Calculating the thickness of the lag for the floor calculator. How to calculate the square meter of a board

In order to accurately calculate floorboards, a calculator created as an online service has been around for many years. With its help, you can calculate the amount of material that will be needed for the construction of logs and flooring.

The calculator is used to determine the amount of volume not only for the floorboard, but also for the material for the subfloor. As with the construction of other structures, the work of creating high-quality floors requires determining the exact amount of fasteners and insulation, end and other parts.

Features of the online calculator

Several parameters of the living space must be entered into the calculator.

The calculation of the floor using the online calculator is based on the dimensions indicated in millimeters. To perform all operations, you will need to clarify:

• floor length and width;
• length and thickness of the log;
• the width and thickness of the boards;
• house parameters (width).

For each value, there are certain designations, among which there are numbers and letters, reflecting:

• the thickness and width of the rough sub-floor boards;
• the number of jumpers between the lags and the step between them;
• the distance between the boards.

You can find out exactly how many boards you need on the floor using one of the offered floor calculator programs. You will need competent high-quality drawings, in accordance with which they construct the flooring and equip the floor.

When starting the choice of material, it is necessary to take into account the peculiarities of their parameters. The most popular are the boards, the thickness of which reaches 4 cm.

Despite the fact that many designers recommend using products, this parameter of which is much higher, often those boards that are not thicker than 2 cm are enough.

They are more flexible and durable, and thanks to high-quality and competent processing of the boards, they are distinguished by increased resistance to moisture and temperature extremes.

Correctly carried out calculations will allow you to lay a solid screed

It is these qualities that allow properly prepared materials to maintain their original shape, avoid cracking, swelling and other damage and deformation.

When you need a calculator

The program will even help you determine the optimal distance between the lags

Other data may also be required, their indication will help the calculator determine the exact area of ​​the room, choose the most suitable parameters of wood materials among the many existing proposals, the program is able to correctly establish the optimal distance between the lags and the components of the structure.

Using the program, the consumer receives specific data on the required amount of not only sawn timber, but also insulation required for arranging and creating insulation under a wooden flooring. For more information on building calculators, see this video:

Another feature of the program is the ability to indicate some options for the layout of the future floor, allowing you to save money and use a minimum amount of wood and insulation during construction work.

To work with the online calculator, there is no need to contact specialists and designers. It is enough to use the Internet services, specifying the requested data.

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Types of boards

• Calculation of the log of a wooden floor

How to calculate the number of boards per floor

Floor board how to calculate the quantity

There are no particular difficulties in calculating the required amount of floorboards, however, even in such simple calculations, there are small nuances.

Floor area calculation

1. First, it is necessary to conditionally divide the entire floor area into equal rectangles.

Having decided to buy a floorboard, you must first calculate the volume of the order.

Much depends on this, the boards must be from the same batch.

They usually proceed as follows:

• - conventionally take one room for a rectangle,
• also take the corridor for the rectangle
• etc.

If the room is not rectangular, then you can conditionally divide it into rectangles.

Then measure the area of ​​each of the rectangles, measuring before that:

Multiplying the length with the width, we get the area (S), which is known to be measured in square meters (m2).

2. Secondly, it is necessary to convert millimeters and centimeters to meters.

• Recall that 1 m = 100 cm = 1000 mm.

And now about the actual calculation of the floor area, and, accordingly, the number of boards on the floor.

Let's start by calculating the area of ​​the floor board of one of the rooms:

• It is calculated by the formula S = a h, where S is the area, a is the width, h is the length.

For example, a room of 7 meters by 5 meters is calculated as follows: S = a h = 7 5 = 35 m2

If you have several rectangles, then you need to act in the same way as described above when finding the areas of the rectangles, then add the resulting area values ​​and find the final area.

S = a1 h1 + a2 h2 + a3 h3 ,:

• where S is the total area,
• a1, a2, a3 - the widths of the 1st, 2nd, 3rd rectangles,
• h1, h2, h3 - the lengths of the 1st, 2nd, 3rd rectangles.

• So, for example, the total area of ​​three rooms (1st - 3m by 4m; 2nd - 5m by 4m; 3rd - 7m by 6m)
• S = a1 h1 + a2 h2 + a3 h3 = 3 4 + 5 4 + 7 6 = 12 + 20 + 42 = 74 m2

Calculation of the number of running meters of the floor board

With regard to the calculation of running meters or a certain number of boards.

We calculate the total area of ​​the order, as described above.

Linear meters have:

• width (W)
• and length (D).
• S = a h = running meters board width.

Order value = S cost per m2 of floor board.

