• Repair
• Repair
• Interior Design
• About everything
• About plumbing

The weight of a cube of wood of natural moisture content is pine. Weight of lumber of basic softwoods

The weight of wood is an important parameter that must be taken into account when transporting or when calculating loads on various designs. However, in most cases, cubic meters are the main quantitative parameter for wood-based materials. Hence some difficulties.

Pine weight

In general, softwoods are considered less heavy than hardwoods. In addition, conifers are usually easier to work with and have a higher resistance to biological factors (due to resin content). The high demand for pine is also due to the fact that sawn timber from this tree can be quite long, which is important in some conditions.

Since high-quality wood materials must be well dried, and pine is no exception here, we are most interested in the weight of dry wood. The weight of dry pine 1 m3 will be 500 kg (plus or minus 100 kg). By "dry" pine is meant material with a moisture content of 10-18%.

By the way, an excessively high weight of wood material may indicate insufficient drying. For example, if the mass of a cubic meter of pine lumber noticeably exceeds 600 kg, they are clearly not dry. high humidity material may indicate improper storage conditions, which, in turn, is fraught with:

• destruction of the internal structure of the tree;
• the development of fungus or mold;
• loss of strength properties;
• deterioration in appearance.

Raw material is not recommended for use in construction due to the above hazards and higher shrinkage. The time spent drying is a downtime that can be avoided by controlling the quality of the purchased materials. Including by comparing the actual weight with the standard.

What can affect weight?

The main factor of influence is humidity. The higher it is, the heavier the given volume of wood materials will be.

Naturally, a freshly felled pine will be heavier than a dried one. On average, a freshly cut pine weighs 900 kg per cubic meter. IN this case Various factors of the procurement region play a role:

• resinous trees;
• Depth ground water(the less - the more water in the tree trunk, the higher the weight);
• The general humidity of the climate in the region.

The harvesting season also plays a role: for example, a tree cut down after January will be 10-15% lighter than a tree cut down in autumn.

However, this is all about fresh pine. Can something affect the weight of dried wood or lumber?

Yes, and the main such factor is the processing of various compounds:

• antiseptics;
• flame retardants;
• waterproof impregnations.

The treated wood material will be heavier by about 15-25%. And, in this case, it will not be an indicator of poor quality or poor storage conditions.

There may be some fluctuation in the weight of pine lumber due to several reasons. For example, a material made from the bottom of a tree will be slightly heavier than a similar material made from the middle or top.

It can also be noted that the core of pine is looser and less dense than the rest of the wood. Accordingly, the materials for the manufacture of which the core went will, on average, be slightly lighter with the same volume.

The wood has been used in construction works ah from a long time ago. Of course, because this material is still very popular due to the presence of excellent specifications. Wood itself is natural material structured type, consisting of wood cells and pericellular voids, which in turn does not guarantee at all that one part of the wood will be equal to another of identical size. Therefore, so often, in the process of work, the question arises of counting the right amount given material and parameters such as: the weight of the wood as a whole and the weight of the cube of wood.

Depending on the type of construction work, it is necessary to measure wood in different ways. The density of the material is of particular importance to the weight of m3 of wood, therefore, in order to correctly resolve the issues raised, it is necessary to determine the value of the density. There are two types of density:

Specific gravity (density of the wood substance)

Volumetric weight (density of a structured physical body)

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.

The density of the wood itself is quite easy to determine under normal conditions. To do this, just weigh a piece of wood and measure its volume. Process the received data with standard arithmetic operations according to the following formula: Y \u003d M / O, where Y - specific gravity wood, M - mass of wood, O - occupied volume.

Table of volumetric weight of 1m3 of wood depending on humidity.

The density of the wood substance, as already mentioned, is a constant. However, wood has a multicellular fibrous structure. complex type. The walls of the wood substance play the role of a frame in the wood structure. Accordingly, for each species and species of trees cell structures, the shape and size of the 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, big role in changing the specific gravity of wood has humidity. 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.

Below is the specific gravity of wood. The table is compiled depending on the moisture content of the material and is calculated such an indicator as the weight of 1 m3 of wood.

In life, there are situations when you are faced with seemingly simple questions, but you cannot give exact answers to them. During construction, for example, you may need to answer the question: how much does a cube of pine weigh? No one can give an exact answer right off the bat. The weight of timber primarily depends on its species. The second important factor is humidity. Its density depends on the type of wood, which, in turn, directly affects the weight.

To know if necessary necessary information, let's figure out how much a pine cube weighs. This may be necessary when purchasing timber to ensure that the goods are shipped correctly.

Humidity indicators are divided into four degrees:

• wet (more than 45%);
• crude (from 25 to 44%);
• air-dry (from 19 to 24%);
• dry (from 10 to 18%).

So, a cube of pine is how much? The results obtained are presented in the form of a table.

Weight depending on the type of raw material

There are several types of pine:

• cedar;
• Siberian;
• ordinary.

The weight of wood also varies from its varieties. If the values ​​for the cedar and Siberian are the same, then the weight of the ordinary differs from them. The figures indicated in the table above are typical for ordinary pine.

The weight of one cubic meter of cedar and Siberian is presented in the table below:

So, knowing the moisture content of wood, using tables, it is easy to determine its weight. This is the easiest way. Such tables are often used in construction, where wood is the main material. They help you pick best option wood for the construction of a structure.

The Drova72 company conducted an experiment, we weighed 1 stacking cube (skladometer) of birch split firewood, natural humidity, ~ 50%. The results of this experiment will be discussed in more detail below.

This experiment in no way claims to be - "scientific" or "100% objective", rather something in between information from the Internet and laboratory research. Nevertheless, this is the first step towards truth and objectivity.

Next time we will repeat the experiment and try to find a moisture meter, as well as film the whole process on video.

