Larch as a building material properties. Larch wood. Main characteristics. Characteristics of larch wood

Larch is a type of coniferous wood. It combines the perfection of useful qualities and longevity. This tree has wide range application, but especially proved in construction. The valuable properties of this tree are not comparable with any other type of wood, which is why the cost of larch is slightly higher than that of pine, but significantly lower than that of many other types of wood. The world of the Forest is truly amazing, and larch occupies the main place in it.

Description of the breed. Larch is a coniferous tree.

Larch - coniferous tree

Many are wondering - larch is a coniferous or deciduous tree. Also, some believe that larch is a deciduous tree. Larch belongs to coniferous tree species. In favorable conditions, an adult tree can reach a height of 50 m in height and a trunk diameter of up to 1 m. The average life span of the breed is from 300 to 500 years. Cases of a plant life span reaching 800 years have been recorded. The tree has a loose crown of a cone-shaped or ovoid shape. Well illuminated by the sun. The needles have a bright green color and a flattened shape. Its location is single or spiral, and on short shoots it is bundled. The branches are arranged in a chaotic manner, without patterns. If the area is windy, the needles can be located only on one side of the tree.
It is worth noting that in autumn the tree sheds "leaves" before the onset of spring. The plant tolerates winter quite easily, this is evidenced by the absence of frostbite-"frostbite" even at a temperature of -60 degrees. Therefore, this tree can be found in the harsh northern regions, farther than any other vegetation. In Russia, the plant occupies large areas of Siberia, the Far East and the south of Primorye. Outside of our country, the larch breed is common in Northern and Western Europe. The soil on which a valuable tree grows does not have special qualities. The tree grows in Siberian moss swamps, as well as mountain slopes. Of course, this location affects the growth and size of the offspring. In favorable areas, a tree can coexist with such species as spruce, pine, birch. A strong root system does not have a pronounced trunk, has a branched shape and deepened lateral roots. This position of the root system allows you to hold on tighter and resist strong gusts of wind.

Reproduction of the breed. Larch cone.

Fruiting of plants begins with the achievement of 10-15 years. And good seed years are repeated at intervals of 5-6 years. Natural reproduction of the tree occurs with the help of seeds. Male ears are small and yellow in color, while female ears are red, pink or green. Pollination occurs in spring or summer, depending on the region. So, in the southern part, pollination begins at the end of April, and in the northern part - in June. Cones ripen in the fall, so they begin to open either immediately or after overwintering. The seeds of the tree are small, with tightly fitting wings. Despite the strength of the plant, the seeds have a low percentage of germination, this is due to the lack of flying sacs in pollen, so many seeds are “idle”.

Artificial breeding of the breed has two options:
Seminal.
Cherenkovy.

It is much easier to grow larch from seeds than from cuttings. For this, mature cones are collected and dried until they open. The seeds are removed, and one month before the upcoming planting, they are soaked in water for one day, mixed with wet coarse sand. The finished mixture is laid out in special wooden boxes and placed in a cool place or refrigerator. It is important to take into account some nuances here, firstly, there should be holes in the boxes for natural ventilation, and secondly, it is necessary to correctly calculate the time of settling so that landing in the ground occurs in late April - early May. It is recommended to plant seeds no more than 1.5 cm deep, and it is strictly forbidden to specifically tamp or sprinkle seedlings with heavy soil. To do this, you can use a sand-peat mixture, which has sufficient porosity to provide good access to oxygen. As a seedling insulation, you can use a film that can be removed after the first shoots. Seedlings should be transplanted to a permanent place after they reach the age of two.
Growing larch using cuttings is a laborious process and requires the provision of many conditions. This is explained by a small percentage of rooting cuttings. Good growth and development of seedlings is affected by humidity, temperature, soil composition and light. To comply with all requirements, special nurseries are used, where experts can provide them with the necessary temperature and humidity conditions and care. It is worth noting that this approach is also explained by the poor rooting of cuttings in the open field.

Varieties of larch

Depending on the location, features of the tree, there are several types of larch species:

- she is ordinary, is a wide representative of the breed in Western and Northern Europe. It reaches a height of up to 50 meters, has a slender strong trunk and a dense crown of irregular shape. In our climatic conditions, an adult average tree reaches a height of 25 meters. The crown of a coniferous plant has the shape of a cone, the color is bright green. Mature cones have a brown tint, and their length reaches four cm, the tree begins to bloom in May. This tree is recognized as the fastest growing among its relatives. It is not afraid of cold weather, has a long service life and aesthetic qualities. It grows well on any soil, but does not tolerate places with stagnant waters. Excellent larch lives on calcareous, chernozem, podzolic soils and loams. In addition, well-draining soil will provide an excellent basis for strengthening and developing both the root system and the entire plant.

Siberian larch occupies 50 percent of the area in the forests of Russia and reaches 45 meters in height. The difference of this breed is a straight trunk, thickening towards the bottom. The plant is covered with thick, light brown bark. The needles of young shoots have the shape of a narrow pyramid and are rare; in adult trees it is wide, pyramidal in shape and raised high. The branches of the Siberian beauty are at an angle of 90 degrees with respect to the trunk, and their ends are bent upwards. The leaves of the Siberian larch of a light green hue are narrow and range from 13 to 45 mm in length. When ripe, the cones acquire light brown and yellow hues. Pollination occurs in late April - early May and lasts for 1.5 weeks. Seed dispersal itself occurs in autumn, preferably in October. How long does a larch live? Siberian larch lives on average 200-300 years, but there are trees over 500 years old.