For example, we need 40 running meters of a floorboard that is 100 mm wide and 35 mm thick.

• We translate millimeters into meters 100 mm = 0.1 m, we get that S of the order is equal to the product of linear meters and the width of the board, that is, S = 40 0.1 = 4 m2
• Price of 1 m2 = 85 UAH / m2, Order cost = S order Cost = 4 85 = UAH 340.

If the number of boards with a known length and width of the board is known, then the calculations are similar and are performed according to the formula:

• S order = number of boards board length board width.

If you know the total area of ​​the order and at the same time you need to calculate the number of boards, then you can use the formulas:

• Linear meters = S order / board width,
• Number of boards = running meters / board length.

• Order volume = S order board thickness (in meters).

Edged boards are in greatest demand in the sawn timber market. Their distinctive feature is four-sided processing and removal of edges with tree bark. The high demand for this type of building materials is explained by their practicality, durability, environmental friendliness and ease of use.

The main areas of application of edged boards are construction and furniture production. In construction, this material can be used for laying floors, ceilings, walls and stairs. In furniture production, boards are used to create solid wood furniture.

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• Calculate the surface area to be covered (eg 10 * 10 = 100 m²);
• Calculate the area of ​​one board (for example, with the parameters of the board 20cm * 5cm * 2000 cm, the area of ​​one will be equal to 0.2m * 2m = 0.4m²);
• Divide the surface area by the area of ​​one board (100 m² / 0.4 m² = 250 pieces).

To calculate the number of boards when buying in cubes, you must:

• Calculate the required number of boards (divide the surface area by the area of ​​one board);
• Calculate the required cubic capacity by multiplying the parameters of the board by the required amount (for example, you need 20 pieces of boards with the parameter 20cm * 5cm * 2000cm, which means the required volume is 20 * 0.2 * 0.05 * 2 = 0.4 m³). In this case, all values ​​must be converted from centimeters to meters.

Types of boards

There are several types of boards that differ in purpose and technical characteristics. Depending on the degree of humidity, there are:

• Raw - boards of natural moisture. It can be used in the construction of low-critical structures.
• Dry - industrially dried. Drying is carried out to avoid deformation of the board and to prevent rotting.

Depending on the quality of the boards, the material is distinguished:

• Selected grade - used in the automotive and shipbuilding industries;
• The first grade - in addition to shipbuilding and the automotive industry, is used in construction and furniture production;
• Second grade - used in the same areas as the material of the first grade;
• The third grade is the production of furniture and packaging products;
• The fourth grade is used for the production of containers and packaging.

  Calculation of boards on the floor: calculator, how to calculate

By the type of cut, the boards are divided into:

• Radial - the saw cut passes in the middle of the trunk, at an angle of 90⁰, due to which the material has high strength and moisture resistance;
• Semi-radial - the cut passes at an angle of 45⁰, the material is of the middle price category;
• Tangential - the most economical type of sawing, boards of this type are more susceptible to moisture. Drying deformation is possible.

Calculator of the number of boards in 1 cube.
Table of sections of sawn timber.

Calculator for calculating the number of boards (timber) in one cubic meter in cross-section and length

ANSWER: in one cube 0 pcs.

The calculator knows the number of boards (timber) - how many cubes are these?

ANSWER: such boards (timber) are 0 m3 worth 0 rubles

Table of standard sizes of sections of boards and beams.

The sections of the boards and beams have standard dimensions that correspond to GOST 24454-80 "Sawn softwood. Sizes"

Thickness, mm	Width, mm
16	75	100	125	150	—	—	—	—	—
19	75	100	125	150	175	—	—	—	—
22	75	100	125	150	175	200	225	—	—
25	75	100	125	150	175	200	225	250	275
32	75	100	125	150	175	200	225	250	275
40	75	100	125	150	175	200	225	250	275
44	75	100	125	150	175	200	225	250	275
50	75	100	125	150	175	200	225	250	275
60	75	100	125	150	175	200	225	250	275
75	75	100	125	150	175	200	225	250	275
100	—	100	125	150	175	200	225	250	275
125	—	—	125	150	175	200	225	250	—
150	—	—	—	150	175	200	225	250	—
175	—	—	—	—	175	200	225	250	—
200	—	—	—	—	—	200	225	250	—
250	—	—	—	—	—	—	—	250	—

Table of how many 6 meter boards are in one cube

For boards with a standard length of 6 meters, the following table is calculated.

We calculate the number of boards - degree of humidity, calculation by the piece

Small section sawn timber available in retail sale is of course less than 6 meters. This is usually 3 m or 2.5 m. To calculate the number of any custom sizes, use the calculator at the top of the page.

