

Depending on the processing method, materials can be called unmilled or milled, that is, planed. The latter are a material in which at least one of the cavities has been cut. In order to produce planed timber, timber is taken only with a certain diameter, so that the blanks for the timber are formed in accordance with the required size. The workpieces must be dried - this is done using steam chambers or in natural conditions. Products are obtained by processing raw materials on machines.

Classification of lumber by size, shape

When processing wood with the use of modern technologies, different types of products are made. The assortment includes bars and sleepers, boards and slats, quarters, slabs, plates and other products. The types of lumber can vary depending on how the raw material is handled. You can familiarize yourself with them in more detail.

Types of lumber

The timber, depending on the number of sides that have been processed, will be called two-edged, three-edged, four-edged. The thickness and width of the products is usually more than 100 mm. The main area of ​​their use is the construction of load-bearing structures, cottages or summer cottages, since these products can perfectly withstand significant loads.

The bar is similar to the bar, but has different dimensions. It is made with a thickness of up to 100 mm, width - less than double thickness. It is used in the furniture and carpentry industry, for finishing buildings, for example, door frames and crossbars are made from them.

Table of shrinkage and mechanical strength coefficients of sawn timber.

Boards are made of logs or beams of sufficient thickness. Boards are available uncut or cut. The thickness is possible no more than 100 mm, the width is more than double thickness. Application - wall decoration, flooring, furniture production.

The sleeper is a product with a short length, but wide and thick. This is in some way a kind of timber, in which the cross-sectional size differs in size. The most common use is for making railroad cloths.

A croaker is a piece of a log, sawed off from the side. In the process of sawing logs into various boards, waste is obtained, which is called slab. It is convenient to make temporary buildings from it like sheds, they are also suitable for the construction of lathing under the roof.

Quarters (obapol) are also obtained from the sides of the logs. One of the surfaces of the product is propylene, the other is not. It is convenient to use for making small joinery.

The plate represents half of the log that is obtained by sawing it in the center. The plates have only one straight side. The length depends on the log used as raw material. They are mainly used for the production of the above products - sleepers, beams, sometimes - for the manufacture of massive boards.

How lumber is classified by wood species

For sawn timber, the grade will also depend on the tree species - they can be deciduous or coniferous.

Coniferous areas include larch, spruce, pine, cedar, fir. Deciduous arrays - oak, birch, beech, aspen, poplar, maple. For the construction of buildings, coniferous trees are more often chosen, since they are less susceptible to moisture, are more convenient to process, have good hardness and are quite durable. They can be used to create structural structures. But it should be borne in mind that conifers in their composition have a lot of resinous substances, which means that any types of lumber created from them are quicker and easier to catch fire.

Spruce wood is especially popular. It also contains the smallest amount of resins, therefore, the propensity to fire is reduced. Oak is widely spread among hardwoods - it is very strong and durable. Lumber can be divided into four grades. So, the selected grade is used in the manufacture of parts in shipbuilding, in the lathing of automobile sides, in other significant areas.

The term "sawn timber" means various types of construction and finishing materials made of wood, standardized sizes and quality indicators.

Lumber: terms, definitions, classifications

Each type of wood has its own specific properties, and therefore it is customary to observe the generally accepted classification, regulated by existing standards, based on the shape and size of sawn timber, wood species and other defining indicators.

External classification:

• Bars- lumber of rectangular shape with a width and section thickness of more than 100 mm;
• Planks- lumber less than 10 cm thick and more than double the thickness;
• Planks, planks, sleepers- a group of auxiliary materials of small size and rectangular cross-section;
• Reiki- a widespread material in construction, which is a thin and narrow board.

By surface treatment method lumber can have wide surfaces (faces), narrow surfaces (edges), end surfaces (ends). By type of sawing wood- radial (sawing from the core to the edges of the trunk), tangential (at a certain distance from the core), mixed sawn timber.

According to GOST, lumber moisture- one of the most important qualities of wood, on the basis of which there is also a separate gradation. By the degree of absolute humidity wood is divided into the following types:

• wet - humidity more than 100%;
• freshly cut - at a humidity of 50 ... 100%;
• air dry - 15 ... 20%;
• room-dry - 8 ... 10%;
• absolutely dry - at a humidity of about 0%.

Common types of lumber and their use

One of the widely demanded lumber today is four-, three- and two-edged timber. It is widely used for the erection of supports and installation of rafters, in the construction of houses, for the construction of temporary buildings, subfloors.