3. Daurian larch

grows in the Far East and under good climatic conditions reaches 30 meters in height. The difference of this breed is the red bark, which becomes much thicker as the tree grows older. Young shoots are straw-coloured and often seen bare and drooping. The needles are light green, up to 30 mm long. The cones of such a larch are small, only 20 mm long, have the shape of an egg or an oval. It is worth noting that the needles of the plant have a light green color in spring, bright green in summer, and golden in autumn. Flowering begins in late April - early May, and dispersal occurs in early autumn. The breed grows both on high mountain slopes and river valleys. Due to the undemanding nature of the soil, Dahurian larch grows in wetlands, rocky slopes and in areas with shallow permafrost.

4. American larch

distributed in the northern hemisphere and reaches only 25 m in height. The trunk diameter is usually from 30 to 60 cm. It is mainly found in Canada and the northeastern United States. The cone-shaped crown is formed by serpentine branches that hang down. The trunk has a dark brown or gray color. The needles of the tree are light green in spring and darker in summer. The leaves reach 30 mm, and the cones are only 10-20 mm. They have a purple hue until completely dry and turn brown after opening. Flowering begins in mid-May, and productive fruiting is observed every 4 years. It should be noted that the growth of this larch is much slower than its sisters.

The varieties of larch do not end there, but unlike the above, most of them have decorative uses due to their small size.

Common larch pests

As with all plants, there are pests on this breed that can harm plants.

- a sucking insect that lays larvae that feed on plant sap. This insect is very small, but adults are able to fly from one tree to another.

The gall midge lives and feeds on plant tissues, the affected shoots begin to suffer from infection and soon die off. Various fungi on the bark of a tree can cause the spread of putrefactive formations and pests.

Many often wonder how to distinguish larch from pine. In fact, it is not as difficult as it seems at first glance. The main difference between these two trees is the needles. Larch is the only plant that sheds needles for the winter. Therefore, if a coniferous, bare tree appeared before your eyes, it is a larch. Pine only changes the color of the needles. You can also distinguish trees by their crown - larch has a conical frame, while pine is more round. Pine leaves are hard and look more like spruce needles, while larch leaves are flattened and soft to the touch. Cones of plants have different sizes, in pine they are larger and round shape, larch is smaller and oval. The difference can also be found in color - mature pine cones have a rich brown color, while larch has a brown one.

Trees can also be distinguished in the form of finished lumber.
The larch bark is much thicker and has a rich reddish tint inside. A sliver of larch will sink much faster than pine. The structure of larch will clearly manifest itself under the influence of water. A marble pattern with a pinkish tint will stand out strongly against the background of a pine product. The smell of pine is not to be confused with anything, while larch will not express such an incense with needles. With the help of a log, it is also easy to distinguish larch - the core and dense one-year-old rings will clearly stand out on the cut. All doubts will be dispelled by arson of splinters from both materials. Larch lights up for a long time and very slowly, unlike pine. The strength of larch is much higher, therefore, if you run a nail over the material, it is unlikely that deep marks will remain on it.

Pine and larch - different trees. Larch has significant advantages over pine, despite their common coniferous species. Main characteristic larch material serves as density. Compared to pine, it is 1.5 times higher. The indicator of this property for larch is 670 kg/m3, while the density of pine is 440 kg/m3. Due to this, the tree has a higher hardness, which is 400 kg / cm2, the same indicator for pine - 200 kg / cm2. These two qualities already speak of the advantages of larch lumber. Building elements are stronger and can withstand significant loads.
Rot resistance is another quality to consider when choosing between two plants. So, pine has a 3-4 degree of stability, and larch 2-3. This shows how a tree can behave in the event of a danger. Pine has a low degree of resistance to decay, while larch has a moderate degree, and therefore is less susceptible to this risk. Fire resistance is an important indicator of wood resistance to fire. Due to its resinous nature, pine does not have high fire resistance, while larch is difficult to ignite, and burns very slowly when ignited. The moisture resistance of pine undeniably loses to its sister, for whom water is a way to increase its strength. The appearance of larch in comparison with a friend is noble and aristocratic. The surface of the material is distinguished by a marble pattern with a pinkish tint.

Due to its properties, larch is widely used in construction. The tree has the following decisive factors:
The strength of larch wood is comparable to oak. On the Brinell scale, the hardness of wood is 109 units, while oak has a hardness of 1 unit higher. Density contributes to strength - this is undoubtedly the advantage of the material, which reaches 660 kg / m3 at 10% humidity. This figure is 1.5 times higher than that of pine. The plant has high rates of compression along the fibers, modulus of elasticity, impact and static bending and chipping. Due to these characteristics, larch is used for the manufacture of parquet boards. Fire resistance is one of important factors when choosing a material. Larch has good fire resistance, the indicator is several times higher than other tree species. Resistance to fungal diseases allows the tree to live for quite a long time. Insects also appear on larch that can harm the tree, but due to the plant's poor susceptibility to pests, they often change their preferences. Water resistance is always taken into account when building with larch wood lumber. Due to this property, larch is used for outdoor structures. A distinctive characteristic - when absorbing water, the plant becomes even stronger. Therefore, earlier this breed was used in the construction of bridges.

