Construction work requires solving many different issues, among which the most important task is the selection and purchase of lumber. It is not difficult to calculate how many linear meters of boards and timber will be needed during the construction process. But the price of industrial wood is indicated per 1 cubic meter, and this often causes difficulties for novice home craftsmen. Ability to correctly select and calculate the amount of edged or unedged lumber in a cube will allow you to save money and avoid a situation where, after completion construction work There is a pile of unused boards left on the site.
Classification and characteristics of lumber
The very name “lumber” suggests that this type of construction raw material is obtained by longitudinal sawing of tree trunks on circular or band saws. Several cutting methods are used to produce boards and timber:
- tangential (in a circle),
- radial.
Tangential cutting involves moving the saw tangentially to the annual rings of the tree, which reduces the amount of waste and, therefore, reduces the cost of building materials. The boards obtained in this way have a beautiful, pronounced pattern, therefore they are often used for finishing purposes. Disadvantages of circular sawing include the tendency of the wood to shrink and swell, as well as a significant difference in texture as it approaches cutting tool to the center of the log.
In the sawmill industry, several methods are used for sawing a trunk.
With radial sawing, the cutting line passes through the core of the tree, so the yield of boards will be smaller, and their price will be higher. However, if necessary, obtain wood High Quality use exactly this method. This is due to the fact that, compared to the tangential method, radial sawing boards have halved swelling and shrinkage rates. In addition to the cutting methods discussed above, a mixed method is also used, which combines the advantages of the first two.
The concept of lumber actually includes not only traditional moldings, which can most often be seen on construction markets. Full list products obtained by sawing logs include:
- board;
- beam;
- bar;
- lagging;
- croaker
The last two types of lumber are classified as waste, which absolutely does not prevent them from being used for certain types of construction work, as well as for finishing purposes.
Boards
Boards include lumber rectangular section with a thickness of no more than 100 mm and a width to thickness ratio of no less than 2:1. Depending on the degree of processing, the board can be edged or unedged. The first is ready product without bark and with smoothly sawn edges, while the second is a “semi-finished product”, removed directly from the saw frame.
The edged board has smooth edges and a constant width along the entire length of the lumber
The most commonly used boards in construction are: standard sizes:
- thickness - 25 mm, 40 mm, 50 mm, 60 mm;
- width - from 75 to 275 mm with gradation every 25 mm;
- length - from 1 m to 6.5 mm in increments of 250 mm.
Boards of other sizes can be obtained by trimming or planing standard lumber, or by making individual order for sawing round timber.
Unedged boards have a lower cost, but without finishing its scope of application is limited
The parameters of lumber used in construction are standardized and determined according to current GOST 8486–86 for coniferous wood and GOST 2695–83 for hardwood.
timber
Timber is lumber whose cross-section is a square with sides of at least 100 mm. The diameter of the timber is unified and can vary from 100 to 250 mm in increments of 25 mm. The standard defines the length of products of this type from 2 to 9 m, but most often square-section lumber with a length of no more than 6 m is used. In some cases, products with a section of 150x100 mm, 200x100 mm or 200x150 mm, which existing classification are much closer to the sleepers.
Timber is an ideal material for the construction of frames and other wooden structures
The bar differs from the beam discussed above only in that its cross-section does not exceed 100x100 mm. The typical length of the bar is also 6 m, and the diameter ranges from 40 mm to 90 mm in increments of 10 mm. To simplify the classification, bars are often classified as slats whose cross-section has rectangular shape, and the ratio of thickness to width is at least 1:2. Standard range of wood slats edges coniferous species looks like this: 16, 19, 22, 25, 32, 40, 44, 50, 60, 75 mm. For hardwood lumber, products of increased width are additionally provided, and the product line itself looks like this: 19, 22, 25, 32, 40, 45, 50, 60, 70, 80, 90, 100 mm.
A variety of bars and slats allow you to strengthen and make any wooden structure as stable as possible.
Obapole and croaker
Obapol represents the very first cut of a round timber, in which outer surface remains unprocessed. Unlike obapol, croaker can have a cut on half of the second side or alternating treated and untreated areas on the bark side. The importance of obapole and slab in construction is secondary, since it is unaesthetic appearance and reduced performance characteristics allow the use of lumber of this type only for auxiliary purposes. Most often, slab and obapol are used as fastening materials, as well as for the manufacture of formwork, sheathing or flooring. scaffolding. This material is also interesting in quality decorative material for decorating walls, fences and other vertical structures.
Despite their external ugliness, croaker and obapole are widely used for minor construction tasks
Technology for calculating the number of boards in a cube
The wood market offers both edged lumber and unedged boards, with wane remaining on the edges. Depending on the type of wood products, several methods are used to determine cubic capacity.
How to find out the number of edged lumber in a cube
The algorithm for determining the cubic capacity of lumber is based on the formula known to every schoolchild for finding the volume of a rectangular parallelepiped. In order to find out the cubic capacity of one board (V) per cubic meter. m, you need to find the product of its length (a) by its width (b) and thickness (h) in meters V=a×b×h.
The desired figure will make it easy to calculate how many boards of this type will fit in one cubic meter lumber. For this, 1 cu. m of lumber is divided by the volume of one product. For example, if you need to find out the cubic capacity of one board with parameters 6000x200x25 mm, then by substituting these numbers into the formula, we get V = 6x0.2x0.025 = 0.03 cubic meters. m. Consequently, in one cubic meter there will be 1/0.03 = 33.3 such products.
