How many boards are there in 1 cube of imitation timber? Standard dimensions of lumber: length and width
- Standard sizes lumber
- The effect of humidity on wood construction material
All lumber is manufactured in accordance with the requirements, which indicate their standard dimensions and permissible deviations from them.
Theoretically, when choosing one option or another, it is enough to turn to the desired regulatory document. In practice, as a rule, it is required to know the parameters of an individual product and the total amount of material required for construction.
In the retail chain, lumber is sold not individually, but as a volume measured in cubic meters. Does the purchased volume correspond to what was previously calculated? This question requires a detailed answer.
Standard lumber sizes
Requirements for deciduous and coniferous species differ significantly from each other. A division by grade has been introduced for lumber.
The first grade is the highest. For him more strict requirements to dimensions and their errors. Additional parameters may be: the number and types of knots, requirements for various types of cracks, permissible processing defects. For example, for materials of the first grade, the roughness should not exceed 1250 microns. The size of wood is also affected by characteristics such as humidity.
In construction, timber, timber, slats, edged and unedged boards, floor boards, and lining are used.
For products from coniferous species the standard length does not exceed 7 m. On special order, a length of 9 m can be made. From hardwood The length standard is no more than 5 m.
Typically, timber and edged boards have a length of 6 or 7 m. Unedged boards and for the floor have a standard of 6 m. Lath and timber do not exceed 2 or 3 m, lining - 3 or 6 m.
The cross section for a beam in millimeters is determined by the dimensions of a rectangle with sides (100, 150, 200) × (100, 150, 200) in any combination.
For example, 100×100; 100×150; 150×200, etc.
Increasing requirements for energy saving caused the emergence of laminated veneer lumber with insulation. German profile such timber is shown.
Standard, such as a 6 m long edged board, measured in mm: (22, 25, 32, 40, 50) × (100, 150, 200). For example, 22×150; 50×150; 22x200 or any other combination.
The sizes of other types are presented in Table No. 1.
Table No. 1.
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The effect of humidity on wooden building materials
How humidity affects the size of lumber can be seen using a specific example.
A spruce board has the following trade indicators: 54×159 mm, length 6 m and standard humidity W=20%. It is easy to calculate the trading volume: V=0.054×0.159×6 = 0.0515 m 3 . There will be 19.41 pieces in 1 m3.
For spruce, the following indicators are taken into account:
- sawing error - ±2 mm in both width and thickness;
- shrinkage coefficient - 0.25%;
- coefficient of variation of the shrinkage coefficient is 30%.
By calculation, the average shrinkage value (mm) is determined: 1.4 in thickness and 4 in width. The average sawing standard is correspondingly 55.4×163, with shrinkage errors of 1 and 3, respectively.
Taking into account the permissible deviations, the actual dimensions of a raw spruce board can have a thickness from 53.4 to 57.4 and a width from 161 to 165 mm. For a material whose moisture content is 20%, the permissible thickness and width can vary from 51.8 to 56.2 and from 155.4 to 162.6 mm, respectively. If the humidity is 12%, the range of thickness and width is from 50.2 to 55.6 and from 150.1 to 161.5 mm, respectively. That is, the moisture content of wood significantly affects the size of lumber and its shrinkage during operation. Calculating the required cubic capacity is not difficult. For example, 40 boards 6 m long with a cross section of 0.04 x 0.15 m are required.
First, determine the volume of one board:
- 0.04×0.15×6 = 0.036 m3.
This means that 1 m 3 of dense wood will consist of 1/0.036≈27.7 pieces. That is, for 40 pieces you should buy 40/27.7 = 1.444 m 3 of wood of this type. When purchasing a product, you should keep in mind that the quality of an individual copy cannot be verified. Therefore, purchase building materials with a reserve. The recommended excess is 10%.
It is also useful to know that wood harvested in winter time, has less humidity, and the house is made of wooden beam or logs, it is advisable to build in the cold period, having prepared the foundation for it in the summer.
It is useful to know the standard sizes of wood both when doing various homemade projects with your own hands and during thorough construction. The dimensions of lumber are regulated by GOST and the products of each sawmill are focused on standardized dimensions.