Environmental properties

Environmental safety is a guarantee of quality of life, therefore any wood carries safety and guarantee of health. The aesthetics of the breed allows you to create various materials that not only fulfill their direct duties, but also decorate the room. The thermal conductivity of larch is much less than that of another tree, this is due to its density, therefore, floors are mainly made from larch.

larch transportation

In order to deliver the wood to its destination, alloy and other types of transportation are used. A feature of larches is the acquisition of greater strength after being in the water, so our ancestors tried not to float the deciduous forest on the water. After all, gaining excess weight, the wood sank. Nowadays, this plant is rafted using cargo ships, which increases the efficiency and speed of timber delivery. For transportation, it is necessary to take into account the weight of the forest of natural moisture, which will be much larger than the dried wood. IN Lately rivers are loaded with traffic, so more and more wood is delivered by rail and road.

Deciduous plantings occupy a large area in Russia, while in other countries this species is not enough. The need for high-quality larch lumber is especially high in countries with desert areas and plantations unsuitable for building purposes. Regular buyers of wood are Iran, Israel, Iraq, the CIS countries, the European Union and China. The last country prefers larch, because it is it that serves as an excellent material for houses on the water. Lumber in the form of,, and is in demand. Abroad, larch is mainly used for decoration of premises and houses, for the production of furniture of excellent quality.
Austrians prefer Siberian larch as building materials for building houses. It combines all the heat and sound insulation qualities, so the houses are solid. The appearance attracts foreigners and allows you to create delightful design complexes. The qualities and characteristics of this material allow it to be used in shipbuilding, railway construction and many other areas. The possibilities of this tree are great, and with the help of modern technologies you can achieve unique results in various fields applications.

The use of larch in construction. Larch lumber.

Larch as logs

The high cost of rock and thermal conductivity are the reasons why complete log cabins are rarely made. The strength of the tree and its lifespan is an excellent solution for the construction of a durable structure, but the thermal conductivity indicator requires additional wall insulation or thickening. Therefore, it is advisable to use rounded logs for the lower crowns of the house. This will serve as an excellent support for subsequent crowns and will not allow the logs to sag much. Also, the first crowns of larch will protect the further tree from moisture, taking all the “blow” on themselves, which will only make them stronger.

This finishing element is highly popular due to its qualities and design features. The material is an array of larch, well dried and processed. This preparation helps to avoid cracking and other deformations. The outer side has a convex surface, and the inner one is flat. With the help of the tongue-and-groove connection, a snug fit of the boards to each other is achieved, which creates a solid, integral structure. With the help of processing, a perfectly flat surface is achieved, and the gutters on the inside of the element serve as ventilation ducts. Coating the finished element with varnishes emphasizes the aesthetic appearance, with the help of which, the building looks beautiful.
The appearance of this material allows it to be used for interior and exterior decoration, regardless of the material of the walls. Usually they are sheathed with frame houses, but it is possible to finish walls made of brick, concrete, timber or panel. Block house is not only a beautiful finishing material, but also protection of the building from adverse conditions, physical influences, humidity and frost. With its help, the thermal insulation performance of the walls increases, the degree of sound from the street decreases, the building acquires a full-fledged aesthetic appearance. Designers can use the block house to create a complex of original buildings.

Batten

The use of larch boards began long before the advent of modern technology. Larch was used for shipbuilding, mainly military, so it did not immediately come into use in houses. Bridges, piers and all buildings adjacent to the water were made exclusively from this breed. Larch flooring has a long service life, good wear resistance and moisture resistance. Natural components allow you to maintain environmental safety and warmth in the house. This element is made from solid wood, which explains its longevity and quality. Details of the required dimensions are cut, processed, subjected to thorough drying at very high temperature. The edges of the outer side are rounded, which creates the integrity of the picture and a good appearance.

Floorboards play a special role in the construction of open areas. Due to the good moisture resistance, the elements serve as a material for covering terraces, garden areas and paths, arbors. The specifics of manufacturing a floorboard is simple, specially made grooves on the outside of the coating act as a feature. Serves as a constructive solution to drain water from the floor and prevent slipping. Particular attention is paid to the processing of boards in open areas. To avoid fading in the sun, dust and dirt getting into the pores, special protective work is carried out with various compositions. The goal of the process is to obtain a film that resists exposure to sunlight and the penetration of dirt. With its help, the material does not lose its aesthetics over the years and pleases the owner with its beauty and sophistication.

Siberian larch (Latin name Larix sibirica) is a coniferous tree from the pine family. The name of this coniferous tree reflects its ability to shed its needles like leaves every autumn. The dimensions of the larch tree itself are on average 50 m high and 2.5 m wide at the base. Larches are long-lived, they usually live from 700 to 1000 years.

In Russia, larches are distributed from the northern border of forests to the border with the forest-steppe. Largest clusters larches are found in the Far East and Siberia. Larch is also found in the European part of our country, but lumber lumber of Siberian origin is of value for construction. Larch, grown in milder European climates, has looser wood, similar in properties to pine wood.

larch properties

Siberian larch has a high resistance to decay. Its wood has a biological resistance twice that of pine. In accordance with European standard EN 350-2; 1994 larch wood is classified as very resistant species, and pine wood as moderately resistant. The resistance to destruction of this wood is explained by a combination of a number of its unique properties:

• high density
• the special composition of the resin,
• high resinity.

