The weight of a cube of wood of natural moisture. The weight of a cubic meter of boards of natural moisture content of different species

For the manufacture of various building materials from wood (lining, board, slats, timber), the material natural humidity. 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 types of wood are used. 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 moisture is the state in which there is a balance of water between 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 calculates 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).

When organizing the transportation of timber, the density of a tree is an important indicator in the selection of a timber carrier and calculation of 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 increasing humidity, the density of wood also increases. However, the density of the wood substance this rule does not apply.

* Fresh. - Freshly cut tree

At construction work associated with the use of lumber from trees coniferous type, correct calculations of specific gravity are very important pine wood. Unlike other various building materials, this variety does not have a single specific gravity, which somewhat complicates the selection process. The fact is that pine wood, like any wood, is natural material porous type. Accordingly, depending on the variety of pine and on the percentage of moisture, the specific gravity of the pine changes.

As mentioned above, the main parameter affecting the volumetric weight of pine is humidity. So, for example, the most high rate specific gravity in still untouched, growing pine. This is due to the fact that the tree needs high humidity for growth. At the same time, humidity is useful substance and a carrier of other, no less useful, vitamins and minerals. The amount of moisture depends entirely on the variety of pine, harvesting season and locality. Moisture indicators of "live" pine can vary from 29% to 81%. The lowest indicator, respectively, is in dried pine, since the humidity in this state tends to zero.

Weight table for 1 m3 of pine depending on its moisture content.

Very difficult to define percentage moisture with improvised means. And this is very important indicator to determine such a parameter as the specific gravity of a cubic meter of pine. Usually, these procedures take place in special technological laboratories.

The easiest way, when buying a material, is to clarify the composition of the humidity from the manufacturer. Then, using the presented table, find out the weight of a pine cube with a flag from 5% to 90% and the density of the material:

Practical value and importance.

Among coniferous building materials, wet, dried, dry and raw pine. However, these terms do not give a definite exact value humidity, so knowing clear numbers is extremely important. So, for example, the requirements for the use of fallen pine are not provided for by legislative acts. But, when performing certain work, GOST establishes humidity standards, for example:

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 rocks at the same moisture content have different weights, 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 highest density of iron and ebony is 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