P / p No.	Section size, mm	Length, mm	Quantity in 1 cube, pcs	The area that can be sewn up using 1 cube, m2
1	16x75	6000	138,89	62,50
2	16x100	6000	104,17	62,50
3	16x125	6000	83,33	62,50
4	16x150	6000	69,44	62,50
5	19x75	6000	116,96	52,63
6	19x100	6000	87,72	52,63
7	19x125	6000	70,18	52,63
8	19x150	6000	58,48	52,63
9	19x175	6000	50,13	52,63
10	22x75	6000	101,01	45,45
11	22x100	6000	75,76	45,45
12	22x125	6000	60,61	45,45
13	22x150	6000	50,51	45,45
14	22x175	6000	43,29	45,45
15	22x200	6000	37,88	45,45
16	22x225	6000	33,67	45,45
17	25x75	6000	88,89	40,00
18	25x100	6000	66,67	40,00
19	25x125	6000	53,33	40,00
20	25x150	6000	44,44	40,00
21	25x175	6000	38,10	40,00
22	25x200	6000	33,33	40,00
23	25x225	6000	29,63	40,00
24	25x250	6000	26,67	40,00
25	25x275	6000	24,24	40,00
26	32x75	6000	69,44	31,25
27	32x100	6000	52,08	31,25
28	32x125	6000	41,67	31,25
29	32x150	6000	34,72	31,25
30	32x175	6000	29,76	31,25
31	32x200	6000	26,04	31,25
32	32x225	6000	23,15	31,25
33	32x250	6000	20,83	31,25
34	32x275	6000	18,94	31,25
35	40x75	6000	55,56	25,00
36	40x100	6000	41,67	25,00
37	40x125	6000	33,33	25,00
38	40x150	6000	27,78	25,00
39	40x175	6000	23,81	25,00
40	40x200	6000	20,83	25,00
41	40x225	6000	18,52	25,00
42	40x250	6000	16,67	25,00
43	40x275	6000	15,15	25,00
44	44x75	6000	50,51	22,73
45	44x100	6000	37,88	22,73
46	44x125	6000	30,30	22,73
47	44x150	6000	25,25	22,73
48	44x175	6000	21,65	22,73
49	44x200	6000	18,94	22,73
50	44x225	6000	16,84	22,73
51	44x250	6000	15,15	22,73
52	44x275	6000	13,77	22,73
53	50x75	6000	44,44	20,00
54	50x100	6000	33,33	20,00
55	50x125	6000	26,67	20,00
56	50x150	6000	22,22	20,00
57	50x175	6000	19,05	20,00
58	50x200	6000	16,67	20,00
59	50x225	6000	14,81	20,00
60	50x250	6000	13,33	20,00
61	50x275	6000	12,12	20,00
62	60x75	6000	37,04	16,67
63	60x100	6000	27,78	16,67
64	60x125	6000	22,22	16,67
65	60x150	6000	18,52	16,67
66	60x175	6000	15,87	16,67
67	60x200	6000	13,89	16,67
68	60x225	6000	12,35	16,67
69	60x250	6000	11,11	16,67
70	60x275	6000	10,10	16,67
71	75x75	6000	29,63	13,33
72	75x100	6000	22,22	13,33
73	75x125	6000	17,78	13,33
74	75x150	6000	14,81	13,33
75	75x175	6000	12,70	13,33
76	75x200	6000	11,11	13,33
77	75x225	6000	9,88	13,33
78	75x250	6000	8,89	13,33
79	75x275	6000	8,08	13,33
80	100x100	6000	16,67	10,00
81	100x125	6000	13,33	10,00
82	100x150	6000	11,11	10,00
83	100x175	6000	9,52	10,00
84	100x200	6000	8,33	10,00
85	100x225	6000	7,41	10,00
86	100x250	6000	6,67	10,00
87	100x275	6000	6,06	10,00
88	125x125	6000	10,67	8,00
89	125x150	6000	8,89	8,00
90	125x175	6000	7,62	8,00
91	125x200	6000	6,67	8,00
92	125x225	6000	5,93	8,00
93	125x250	6000	5,33	8,00
94	150x150	6000	7,41	6,67
95	150x175	6000	6,35	6,67
96	150x200	6000	5,56	6,67
97	150x225	6000	4,94	6,67
98	150x250	6000	4,44	6,67
99	175x175	6000	5,44	5,71
100	175x200	6000	4,76	5,71
101	175x225	6000	4,23	5,71
102	175x250	6000	3,81	5,71
103	200x200	6000	4,17	5,00
104	200x225	6000	3,70	5,00
105	200x250	6000	3,33	5,00
106	250x250	6000	2,67	4,00

Calculation of boards for the floor is an important point at the stage of repair or construction of a house.