A well-known proof of the strength and durability of larch is the piles on which Venice stands, made from this particular tree. They stand in the water and do not require replacement for more than 1000 years.

The resistance of larch to decay makes it possible to use it in places where the wooden structure is forced to come into contact with water or earth: in the decoration of swimming pools, moorings, in the exterior decoration of houses, to create wooden floors in the open air, piles, paths, etc.

Larch has a very hard wood, it is almost equal to the hardness of oak wood, and its strength in bending, stretching and compression bush than oak. And the beautiful texture of larch, combined with its strength, makes it possible to widely use Siberian larch as a floorboard, designed to be used for many decades.

As already noted, the pattern of larch wood is very beautiful. It has a pronounced structure, a special silky sheen and a wide range of 12 colors: it is formed by light yellow, red and golden brown colors.

The value of larch wood is that it has a very small number of knots and other defects. Therefore, a large amount of high-quality wood can be obtained from a larch trunk. The absence of flaws makes it possible to use larch in the design of the most expensive interiors.

Larch wood has a high fire resistance.

The use of larch in interior decoration

Larch wood has many valuable properties, it is slightly inferior to oak wood in terms of mechanical properties and has a remarkable quality: when dried, it acquires significant strength and is very weakly subject to mechanical and biological influences. The average density of larch wood at standard humidity (12%) is 665 kg /m3, absolutely dry 635 kg/m3, average basis density-540 kg/m3. The density of larch wood significantly depends on the type and place of growth. The most dense wood is found in larch timber obtained in Altai (725 kg/m3), followed by the Urals and the Urals (675 kg/m3). European larch has the lowest density (510 kg/m3).

The practice of wooden housing construction shows that houses built of larch 300 years ago are still standing. There are many buildings made of larch wood, whose age exceeds 500 years. Larch wood is very good in the construction of critical structures (piles) and railway tracks (sleepers). illustrative example This is Venice, which has been standing on piles of larch for many centuries. This was possible due to the presence of gum in larch wood, which makes it inaccessible to marine animals that grind through any other wood. Scientists have found that prolonged exposure to water leads to a noticeable increase in larch hardness. During the construction of Venice, about 400 thousand pieces of larch piles were hammered to strengthen the foundations of various structures. In 1827, i.e. 1000-1400 years later, part of the piles was examined. In the conclusion about their strength, it is said that the larch forest piles on which the underwater part of the city is based “as if petrified, the tree has become so hard that an ax and a saw can hardly take it.”

Larch wood is a traditional material for wooden shipbuilding. Even now, when the age of high-strength composite materials has come, the hull lining of expensive yachts is often carried out with larch. The drying technology of larch is different from drying wood of other coniferous species. To protect larch wood from cracking and warping during drying, it must be kept in the steaming mode for a long time and subjected to drying in the “soft” mode. In a number of old publications, it was noted that in Europe larch was used to extract resin, which was called "Venetian turpentine" for sale. For the extraction of resin, holes were made in the trunks, reaching the very core. Outside, the hole was closed. After a certain time, the turpentine collected in the hole was raked out. Each such channel made it possible to collect up to a quarter kilogram of turpentine. In Russia, they did not industrially engage in the extraction of resin from larch, because. the use of larch was allowed exclusively for government and ship structures. Despite the lower strength than reinforced concrete sleepers, larch sleepers have modern application due to more low level structural noise, which has a positive effect on the durability of the rolling stock transmission and safety.

Recently, due to the special popularity of suburban housing construction and the high consumer properties of larch (strength and durability), the use of larch wood for the construction of open building structures, such as pergolas, arbors, piers and terraces, has become popular. Recently, due to the rich texture and high consumer properties, the interior and exterior decoration of houses with larch has become very popular: floor board, lining, planken (cladding board), terrace board and, as well as other types of molded products.

Characteristics of larch

Larch - monoecious tall tree with heterosexual flowers and soft falling needles. Male and female inflorescences are located nearby on the same branches, which is extremely necessary, since larch pollen has no air sacs and is therefore poorly carried by the wind. This makes larches prone to self-pollination, which degrades quality and leads to the formation of a large number of empty seeds. Larch reaches a mature age of enormous growth - up to 30-50 m. In our country, Siberian larch is common in northeastern Russia. In Siberia, it is one of the most common trees, where it forms continuous forests on its own or mixed with pine and other trees. IN Western Siberia this is a real Siberian, in the East - Dahurian larch. In the west of Europe, larch grows in the Carpathians and the Alps.

Larch wood is rightly considered an excellent building material. During flowering, which happens in spring, larch emits a myriad of fruitful dust, which in windy weather is carried by clouds over long distances and, falling to the ground, covers it, as it were, with sulfuric rain. This phenomenon is often observed near Irkutsk. North America has its own species of larch, of which some are close to European, these are: Larix microcarpa Lamb., Larix Lyallei Par Larix, and in the Himalayas, at a height of 8 to 12 feet. - Larix Griffiti Hook. A. B.