A tongue and groove board has a groove on one side and a tongue on the other. Since both of these elements are approximately equal to each other, their parameters can be neglected. That is why the cross-sectional size of tongue-and-groove lumber is measured without taking into account the locking part.
In the case of boards that have the same dimensions, the calculation can be simplified by substituting the dimensions of the stack of lumber into the formula. Of course, its installation should be as tight as possible, otherwise the gaps between the individual elements will affect the accuracy of the calculations. Considering that the cost of individual types of wood reaches tens of thousands of rubles, such an error can cost a pretty penny.
To simplify calculations, you can use special tables that allow you to quickly determine the cubic capacity or the amount of wood in 1 cubic meter. m of lumber.
Table: number of edged boards in 1 cubic meter. m of standard length lumber
| Board size, mm | Number of boards 6 m long in 1 cubic. m | Volume of one board, cubic meters. m |
| 25x100 | 66,6 | 0.015 |
| 25x150 | 44,4 | 0.022 |
| 25x200 | 33,3 | 0.03 |
| 40x100 | 62,5 | 0.024 |
| 40x150 | 41,6 | 0.036 |
| 40x200 | 31,2 | 0.048 |
| 50x100 | 33,3 | 0.03 |
| 50x150 | 22,2 | 0.045 |
| 50x200 | 16,6 | 0.06 |
| 50x250 | 13,3 | 0.075 |
The cubic capacity of timber of standard sizes can also be determined using the table below.
Table: amount of timber in 1 cubic meter. m of lumber
| Beam size, mm | Number of products 6 m long in 1 cubic. m | Volume of 1 beam, cubic. m |
| 100x100 | 16.6 | 0.06 |
| 100x150 | 11.1 | 0.09 |
| 100x200 | 8.3 | 0.12 |
| 150x150 | 7.4 | 0.135 |
| 150x200 | 5.5 | 0.18 |
| 150x300 | 3.7 | 0.27 |
| 200x200 | 4.1 | 0.24 |
Very often it is necessary to determine the surface area (floor or wall) that can be covered with a board of one thickness or another with a volume of 1 cubic meter. m. To do this, you can use the formula S = 1/h, where h is the thickness of the lumber. So, one cubic meter of 40 mm board will be enough to arrange S = 1/0.04 = 25 square meters. m of floor. To facilitate the process of calculating the area, a table called a cubeturner allows you to simplify the process of calculating the area. It contains data on the cross-section of the boards, their number in 1 cubic meter. m and the required area that they can cover.
Method for calculating the cubic capacity of an unedged board
Unedged lumber is not trimmed at the edges, so not only the cross-sectional size of individual products varies, but also the width different parts one board. In this regard, it is possible to calculate the volume of a stack of unprocessed lumber only approximately. The same applies to calculating the cubic capacity of individual unedged lumber, although the error in this case will be much smaller.
So, to calculate the cubic capacity unedged boards There are two constant quantities - thickness and length, and one variable - width. To avoid complex calculations using differential algebra methods, the last parameter is simply averaged. To do this, the board is measured in several places and the arithmetic average is found. For example, for a board with a diameter of 400 mm at the base, 350 mm in the middle and 280 in the top, the calculated value will be (430+340+260)/3=343 mm. Further calculations are carried out in exactly the same way as for edged lumber.
Most often, the width of an unedged board is determined only on the basis of measurements along the edges of the lumber. It should be noted that the accuracy of calculations directly depends on the number of measurements, so in critical cases their number is increased.
If you need to find out the cubic capacity of a package of unedged wood, then the products are stacked on top of each other in such a way that the following conditions are met:
- the stacks must be aligned along the front end;
- boards in a stack should not be stacked overlapping;
- It is not allowed to change the width of the package along the entire length of the lumber;
- the protrusion of the outermost products beyond the stack should not exceed 100 mm.
By measuring the height, length and width of a package of unedged wood with a tape measure, the approximate cubic capacity is determined using the formula V=a×b×h. To find out a more accurate value, the result obtained is multiplied by the stacking coefficient, which can be found in special tables.
This question is the most pressing when it comes to building a house from a log. How to calculate the cubic capacity of a house yourself? How to check the declared forest cubes in the estimate from the developer?
Here is a table showing the cubic capacity round timber depending on the diameter of the log. These calculations are given in accordance with GOST 2708-75, which is valid in the territory Russian Federation since 1975. The table allows you to calculate how many cubes of round timber will be needed to build a house from logs from the manufacturer.
Standard length of logs used for the construction of log houses is 6 meters. Blanks of this length are most often used. Logs longer than 6 meters are used to make houses manual cutting very rarely.
Most often, the architect optimizes the log house according to the cutting map in such a way as to avoid (or minimize) the use of long lengths. It is technically impossible to produce a rounded log over 6 meters.Below in the table you can see a block of round timber, and for your convenience, we have highlighted a column of 6-meter blanks.
