How to calculate the cubic capacity of roundwood: the main methods. How to correctly calculate the cubic capacity of roundwood: instructions for calculating the cubic capacity of roundwood from 1 meter

When carrying out construction work on the construction of a residential building, a specialist needs to perform a large number of various tasks, some of which are: drawing up and calculating the estimated cost before the final finishing of the premises of a residential building. It is mandatory to calculate the required amount of various building materials, which is quite difficult to do. Therefore, such knowledge - how many boards are in a cube, is very important for a specialist who is engaged in the construction of a residential building and wants to do the job as efficiently as possible and quickly in time.

Buyer's club: existing types of boards

To calculate exactly how many pieces of a board are in a cube, you will need to know not only what exactly the cube of the board means, but it is worth understanding the important point that there are different types of boards and what is possible to purchase on the modern market to perform a variety of construction work. It should be noted that the cube of almost all materials, regardless of the type of material, is calculated in the same way, that is, according to one specific method. The types of boards have no influence on the calculation of the cubic capacity of this building material.

The non-grooved type of lumber is: timber, various edged boards, as well as unedged boards (they are an exception when calculating cubic capacity, because this process is a little different). Grooved types (which have special grooves for the joint) include: modern lining, blockhouse, flooring material, as well as imitation of natural timber. When you choose to buy a tongue-and-groove type of building material, then you need to pay attention to the fact that when making a calculation, only the working width of the board without a spike is used. If we talk about a blockhouse (imitation of a log), then when calculating the cubic capacity, only the thickness at its highest point is taken.

How many boards are in 1 cube: performing a calculation

Any person, since his school days, understands how the cubic capacity is calculated. For this procedure, it is necessary to calculate quantities such as: length, width and height. A similar principle is also used to calculate the cubature of 1 board. It is recommended that when performing such calculations, convert all available values ​​​​in meters. Cubic capacity of 1 board, which has a section of 150x20 mm. and a length of 6 m., is calculated as follows: 0.15 is multiplied by 0.02 and by 6, so that the cubic capacity of this board will be 0.018 cubic meters.

Apply the volume formula V= L*h*b (where L is the length, h is the height, b is the width).

L=6.0; h=0.02; b=0.15.

Thus, V \u003d 6.0 * 0.02 * 0.15 \u003d 0.018 m 3.

To determine how many boards are in one cube: 1 m 3 is divided by the cubic capacity (the volume of one board).

1 m 3 / V = ​​N pcs.

1 m 3 / 0.018 m 3 \u003d 55.55 pcs.

Thus, the number of boards in one cube is 55.5 pieces.

It is quite easy to find out the cost of a certain type of board when its volume values ​​\u200b\u200bare known: 0.018 is multiplied by the price of 1 cubic meter. When 1 cube of a certain type of board has, for example, a cost of 5500 rubles, then the cost will be 99 rubles. At this point in the calculation, there is some trick of sellers and managers in hardware stores, because the cubic capacity of the material is rounded up to some integer values.

Such rounding can lead to such a moment that the price of 1 board (when 1 cube costs 5500) will be completely different values. In addition to all this, it should be noted that for various boards for construction, which make up a nominal length of 6 meters, in fact, the length is 6.1 - 6.2 m, which is not taken into account when selling this building material. This also applies to the acquisition of a significant number of boards. This is quite clearly visible if, for example, a 150x20 mm board is used. The number of boards in a cube is a value of 55.5 pieces. But, in a cube, 55 pieces are considered, which, when calculating, will have a value of 0.99 cubic meters. In fact, it follows from this that the overpayment for 1 cubic meter of this popular building material can be 1% of the real price. For example, 5500 instead of 4995 rubles.

To calculate the cubature for a non-cut-off type of board, slightly different methods are used. When it comes to buying 1 board, then measuring its thickness, as well as the total length, is done in the same way as when choosing a cut building material. In this case, the width for calculations is taken as an average - between a large value and a small one.

For example, when at the end the width of the board is 25 cm, and at the other 20, then the average value will be approximately 22 centimeters. When it is necessary to calculate the volume of a significant number of such boards for construction, then it will be necessary to decompose them so that the wide one does not differ from the narrow one, more than 10 cm. The main length of this material in the unfolded stack should be approximately the same. After that, using an ordinary tape measure, an accurate measurement of the height of the entire stack of boards is made, the width is measured (approximately in the middle). The result obtained will then need to be multiplied by a special coefficient ranging from 0.07 to 0.09, in direct proportion to the existing air gap.