The traditional places for harvesting larch are the Irkutsk and Krasnoyarsk regions. Since they are taken into account collectively, without division by larch species, it is not possible to determine the share of the area occupied by forests of each larch, especially since it is far from easy to distinguish between them. The fact is that diagnostic signs (features by which species differ) vary greatly depending on the growing conditions. Therefore, parts of a tree (seeds, cones, shoots) taken from different regions turn out to be incomparable. For the same reason, comparison of trees by individual features does not give reliable results. To accurately determine the type of larches, they must be compared at once on several grounds. With such a comparison, larches differ quite clearly. For example, Siberian larch cones are relatively large (2.5-3.5 cm long); seed scales are tightly pressed and do not open wide when dried; seed scales are pubescent and concave spoon-shaped. Their edge is smooth, the floor is rounded, without notches; the tips of the covering scales everywhere protrude above the seed scales; in cones there are 3-7, on average 4 parastihi (spirals along which the scales are placed in the cone); young cones are most often reddish, and light shoots are straw-yellow, less often grayish-yellow. Larch bark is richer in tanning agents than the bark of well-known tanning agents: oak, sedge, willow, and spruce. Dahurian larch cones are smaller, usually not longer than 2.5 cm; their seed scales do not fit tightly and, when dried, are strongly spread apart; seed scales are flat, sometimes even with an edge turned inside out; they usually do not have pubescence; the edge of the seed scales is uneven, with teeth and depressions; the tips of the covering scales protrude above the seed scales only at the base of the cone; in cones there are 2-5, on average 3 parastihi; young cones are most often greenish, and the shoots are yellowish-brown (darker than that of Siberian larch).

According to the structure and size of the needles, the number of needles in bunches, the shape of the cones, the ratio of the length and width of the seed scales, these types of larch almost do not differ. Young trees of these larch species are almost indistinguishable. Old Dahurian larch trees are characterized by a thicker bark and a strong buttiness of the trunks. The area of ​​growth of larch is rather conditional, since the determination of the species of larch in each region is very difficult due to the small difference in morphological features between species. Within its range in the Irkutsk region, Siberian larch is unevenly distributed. Its forest-forming role in the Angara region generally increases from the southwest to the northeast. In the mountains of the western part of the Eastern Sayan and on the Leno-Angara plateau, it forms forests in the lower part of the slopes. In other places it is found on different elements of the relief. The Gmelin larch is distributed almost everywhere within its range. Only on sufficiently moist heated slopes does it give way to cedar, and on sandy and skeletal soils to pine. Morphologically and ecologically, Chekanovsky larch is very heterogeneous, which in the western part of its distribution zone occupies colder and wetter habitats, yielding the best to Siberian larch, and in the upper part of the slopes to cedar. In the eastern part, on the contrary, it grows in more comfortable forest conditions compared to the cold-resistant Gmelin larch.

Until recently, it was believed that Siberian larch lives up to 450 years, reaches a height of 45 m and a diameter of 1.8 m. This characteristic is true for this breed at the eastern border of its range - on the left bank of the upper river. Lena. In the Angara region, its largest specimens reach a height of more than 50 m with a diameter at chest height of about 1.8 m, and up to 2.5 m at the root neck. Occasionally there are trees a little over 60 m, although in the mass specimens over 45 m are rare. It is difficult to determine the age limit of this breed, especially since very old trees are usually affected by heart rot. In the Bratsk region there are larches older than a thousand years (1052, 1280 and 1348 years). In general, 800-900-year-old larches come across relatively rarely, but the age of 700-750 years is already quite common for old trees of this species. Larch aged 400-500 years in the Angara region has a well-finished crown without external signs aging. On fertile soddy-calcareous soils near Bratsk, larch forests with a second layer of spruce had a very significant age (more than 700 years), average height 43 m and timber stock over 1200 cu. m/ha. Growing in more severe conditions, Gmelin larch is much inferior to Siberian larch in size and durability. Only in terms of diameter on the stump, the difference between them is not so great, since the Gmelin larch has trunks that are very thick in old trees, especially since its bark in this place reaches a thickness of 25 cm. The Chekanovsky larch occupies an intermediate position in these, as well as in other features. .

The deciduousness of larches, which greatly reduces the evaporation of a tree in the most difficult early spring period for it, is an important adaptation to continental climate. The annual renewal of needles increases the resistance of larches to forest fires and damage by needle-eating insect pests.

Pollination in larches occurs simultaneously with the blooming of needles in May. Seeds ripen in the same year in September a little earlier than cedar. Cones open gradually in dry weather, so the seeds spill out throughout the year. By the time of flowering in last year's cones there are still a few seeds. The cones stay on the tree for 3-4 years. The cones of the last year are lighter than the old ones, in which there are no seeds. Seed production occurs in free-standing larches at the age of 15-20 years, in forest stands - from 30-50 years. With the deterioration of forest conditions, the onset of seed production is delayed by 15-20 years. Harvest years occur in 3-5 years, average harvests - in the same sequence. Complete absence of seed production is rare. In the harsh conditions of the north-east of the region and in the mountains, harvest years are repeated somewhat less frequently.

