Pine cube weight. How much does a cube of raw pine board weigh - How much does one dry and wet wood suitable for construction weigh

For the manufacture of various building materials from wood (lining, board, slats, timber), natural moisture material is used. However, according to the requirements of GOST and building codes raw wood floor boards must be dried before laying. From this indicator depends on how much the cube of the board of natural humidity weighs. Although the price of the material is charged for its volume, the weight of the board of natural moisture is important when transporting products. We will tell you how much a cube of natural moisture boards of different breeds weighs.

The concept of material moisture

Before you tell how much a natural moisture edged board and other lumber weigh, you need to understand the basic concepts. For the manufacture of grooved, terraced, planed and edged boards, different breeds tree. Each breed has its own specific hygroscopicity, that is, the ability to absorb moisture from the air.

Depending on the absorption of moisture, porosity and structure cell membranes Each type of wood has its own absolute moisture content. The maximum value of this indicator is 30.

In addition, a natural moisture board can absorb water in direct contact with it during precipitation or when the room is flooded. Dampness in the room is also the reason wood absorbs moisture. If the surrounding air becomes very dry, it releases moisture.

Important! Most often, moisture loss occurs through the ends of the product.

The normal process of absorbing and releasing moisture into wood is called "breathing". Equilibrium humidity is the state in which there is a balance of water between the environment and inner space wood.

The indicator of natural saturation with water depends on the location of the fibers in the structure. Moisture evaporates faster in the longitudinal direction of the fibers, and not in the transverse direction. That is why the floor from the board of natural moisture quickly releases moisture at the ends of the floorboards.

To understand what is batten normal humidity, you need to understand the concept of absolute and relative humidity:

1. Relative saturation moisture is the percentage of its mass in wood to the mass of a wet product.
2. Absolute indicator always more than relative. This is a percentage of the mass of moisture in wood to the weight of ordinary dry material.

Important! Since the hygroscopic intracellular fluid collects in the cell walls, it is more difficult to remove. In this regard, hygroscopic moisture has a greater effect on the geometry of the board, its weight and characteristics.

The weight of a natural moisture cut board also depends on the unbound free liquid in the material, which collects in the intercellular spaces and inside the cells. Such moisture evaporates quickly and does not affect the performance of the product.

Natural moisture refers to the moisture content of freshly sawn wood that has not been dried. This non-standardized indicator can be in the range of 30-80 percent. The weight of 1 m3 of natural moisture cut board depends on:

• conditions in which the tree grows;
• the season when the split was made (winter wood is less saturated with moisture than the one that was cut in the summer season).

The dependence of the weight of the board on moisture

If you need a board of natural moisture, the price depends on the weight of the cube of the material and its saturation with moisture:

• semi-dry products have a humidity of 18 to 23 percent;
• a raw product with a moisture content of more than 23% is the cheapest - from $ 30 per cubic meter;
• dry edged board with humidity in the range of 12-18 percent costs $40-50 per cubic meter;
• dry lumber with a humidity of 6-12 percent are the most expensive - from $ 60 per m³.

Depending on the dampness, the weight of the material also changes. For example, a cube of wet oak floorboards weighs 990 kg. If the material is dried to a moisture content of 10%, then the mass of the cube will decrease to 0.67 tons. But the price for dried lumber will increase.

The increase in price depending on the saturation with moisture is justified by the fact that the characteristics of the product also increase:

• dried wood has dimensional stability;
• it is resistant to decay;
• the material is durable and flexible;
• the tree is quickly and easily processed;
• provides a strong adhesive fixation;
• the product will last longer.

Attention! Wet wood is prone to mold, rot and warping. Ideally, if the moisture content of the lumber is brought to the point at which the shrinkage and swelling of the wood stop. That is why the cost of such products is the highest.

How much does a cube of boards from different breeds weigh?