Table for calculating the cubic capacity of round timber with a diameter of 10 to 100 cm and a length of 3 to 8 meters |
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|
|
3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| 0,026 | 0,031 | 0,037 | 0,044 | 0,051 | 0,058 | 0,065 | 0,075 | 0,082 | 0,09 | 0,1 | |
| D 11 cm | 0,032 | 0,037 | 0,045 | 0,053 | 0,062 | 0,07 | 0,08 | 0,09 | 0,098 | 0,108 | 0,12 |
| D 12 cm | 0,038 | 0,046 | 0,053 | 0,063 | 0,073 | 0,083 | 0,093 | 0,103 | 0,114 | 0,125 | 0,138 |
| D 13 cm | 0,045 | 0,053 | 0,062 | 0,075 | 0,085 | 0,097 | 0,108 | 0,12 | 0,132 | 0,144 | 0,158 |
| D 14 cm | 0,052 | 0,061 | 0,073 | 0,084 | 0,097 | 0,11 | 0,123 | 0,135 | 0,15 | 0,164 | 0,179 |
| D 15 cm | 0,06 | 0,071 | 0,084 | 0,097 | 0,11 | 0,125 | 0,139 | 0,153 | 0,169 | 0,182 | 0,199 |
| D 16 cm | 0,069 | 0,082 | 0,095 | 0,11 | 0,124 | 0,14 | 0,155 | 0,172 | 0,189 | 0,2 | 0,22 |
| D 17 cm | 0,077 | 0,092 | 0,107 | 0,124 | 0,14 | 0,157 | 0,174 | 0,191 | 0,209 | 0,225 | 0,25 |
| D 18 cm | 0,086 | 0,103 | 0,12 | 0,138 | 0,156 | 0,175 | 0,194 | 0,21 | 0,23 | 0,25 | 0,28 |
| D 19 cm | 0,097 | 0,115 | 0,134 | 0,154 | 0,173 | 0,193 | 0,212 | 0,235 | 0,255 | 0,275 | 0,305 |
| 3.0 m | 3.5 m | 4.0 m | 4.5 m | 5.0 m | 5.5 m | 6.0 m | 6.5 m | 7.0 m | 7.5 m | 8.0 m | |
| D 20 cm | 0,107 | 0,126 | 0,147 | 0,17 | 0,19 | 0,21 | 0,23 | 0,26 | 0,28 | 0,3 | 0,33 |
| D 21 cm | 0,119 | 0,14 | 0,163 | 0,185 | 0,21 | 0,23 | 0,255 | 0,285 | 0,31 | 0,335 | 0,365 |
| D 22 cm | 0,134 | 0,154 | 0,178 | 0,2 | 0,23 | 0,25 | 0,28 | 0,31 | 0,34 | 0,37 | 0,4 |
| D 23 cm | 0,114 | 0,169 | 0,194 | 0,22 | 0,25 | 0,275 | 0,305 | 0,335 | 0,37 | 0,4 | 0,435 |
| D 24 cm | 0,157 | 0,184 | 0,21 | 0,24 | 0,27 | 0,3 | 0,33 | 0,36 | 0,4 | 0,43 | 0,47 |
| D 25 cm | 0,171 | 0,197 | 0,23 | 0,26 | 0,295 | 0,325 | 0,36 | 0,395 | 0,43 | 0,465 | 0,505 |
| D 26 cm | 0,185 | 0,21 | 0,25 | 0,28 | 0,32 | 0,35 | 0,39 | 0,43 | 0,46 | 0,5 | 0,54 |
| D 27 cm | 0,203 | 0,23 | 0,27 | 0,305 | 0,345 | 0,38 | 0,42 | 0,46 | 0,495 | 0,54 | 0,585 |
| D 28 cm | 0,22 | 0,25 | 0,29 | 0,33 | 0,37 | 0,41 | 0,45 | 0,49 | 0,53 | 0,58 | 0,63 |
| D 29 cm | 0,235 | 0,27 | 0,31 | 0,355 | 0,395 | 0,44 | 0,485 | 0,525 | 0,57 | 0,62 | 0,675 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 30 cm | 0,25 | 0,29 | 0,33 | 0,38 | 0,42 | 0,47 | 0,52 | 0,56 | 0,61 | 0,66 | 0,72 |
| D 31 mm |
0,265 | 0,31 | 0,355 | 0,405 | 0,45 | 0,5 | 0,555 | 0,6 | 0,655 | 0,72 | 0,77 |
| D 32 cm | 0,28 | 0,33 | 0,38 | 0,43 | 0,48 | 0,53 | 0,59 | 0,64 | 0,7 | 0,76 | 0,82 |
| D 33 cm | 0,3 | 0,35 | 0,405 | 0,46 | 0,51 | 0,565 | 0,625 | 0,68 | 0,74 | 0,805 | 0,87 |
| D 34 cm | 0,32 | 0,37 | 0,43 | 0,49 | 0,54 | 0,6 | 0,66 | 0,72 | 0,78 | 0,85 | 0,92 |
| D 35 cm |
0,34 |
0,395 | 0,455 | 0,515 | 0,57 | 0,635 | 0,7 | 0,76 | 0,83 |
0,9 |
0,97 |
| D 36 cm | 0,36 | 0,42 | 0,48 | 0,54 | 0,6 | 0,67 |
0,74 |
0,8 | 0,88 | 0,95 | 1,02 |
|
0,375 |
0,44 | 0,505 | 0,57 | 0,635 | 0,705 | 0,78 | 0,85 | 0,925 | 1,0 | 1,075 | |
| D 38 cm |
0,39 |
0,46 | 0,53 | 0,6 | 0,67 | 0,74 | 0,82 | 0,9 |