When erecting rough structures and temporary fences, unedged boards are no less popular. Edged board is used in construction everywhere: making wooden windows and doors, laying wooden floors, erecting walls, stairs, floors. For interior decoration, block house and lining are in great demand.

All these and other types of sawn timber are produced according to generally accepted standards (GOST) that regulate the quality of sawn timber. GOST 2140-81 assumes a general gradation of 4 lumber grades based on product quality indicators:

• First grade- lumber that has practically no defects (knots, cracks, through-growth, browning, mold, rottenness, etc.)
• Second grade permits a small number of defects, while there should be no dropping out knots, deep cracks, damage, rottenness, foreign inclusions.
• For the third grade many defects are allowed, but there are also certain ratios of the number of defects per unit of material.
• Fourth grade allows almost all defects, provided that the integrity of the material is preserved.

Softwood and hardwood lumber

All timber and types of timber made from them are also classified as two large categories - coniferous and deciduous.

Coniferous lumber are made from such tree species as spruce, pine, cedar, fir, larch, and are distinguished by a particular breadth of application. Graduation of sawn softwood into grades carried out in accordance with the following indicators:

1. Compliance of sawn timber to the dimensions established by GOST. Sizes of softwood lumber are regulated by GOST 24454-80. According to this GOST, the dimensions of lumber, including the width and thickness of the ends, the width of the layers, are regulated by the relevant standards or can be made according to the customer's dimensions.
2. Moisture - lumber can be produced raw (moisture more than 22%), dry (less than 22%) and moist antiseptic.
3. The roughness of the surface (arithmetic mean of the maximum heights of irregularities) should not exceed 1250 microns for grades 0-3, 1600 microns for grades 4 (GOST 7016-82).
4. Parallelism of faces and edges. In this case, non-parallelism is allowed within the limits of deviations from the regulated sizes of sawn softwood (GOST 24454).
5. The presence of wood defects (knots, cracks, fungi, rot, etc.) is standardized by GOST 8486-86.

Hardwood lumber, made from trees of almost any deciduous species, are distinguished by their special density, beautiful wood texture and durability. They are widely used for cladding ceilings, partitions, walls, as well as for the manufacture of various architectural details.

According to GOST, hardwood lumber is differentiated into 3 grades(GOST 2695-83). The list of quality indicators of hardwood lumber, in accordance with which the division into grades is made, includes the presence of the following defects: accrete, falling out, rotten knots, cracks, browning, sprouting, wane, warping and some other defects.

Today, almost any branch of the national economy uses wood products for different purposes. This is due to the unique properties of this material. Synthetic products are not yet capable of replacing it. Therefore, it produces a variety of types of lumber.

Their properties and classification deserve detailed consideration.

Main characteristics

Wood products are made by sawing. This is where the name comes from. The demand for this material is due to its availability and a number of unique qualities. The existing types of sawn timber are very diverse. They are environmentally friendly and aesthetically pleasing. In addition, they are durable, characterized by a long service life.

However, wood also has negative features. If lumber has been improperly processed or is used in unfavorable conditions, their rotting and destruction may occur.

In the selection process, it is necessary to pay attention to the quality of their processing. If the wood has been poorly dried, it will deform. Therefore, you should know what properties each type of product has.

Classification

There are many signs that divide the main types of lumber into groups. The most popular is the classification by the type of cut:

1. Board.
2. Bar.
3. Bar.
4. Sleeper.
5. Croaker.

There are also edged and unedged materials. In the first case, the workpiece is processed from all sides, and in the second, only from one side. There are mixed varieties of them.

According to the cutting method, radial and tangential blanks are distinguished. This classification depends on the positioning of the cut relative to the tree rings.

Another important classifying factor is humidity. Dry materials have this indicator at the level of 8-10%. Such products are solid, used for furnishing, for example, flooring. Universal sawn timber has a moisture content of 12-15%. These are blanks for skirting boards, platbands, timber. External lumber has a moisture content of over 18%. They are suitable for cladding the facade, creating a rafter system.

Material

The first type is lightweight but durable. It is made most often from tropical woods. The window sill board has a special impregnation and is characterized by good drying. Engineering varieties have a bottom layer of plywood, and the top is made of natural wood.

Lining

One of the most popular types of boards today is lining. These types of lumber are used for indoor and outdoor cladding. Even in technical documents, this type of product is called a sheathing board.

The profile of the lining can be different. The material from which it is produced is also characterized by a wide range. When choosing it, the operating conditions are taken into account. Coniferous and soft deciduous species are suitable for dry rooms.