The weight of a cube of material is directly related to the type of wood from which it is made:

1. An oak board of natural moisture content weighs 990 c/m³. A cube of dried wood weighs 670 centners.
2. Wet pine floorboards weigh 820 kg / cu. The dried elements have a weight of 470 c/m³.
3. Cube boards from wet spruce wood weighs 760 q, and dried board - 420 q.
4. Wet larch products have a weight of 940 kg / cu. A cube of dry larch weighs 630 kg.
5. birch lumber undried weigh 870 centners / m³, and dry - 600 centners / cu.
6. Aspen floorboards from wet wood - 760 centners / cubic meter, and dried - 470 centners.
7. Alder wood cube after saw cut, it has a weight of 810 centners, and the dried material - 490 centners.

Why is it necessary to know the weight of a cubic meter of wood?

Since the manufacturer charges the price for lumber depending on the type of wood, moisture content and volume, the weight of the material is not taken into account. This indicator will be needed when transporting lumber, since the choice depends on it. vehicle and the cost of transportation.

Also, the weight of wood is taken into account when calculating the loads on building construction. As a rule, an ordinary consumer does not need such a calculation. It is made by designers and designers at the stage of project development.

Artificial and natural drying

Natural drying of lumber is very slow and stretches for a long time. However, such a drying process is considered the most gentle, since cracks and other deformation defects do not appear in the wood. With aggressive chamber drying there is a high probability of cracking and deformation of lumber.

Important! Natural drying is carried out in a special well-ventilated place, which is reliably protected from atmospheric moisture and direct sunlight.

Humidity of a freshly cut tree reaches 50-80%. With natural drying, this figure drops to 18-22 percent. This drying method is the easiest to organize, since it does not require the use of special equipment and comply with certain temperature regime. The disadvantages of natural drying are the duration of the process and low intensity.

Artificial drying in chambers proceeds much faster. At the same time, the humidity index decreases to 10-18 percent. During the drying process, you can adjust the temperature and control the whole process. Products placed in stacks are placed in the chambers, each of which contains sawn timber of the same thickness and breed.

Advantages of artificial drying:

• protection against mold and rot;
• you can dry wood treated with special protective compounds;
• drying speed (usually it takes a week).

To begin with, it is worth accepting the fact that coniferous wood is considered lighter than lumber from hardwood tree. In addition, such options are easy to process and have a long service life. They are resistant to decay due to a large number resins, and therefore are often used as a facing material for the facades of structures.

Before calculating the weight of lumber, it is worth considering the basic concepts:

• Dry wood is a material whose moisture content does not exceed 18%. Such products have already passed the technological bitch or long time stored in a warehouse or other dry place.

• Air-dry lumber is wood with a moisture content of 19 to 23%. It differs in that it has an equilibrium moisture content. This definition should be understood as the state of a tree when its humidity is in equilibrium with the same air parameter environment. This characteristic achieved with long-term storage of products in vivo. Lumber with this level of moisture excludes the use of technological drying.
• Raw wood - has a moisture content of up to 45%. This forest is still in the drying stage.
• Fresh wood - as a rule, such materials are characterized by a moisture content of over 45%. These are recently felled trees or those that have been under the influence of water for a long time.

It should be understood that determining the specific gravity of the forest is not so simple. At the same time, it can be said which breed will be relatively lighter and which will be heavier. So, coniferous varieties will be guaranteed to be lighter than hardwoods, such as oak or beech. But when transporting a significant amount of timber, all sorts of incidents can happen. As a rule, all these nuances relate to the almost unpredictable weight of raw wood due to high humidity. Therefore, this issue should be dealt with.

Weight of 1 cube of coniferous forest in practice and according to GOST

Depending on the type of wood, 1 m3 of lumber may have a different weight. Yes, for conifers, especially if they are raw, weight gain due to resins is characteristic. The moisture content of the forest itself largely depends on the season when the felling was carried out. The conditions for the development of the tree also play a role.

It should be understood that there is lumber from the upper and lower parts of the tree trunk. It is not difficult to guess that the first option will be somewhat easier due to the fact that they initially have high humidity.

Note! Humidity plays the main role in the characteristics of the forest. Raw and dried lumber can have a different weight. Sometimes the differences can be almost twofold.

It is worth considering the provisions of the regulatory literature. So, the current GOST takes for standard value humidity mark 12%. Under these conditions, light species rarely leave the mark of 600 kg per cubic meter of timber. The lightest among conifers is Siberian fir. The weight per unit volume of such a breed barely reaches 390 kg. But larch, which is also classified as medium, has a weight of 660 kg. Thus, it is heavier than birch, but slightly lighter than oak.