0,97 |
1,05 | 1,13 |
| D 39 cm |
0,41 |
0,48 | 0,555 | 0,63 | 0,705 | 0,78 | 0,86 | 0,945 | 1,02 | 1,105 | 1,19 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
|
0,43 |
0,5 | 0,58 | 0,66 | 0,74 | 0,82 | 0,9 | 0,99 | 1,07 | 1,16 | 1,25 | |
| D 41 cm | 0,45 | 0,53 | 0,61 | 0,695 | 0,775 | 0,86 | 0,95 | 1,035 | 1,125 | 1,22 | 1,315 |
| D 42 cm |
0,47 |
0,56 | 0,64 | 0,73 | 0,81 | 0,9 | 1,0 | 1,08 | 1,18 | 1,28 | 1,38 |
| D 43 cm |
0,495 |
0,585 | 0,67 | 0,765 | 0,85 | 0,945 | 1,045 | 1,14 | 1,24 | 1,34 | 1,34 |
| D 44 cm |
0,515 |
0,61 | 0,7 | 0,8 | 0,89 | 0,89 | 1,09 |
1,2 |
1,3 |
1,4 | 1,51 |
| D 45 cm |
0,543 |
0,64 | 0,735 | 0,835 | 0,935 | 1,035 | 1,14 | 1,25 | 1,355 | 1,465 | 1,48 |
| D 46 cm |
0,57 |
0,67 | 0,77 | 0,87 | 0,98 | 1,08 | 1,19 | 1,3 | 1,41 | 1,53 | 1,65 |
| D 47 cm |
0,595 |
0,7 | 0,805 | 0,91 | 1,02 | 1,13 | 1,245 | 1,355 | 1,475 | 1,6 | 1,725 |
| D 48 cm |
0,62 |
0,73 | 0,84 | 0,95 | 1,06 | 1,18 | 1,3 | 1,41 | 1,54 | 1,167 | 1,8 |
| D 49 cm |
0,645 |
0,76 |
0,875 | 0,99 | 1,105 | 1,23 | 1,355 | 1,475 | 1,605 | 1,74 | 1,875 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 50 cm |
0,67 |
0,79 | 0,91 | 1,03 | 1,15 | 1,28 | 1,41 | 1,54 | 1,67 | 1,81 | 1,95 |
| D 51 cm |
0,7 |
0,825 | 0,95 | 1,075 | 1,2 |
1,335 |
1,47 | 1,605 | 1,74 | 1,89 | 2,035 |
| D 52 cm |
0,73 |
0,86 | 0,99 | 1,12 | 1,25 | 1,39 | 1,53 | 1,67 | 1,81 | 1,97 | 2,12 |
| D 53 cm |
0,765 |
0,895 | 1,03 |
1,165 |
1,3 | 1,445 | 1,59 | 1,735 | 1,885 | 2,045 | 2,205 |
| D 54 cm |
0,8 |
0,93 | 1,07 | 1,21 | 1,35 | 1,5 | 1,65 | 1,8 | 1,96 | 2,12 | 2,29 |
| D 55 cm |
0,83 |
0,97 | 1,115 | 1,26 | 1,405 | 1,56 | 1,715 | 1,875 | 2,035 | 2,2 | 2,375 |
| D 56 cm |
0,86 |
1,01 | 1,16 | 1,31 | 1,46 | 1,62 | 1,78 | 1,95 | 2,11 | 2,28 | 2,46 |
| D 57 cm |
0,89 |
1,045 | 1,205 | 1,36 | 1,515 | 1,68 | 1,875 | 2,015 | 2,19 | 2,365 | 2,545 |
| D 58 cm |
0,92 |
1,08 | 1,25 | 1,41 | 1,57 | 1,74 | 1,91 | 2,08 | 2,27 | 2,45 | 2,63 |
| D 59 cm |
0,955 |
1,12 | 1,29 | 1,46 | 1,625 | 1,8 | 1,98 | 2,155 | 2,345 | 2,535 | 2,72 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 60 cm |
0,99 |
1,16 | 1,33 | 1,151 | 1,151 | 1,86 | 2,05 | 2,23 | 2,42 | 2,62 | 2,81 |
| D 61 cm |
1,025 |
1,2 | 1,38 | 1,565 | 1,74 | 1,925 | 2,115 | 2,3 | 2,495 | 2,7 | 2,9 |
| D 62 cm | 1,06 | 1,24 | 1,43 | 1,62 | 1,8 | 1,99 | 2,18 | 2,37 | 2,57 | 2,78 | 2,99 |
| D 63 cm |
1,095 |
1,285 | 1,475 | 1,67 | 1,855 | 2,05 | 2,25 | 2,445 | 2,65 | 2,865 | 3,08 |
| D 64 cm |
1,13 |
1,33 | 1,52 | 1,72 | 1,61 | 2,11 | 2,32 | 2,52 | 2,73 | 2,95 | 3,17 |
| D 65 cm |
1,165 |
1,365 | 1,565 | 1,77 | 1,965 | 2,17 | 2,38 | 2,59 | 2,805 | 3,03 | 3,275 |
| D 66 cm |
1,2 |
1,4 | 1,61 | 1,82 | 2,02 | 2,23 | 2,44 | 2,66 | 2,88 | 3,11 | 3,38 |
| D 67 cm |
1,235 |
1,445 | 1,655 | 1,87 | 2,075 | 2,29 | 2,505 | 2,735 | 2,965 | 3,21 | 3,485 |
| D 68 cm |
1,27 |
1,49 | 1,7 | 1,92 | 2,13 | 2,35 | 2,57 | 2,81 | 3,05 | 3,31 | 3,59 |
| D 69 cm |
1,305 |
1,53 | 1,75 | 1,97 | 2,19 | 2,415 | 2,645 | 2,89 | 3,14 | 3,41 | 3,695 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 70 cm |