Scheme for calculating boards on the floor.

The board is the optimal material for the subfloor.

But before buying it, it is important to make a careful calculation, otherwise it may happen that too many units are purchased and a large amount of money is wasted. Those who think that when there is a shortage of coverage there is always an opportunity to buy the missing part of the material, you need to know that for a successful installation process they must be from the same batch. The most popular options for flooring are the following types of wood: timber, unedged, edged and planed boards. In each case, the required amount of lumber is calculated differently. This is due to the fact that each material has individual characteristics that must be taken into account during the calculation.

So, how can you make the correct calculation of the amount of lumber?

Find out the size of square meters

Scheme for calculating the required number of boards on the floor.

1. For this, the room is conventionally divided into a rectangle, if it does not have a strict rectangular shape, then it is divided into several rectangular parts, which are then measured. Measurements are designed to find out the area of ​​the room. The following formula will help you find it out: S = a × b, where S is the area, a is the width of the room, b is its length. The result will show you the required amount of square meters of coverage to be laid on the floor.
2. If the room is not rectangular, the area is calculated for each rectangle separately, after which the resulting figures are to be added.

   Lag and floorboard calculator

   For example: S = (a1 × b1) + (a2 × b2) + (a3 × b3), where S is the final area, a1, a2, a3 is the width of 1, 2, 3 rectangles, b1, b2, b3 is the length of 1 , 2, 3 rectangles. You can use these calculations not only when the room is not rectangular, but also if you need to calculate the total amount of material in several rooms at once.

We calculate running meters

In order to find out how many boards are enough for lining the floor, a ready-made rule will help you:

S = a × b = the width of the timber × linear meters.

It is quite easy to find out the number of boards it will take to cover the floor. To do this, you need to use the following calculation: S = a × b × the number of lumber.

Or with ready-made calculations:

Quantity = Sum of running meters / b

So, in order to successfully calculate how much lumber will take to cover, you will need the following:

• availability of ready-made formulas;
• calculator;
• information about segments a and b in the room;
• information about the thickness of the timber, its length and width;
• roulette;
• pencil and notepad.

Thus, anyone can do the calculations. With the necessary formulas at hand and with minimal knowledge of mathematics, you can easily learn the squaring of the required lumber for flooring.

How to calculate the amount and volume of lumber for the construction of your house, bathhouse, veranda

The first step is to decide on the amount of work and on the materials from which you will build a house, a bathhouse or attach a veranda. Softwood lumber is best suited for any construction. Coniferous wood is light in weight, has natural antiseptic properties, and is most resistant to our climate.

If you have capital construction, then you will definitely need a bar. But what size depends on your plans. For one-story light buildings, you can buy a beam with a thickness of 100-150 mm. For higher and capital buildings, a thickness of 200 and higher is required. It is worth deciding on the construction budget. The most demanded timber is planed. Its plus is the lowest cost. He has a clear geometry, it is easy to work with him. Houses made of planed timber have good thermal insulation and accumulate less moisture. However, buildings made of such a bar give a slight shrinkage when they dry. Therefore, do not rush to make a decision, think carefully about what you want to get as a result.

If you need to make wall cladding, lay floors or attach a summer veranda, then you will need a board, edged or unedged

How to calculate the cubic capacity of lumber

Before starting any construction, it is important to correctly calculate the lumber. How many beams you need to buy to erect walls or make support structures, how many boards you need to cover the required number of square meters, it is easy to calculate.

Calculation of the floor, lag and floorboard

We multiply the length and width of the board and get the area of ​​one board. It is more difficult to calculate how many cubic meters of lumber you need to buy in production. This information will be useful both for newcomers to construction and for customers who want to monitor construction crews and keep abreast of construction materials costs. Indeed, often builders are cunning and hammer into the estimate much more lumber than is needed for the construction of one project. Where the surplus goes is easy to guess. Knowledge of basic calculations will allow you to avoid deception and achieve quality work.

Lumber for the construction of load-bearing structures - beams, large-section boards - are calculated and sold not by the piece, but in cubic meters. The price in the price lists is indicated exactly for a cubic meter of sawn timber. Correct calculation will help to avoid unnecessary construction costs and will not allow a shortage of material when you need to pay for another delivery and interrupt work. Experienced craftsmen usually take lumber with a small margin.

The calculation of the cubic capacity depends on the type of lumber.