However, calculation tables cannot always give a 100% guarantee that a particular timber at a certain volume will weigh as indicated.

Results

In addition, for the convenience of carrying out calculations, you can use special programs. One of these is the cubic forest. It will allow you to find out without tables how much this or that breed weighs, based on its main parameters. Using the software, there is no need to search for the necessary positions in the table for a long time, it is possible to interpolate. Everything is quite simple. Similar programs show the weight of the forest in kilograms per cubic meter.

When organizing the transportation of timber, the density of the tree is important indicator when selecting a timber carrier and calculating the cost of transportation. This will help to avoid overloading, which will accordingly reduce the penalty.

On the weight of m3 of wood, the density of the material is of particular importance, respectively, for right decision of the questions posed, it is necessary to determine the value of the density. There are two types of density: volume weight (density of a structured physical body) and specific gravity(density of the wood substance).

Volumetric weight of wood

Calculator for calculating the volumetric weight of a tree.

Tree White Acacia Birch Beech Elm Oak Hornbeam Spruce Norway Maple Linden Larch Alder Walnut Aspen Siberian Fir Caucasian Fir Scots Pine Cedar Pine Poplar Ash

Volume, m3:

Specific gravity of wood

Wood substance is called mass hard materials wood without natural voids. This type density is measured in laboratory conditions, as it requires additional measurements that are impossible under normal conditions. For each wood of all types and species of trees, this value is a constant and is 1540 kg/m3. However, wood has a multicellular fibrous structure of a complex type. The walls of the wood substance play the role of a frame in the wood structure. Accordingly, for each breed and species of trees, the cell structures, shapes and sizes of cells vary, as a result of which the specific gravity of the tree will be different, as well as the different weight m3 of the tree.

Also, humidity plays an important role in changing the specific gravity of wood. Due to the structure of this material, with an increase in humidity, the density of wood also increases. However, the density of the wood substance this rule does not apply.

* Fresh. - Freshly cut tree

1. Tree species groups
2. Humidity dependence
3. Impact on wood quality

The density of wood is one of the main characteristics of a cubic meter of material, which is taken into account when calculating structures, choosing raw materials for the production of various products. The term refers to the ratio of the mass of the material to the measured volume.

What can be the density of the forest

Different tree species have approximately the same composition, therefore, in dry form, the absolute specific gravity for all will be conditionally the same. Its average value is 1.54 (dimensionless value). But in the table of wood density for different species, their numbers are given. The fact is that in a completely dry state it is almost impossible to measure the absolute parameter. To do this, it is necessary to completely get rid of moisture in the test sample, to eliminate air voids. In practice, as it turned out, it is difficult to fix the parameter, and it is unsuitable for calculations.

To determine the density of lumber, the calculation of its specific gravity is more suitable..

It is affected by:

• humidity;
• rock porosity.

Specific gravity wood has the form of the average value of density calculations in its different states. Sources may vary slightly. The difference is due to a change in the level of moisture inside the trunk. To avoid confusion, we present a table with the average values ​​of the specific gravity for each individual moisture level of different types of wood in ascending order.

Table of wood density of different moisture content (kg / m 3)

Tree species groups

Typically, the tabular value of the density of timber and other lumber is measured at a moisture content of 12%. Depending on the value obtained, tree species are divided into 3 groups:

1. With a low bulk density (less than 540 kg / m 3). These include coniferous trees: pine, spruce, fir, cedar and some deciduous. These are all types of alder, poplar, linden, aspen, chestnut.
2. With an average specific gravity of 550–740 kg / m 3: beech, elm (elm), larch, all types of maple, mountain ash, apple tree, ash.
3. FROM high level density over 750 kg / m 3: birch, oak (Araksinsky, chestnut-leaved), hornbeam, dogwood, pistachio.

Of course, this is an incomplete list of breeds. According to the indicated wood density values ​​in the table, it is possible to determine whether the species belongs to the group.

Humidity dependence

All lumber contains water. Its quantity mainly determines the density of the timber and other raw materials: the more moisture in the product, the higher the weight in the measured volume.