Lumber can be edged, unedged, boards, beams and beams, etc. Dimensions
Wood quality.
Deciduous wood is divided into three grades, coniferous - into five.
Lumber the best grade are called selective ( marked horizontal stripe or the letter "O"), other varieties are designated by numbers 1-4 ( are marked accordingly. number of dots, vertical stripes or just a number) .
The quality of lumber is assessed based on the worst side or edge.
The grade is determined by the presence/absence of knots, rot, cracks, warping and deformation, wormholes, degree of accuracy machining (non-parallelism of planes and edges is regulated by GOST 24454-80).
Wood 1st grade used for the manufacture of elements of building structures, windows, doors, stairs ( For standard dimensions of staircase elements, see In this article ) , finishing floor and walls.
2nd grade goes to the floorings bearing building construction (II category) formwork, lathing and planed parts ( GOST 8442-75 and GOST 475 -78).
3rd grade used for making load-bearing structures (III category).
4th grade Suitable for the manufacture of containers and small workpieces.
The permissible humidity of the 4th grade is not standardized. The humidity of other varieties should not exceed 22%.
If this value is exceeded, the lumber is called “raw” - a significant loss of its strength occurs.
Conventions.
In the designation the material is written in plain text ( board, block, timber), then a number indicating the grade, type of wood ( hv. - coniferous or individual species - pine, spruce, larch, cedar, fir), size cross section in mm. and designations of the regulatory standard.
Example: Board - 2 - pine - 40 x 150 - GOST 8486-86
Responsible manufacturers also indicate length and cubic capacity in their price lists, i.e.:
Board - 2 - pine - 40 x 150 x 6000 - GOST 8486-86 Quantity per cube: 27 pcs
How to measure lumber correctly.
The length of lumber and blanks is fixed at the shortest distance between the ends, and the width anywhere, but at a distance of 150 mm. from the ends.
The thickness is measured similarly at an arbitrary point with an indentation of 150 mm. The width of unedged lumber is determined in the middle of the length ( excluding bark).
The volume can be determined in cubic meters based on the dimensions defined by GOST 5306 - 83.
Edged boards. Dimensions. Weight. Tables
Interstate standard. GOST for softwood lumber
The cross-sectional dimensions (a x b) and length (L) of edged boards are determined by GOST 8486-86
Length 1 - 6.5 m with gradation every 0.25 m.
Today, consumers are increasingly offered sawn timber exactly 6 m long, which has already become a standard.
Size a (width) edged boards: 75, 100, 125, 150, 175, 200, 225, 250, 275 mm.
b (thickness) 16, 19, 22, 25, 32, 40, 44, 50,60, 75 mm.
Table how many boards are in 1 cube (pieces/meters)
|
Board dimensions |
Volume of 1st board |
Boards in one cube (pieces) |
|---|---|---|
Finding out the number of meters of edged boards in 1 cube is very simple. If we multiply the number of boards in a cube (third column of the table) by the length of the board (in table 6m), we will find out how many familiar linear meters boards in 1m3.
How much does a cube of board weigh?
Weight is calculated using a simple formula: M= V*P
P - wood density depends on the type of wood, its humidity, place of growth, and the specific part of the trunk from which the board is cut.
Did you know?
Weight 1m3 edged lumber freshly sawn wood (pine) depends on many factors.
If a beam 18*18 will be lighter than a board 0.025*0.18, because the core of the trunk itself is looser and the board that is usually cut from the edges of the trunk is denser.
Sometimes the forest (pine) comes across “cut”, i.e. This is the forest from which resin was once collected (there was an organization called “Khimles”), the lumber is not rotten, not blue, and may be almost twice as light.
Timber (pine) harvested in winter after January will be approximately 10-20% lighter
Lumber always has an exact length, for example, if a timber is considered to be 6 meters long, then as a rule it has a length from 6.05 to 6.25 and maybe more, depending mainly on the sobriety of the “gooseberry”
On the number of knots on the lumber.
From many different standards for measuring the mass of 1m3 of lumber.