Beams and edged boards have clear geometric contours and constant values ​​of length, thickness and width. It is easy to calculate the cubic capacity here: you need to multiply the three known dimensions of the board, you get the cubic capacity of one board. To find out the number of pieces in a cube, you need to divide 1 cubic meter by the cubic capacity of the board.

It is important to know that cubic capacity is determined by GOSTs; you can use lumber tables with ready-made calculations.

GOST planed timber cubes table

Companies that have been working on the market for a long time and value their reputation clearly comply with all the requirements of GOSTs, and when buying sawn timber, the quantity will be clear and predictable.

Unedged board is not processed on the sides, different parts of the logs go to it, therefore its width is not constant. Therefore, it is possible to calculate the volume of the required lumber, having counted the cubic capacity of one board, only approximately.

For surface cladding, piece lumber is used - a small section edged board, planed board, lining, imitation of a bar.

Experienced craftsmen quickly make all the necessary calculations. For those who do not have much experience, it is better to turn to specialists in order to avoid mistakes and correctly determine the type of lumber and its required volume. The best and most reliable information about lumber is held by manufacturers, not by the employees of the resale companies. Therefore, it is better to contact the manufacturers for advice, advice and purchase.

Employees of our company "Industrial Complex Technologies" will help make all the necessary calculations and determine the amount of lumber. We are not trying to sell you as much timber or boards as possible. Our task is to make your construction or renovation the least expensive and provide you with high-quality sawn softwood in the amount you need. We will deliver the goods to any point in Vladimir, Moscow, Ryazan, Nizhny Novgorod, Ivanovo, Yaroslavl regions. The closest cities to us are Kolchugino, Aleksandrov, Kirzhach, Vladimir, Yuryev-Polsky.

Beams in a house usually refer to a rafter system or floor, and in order to obtain a reliable structure, the operation of which can be carried out without any fears, it is necessary to use beam calculator.

What is the beam calculator built on

When the walls have already been brought under the second floor or under the roof, it is necessary to make, in the second case, smoothly turning into the rafter legs. In this case, the materials must be selected so that the load on the brick or log walls does not exceed the permissible, and the strength of the structure is at the proper level. Therefore, if you are going to use wood, you need to choose the right beams from it, make calculations to find out the required thickness and sufficient length.

Subsidence or partial destruction of the overlap can be caused by various reasons, for example, too large a step between the lags, deflection of cross-members, too small their cross-sectional area or defects in the structure. To exclude possible excesses, you should find out the estimated load on the floor, whether it is basement or interfloor, and then use the calculator of beams, taking into account their own mass. The latter can change in concrete lintels, the weight of which depends on the density of the reinforcement; for wood and metal with a certain geometry, the mass is constant. An exception is damp wood, which is not used in construction work without preliminary drying.

The forces acting on the bending of the section, on the torsion, and on the deflection along the length exert a load on the beam systems in the ceilings and rafter structures. For the rafters, it is also necessary to provide for snow and wind loads, which also create certain forces applied to the beams. You also need to accurately determine the required step between the lintels, since too many crossbars will lead to excess weight of the floor (or roof), and too small, as mentioned above, will weaken the structure.

You may also be interested in an article on calculating the number of unedged and edged boards in a cube:

How to calculate the load on a floor beam

The distance between the walls is called a span, and there are two of them in the room, and one span will necessarily be less than the other, if the shape of the room is not square. The lintels of the interfloor or attic overlap should be laid along a shorter span, the optimal length of which is from 3 to 4 meters. Larger spacings may require irregular sized beams, which will result in some flutter in the deck. The best way out in this case is to use metal crossbars.

As for the section of a wooden beam, there is a certain standard that requires that the sides of the beam are in a ratio of 7: 5, that is, the height is divided into 7 parts, and 5 of them must make up the width of the profile. In this case, the deformation of the section is excluded, but if you deviate from the above indicators, then with a width exceeding the height, a deflection will result, or, in the opposite case, a bend to the side. To prevent this from happening due to the excessive length of the beam, you need to know how to calculate the load on the beam. In particular, the allowable deflection is calculated from the ratio to the length of the lintel, as 1: 200, that is, it should be 2 centimeters by 4 meters.

To prevent the timber from sagging under the weight of the logs and flooring, as well as interior items, you can grind it from below by a few centimeters, giving it the shape of an arch, in which case its height should have an appropriate margin.