If this is a bathhouse, then the use of resinous types of wood is not allowed. Otherwise, you may get burned. They are used for street cladding. They are treated with various substances to extend the service life.

Sleepers, small molding

In addition to the products considered, such types of lumber as sleepers, as well as small moldings, are in demand today. These are narrowly focused products, but their importance can hardly be overestimated.

Wood sleepers have a number of advantages when compared with reinforced concrete varieties. They dampen train vibration well and hold the rails securely.

The need for regular maintenance of existing communication lines, as well as the installation of new lines, require a large number of high-quality sleepers. They are made from expensive types of wood, because sleepers are exposed to heavy loads and adverse environmental influences. They are impregnated with special substances in order to avoid decay processes, rapid destruction. Sleepers of different strength classes are used depending on the type of trains moving along the communication line.

Also narrowly targeted varieties of sawn timber are small molded products. These include skirting boards, corners, platbands, glazing beads. They are produced in various dimensions. This allows you to choose the best option for everyone.

Croaker

In the process of making timber or boards, a slab is obtained. This is the side of the log. On the one hand, these lumber is convex, and on the other, it is flat.

This material is also in demand today. For the arrangement of temporary buildings, technical premises, the slab is quite applicable.

It has also become quite popular today to carry out decorative finishes using this type of lumber. The croaker is mechanically processed only from the lean-to side, therefore, before installation work, it is imperatively impregnated with a special antiseptic. Otherwise, after a couple of years, the croaker will turn into dust. The relatively low cost makes it in demand. New areas are emerging in which this material is applied.

Dimensions (edit)

The types of lumber and their use determine the size. Each type of processing has its own clearly defined shape boundaries. Dimensions sometimes even determine the name of the product. A board is an edged product, the width of which is greater than double thickness.

If this ratio is not met, the product is called a bar. Its width is less than double the thickness. And the bars generally have the minimum specified dimensions. Their thickness and width must exceed 100 mm.

The usual one is 6 m. The parameters of width and thickness are standardly 100 by 100 mm, 100 by 150 mm or 150 by 150 mm. If the project requires the use of a material with even larger dimensions, the product is made to order. But the cost will be much higher than the standard one. Therefore, when developing a project, the engineer must take these dimensions into account.

The board is also produced in accordance with the standards. Its thickness is 25, 40, 50 mm. The length is usually 4, 5 or 6 m, and the width is 100 or 150 mm. The bar is usually made with standard dimensions of 40 by 40 or 50 by 50 mm. The length of the workpiece can be 3, 4, 5 or 6 m.

For the arrangement of flooring, a certain type of boards is produced today. They are 85 to 140 mm wide. Depending on the load level, its thickness ranges from 27 to 45 mm. Standard dimensions must be taken into account in the design process.

Having considered the main types of lumber, their properties, scope, everyone can choose the best type of product for their conditions. The variety of shapes, sizes and materials allows them to be used in almost any field of human activity.

In the woodworking industry, there is a scrupulously compiled instruction according to which types of lumber are sorted. The complexity of this system is that the gradation is carried out according to:

• The type of wood;
• The way of processing;
• Dimensions and geometric parameters of the finished product.

That is, for the complete identification of sawn timber, it must be linked to all three criteria. And the lumber itself is a product of the woodworking industry, corresponding to certain parameters and in which there are at least two flat parallel surfaces.

There are two types of commercial timber:

• Deciduous;
• Coniferous.

It is generally accepted that deciduous species are hard, and conifers are soft. But in fact, linden, aspen or alder, although deciduous trees, have soft wood. Larch, yew or cedar, on the other hand, are extremely hard.

To a greater extent, they differ in the presence of resinous substances in the wood mass. It is for this reason that coniferous wood boards are not used in rooms where a microclimate is created that favors the release of resin to the surface.

The steam room and showers do not get off with coniferous wood just because of this.

But there is also an exception - yew. Although yew boards are not so often presented in the building materials markets, its timber is not considered valuable.

Special category

It is impossible to find products made of it in widespread use. Sometimes it is used as inlay, or veneer is made from it for decorating pieces of furniture.

Such wood almost always has a unique combination of different properties that make it original and truly valuable.

Tree cut

For example, the wood of the rosewood, which grows only in Brazil and Paraguay, exudes the scent of roses for several decades. In addition, she has a beautiful textured pattern and a yellow-pink color. But the price for a 6-meter board, 3 cm thick and 9 cm wide, exceeds $ 2,000.