1,34 |
1,57 | 1,8 | 2,02 | 2,25 | 2,48 | 2,72 | 2,97 | 3,23 | 3,51 | 3,8 |
| D 71 cm |
1,375 |
1,615 | 1,85 | 2,08 | 2,315 | 2,55 | 2,795 | 3,055 | 3,325 | 3,615 | 3,91 |
| D 72 cm |
1,41 |
1,66 | 1,9 | 2,14 | 2,38 | 2,62 | 2,87 | 3,14 | 3,42 | 3,72 | 4,02 |
| D 73 cm |
1,45 |
1,705 | 1,955 | 2,2 | 2,45 | 2,695 |
2,95 |
3,23 | 3,52 | 3,82 | 4,135 |
| D 74 cm |
1,49 |
1,75 | 2,01 | 2,26 | 2,52 | 2,77 | 3,03 | 3,32 | 3,62 | 3,92 | 4,25 |
| D 75 cm |
1,53 |
1,8 | 2,065 | 2,325 | 2,595 | 2,845 | 3,115 | 3,415 |
3,715 |
4,03 | 4,365 |
| D 76 cm |
1,57 |
1,85 | 2,12 | 2,39 | 2,67 | 2,92 | 3,2 | 3,51 | 3,81 | 4,14 | 4,48 |
| D 77 cm |
1,615 |
1,9 | 2,18 | 2,455 | 2,745 | 3,0 | 3,29 | 3,605 | 3,925 | 4,255 | 4,6 |
| D 78 cm |
1,66 |
1,95 | 2,24 | 2,52 | 2,82 | 3,08 | 3,38 | 3,7 | 4,04 | 4,37 | 4,72 |
| D 79 cm |
1,7 |
2,0 | 2,295 | 2,59 | 2,895 | 3,16 | 3,475 | 3,8 | 4,15 | 4,485 | 4,835 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 80 cm |
1,74 |
2,05 | 2,35 | 2,66 | 2,97 | 3,24 | 3,57 | 3,9 | 4,26 | 4,6 | 4,95 |
| D 81 cm |
1,785 |
2,1 | 2,41 | 2,73 | 3,05 | 3,325 | 3,66 | 4,005 | 4,365 | 4,51 | 5,085 |
| D 82 cm |
1,83 |
2,15 | 2,47 | 2,8 | 3,13 | 3,41 | 3,75 | 4,11 | 4,47 | 4,82 | 5,22 |
| D 83 cm |
1,875 |
2,205 | 2,53 | 2,87 | 3,205 | 3,495 | 3,845 | 4,215 | 4,585 | 4,495 | 5,345 |
| D 84 cm | 1,92 | 2,26 | 2,59 | 2,94 | 3,28 | 3,58 | 3,94 | 4,32 | 4,7 | 5,07 | 5,47 |
| D 85 cm |
1,965 |
2,315 | 2,65 | 2,985 | 3,34 | 3,675 | 4,035 | 4,43 | 4,82 | 5,195 | 5,595 |
| D 86 cm |
2,01 |
2,37 | 2,71 | 3,03 | 3,4 | 3,77 | 4,13 | 4,54 | 4,94 | 5,32 | 5,72 |
| D 87 cm |
2,06 |
2,425 | 2,78 | 3,13 | 3,5 | 3,86 | 4,235 | 4,655 | 5,06 | 5,445 | 5,86 |
| D 88 cm |
2,11 |
2,48 | 2,85 | 3,23 | 3,6 | 3,95 | 4,34 | 4,77 | 5,18 | 5,57 | 6,0 |
| D 89 cm |
2,16 |
2,535 | 2,915 | 3,3 | 3,685 | 4,045 | 4,45 | 4,88 | 5,3 | 5,7 | 6,135 |
| 3m | 3.5 m | 4 m | 4.5 m | 5 m | 5.5 m | 6 m | 6.5 m | 7 m | 7.5 m | 8 m | |
| D 90 cm |
2,21 |
2,59 | 2,98 | 3,37 | 3,77 | 4,145 | 4,56 | 4,99 | 5,42 | 5,83 | 6,27 |
| D 91 cm |
2,255 |
2,65 | 3,045 | 3,45 | 3,45 | 4,24 | 4,67 | 5,105 | 5,545 | 5,96 | 6,41 |
| D 92 cm |
2,3 |
2,71 | 3,11 | 3,53 | 3,94 | 4,34 |
4,78 |
5,22 | 5,67 | 6,09 | 6,55 |
| D 93 cm |
2,355 |
2,77 | 3,18 | 3,605 | 4,025 | 4,43 | 4,89 | 5,345 | 5,795 | 6,225 | 6,69 |
| D 94 cm |
2,41 |
2,83 |
3,25 | 3,68 | 4,11 | 4,52 | 5,0 | 5,47 | 5,92 | 6,36 | 6,83 |
| D 95 cm | 2,46 | 2,89 | 3,32 | 3,76 | 4,2 | 4,625 | 5,11 | 5,58 | 6,045 | 6,495 | 6,975 |
| D 96 cm |
2,51 |
2,95 | 3,39 | 3,84 | 4,29 | 4,73 | 5,22 | 5,69 | 6,17 | 6,63 | 7,12 |
| D 97 cm |
2,565 |
3,01 | 3,46 | 3,92 | 4,38 | 4,83 | 5,335 | 5,81 | 6,3 | 6,77 | 7,28 |
| D 98 cm |
2,62 |
3,07 | 3,53 | 4,0 | 4,47 | 4,93 | 5,45 | 5,93 | 6,43 | 6,91 | 7,44 |
| D 99 cm |
2,67 |
3,135 | 3,6 | 4,085 | 4,56 | 5,035 | 5,565 | 6,06 | 6,565 | 7,055 | 7,585 |
| D 100 cm |
2,72 |
3,2 | 3,67 | 4,17 | 4,65 | 5,14 | 5,68 | 6,19 | 6,7 | 7,2 | 7,73 |
How is the cubic capacity of a wooden house calculated during preliminary calculations?