Now let's turn to the formulas. The same deflection, which was mentioned earlier, is calculated as follows: f nor = L / 200, where L Is the span length, and 200 is the permissible distance in centimeters for each unit of timber subsidence. For a reinforced concrete beam, distributed load q which is usually equal to 400 kg / m 2, the calculation of the ultimate bending moment is performed according to the formula M max = (q · L 2) / 8. In this case, the number of reinforcement and its weight is determined according to the following table:

Cross-sectional areas and masses of reinforcing bars

Diameter, mm	Cross-sectional area, cm 2, with the number of rods									Weight of 1 running meter, kg	Diameter, mm
Wire and rod fittings
Seven-wire ropes of K-7 class

The load on any beam made of a sufficiently homogeneous material is calculated using a number of formulas. To begin with, the moment of resistance W ≥ M / R is calculated. Here M Is the maximum bending moment of the applied load, and R- design resistance, which is taken from reference books, depending on the material used. Since most often the beams are rectangular, the moment of resistance can be calculated differently: W z = b h 2/6, where b is the width of the beam, and h- height.

What else you should know about beam loads

The overlap, as a rule, is at the same time the floor of the next floor and the ceiling of the previous one. This means that you need to make it such that there is no risk of combining the upper and lower rooms by banal overloading with furniture. Especially this probability arises when the step between the beams is too large and the logs are abandoned (plank floors are laid directly on the timber laid in the spans). In this case, the distance between the crossbars directly depends on the thickness of the boards, for example, if it is 28 millimeters, then the length of the board should not be more than 50 centimeters. In the presence of lags, the minimum gap between the beams can be up to 1 meter.

Also, be sure to consider the mass used for the floor. For example, if mineral wool mats are laid, then a square meter of the basement floor will weigh from 90 to 120 kilograms, depending on the thickness of the thermal insulation. Sawdust concrete will double the mass of the same area. The use of expanded clay will make the overlap even harder, since the load per square meter will be 3 times more than when laying mineral wool. Further, one should not forget about the payload, which for interfloor floors is at least 150 kilograms per square meter. In the attic, it is enough to take a permissible load of 75 kilograms per square.

A wooden house and a bathhouse are the dream of many townspeople. Each of those who had to build a log house with their own hands, knows perfectly well the purpose of logs and beams. These are the supporting structures of the building, therefore, the material for them, as well as their number, must be selected very carefully. Floor logs are recommended to be made of dry first-class material, treated with antiseptic and fire retardants. The most common way to install them is on beams cut into the walls during construction.

Calculations of the lag for the floor are done, taking into account the basic parameters, the lags should be 1.5-2 times higher than the height of the flooring, otherwise the nails will not be able to firmly hold the floor boards.

They are installed taking into account the fact that insulation material is usually placed between them. It can be expanded clay, polystyrene, but most often mineral wool is used, pressed into slabs 50-60 cm wide. Logs are mounted at the same distance from each other. A wooden floor is laid on them, which, if properly installed, will last for several decades. Logs are made of bars, beams, boards. They serve to redistribute loads from the floor, and are also a fixture that unites all units and parts into an integral system.

Benefits of using lag

The floor on the logs has a certain degree of functionality. In the space between them, you can lay pipes, wires, thermal insulation materials.

The bars are relatively inexpensive. Installing them is available to everyone.

These floor supports are capable of withstanding a load of 5 tons per square meter.

Figure 1. Scheme of fastening wooden beams.

When repairing a floor, it is often enough to repair a log. There is no need to re-layer the floor.

The design is lightweight. The load on the floor is much less than with a cement screed.

The space filled with mineral wool will keep the house warm and protect it from unnecessary noise.

The bars allow you to bring the floor plane to any height.

The structures put in place do not require additional work. You can install the flooring immediately.

Disadvantages of the floor on the logs:

1. The room loses several centimeters of height.
2. High labor intensity. It is required to carefully mark and align all structural elements.

Calculation of some lag parameters

The calculation of the lag for the floor is made taking into account the basic parameters. The lags for the floor should be 1.5-2 times higher than the height of the flooring, otherwise the nail will not be able to firmly hold the floor boards. If the thickness of the floorboard is 50 mm, then the height of the planks should be about 100 mm. If the subfloor is made of plywood or other sheet material with a thickness of 20 mm, the beams can be significantly lower, 30-40 mm.

The material for the manufacture of wooden logs should be chosen from conifers. The moisture content of the workpieces should not exceed 20%. The cross-section of the bars is selected rectangular. They can be cut from a board 50-60 mm thick. Finished products are laid across the light coming from the windows. The laying step is from 40 to 70 cm. Knowing the laying step and the size of the room, it is easy to calculate the required number of elements. Before installation, all wooden elements are treated twice with an antiseptic compound. The antiseptic can be replaced with regular hot bitumen.

Figure 2. Adjusting sleeves. They are used to level floors on joists.