In harvest years, Siberian larch in the Irkutsk region produces up to 9 million seeds per hectare, but usually no more than 5 million. On average, larch forests produce about 1 million seeds per hectare, that is, much more than other conifers. However, birds and mammals that prefer larch seeds to all other seeds, except for cedar, destroy a significant part of the crop. Therefore, seeding can occur only in productive years, especially since larch seeds usually have a low germination rate, generally lower than that of other conifers, and many seeds are empty.

Annual layers are clearly visible in all cuts. The width of the annual layer is 0.8-3 mm. With increasing age, the width of the annual layer decreases. The specific volume of late wood in annual layers is 30-35%. The larch trunk consists of 70% of the core, which stands out sharply in terms of properties and color. The core part of the wood contains the main part of the substances that give larch increased durability. Dark. The sapwood of larch is narrow, 8-20 mm, 25-30% of the wood mass. Light. In terms of physical and mechanical properties, it is inferior to the core.

Valuable strength and operational properties make it possible to use its wood in home improvement and construction of durable and environmentally friendly structures. The use of the material in the construction of log cabins, installation of the truss system and individual pieces of furniture is most in demand.

To increase the service life, stable and durable types of wood are introduced into the design of most buildings. The spread of larch in mass construction is hindered by a significant cost, so its use is often limited to the most critical long-term and load-bearing elements. Consider the main building structures in which they try to use larch wood.

classic houses

Built from brick or stone blocks. In such buildings, wooden elements are usually used for the manufacture of rafters, ridge and interior decoration. Sheathing the house from the inside with hardwood clapboard lowers the thermal conductivity of the walls and makes living in frost and summer heat more comfortable.

If the attic of the house is residential, then its load-bearing elements will carry a significant load from the mass of roofing and finishing materials. Additional impact is high humidity caused by the proximity of the roof. Beams and rafters made of larch can withstand significant weight and do not deteriorate in a humid environment.

In the photo - examples of such houses

House #1 House #2 House #3

Log cabins from larch of large diameter

Due to the high cost of larch logs, they are usually used only in the lower crowns of the house. They give somewhat greater strength and do not collapse during floods and in rainy time of the year. A short stay in a flooded area does not harm such a log house.

Log home designs often include a combination of larch and softer, lighter pine. The slightly weighted hardwood base provides stability to the house and reduces costs. The greater hardness of the wood increases the complexity of processing due to the numerous splits that increase the overall value of the house.

Baths

The abnormally low thermal conductivity of larch makes it a useful element in the construction of baths and saunas, as well as the installation of interior cladding. The natural antimicrobial properties of the material prevent the formation of fungus, and the low hygroscopicity minimizes the processes of swelling and destruction. It is pleasant to touch larch wood even in a hot room.

Deciduous bath fonts retain the initial temperature of the water for a long time, allowing you to quickly refresh yourself after leaving the steam room. The fonts are made of untreated wood and are distinguished by their durability.

Photos of finished baths

Bath №1 Bath №2 Bath in Russian style

Interior elements made of larch wood

Unlike solid houses, furniture and interior decoration are made from this material much more often. Larch is used to make individual house structures and pieces of furniture, including floors, doors, stairs and windows.

Floors at home

Due to its high resistance to abrasion, larch is optimal in the production of flooring. This board is great for flooring in the bath and bathrooms.

The main types of hardwood floors:

• parquet- is a mechanically resistant and durable coating that can be periodically disassembled, machined and cleaned. The cost of hardwood parquet is high, but long-term operation partially compensates for this drawback;
• parquet board- is produced in the form of a three-layer product, the upper part of which is made of larch. The middle and lower parts are softer and more easily processed species - pine or spruce;
• batten- is made in the form of a solid array of wood, having grooves for laying at the ends. On the one hand, the groove is a regular notch (tongue), and on the other, a protruding rectangular profile (ridge).

In the photo - a floor board made of Siberian larch

Laying arrays of larch boards is carried out in several stages:

• Stage 1- preparation of the floor surface, including insulation, waterproofing and laying the base (usually plywood);
• Stage 2- laying boards. It is made from the wall and consists in matching the crest and tongue of adjacent boards. The lower part of the floor is attached to the base with glue, and the boards are interconnected with self-tapping screws;
• Stage 3- installation of skirting boards and subsequent varnishing, carried out as needed.

Photo of the floor laid in the apartment

Kitchens

The main use of this wood is in the manufacture of countertops, which are used instead of classic stone slabs in the kitchen. The wooden countertop is easily damaged, but just as easily restored by grinding and coating with protective compounds. The high resistance of larch to water extends its use up to the area around the sink, which is subject to strong moisture.

Furniture

It is partly analogous, since it has close strength and anti-wear properties. Classic hardwood furniture is quite expensive, but it has high hypoallergenicity, durability, stability and aesthetics. Larch is used to produce cabinets, tables, armchairs, chairs and chests of drawers.

Hardwood tables are lighter than oak tables, so they are more ergonomic and retain their performance. In furniture made of solid larch, wardrobe items and linen do not lose contact with fresh air, therefore they do not acquire an unpleasant odor.

Wooden windows and doors

Window frames have low vapor permeability and provide heat retention even when there is a large temperature difference between inside and outside the house. Tightly fitted doors made of larch wood are weakly subject to shrinkage and swelling, therefore, they almost do not change their geometric dimensions at different times of the year.