Drawing and texture

These parameters show the ontological qualities of wood. The ability of fibers to intertwine or follow strict parallel courses, to be twisted or cross-layered, to one degree or another, is present in every tree species. But they are combined in an extremely narrow-profile combination, which helps to accurately determine the type of wood.

Moreover, the place where the tree grows and the concentration of certain elements in the soil have a special effect on the texture of wood. In particular, the presence of iron-containing minerals in the soil increases the cross-bedding of some tree species.

Greater importance is attached to the pattern and texture of wood if these types of lumber are intended for finishing work.

But in this case, some defects of wood, which reject it from the category of structural materials, increase the value of the product from such a workpiece. For example, curliness dramatically reduces the strength characteristics of lumber, but with skillful processing and sawing, it is possible to produce finishing boards with an exclusive pattern. For this property, birch and holly elm are valued.

The color palette also characterizes the wood species, but in some cases it can change during processing or use. Moreover, these changes may indicate the beginning of destruction, for example, rotting. But changes in the shade of wood can be due to a change in the physicochemical parameters of lignin and oily or resinous fractions, which sometimes, on the contrary, increases the operational characteristics of the product. For example, larch heartwood has a resin with a unique quality composition. Upon contact with water, this resin polymerizes, and the material from sound larch can no longer be damaged or processed. It is easier to grind with a file.

Strength characteristics

These parameters also have a lot of gradations that are rarely known to the average consumer. For example, strength is measured according to the following criteria:

• Compression;
• Bending:

1. Static;
2. Dynamic;
3. Tangential;
4. Longitudinal.

• Tensile;
• Break:

1. Along the fibers;
2. Across the fibers;

• Twisting;
• On a chip;

Plus, the hardness of the wood is also measured.

In everyday practice, boards made of oak, hornbeam, larch, and beech are considered durable lumber. But they, with the exception of larch, are almost always used in interior decoration or joinery.

As a structural material, coniferous lumber is almost always used.

Softwood from linden, poplar, aspen. It has little resistance to the destructive effects of atmospheric factors, being outdoors, therefore, these types of lumber are used in interior decoration and artistic creation.

Processing methods

Although the gradation is complex, it is more systematized.

Lumber elements

Depending on the surface treatment, lumber can be:

• Trimmed;
• Untrimmed;
• Edged;
• Unedged;
• Unilaterally trimmed;
• Planed;

At the same time, depending on the grade, some flaws are allowed in the finished product, for example, wane.

According to the orientation of the lumber in the workpiece, there are two main options:

• Radial;
• Tangential.

The rest of the options, to one degree or another, rely on these two.

Log sawing options

The difference in product yield when sawing a log in different ways does not differ much, and significantly affects the yield of a bar. To a much greater extent, this affects the manifestation of certain characteristics of the boards.

Scheme of dependence of the output of finished products on the type of sawing of logs

In particular, it is possible to achieve a more pronounced manifestation of the pattern, or an increase in the strength characteristics for the longitudinal fracture of the beam.

Classification by size and shape

In this gradation, the sequence is quite simple:

But when sawing logs, by-products are also formed, such as slab and obapol.

Although they are similar, there is a difference between them. If the tiltiness of the log was higher than the norm, then at the first cut, the obapol is removed. This is a woodworking product that has only one face.

Sawing scheme

The next cut if the croaker. In this product, one of the faces will have only partial processing.

Further cuts give, depending on the thickness and width, the following types of lumber: timber, bar or boards. By the depth of processing, they can be edged or unedged.

There is another type of lumber that is included in this classification, but which is separate, these are sleepers.

The scope of their use for their intended purpose is very limited, and their size and strength characteristics are regulated by the internal documents of Russian Railways.

Other building materials made of wood, such as: lath, plank, glazing bead, etc., are already created from lumber.

Scope of application

The scope of use of sawn timber is limited to two areas:

1. Industrial construction direction;
2. Furniture and finishing direction.

But in these two categories, almost all types of human activities are included. At the same time, in the production of furniture and decorative finishes, a much deeper processing of lumber is carried out.

In addition to planing and grinding, the following can be used:

• Thread;
• Etching;
• Dancing boards;
• Coloring;
• Varnishing, etc.

Separately, I would like to mention the work on giving plasticity to lumber. This is necessary for the formation of products of unusual shapes.

With the right choice of lumber, even such fantastic structures can be made.

These technologies are very time consuming and require good technological equipment. In principle, it resembles heating in a huge microwave operating in a special mode.

What attracts in this technology is the ability to re-process lumber according to this technique - if you don't like the shape, then you can change it.