In short, the results

At humidity ~50% and log length ~50cm:

• 1 folding cube weighs ~561 kg;
• 1 tight cubic cube weighs ~790 kg.

In the text below, we reveal in detail the essence of the experiment. The calculation is made on the basis of information from GOST "a 3243-88 and a guide to sawmilling.

Why do we need this?

small digression

The volume of firewood in stock meters is measured by multiplying the length, width and height of the woodpile. But, the concept of "1 storage cube of firewood" is rather vague, because. firewood in the woodpile can be stacked with different stacking densities and there is no GOST or regulation that would explain what "packing density" is and how to measure it. That is, the same amount of firewood (1 conditional storage meter) can fit from ~0.7 to ~1.3 stock meters, depending on the stacking density and the condition of the logs (their curvature, the presence of knots).

For clarity, look at the photo below. It is obvious that the firewood on the right is stacked thoroughly and the number of poles in such a woodpile is greater than in the one on the left. In this case, in both cases, the volume of firewood in the warehouse meters will be the same, but the mass is different. Those. in fact, the amount of firewood in the photo on the left is less.

In the photo above, please ignore the different type firewood, this image shows the density of stacking firewood in a woodpile.

specifics

Sometimes we have disagreements with our clients about the volume of firewood in the warehouse meters. We brought firewood to stacking in one volume, the client transferred the firewood to his woodpile, measured it, and his volume turned out to be less than originally declared.

In the example above, the contention is almost always due to stacking density. Therefore we decided weigh 1 stack of birch firewood, and correlate its weight (mass) with the data, which are presented in GOST 3243-88 and in the Sawmill Handbook, Moscow, Forest Industry Publishing House, 1980.

By comparing the weight of our firewood storage meter with the data from the above sources, we will understand whether we stack the firewood tightly enough in the car before delivering it to the buyer.

Sequencing:

1. First, we will put 1 stacking cube in the woodpile.
2. Weigh this cube on the scales.
3. We will compare the resulting weight with the data from GOST 3243-88 and the Sawmill Handbook.

By different sources, the moisture content of freshly sawn birch can vary from 60 to 80%. We buy firewood birch, which is harvested (cut down) from 1 to 4 months ago from the moment when it is brought to us for further processing. The humidity of such a birch is on average 40-50%. We will do the calculation based on 50% humidity.

In the guide to sawmilling, the weight of a dense cube of ordinary birch at a moisture content of 50% is 790 kg. To convert the weight of the warehouse meter to a dense cube (or vice versa), you need to apply a coefficient. We will take it from GOST 3243-88, with a log length of up to 0.5 meters of split hardwood - coefficient is 0.71.

790 * 0.71 = 560.9 kg

Those. the mass of our split birch firewood storage meter must be at least 561kg.

We weigh

Conclusions and comments

First of all, we wanted to test ourselves, because. sometimes there were doubts about honesty in relation to our firewood buyers. Now the doubts have been dispelled. Our stacking density and volume of firewood in stacked cubic meters meets the necessary requirements.

If we turn again to the guide to sawmilling (Note 1), it is obvious that the weight of 1 storage cube at a moisture content of 50% will not always be 560.9 kg, because. the weight of one dense cube of 790 kg is an average value and can range from 553 kg to 1027 kg. And, therefore, 1 birch chipped firewood storage meter (taking into account the coefficient 0.71) can weigh from 392kg to 729kg. This is probably due to the different density of trees and poles.

Of course, this experiment cannot be considered 100% objective, because. At a minimum, a moisture meter is needed to determine humidity. Our forest can have different humidity levels. There are many suppliers and the terms of harvesting and delivery are different for everyone, respectively, the moisture content of the forest can vary from 30 to 60%.

If you have any suggestions or comments on this material- please write to our email: mail@site.

The weight of lumber has an impact on transportation and storage. When erecting wooden structures weight is also important in determining the loads being transferred to the load-bearing members or foundation. However, when selling lumber, it is measured in cubic meters, which causes difficulties.

What affects the weight of lumber?

Consider the factors affecting weight wooden materials given volume:

wood species. This factor determines the density of the material, since wood of the same species is characterized by similar density values. This indicator already directly affects the weight - the denser the material, the heavier. Average, deciduous trees denser than conifers, so the cube of an oak board is heavier than a cubic meter of a pine board.

So, in front of you is a board cube - how much does this or that breed weigh? The weight of wood per cubic meter of lumber is given in the table (kg).

Humidity. Wood is characterized by the ability to accumulate moisture. There are two options here: the board is poorly dried, and retained its natural moisture, or was stored in improper conditions. The higher the moisture content of lumber, the heavier it will be. Therefore, even the same breeds weigh differently. This, by the way, is a way to determine the materials stored in bad conditions or slightly dried.

The use of such components in construction is fraught with negative consequences, of which strong shrinkage is not the worst.

It is also unreasonable to use such a board in construction.

Internal defects. Similar to the previous point, internal defects in wood lead to a decrease in density and weight loss.

Artificial and natural drying

Ideally, lumber should dry naturally, i.e. in a ventilated room with a roof or on outdoors under a canopy.

Since dry lumber is more in demand than natural moisture material, accelerated drying methods are used. The question of how safe this is for the material remains debatable. It is believed that artificial drying leads to too rapid evaporation of moisture, which causes a change geometric dimensions boards. Due to microscopic damage to the fibers, curvature and irregularities are formed. In especially advanced cases, cracks appear.

However, drying with the use of forced air, including warm air performed without fanaticism is unlikely to lead to such obvious negative consequences.

Wood moisture should be taken into account when arranging transportation. Let's say you bought dry boards, but during storage they were exposed to rain and did not completely dry out. Their weight, of course, will no longer be the same as when delivered.