The low thermal conductivity of the material additionally contributes to the preservation of heat and coolness in the room, reducing the cost of heating and air conditioning. The high strength of larch doors makes rough break-in difficult, but it requires more expenses to obtain a uniform door free of chips and cracks.

This is how larch doors look like in the photo

Solid wood doors Interior doors

stairs

They are valued for their ability to retain their original properties for a long time. When using high-quality dried material, the stairs are practically not subject to destruction and will not loosen and creak after several years.

Steps are usually made from a thick solid wood, since they directly perceive the main load. The handrail and poles can be made by spreading thick boards or thin beams. The string of the stairs is a solid board of medium thickness.

Photo of stairs made of larch wood

Staircase #1 Staircase #2 Staircase #3

What is made from larch for the household

A number of elite houses, known for their ecological properties, use hardwood tiles. Resistance to moisture makes such a roofing sufficiently durable and stable for decades. The wood structure allows the room to "breathe" and reduces the likelihood of rot.

Larch gazebos retain their aesthetic appearance longer and do not acquire a blue color. The best fire resistance of larch helps to protect the structure during short-term exposure to fire. The complexity of wood processing leads to a significant increase in the cost of complex carved elements.

In the manufacture of a fence, larch wood allows you to maintain its integrity and strength properties for a long time. Supports buried in the ground are less susceptible to rotting, which is minimized after treatment with resin protective compounds. Larch fence rarely stained, emphasizing the naturally beautiful texture with stain or oil.

Deciduous false beams bring the aroma of wood into the room and have a sanitary effect. Increased fire resistance allows you to mount individual elements of the wiring and lighting system to them.

Larch facades are a good alternative to plastering and give the building a special touch. The wood base is usually treated with flame retardants and varnished to protect it from the abrasive effects of dust in strong winds.

You can watch a video on how to choose the right larch finishing material below:

Application in natural economy

To improve the aesthetic component and protect water bodies, the banks are strengthened with larch. For this purpose, a protective layer is erected, consisting of thin logs (up to 10-15 cm in diameter) or thick boards. Unlike other wood, strengthening with larch is a long-term measure, since it does not collapse after installation for many years.

This protection measure is popular in the maintenance of artificial ponds. They look more aesthetically pleasing not only due to the wooden posts outlined around the perimeter, but also due to greater transparency. The improvement of the shore prevents the formation of persistent opaque suspensions in the water of the lake.

The reason for this publication was the numerous appeals to the editorial office of readers who are thinking about the prospects of working with unclaimed wood species and who want to learn about their features. Among the objects of their interest, the undoubted leader is larch, the most common species in Russia. Its reserves account for more than one third of the total volume of timber (about 28 billion m 3 out of about 82 billion m 3 ). The main plantings are located in Eastern Siberia and in the Far East.

For illustrations, see

In the Middle Ages, larch was widely used in the construction of houses, ships and bridges. Until 1862, more than 500 warships were made from this wood in Arkhangelsk. Larch was often used for the construction of roads. natural properties favorably distinguish it from other types of wood and allow it to be used as a structural material. For example, the strength of larch wood is 30–60% higher than that of pine wood. The larch kernel is characterized by extraordinary biostability due to its density and high content of extractives.

However, the volume of workpiece and industrial applications larch in Russia does not exceed 5%. One of the reasons for its limited use is the difficulty of processing, which is due to the structure and properties of this wood.

In Russia, two types of larch are widespread - Larix sibirica Ldb and Larix dahurica Turcz, which are not subject to decay. Such a high degree of biostability and excellent mechanical properties allow this wood to be used in a variety of applications. It is well known that the European larch L. decidua is also characterized by increased natural biostability. However, the Siberian and Daurian are superior to the European in this respect due to the greater density of wood, which will be discussed in this publication. In addition, the results of the work of scientists involved in the study of properties, the creation of processing technology, as well as the determination of the areas of use of larch will be presented here.

Forests and timber stocks

The main stocks of standing larch - more than 95% of all larch growing in our country - are located in Eastern Siberia and the Far East (Table 1). More than ten species of larch grow on the territory of Russia, 99% are accounted for by two species: Dahurian larch (Larix dahurica) - 86% and Siberian larch (Larix sibirica) - 13%.

The structure and properties of wood

Tab. 4. Dependence of larch wood density at
humidity 12% of the width of the annual layer

Tab. 5. Influence of geoclimatic conditions on physical
mechanical properties of larch wood
(according to A. I. Terletsky)

Larch can reach a length of 30-45 m and up to one meter in diameter. Among coniferous tree species, it is characterized by a relatively large trunk volume (Table 2).

Larch, being a sound rock, has a thin layer of sapwood, not exceeding 8–20 mm. The width of the annual layer is from 0.4 to 2.2 mm and depends on the geoclimatic growth conditions and the age of the tree. The width of the late wood is in the range of 0.07–0.76 mm, that is, it is 20–30% of the width of the annual layer. Among the common coniferous wood species, larch has the maximum volume of late wood, reaching 39% (for comparison: in fir - up to 31%, in pine - up to 27%), which explains its high physical and mechanical properties.

The main structural element of conifers are tracheids; in larch they make up more than 90% of the volume. Of the conifers (Table 3), larch has the maximum thickness of the tracheid wall, which can also explain its increased strength.