In practice, very often the height of the lag is chosen taking into account the thickness of the insulation layer. As insulation for the floor, mineral wool is usually used, produced by slabs, the thickness of which is 50 mm. The joists for the floor should be of the same height. If it is decided to lay the thermal insulation in a double layer, then the bars are needed with a height of 100 mm. The distance between them depends on the thickness of the subfloor material. The thinner the rough flooring, the more often logs are installed. With a thickness of plywood that can be used as a backing for finishing flooring, 12 mm, the gap between the bars is 30 cm.

Most often, the subfloor is made of a grooved board. Boards should be spruce, pine or fir. They are not suitable for a finished floor, since the wood is very soft, even traces of thin heels remain on it. It is imperative to lay a laminate or other topcoat on top. The thickness of the boards with a normal pitch of 50 cm is recommended at least 35 mm. In most cases, the calculation of the pitch of the bars is carried out taking into account the thickness of the floor material:

Figure 3. Fasteners. It is used for fastening wooden structures.

Board thickness (mm) - lag step (mm):

• 20 – 300;
• 24 – 400;
• 30 – 500;
• 35 – 600;
• 40 – 700;
• 45 – 800;
• 50 – 1000.

For the manufacture of these parts, not only wood is used, but also reinforced concrete, various polymers and metals. Reinforced concrete products are highly durable. They can be used when building a house outside the city. The rest of the materials can be used when repairing floors.

If the base of the floor is wooden beams, the joists can be installed by attaching them to the side using self-tapping screws (Fig. 1). The size of the fasteners should be 2.5 times the thickness of the bar with a diameter of 6 mm. The positive aspect of this method is that when adjusting the height of individual logs, no additional adjusting pads are required.

In construction, special wooden or plastic products are sometimes used that have holes into which small plastic adjusting bushings are inserted. They contribute to the rapid leveling of the surface formed by the lags. Such products are installed very quickly and do not require the use of pads (Fig. 2).

Figure 4. Floor mounting scheme on joists.

Before installation, wooden elements must be protected from various microorganisms and wood-boring pests by treating the material with a disinfectant, then a water-repellent compound.

In rooms with low ceilings, it is better to use other methods of floor installation. When performing the calculation, one must not forget that the bars reduce the size of the room in height by 10 cm or more.

Floorboards or subfloor sheets should be attached to each joist.

The ends of structural elements should not touch the walls of the building. There must be a gap of at least 5 cm between them.

Instead of a certain section of a wooden beam, you can use boards connected in pairs to each other and reaching the size of the desired beam in diameter. Somewhat larger sizes are not prohibited. The boards are installed on the edge.

The logs can be attached to the concrete base with special galvanized metal corners, which are fixed on the base using dowels and self-tapping screws. Instead of corners, U-shaped devices are often used (Fig. 3).

If necessary, the bars from which the logs are made are joined to each other to achieve the desired length. There must be a solid support under the joint. This support is often a brick pillar. Under its construction, you need to dig a hole about 10 cm deep. It is covered with sand and watered abundantly with water. Cover the sand pillow with a layer of polyethylene. A cement-sand mortar is placed on it and a column of red brick is laid out.

You can lay out the columns in rows and fix the logs on them (Fig. 4). The size of the columns is 25x25 cm. The calculation of the number of bricks is not difficult.

The construction of the floor on the joists allows you to immediately mount the rough and final flooring.

Lags can be made from various materials. Most often, a wooden block or board is used for their manufacture. And there are a lot of materials for finishing. Their choice depends only on the preferences of the owners and the contents of their wallet. A plan of rooms with precisely specified dimensions, made on paper, will help to calculate the materials for making logs for the floor. All calculations are best done before starting the basic installation work.

In order for the floor covering to serve for a long time and to be durable, the floorboards do not creak or bend underfoot, you must first correctly calculate all the design parameters, including at what distance to lay the floor logs. The correctness of this calculation will determine not only the durability of the floor covering, but also the amount of material used for it, and hence the cost of the work.

• What determines the choice of lag?
• What should be considered when calculating?
• An example of calculating the distance between floor joists
• Step lag depending on the floor covering
• What can an error in calculations lead to?

What determines the choice of lag?

The size of the selected logs will also depend on the place of laying. So, in apartment buildings with ready-made wooden or concrete floors, a thin beam can easily serve as a lag, on which the floorboards will rest. At the same time, in a frame building, logs are usually at the same time elements of the frame of the house, take a significant load, that is, they have load-bearing functions, so they must have a much larger section.

What should be considered when calculating?

When performing the calculation, the following factors are taken into account:

• the thickness of the flooring material (chipboard, boards, etc.);
• approximate step between floor lags;
• estimated specific maximum floor load.