First you need to calculate how many blanks are needed to build a house from a log. IN finished projects from "THE ABC OF THE FOREST" this information contained in the “Cutting Cards” section. The photo below shows summary information for construction by.
This data is for a rounded log with a diameter of 240 mm and a length of 6 meters. We see from the cutting map that for construction we will need 547 blanks; when converted to cubic meters according to the table presented above, it turns out to be 146.71 m3. These data are automatically calculated by the AT - WENTS program.
The program in which our architects design wooden houses gives the exact cubic capacity without window and door openings, taking into account all design features wooden house. It is almost impossible to achieve such accuracy with manual calculations.
547*0.33= 180.51 m3.
Thus, we got the result taking into account the lunar groove - the log, relatively speaking, is calculated as a cylinder, and the program calculates minus the lunar groove.
This calculation once again proves the importance professional project and the availability of cutting maps, which allow you to very accurately calculate the amount of logs and lumber and rationally use construction budget. But for approximate calculations To understand the order of prices, this method is very informative.
Mathematical method for calculating the cubic capacity of a wooden house (with a practical example)
What to do if you like the house in the picture, and you don’t have any complete project, and even more so cutting cards? In this case, you need to be patient and manually calculate the length of all the logs according to the plan. It must be understood that in this case the error with the real result can be significant, and in both directions.
The task is to calculate how many blanks are needed to build a house from a log. The standard length of a log, as we have previously informed you, often does not exceed 6 meters. It is very important at this stage to determine the height of the floors! And according to this, calculate the number of crowns.
To do this, we need a table of the height of the log profile depending on the diameter. It is presented below. We count the length of all crowns (logs), including pediments, and divide the resulting number by 6.
| Log diameter, mm | Crown height, m | Crown height, mm |
| 220 | 0,1905 | 190,5 |
| 240 | 0,2078 | 207,8 |
| 260 | 0,2252 | 225,2 |
| 280 | 0,2425 | 242,5 |
| 300 | 0,2598 | 259,8 |
| 320 | 0,2771 | 277,1 |
| 340 | 0,2944 | 294,4 |
| 360 | 0,3225 | 322,5 |
| 380 | 0,3399 | 339,9 |
| 400 | 0,3572 | 357,2 |
EXAMPLE:
Let's assume that we want to build a house from chopped logs with a diameter of 320 mm. One full floor, the second floor is an attic. The desired height of the first floor after shrinkage is 3100 mm, the desired height of the attic against the wall is 1500 mm. The height of one crown with a diameter of 320 mm is 0.2771 mm.
Important! The average height of the first floor of any log house before shrinkage is 3.2 m, the height of the attic wall in the attic is on average 1.5-1.7 m. After shrinkage, the height of the walls will decrease by approximately 7-10%, so this must be taken into account in the initial calculations . It is also necessary to take into account the composition of the floor of the first and second floors. A competent architect will always tell you how to do this correctly.
So, in our example:
- First floor before shrinkage: 12 crowns, which will be equal to 3.33 m.
- Attic wall in the attic before shrinkage: 6 crowns, which is equal to 1.66 m.
Now we need the length of the walls of each floor. To do this, it is necessary to calculate the perimeter of all walls (load-bearing and internal) according to the plan.
Let's assume that the length of the first floor is 100 linear meters, and the length attic floor amounted to 85 m.p.This is the result without subtracting window and door openings. If you need a more accurate number, then you need to calculate all openings in length and height and subtract them from the total number.We will consider a more simplified version of calculating the cubic capacity of a log house from the manufacturer.
So,
- First floor 100 m*12 crowns = 1200 m.p.
- Attic floor 85 m * 6 crowns = 510 m.p.
Thus, we received the total length of the walls only, excluding gables, balconies, terraces, vertical support pillars, chopped trusses and other elements that may be included in the house project.
Important! To the resulting cubic capacity result, you need to add 5%, which will be for figured log releases and ridge logs. The exact number depends on the diameter of the log and the cutting method. For approximate calculations, we will limit ourselves to 5%.So, we divide the resulting length by 6 meters and get 1718 /6 = 286.33 pcs. Thus, to erect walls in our log house, 287 blanks will be required. We multiply this number by 0.59 (data from the “Table for calculating the cubic capacity of round timber”) and get169.33 m3.
We need to add pediments to the resulting cubic capacity. In the simplest case there are 2 of them, they are triangular. The area of 2 triangles will be approximately equal to the area of the rectangle. Therefore, we calculate the length of one wall, where the pediment is. We multiply by the number of crowns and get the length of the log in both gables. Divide the result by 6.
Important! The sum of the attic crowns and gables is equal to the height of the first floor. Therefore, if we have 12 crowns on the first floor, and 6 crowns in the attic, then there will be 6 crowns in the gables (12–6=6).Let's assume that the length of the pediment is 11 meters, we have 6 crowns. This means that 11 * 6 = 66 m. Divide by 6, we get 11 pieces. 11 *0.59 = 6.49 m3
Thus, the cubic capacity of our house made of logs with a diameter of 320 mm is 169.33 + 6.49 = 175.82 m3. When rounded we got 176 m3.
It was possible to go the other way around, first count the number of all blanks, and then convert them into cubic meters. Let's check our result in this way:
287 (blanks for walls) + 11 (blanks for gables) = 298 * 0.59 = 175.82 m3, rounded, 176 m3.
That is, everything was calculated correctly.