How many boards in 1 cube: special tables

To calculate exactly what number of boards of a certain width, length in 1 cubic meter, various tables are used. Below are several such specialized tables, which indicate the cubature of the common and popular types of this material today. It is possible to calculate the volume of various boards having different sizes, for example, material for erecting a fence on your site, using the available formula, which is presented above.

Table of the number of edged boards in 1 cubic meter

Table of the amount of timber in 1 cubic meter

Table of the number of unedged boards in 1 cubic meter

Debarked roundwood (logs) is a very popular material. Unlike rounded logs, debarked logs have a significant advantage, because they have preserved the top layer of the popular print, which effectively protects the inner wood from various pests and bacteria. Thanks to this, a log house made of barked logs will last much longer and require less antiseptic costs than a house made of logs. When purchasing logs for building a house, it is necessary to determine not only their quantity, but also the volume, because all suppliers sell logs by volume. You can convert quantity into volume either manually, remembering school lessons in algebra and geometry, or using tables or special tools. In this article, we will talk about various calculation methods that will help you correctly determine the required volume when ordering and buying logs.

Calculation of log volume manually

The method for determining the volume of a log is detailed in two documents adopted back in the Soviet Union - GOST 2292-88 And GOST 2708-75. Since then, no changes have occurred in this technology, so all the recommendations set out in the GOSTs are still relevant today. Here are the main points regarding both the measurement of an individual log and the determination of the volume of stored logs:

• the diameter is determined by the upper (thin) edge of the log using mechanical measuring forks (analogue of a caliper);
• the diameter of the upper part of the log is measured twice, with a deviation of 90 degrees, if the values ​​\u200b\u200bare different, then they are averaged;
• when determining the diameter of a log, the thickness of the bark is not taken into account;
• the diameter is rounded to the nearest half centimeter;
• the volume of logs for the construction of houses is determined by multiplying the average log volume by the number of logs in the stack;
• measuring the volume of logs by multiplying the height, width and length of the stack is unacceptable.

After determining the diameter and length of the log, its volume is calculated by the formula. For example, the volume of a log 10 meters long and 15 centimeters in diameter is 0.176 m³. Therefore, there will be 5.5 logs in one cubic meter.

Video - Calculator - cubature

Determining the volume of a log using a computer caliper

The computer caliper determines the volume of each log by measuring the diameter and entering the length. Using this tool allows you to avoid tedious work with tables and numerous calculations. After determining the thickness and entering the length of the log, the fork independently determines its volume and displays the data on the display. Due to the high cost, this tool is used only in timber processing enterprises.

It makes no sense to make the same calculations several times if the original data does not change. A rounded log with a diameter of 20 cm and a length of 6 meters will always have the same volume, regardless of who and in which city conducts the count. Only the formula V=πr²l gives the correct answer. Therefore, the volume of one OCB will always be V=3.14×(0.1)²×6=0.1884 m³. In practice, in order to exclude the moment of carrying out standard calculations, cubes are used. Such useful and informative tables are created for various types of lumber. They help to save time and find out the cubic capacity of round timber, boards, CBM, and timber.

The name of this building guide is due to the fact that the volume as a physical quantity is measured in cubic meters (or cubic meters). For a simpler explanation, they say "cubature", respectively, the table was called "cubature". This is an ordered matrix, which contains data on the volume of one product for various initial parameters. The base column contains sections, and the row contains the length (molding) of the material. The user only needs to find the number located in the cell at their intersection.

Let's consider a specific example - a cubic yard of roundwood. It was approved in 1975, is called GOST 2708-75, the main parameters are diameter (in cm) and length (in meters). Using the table is very simple: for example, you need to determine the V of one log having Ø20 cm with a length of 5 m. At the intersection of the corresponding row and column, we find the number 0.19 m³. A similar cube for round timber exists according to another standard - ISO 4480-83. Reference books are very detailed in increments of 0.1 m, as well as more general, where the length is taken in 0.5 m.

little secrets

The very use of the cube is not difficult, but the main nuance is the correct data. Round wood is not a cylinder, but a truncated cone, in which the lower and upper cuts are different. One of them can be 26 cm, and the other - 18. The table assumes an unambiguous answer for a particular section.