The specific gravity of wood in the table is given in average values, since the amount of moisture in one volume is constantly changing - this is a relative value.

The changes are due to:

• external weather conditions(rain, fog, snow);
• anthropogenic factor (wetting due to human activity).

Thus, a completely dry board practically does not exist. Wood moisture content is always above 0%. This indicator can be determined using special device- moisture meter.

Impact on wood quality

The average specific gravity is the main characteristic of raw materials when making calculations, since the value includes an average estimate of the tests of lumber in different states of water saturation.

According to the laws of physics, the calculated density is directly related to the strength of the material: the higher specific gravity the volume of the product, the greater the load it can withstand. This rule also applies to wood.

Let's look at an example:

• Oak has a high specific gravity and is famous for its reliability and durability. It has almost no empty pores, the entire volume is filled with strong wood fibers and moisture. Made from oak bearing structures houses and industrial facilities. Wood with a high specific gravity is rigid, practically does not bend.
• Cedar and birch beams are characterized by low volumetric weight, therefore they are not used to create load-bearing elements of the skeleton of structures. These breeds are more suitable for finishing works, where the load on the products is minimal. Wood with low porosity is plastic, lends itself to bending.

Dependence of density and thermal conductivity

This indicator is important for choosing a tree when harvesting firewood. The dependence is direct: the higher the density index, the more fuel in the chocks, the longer they will burn. tree species with high value the ratio of mass to volume is called solid fuel. They burn for a long time, give a good heat, but due to the dense structure it is difficult to prick. The advantage of firewood and fuel from light wood species is their flexibility in sawing and chopping, but they have a relatively small energy reserve. Logs will burn for a much shorter amount of time.

Starting the construction of a house, or making repairs, sometimes you have to deal with questions that seem to be simple at first glance, but you can’t give an answer to them right away. It seems awkward to address such a question to specialists, but you need to know for sure. For those who can access the Internet, it’s easier - I typed in the search engine “How much does a cube of wood weigh” and in half a minute I got an exhaustive result. And by the way, really, how much?

Influence of humidity on wood weight

The weight of wood does not always have the same indicator. What does it depend on? First of all, from the moisture of the tree. If we compare, for example, oak and birch, it turns out that a cubic meter of oak weighs 700 kg, and birch weighs 600 kg. But it may be otherwise. Weighing a cubic meter of birch, we get 900 kg, and oak will show the same 700. Or in both cases it will be 700 kg. Why are there such different numbers? In this case, the moisture content of the wood plays a role.

There are four degrees of humidity: dry (10-18%), air-dry (19-23%), damp (24-45%) and wet (above 45%). Thus, it turns out that different breeds at the same humidity have different weight, as in the first example above. If the humidity is not the same, then the weight can fluctuate in one direction or another. The standard humidity is 12%.

Different density - different weight

Another factor that affects the weight of wood is its density. The most high density for iron and ebony - from 1100 to 1330 kg / m 3. Boxwood and bog oak are close to them - 950-1100. In ordinary oak, beech, acacia, pear, hornbeam, the density is about 700 kg / m 3. It is even lower in pine, alder, bamboo - 500 kg / m 3. And the lowest is cork tree, only 140 kg/m 3 .

Why do you need to know the weight of a cubic meter of wood

Having knowledge in this area is sometimes very important. By purchasing construction material, its amount is impossible for a non-specialist to determine by eye. Knowing the dimensions of the timber or lining, the material from which they are made and its moisture content, simple calculations allow us to determine the weight of the purchased goods. How much does a cube of wood weigh - in this case, the answer to this question will help you figure out whether the seller released the goods to you correctly.

Heat dissipation of wood

In addition, there is another indicator - heat transfer. She will come to the aid of those who use wood as firewood for heating. The higher the hardness, i.e. the density of the wood species, the higher its calorific value. Of course, no one will heat the room with boxwood, but choosing between linden and pine or birch and acacia, you can get much more heat if you know which of these rocks are the hardest. Information about the density of each tree can be gleaned from the tables, since all this information is systematized for ease of use.

Weight of dense cubic meter, kg

The table shows the average weight values. Possible maximum and minimum value masses are respectively 1.3 and 0.7 of its average value