Important! Don't forget that this is not the final result yet. You need to study the sketch and if there are terraces, balconies and vertical pillars, they need to be added to the total number. We count this manually, because... The calculation you and I have is mathematical. For example, if there are pillars, then each pillar is considered one 6-meter blank of the required diameter. We also consider terrace fencing, cut-overs, chopped trusses and other elements.
Now you know how to calculate the cubic capacity of a log house or a house made of rounded logs. If you DO NOT want to deal with complex calculations yourself, contact our specialists! We will make a detailed estimate for you. This is a free service and does not oblige you to anything.
When ordering a house project made from rounded logs, all lumber will be automatically calculated as accurately as possible.
Ready-made projects of houses and baths from "AZBUKA LESA" are presented in our.
To receive an estimate, send a plan of your future home to
In the letter, indicate the desired diameter of the log, the expected height of each floor, construction technology and other data that the manager needs to know to draw up an accurate estimate.
When industrially harvesting roundwood, it is quite difficult to determine its cubic capacity. To accurately calculate the volume of each log, you can use the formula for the volume of a truncated cone, which takes into account the main diameters of both cuts and the length of the log itself.
Round timber is very convenient and practical for building houses, bathhouses and other residential and non-residential premises.
In fact, the cubic size of round timber is not calculated in such a complex way. It is accepted all over the world to be considered more in a fast way. Special tables are used for this.
How to calculate the cubic capacity of a single tree without additional measurements?
Just a few years ago, to calculate the volume of a single tree, they used the product of the arithmetic average of the area of the cuts and the length of the tree. Using a meter (reminiscent of an ordinary caliper), the diameter of the tree in its middle part was determined. Then it was multiplied by 3 to obtain the cross-sectional area.
Next, the resulting number was multiplied by the length of the workpiece, and a volumetric result was obtained. This method of calculation is inaccurate, since the thickness of the bark is not taken into account. The number Pi was taken with a large deviation from the real one, and the formula in its distorted form gave large errors.
The formula itself looks like this: the diameter of a rounded log is divided by 2 and squared, then multiplied by Pi and the length of the log.
Even if you measure the thickness of the bark and take this into account to determine the diameter of the tree, deviations from real indicators will be inaccurate, although with a smaller error. More precise calculations showed that actual deviations in calculations of the cubic capacity of a round log during primitive measurements have a certain dependence on the parameters of the tree, which was taken into account when compiling the corresponding tables to determine the volumetric parameter. Let's try to figure out how to calculate the cubic capacity of the forest. For this you will need:
- roulette;
- corresponding calculation tables, where there is a finite cubic capacity.
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Peculiarities .
How much does a cube of board weigh?Technology for calculating the volume of a single log
First, you need to use a tape measure to measure the length of the tree and its diameter at the top of the cut (excluding the bark). After this, let’s look at the tabular parameters: at the intersection of the line indicating the length of the tree and the column indicating the corresponding diameter, we find the volume of the measured body. Everything is simple and reliable.
Such calculations also cannot be called absolutely accurate, since the features in which the forest was grown and the shape of the trunk are not taken into account. But with large volumes of workpieces, it is customary not to pay attention to such trifles.
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Calculation of cubic capacity of stored timber
For industrial volumes of round logs, other techniques and tabular data are used. In essence, a round forest in a stored state has the shape of a rectangular parallelepiped. Calculations of its volume are familiar to everyone from school. But this method cannot be used, since the size of the voids between the logs will not be taken into account. By the way, they also directly depend on the diameter of the logs, which can be calculated mathematically.
Through numerous calculations, a coefficient was determined, with the help of which a special table was compiled. It works similarly to the previously described table, with the only difference being that the volume of the mentioned parallelepiped and the average thickness of the upper cut are taken into account. The cubic capacity of the forest can be calculated with great accuracy.
But one cannot hope for good accuracy of calculations when stacking forest products inaccurately. This procedure is not used when warehouse storage timber, since in this case the volume occupied by round timber directly in the warehouse is estimated.
It is very easy to calculate the cubic capacity after preliminary weighing of the forest.
Next, you need to calculate the volume by dividing the mass of the forest by the density, which corresponds to the type of wood. This calculation also cannot be considered ideal, since the forest has a deviation in density at different degrees of maturity. The moisture content of the wood can also play a special role here.
There is no point in making the same calculations several times if the source 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 is doing the counting and in which city. Only the formula V=πr²l gives the correct answer. Therefore, the volume of one central bank will always be V=3.14×(0.1)²×6=0.1884 m³. In practice, in order to eliminate the time of carrying out standard calculations, cubatures are used. Such useful and informative tables are created for various types lumber. They help to save time and find out the cubic capacity of round timber, boards, central fiber boards, and timber.
The name of this construction guide is due to the fact that the volume is physical quantity measured in cubic meters (or cubic metres). For a simpler explanation, they say “cubature”, accordingly, the table was called “cubature”. This is an ordered matrix that contains data on the volume of one product for different initial parameters. The base column contains sections, and the row contains the length (molding) of the material. The user just needs to find the number located in the cell at their intersection.
Let's consider specific example- round timber cube. It was approved in 1975, 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 with a diameter of 20 cm and a length of 5 m. At the intersection of the corresponding row and column, we find the number 0.19 m³. A similar cubature for round timber exists according to a different standard - ISO 4480-83. Directories are very detailed in increments of 0.1 m, as well as more general, where the length is taken in 0.5 m increments.