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Breed |
Density, kg/m 3 |
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Lightweight |
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Siberian fir |
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Poplar gray |
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Average density |
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horse chestnut |
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Common yew |
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Walnut |
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White maple (sycamore) |
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Virginia maple (bird-eyed) |
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Larch |
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Teak |
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Switenia (mahogany) |
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Sycamore (plane tree) |
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Dense rocks |
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Pecan (cariah) |
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Olive tree (olive) |
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Ceylon ebony (ebony) |
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Calculation example:
For example, we need to find out the weight of one cube of pine board:
m= 1m3*520kg/m3= 520kg at humidity 12%(physical and mechanical properties of wood are determined by this indicator )
For absolutely dry wood the density will be lower ( equilibrium wood moisture content for indoor use 6-8% ), and for natural humidity it is higher. Natural humidity is not standardized and can range from 30% to 80%. When using wood in contact with external environment(any external wooden elements houses, wooden window frames, exterior cladding, etc.) we exactly fall into 12% humidity for which the table above is given.
Construction timber. Dimensions
A beam is a board whose dimensions correspond to the inequality: a/b< 2
The length of the beam is similar to the length of the edged board. Other sizes can always be made to order for you.
Size a (width) of timber: 50, 60, 75, 100, 130, 150, 180, 200, 20, 250 mm.
b (thickness) 130, 150, 180, 200, 220, 250 mm.
When ordering lumber, the issue of transporting the required quantity is usually acute.
The table shows the volume of 10 m long softwood timber. (m 3)
| Width | Thickness mm. | |||||||||
| 50 | 60 | 75 | 100 | 130 | 150 | 180 | 200 | 220 | 250 | |
| 130 | 0,065 | 0,078 | 0,0975 | 0,13 | - | - | - | - | - | - |
| 150 | 0,075 | 0,09 | 0,0113 | 0,15 | 0,195 | 0,225 | - | - | - | - |
| 180 | 0,09 | 0,108 | 0,0135 | 0,18 | 0,234 | 0,27 | 0,324 | - | - | - |
| 200 | 0,1 | 0,12 | 0,015 | 0,2 | 0,26 | 0,3 | - | 0,4 | - | - |
| 220 | 0,11 | 0,132 | 0,0165 | 0,22 | - | - | 0,395 | - | 0,434 | - |
| 250 | 0,125 | 0,15 | 0,188 | 0,25 | - | - | - | 0,5 | - | 0,625 |
Bars. Dimensions
From softwood:
Width (a) and thickness (b): 16, 19, 22, 25, 32, 40, 44, 50, 60, 75 mm.
Hardwood:
Width (a) thickness (b): 19, 22, 25, 32, 40, 45, 50, 60, 70, 80, 90, 100 mm.
The length of the bars is similar to the length of the edged board.
Wood thermal conductivity table
How to save money when buying lumber?
- Edged board of working section.
This trick has long been known to professionals and they use it to the advantage of their wallets. Why are we worse? The so-called “edged board of working section” is produced in an assortment similar to lumber in accordance with GOST 8486-86, but has a smaller cross-sectional size (by 5 mm).
The quality of the board corresponds to the edged board of the first grade, however, the same number 1 m 3 boards will be 10-15% cheaper than edged boards according to GOST.
- As an owner, you can apply for a logging quota to the village council. After agreement with the foresters, we deliver the timber to the sawmill and receive the lumber in required quantity at ridiculous prices.
- In winter, during the off-season, it is sometimes possible to “catch” excellent discounts both for processing at the sawmill and from sellers who store unsold warm time years, lumber is not available. Use it!
Ready-made cubatures have long been used by specialists in the logging industry and trade as the main assistants for calculations. These are tables that make it easy to determine the cubic capacity of round timber, timber or any other lumber. Knowing the length (in meters) and diameter or cross-section, you can instantly find the volume.
The first official cubature was GOST 2708-75 for round timber. It provides calculations for logs with a diameter from 1 to 9.5 cm (0.5 cm increments). Length range - from 3 to 120 meters. There is a similar table according to the ISO 4480-83 standard. Its only difference is that the footage starts at 4 meters and ends at 79 m. The diameter of the untreated timber is the arithmetic mean between the largest and smallest diameter of the available logs. The user just needs to find the number in the cell where the diameter column and the meter row intersect. For example, for 16 meters of round timber Ø 6 cm, the volume is 0.15 m³, and for 120 meters Ø 9.5 cm we have 13.67 m³.