All these parameters will determine the cross-section of boards, beams and other lumber used for arranging the floor.

When calculating what distance should be between the floor logs, it should be remembered that the extreme logs cannot be located further than 30 millimeters from the walls, it is imperative to make a correction for this in the calculations.

As a result of calculations, usually not an integer number is obtained, but it should always be rounded up so that the real number of lags does not turn out to be less than the calculated one. Otherwise, the strength of the floor structure may not be sufficient, especially when you consider that the savings will be quite small compared to the likely risk.

The cheapest floor logs can be found on sawmills, followed by construction online stores.

When it comes to installing the floor, it is not advisable to save too much. The lags must have not only a suitable cross-section, but also sufficient density. If you make the lag step for the floor of the boards too large, then the boards will begin to bend, "play". Similarly, if the distance between the lags for the OSB floor is made more than permissible, then the plates will begin to crumble and crack.

An example of calculating the distance between floor joists

The distance between the joists of the floor under the board can be relatively large, since thick board is a stronger material than, for example, thin plywood. Accordingly, for thinner finishing materials, more frequent lagging will be required.

For clarity, consider an example of a floor arrangement with the following data:

• the room is 12 meters long;
• use of a beam of 100x180 mm for logs;
• using 30mm boards as a topcoat.

Table of the distance between the floor joists under the board:

According to the table above, for a 30 mm board, the optimal distance between the floor joists should be 50 cm.

Let's designate the total number of beams by the letter "k".
Then the total width of all lags will be ( 100 mm * k).
The distance between the wall and the extreme beams will be 30 mm.
Accordingly, the step between adjacent lags will be ( k - 1).
The distance between all elements will be ( 0.5 * (k - 1)).

The calculation of the distance between the floor joists begins with determining the step between the beams according to the following equation:

the length of the room = the total width of the beams + the sum of the distances between the beams + the indents from the walls

12 m = 100 mm * k + 0.5 * (k - 1) m + 30 mm * 2

It is important to bring the equation to a unified system of calculation. As a result, we get:

12 m = 0.1 m * k + 0.5 * (k - 1) + 0.03 * 2

Remembering the school course in algebra, we solve the equation:

12 = 0.1 * k + 0.5 * k - 0.5 + 0.06;
12 + 0.5 - 0.06 = 0.1 * k + 0.5 * k;
12.44 = 0.6 * k;
k = 20.7 pcs.

Since the number of beams can only be an integer, it is rounded up, that is, 21 bars.

The sum of all the intervals between the lags will be:

12 - 21 * 0.1 - 0.06 = 9.84 m

It is necessary to divide the resulting amount by the number of intervals, and we get the distance between adjacent lags:

9.84 / (21 - 1) = 0.492 m

Thus, we were able to establish through what distance to lay the logs for the floor in this example - 0.492 m or 49.2 cm.

Step lag depending on the floor covering

There is a linear relationship between the thickness of the covering to be laid and the step of the log: the thicker the flooring, the larger the step can be.

Here is the distance between the floor logs should be done if the flooring is carried out with boards of different thicknesses:

• with a flooring board thickness of 20 mm, the lag step should not exceed 30 centimeters;
• for boards with a thickness of 25 mm, a step of 40 cm is required;
• for "thirty" - 50 cm;
• for 35 mm - 60 cm;
• for "forty" - 70 cm;
• for 45 mm - 80 cm;
• for "fifty" - 1 m.

The distance between the floor joists for plywood or OSB is determined somewhat differently. On the one hand, these materials are thinner, but on the other, they have greater bending resistance.

• If the flooring has a thickness of 15-18 mm, then the lag step for a plywood floor will be 40 cm.
• With a thicker flooring (22-24 mm), the step can reach 60 cm.

What can an error in calculations lead to?

What can the wrong choice of the section of the lag and the calculation of the distance between them threaten? If the floors are laid on a concrete base, then the most important thing will be the size of the step between the lags, which directly affects the behavior of the floor covering. If a chipboard plate is attached to too rarely mounted logs, then it can sag and even break. If ceramic tiles are placed on top, they will crack or fall out. Boards will simply "walk" and bend. Any of these options will require rework.

It will be much more serious to make a mistake, through what distance the logs are placed for the floor, which at the same time serve as elements of interfloor ceilings. If, in this case, an insufficient number of such load-bearing elements is installed, then the strength of the building structure itself will decrease, which is fraught with the most serious consequences - from irreversible deformations to the complete destruction of floors.

Do you have experience with lag installation? Do you do calculations or do you only use tables? Write about it in the comments.