Little secrets
Using the cubeturner itself is not difficult, but main nuance– correct data. Round timber is not a cylinder, but a truncated cone, in which the lower and upper cuts are different. One of them may be 26 cm, and the other 18. The table assumes a clear answer for a specific 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 the cubature GOST 2708-75, the diameter of the top cut of the log is taken. Why is the moment of initial data 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 cubatures. 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, who make up their own cubatures, take “liberties”. For example, instead of 0.156 m³ there is already the number 0.16 m³. Quite often, websites on the Internet contain frankly erroneous cube-turners, in which the volume of a log 5 meters long with a diameter of 18 cm is indicated not as 0.156 m³, but as 0.165 m³. If an enterprise uses such directories when selling round timber to consumers, then it makes a profit, actually deceiving customers. After all, the difference on 1 product is significant: 0.165-0.156 = 0.009 or almost 0.01 m³.
The main problem of round timber is the different cross-section. Sellers offer solutions to settlement issues in the following ways:
- calculating the volume of each unit and summing the obtained values;
- storage method;
- finding the average diameter;
- method based on wood density.
1. It must be said right away that the first one gives the correct results. the above options. Only calculating the volume of each log and then adding up the numbers guarantees that the buyer will pay for the timber that he receives 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. Storage method.
It is assumed that the stored round timber occupies a part of the space shaped like a rectangular parallelepiped. In this case, the total volume is found by multiplying the length, width and height of the figure. Considering that there are voids between the folded trunks, 20% is subtracted from the resulting cubic capacity.
The downside is accepting as an indisputable fact that the tree occupies 80% of the total space. After all, it may well happen that the beams 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 cubic capacity is easily found by dividing the first number by the second. But the result will be very inaccurate, since wood of the same type has different densities. The indicator depends on the degree of maturity and humidity.
4. Average method.
If the trunks of the harvested trees are almost identical in appearance, then choose any 3 of them. The diameters are measured and then the average is found. Next, using the cubature, the parameter for 1 product is determined and multiplied by required quantity. Let the results show: 25, 27, 26 cm, then Ø26 cm is considered average, since (25+26+27)/3=26 cm.
Considering the disadvantages of the considered methods, the only the right way The calculation of cubic capacity can be considered by finding the volume of each log using a cubic meter GOST 2708-75 or ISO 4480-83 and summing up the data obtained.
- How to calculate cubic capacity without using tables?
When industrially harvesting roundwood, it is quite difficult to determine its cubic capacity. To accurately calculate the volume of each log, you can use the formula for the volume of a truncated cone, which takes into account the main diameters of both cuts and the length of the log itself.
Round timber is very convenient and practical for building houses, bathhouses and other residential and non-residential premises.
In fact, the cubic size of round timber is not calculated in such a complex way. It is accepted all over the world to count it in a faster way. Special tables are used for this.
How to calculate the cubic capacity of a single tree without additional measurements?
Cubic meter of timber and folding cubic meter of round timber.
Just a few years ago, to calculate the volume of a single tree, they used the product of the arithmetic average of the area of the cuts and the length of the tree. Using a meter (reminiscent of an ordinary caliper), the diameter of the tree in its middle part was determined. Then it was multiplied by 3 to obtain the cross-sectional area.
Next, the resulting number was multiplied by the length of the workpiece, and a volumetric result was obtained. This method of calculation is inaccurate, since the thickness of the bark is not taken into account. The number Pi was taken with a large deviation from the real one, and the formula in its distorted form gave large errors.
The formula itself looks like this: the diameter of a rounded log is divided by 2 and squared, then multiplied by Pi and the length of the log.
Even if you measure the thickness of the bark and take this into account to determine the diameter of the tree, deviations from real indicators will be inaccurate, although with a smaller error. More accurate calculations showed that the actual deviations in the calculations of the cubic capacity of a round log during primitive measurements have a certain dependence on the parameters of the tree, which was taken into account when compiling the corresponding tables to determine the volumetric parameter. Let's try to figure out how to calculate the cubic capacity of the forest. For this you will need:
- roulette;
- corresponding calculation tables, where there is a finite cubic capacity.
Return to contents
Technology for calculating the volume of a single log
First, you need to use a tape measure to measure the length of the tree and its diameter at the top of the cut (excluding the bark). After this, let’s look at the tabular parameters: at the intersection of the line indicating the length of the tree and the column indicating the corresponding diameter, we find the volume of the measured body. Everything is simple and reliable.
Such calculations also cannot be called absolutely accurate, since the features in which the forest was grown and the shape of the trunk are not taken into account. But with large volumes of workpieces, it is customary not to pay attention to such trifles.
Return to contents
Calculation of cubic capacity of stored timber
For industrial volumes of round logs, other techniques and tabular data are used. In essence, a round forest in a stored state has the shape of a rectangular parallelepiped. Calculations of its volume are familiar to everyone from school. But this method cannot be used, since the size of the voids between the logs will not be taken into account. By the way, they also directly depend on the diameter of the logs, which can be calculated mathematically.
Through numerous calculations, a coefficient was determined, with the help of which a special table was compiled. It works similarly to the previously described table, with the only difference being that the volume of the mentioned parallelepiped and the average thickness of the upper cut are taken into account. The cubic capacity of the forest can be calculated with great accuracy.
Types of lumber and their volume.
But one cannot hope for good accuracy of calculations when stacking forest products inaccurately. This procedure is not used when storing timber in a warehouse, since in this case the volume that round timber occupies directly in the warehouse is estimated.
It is very easy to calculate the cubic capacity after preliminary weighing of the forest.
Next, you need to calculate the volume by dividing the mass of the forest by the density, which corresponds to the type of wood. This calculation also cannot be considered ideal, since the forest has a deviation in density at different degrees of maturity. The moisture content of the wood can also play a special role here.