Various sources suggest doing it in two ways: calculate the average value and take the volume from the reference book for it, or take the size of the upper cut as the main section. But if the tables were compiled according to certain standards, then they must be used in accordance with the accompanying instructions. For a cubature GOST 2708-75, the diameter of the upper saw cut of the log is taken. Why is the raw data moment so important? Because with a length of 5 meters for Ø18 cm we get 0.156 m³, and for Ø26 cm - 0.32 m³, which is actually 2 times more.

Another nuance is the correct cubes. If complex formulas for truncated cones were used in the GOST 2708-75 table, calculations were carried out, and the results were rounded to thousandths, then modern companies that make up their own cubes allow themselves “liberties”. For example, instead of 0.156 m³, there is already the number 0.16 m³. Often, frankly erroneous cubic meters are posted on Internet sites, in which the volume of a log 5 meters long with Ø18 cm is indicated not 0.156 m³, but 0.165 m³. If an enterprise uses such directories, selling roundwood to consumers, then it makes a profit, in fact deceiving customers. After all, the difference in 1 product is significant: 0.165-0.156=0.009 or almost 0.01 m³.

The main problem of round timber is a different section. Sellers offer to resolve issues with calculations in the following ways:

• calculation of the volume of each unit and summation of the obtained values;
• storage method;
• finding the average diameter;
• method based on the density of the wood.

1. It must be said right away that the first of the indicated options gives the correct results. Only the calculation of the volume of each log and the subsequent addition of the numbers ensures that the buyer will pay for the timber that he will receive from the company. If the length is the same, then it is enough to find the cross-sectional areas of all the trunks, add them up, and then multiply by the length (in meters).

2. Warehousing method.

It is assumed that the stored round timber occupies a part of the space that has the shape of a rectangular parallelepiped. In this case, the total volume is found by multiplying the length, width and height of the figure. Given that there are voids between the stacked trunks, 20% is subtracted from the resulting cubic capacity.

Minus - the acceptance as an indisputable fact that the tree occupies 80% of the total space. After all, it may well happen that the bars are folded inaccurately, thereby the percentage of voids is much greater.

3. Density based method.

In this case, you need to know the mass of the forest and the density of the wood. The cubature is easily found by dividing the first number by the second. But the result will be very inaccurate, since a tree of the same species has a different density. The indicator depends on the degree of maturity and humidity.

4. Average method.

If the trunks of harvested trees are almost the same in appearance, then any 3 of them are chosen. Measure the diameters, and then find the average value. Further, according to the cubature, the parameter for 1 product is determined and multiplied by the required amount. Let the results show: 25, 27, 26 cm, then the average is Ø26 cm, since (25 + 26 + 27) / 3 = 26 cm.

Given the disadvantages of the considered methods, the only correct way to calculate the cubature can be considered to be the volume of each log using the cubature GOST 2708-75 or ISO 4480-83 and summing up the data obtained.

The cubic capacity of a log is a certain volume of lumber, the unit of which is a cube. m. This parameter is used in the construction of wooden houses to calculate the required volume of roundwood. The indicator being determined is very important when calculating the payment for the sold lumber for building a house, since it is necessary to know the cost of each cube. m tree.

Round wood is very convenient and practical for building houses, baths and other residential and non-residential premises.

How to properly count lumber

There are various options that allow you to calculate the cubature of a log, which is a round cylindrical lumber. This rating is indicative. In the methods used, the initial geometric parameters are provided, on the basis of which the calculations are made.

Industrial lumbering is associated with rather complex calculations that are carried out to find out the cubic capacity of the forest. For accurate calculations, a special truncated cone formula is used. It is built on the basis of determining the main diameters of each of the two cuts of a tree and the length of the logs.

In practice, this complex method is rarely used, since the world standards that determine the cubic capacity of roundwood require the use of special tables. Calculating the cubic capacity of the forest when building a house in this way is not particularly difficult. The result is quite accurate, and the calculation is based on the value of the volume of the material in the form of a parallelepiped and the average value of the thickness index of the cut of the log in its upper part.

How to calculate the cubic capacity of a log in a single version correctly?

Until now, the calculation of the cubature of a single tree was determined by multiplying its length by the arithmetic mean of the total area of ​​all cuts. This method involved the use of a special measuring device that resembled a caliper.