Similar cubatures are compiled for various types lumber. They are convenient if a person (or company) is constantly engaged in the manufacture of custom-made wood products. Here it is not GOSTs that are important, but practical considerations. If timber is being produced, then you need to have on hand a table with its cubic capacity, calculated for different footage.
What kind of cubatures exist?
The calculation can be carried out for any material:
- edged boards;
- unedged boards;
- timber;
- rounded logs;
- linings;
- bar;
- slats.
The cubic capacity is calculated using standard methods:
- V=a×b×c (V – volume, a, b, c – linear dimensions).
- V=S×l (S – cross-sectional area, l – product length).
The obtained data is systematized and entered into a table. Such a cubator for produced lumber can be used daily.
For everyday work, there is no need to have a long “sheet” with you, which is a cubature according to GOST. The standard lumber calculation table contains too many data options. It is used only by companies engaged in wholesale sales or logging on a significant scale. In practice, several “running” positions are used, and in the case individual order The cubic capacity is calculated in a couple of minutes.
Compiling a table yourself
You can use a ready-made table by making a selection from it required sizes, or make your own. In the second option, the sequence of actions will be as follows:
1. Finding parameters.
First important point– decide on the parameters (footage and sections). If the company produces only timber 100x100 and 150x150 4-6 meters each, then only this data needs to be entered. In addition, columns are added in which the number of products per 1 m³ is calculated, and in some cases the weight and humidity are indicated.
2. Mathematics.
Calculations are based on the formulas V=a×b×c or V=S×l. It would be more rational to use the second one. First, the areas are calculated, and only then the volumes.
3. Formatting the obtained data in the form of a table.
1. Bar.
The company produces bars 40x40, 40x80 and 50x50 with a length of 3/4/6 meters.
Sectional areas are calculated:
- S1=0.04×0.04=0.0016 (m²).
- S2=0.04×0.08=0.0032 (m²).
- S3=0.05×0.05=0.0025 (m²).
Then the volumes for each footage are calculated. For a 40x40 block it turns out (in m³):
- V=0.0016×3=0.0048.
- V=0.0016×4=0.0064.
- V=0.0016×6=0.0096.
Similarly for other sections. The number of products per cubic meter is determined by division: 1/0.0048 = 208.33 (pieces).
The final table looks like this:
| Section, (mm) | Length, (m) | V 1 bars, (m³) | Number of pieces per 1 m³ |
| 40x40 | 3 | 0,0048 | 208,33 |
| 4 | 0,0064 | 156,25 | |
| 6 | 0,0096 | 104,17 | |
| 40x80 | 3 | 0,0096 | 156,25 |
| 4 | 0,0128 | 78,125 | |
| 6 | 0,0192 | 52,08 | |
| 50x50 | 3 | 0,0075 | 133,33 |
| 4 | 0,01 | 100 | |
| 6 | 0,015 | 66,67 |
Another option for table design is possible, when only the volume is recorded:
2. Several types.
If the manufacturer’s assortment includes 2, 3 or more lumber, then in this case it is possible to create a cube. First, calculations are carried out for each type, then the data obtained is entered into a summary table.
For beams, whetstones, edged boards and slats we have the result:
| Name | Dimensions, (mm) | Volume 1 piece, (m³) | Quantity (pcs/m³) |
| timber | 100x150x6000 | 0,09 | 11,11 |
| 200x200x3000 | 0,12 | 8,33 | |
| Bar | 40x40x4000 | 0,0064 | 156,25 |
| 40x80x4000 | 0,0128 | 78,125 | |
| Edged board | 22x100x4000 | 0,0088 | 113,64 |
| 50x200x4000 | 0,04 | 25 | |
| Rail | 22x50x2000 | 0,0022 | 454,55 |
| 25x50x2000 | 0,0025 | 400 |
Having cubic meters with the range of lumber produced at hand, it is much easier for the company manager to carry out calculations on cubic capacity and cost.