Main physical property wood, affecting its strength, is the density, which, in turn, depends on the width of the annual layer (Table 4) and growing conditions (Table 5).

The average values ​​of the mechanical properties of conifers are given in table. 6. As can be seen from the data in the table, the wood of Siberian larch, which grows in Western Siberia, differs in maximum strength.

A unique property of larch is its high natural biostability, confirmed by both field and laboratory studies. In the 60s of the last century, a large amount of field research was carried out by scientists from the Institute of Forestry and Wood of the Siberian Branch of the USSR Academy of Sciences and the Siberian Technological Institute. Communication line poles installed in the regions of Eastern Siberia were chosen as objects of research. Field tests of samples were carried out in the Senezh laboratory of TsNIIMOD various breeds wood (Table 7). Laboratory studies of biostability were carried out by L. A. Petrenko (Table 8) in the middle of the last century. Currently, laboratory tests are being carried out at the St. Petersburg State Forest Engineering Academy of both natural solid and glued larch wood, during which their properties are compared with those of other coniferous wood (Table 9) .

Larix gmelinii (Rupr.) Litv. Gmelin larch,
or Dahurian

Wood processing

By biological characteristics larch wood is an excellent raw material for lumber. A large average diameter (30–40 cm), a slight run-off, on average not exceeding 1 cm per 1 m of the length of the whip, high natural biostability are the competitive advantages of larch sawlogs.

Despite the high physical and mechanical characteristics and natural biostability, larch is still a low-demand species. One of the reasons for this is the specific properties of its wood:

• high density and large difference in density between sapwood and heartwood, early and late wood;
• high content of natural resins and gums, reaching 22.6% in Dahurian larch (for comparison: in pine - up to 4.6%);
• low steam and gas conductivity.

As a result, during the industrial processing of larch raw materials:

• the cutting tool is tarred, the sinuses of the saw teeth are clogged;
• in lumber, high internal stresses occur during drying, leading to cracking and a change in their shape;
• in the veneer package, a vapor-gas mixture is formed with a high internal pressure, leading to the destruction of the adhesive bonds of plywood.

Tab. 10. The number of defects (knots) on the surface of the logs
larches and pines

In addition, larch wood has a reduced ability to glue and stick compared to wood of other conifers, which complicates the formation of adhesive joints.

These and other technological difficulties of larch processing are investigated, ways to overcome them are determined.

The lower occurrence of defects in larch wood (Table 10), primarily knots, compared with other coniferous species, makes it possible to increase the quality yield of lumber. According to Y.R. Bokshanin, the amount of high-quality material obtained from larch is on average 1.2% higher than from other conifers.

Processing and use of larch lumber in last years much attention is paid in the Scandinavian countries. Of particular interest is the use of larch in prefabricated wooden housing construction, not only in the form of sawn timber and timber glued from planed sawn timber, but also in the form of plywood and glued veneer beams (LVL).

Glued materials from larch veneer have a number of advantages compared to sawn timber due to the uniform distribution of defects over the area and cross section of the material, the exclusion (cutting) of some of them during the production process, and strong and waterproof adhesive joints. That is why the mechanical characteristics of glued veneer beams are 1.4–1.6 higher than those of lumber.

Anatoly CHUBINSKY, Maxim CHUBINSKY, Galina VARANKINA,
SPbGLTA

References

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1949. - T. 4. - S. 173-193.

2. Petrenko I. A. Resistance of sapwood of the Siberian larch kernel to lesions by various species.

house mushrooms. Larch. - Krasnoyarsk: vulture. TI, 1964. - S. 261-264.

3. Chudinov B. S., Tyurikov F. T., Zuban P. I. Larch wood and its processing. - M.: timber industry, 1965. - S. 13-50.

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M.: AN SSSR, 1957. - 165 p.

6. Bokshanin Yu. R. Processing and application of larch wood. - M.: Timber industry, 1982. - 216 p.

7. Chubinsky A. N., Chubov A. B. Production of plywood from larch wood. - L.: LDNTP, 1982. - 19 p.

8. Chubinsky A. N. Formation of glued structural materials from softwood veneer: abstract of diss. for the competition uch. degrees

Doctor of Technical Sciences. - St. Petersburg: SPbGLTA, 1995. - 36 p.

9. Chubinsky M. A. Biostability of larch wood: abstract of diss. for the competition uch. degree cand. biological sciences. - St. Petersburg: SPbGLTA, 2003. - 16 p.

10. Polubojarinov O. I., Chubinsky A. N., Martinsson O. Decay Resistance of Sibirian Larch Wood. - Ambio. - Vol. 29. - No. 6. - 2000. - P. 352-353.

11. Barzut VN The use of larch wood in Sweden / / Larch forests of the Arkhangelsk region, their use and reproduction. -

Arkhangelsk: AGTU, 2008. - S. 126-128.

12. Ytikkonen S., Luostarinen K., Piispa Kimmo. Kiln drying of sibirian larch (Larix sibirica) timber. - Mikkeli: MUAS, 2007. - 92 p.

13. Martinsson O., Lesinski I. Sibirian Larch Forestry and Timber in a Scandinavian Perspective. - Bispgarden IiLU, 2007. - 90 p.