1. Roulettes.
2. Calculation tables indicating the final cubic capacity.

Before calculating the cubature of the log, the size of its diameter in the middle part was increased three times, obtaining a certain value of the cross-sectional area. It had to be multiplied by the length of the workpiece in order to obtain the value of the material volume as a result. This method was not accurate, since the thickness of the tree bark was not taken into account.

The value of Pi in the circle formula was used with a very large deviation, so the distorted form of the formula did not allow accurate calculations to be made without errors. In practice, the following formula is used: the diameter of a round tree divided by 2 is squared, after which the result is multiplied by the number Pi and the length of the tree.

It cannot be argued that it is correct to calculate the cubic capacity of the forest for building a house only on the basis of tables, special measurements and corresponding formulas. The simplest is the method associated with the determination of the density of the tree species.

If we consider the cubic capacity of roundwood by measuring the thickness of the bark of lumber for the construction of houses, then it is unrealistic to determine the diameter of the logs without possible errors. The calculated parameters will be inaccurate. To correctly calculate the volume of a single wooden material, measure its length with a tape measure, then measure the diameter of the cut at the top, not taking into account the thickness of the bark.

Next, you should look into a special table in which at the intersection of rows and columns with the given values ​​​​of the length of the tree, as well as its diameter, the volume of the material is determined. This method is reliable. Before calculating the cubic capacity of the forest in this way, you should know that it is not perfectly accurate, since the shape of the trunk and the conditions associated with growing forests for building houses are not taken into account. However, these little things are usually ignored.

How to calculate the cubic capacity of stockpiled round wood?

Image 1. Calculation of the cubic capacity of stockpiled roundwood.

If we consider the industrial volumes of round timber blanks, then other tables and parameters of a round log are used here, allowing to calculate the cubic capacity. As shown in the figure (PICTURE 1), the roundwood in storage conditions has the shape of a parallelepiped in the form of a rectangle.

The method for calculating this volume is simple and known from school knowledge. In practice, the use of this method does not give an accurate result, since the dimensions of the voids between single logs are not taken into account. The dimensions of the voids depend on the diameter of the logs and can be calculated mathematically. It will not work to calculate the exact values ​​​​in the case of inaccurate stacking of log blanks. This procedure is not carried out in the course of evaluation of the wood in storage, since the volume occupied by the roundwood in the warehouse itself is estimated.

If you carry out a preliminary weighing of the forest, then it will not be difficult to calculate the cubic capacity, since it is not completely filled with wood material. The desired value should be reduced using the void coefficient. When carrying out construction calculations, the value of the coefficient of voids is 0.8, which is 20% of the area of ​​space that is occupied by the air void, and 80% falls on the volume of the tree.

The sequence of actions in determining the cubic size is reduced to the following main steps:

1. Measuring the width, length, height of a space that is rectangular.
2. Multiplying certain values ​​​​together to calculate the result of the volume.
3. Multiplying the result by a factor of 0.8, which takes into account the number of voids between logs, which is an approximation.
4. Acceptance of the obtained value for the effective one.

With this method, the cubic capacity of roundwood, which is heterogeneous in size, is calculated.

Carrying out calculations depending on the type of material

To calculate the volume of lumber by dividing the mass of the forest by its density, it is necessary to take into account the type of wood.

Image 2. Table for calculating the cubic capacity of unedged and edged boards, bars, lining, slats, etc.

The result obtained will be far from ideal, since the forest can have different degrees of maturity, hence different deviations in density. The main role belongs to wood moisture.

The woodworking industry is characterized by concepts associated with dense cubic meters and storage. The price list for such lumber will contain information about the volume in its dense mass, it will be necessary to convert the storage cubic meter into a dense mass. For this purpose, conversion factors are used.

The volume of the forest area of ​​coniferous or deciduous species is calculated by two methods:

1. By measuring all units of the tree.
2. Through the use of a standard, that is, a cubature, developed in accordance with GOST.

The cuber is designed to calculate the volume of edged wood material based on standard tables. In one, you can find the volume of a meter of a tree, and in the second - units, which allows you to calculate the cost of the forest.

The proposed table (IMAGE 2) contains calculations of the cubic capacity of unedged and edged boards, bars, lining, slats, etc. The measurement has its own specifics, that is, the size of the width of any board is equal to half the size of the width of the narrow and wide layers, measured in the middle part of the board. The calculation of the volume of round material is correct if each log is measured.

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