The distance between the floor lags during laying and other design parameters

Due to environmental friendliness, aesthetics, naturalness, provided warmth and comfort in the house, wood floors do not lose popularity so far. When choosing them, many questions arise - what should be the distance between the floor joists in a wooden house, what material to choose, how to mount it correctly, etc. This article will answer all your questions.

Choosing a beam for a log

1. Choose material from coniferous wood, the price of which is low - spruce, pine or fir. If the room is damp, purchase larch slats. It is more expensive, but it almost does not rot from moisture.
2. In order to save money, you can purchase 2/3 grade lumber with a moisture content of 18/20%.
3. The bars must have a rectangular cross section. At the same time, their height should be 1.5/2 times greater than their width. Having such a cross section, the logs will be operated optimally, withstanding high loads.
4. The dimensions of the beam must be selected based on the span, that is, the distance between the beams of the lower trim. The thickness of the insulation used is also important.

Below are the sections of the log (with a step between them of 0.7 m) for different spans.

1. When the span width has an intermediate value, you need to choose the short-range option, taking into account the margin of safety.
2. When purchasing a timber, inspect it for defects. Before you calculate the logs for the floor, take into account their margin of 10/15%.

Note! To protect wood from harmful insects, mold and fungi, it must be impregnated with an antiseptic. On the underside, the bars must be treated twice, allowing the first layer to dry for 4/5 hours.

How to determine the step between the lags

This value depends directly on the thickness of the floor covering.

Table that can be used

When thick boards with good strength are used for flooring, logs can be placed relatively rarely. If the finish is thin, the timber should be placed frequently. Below is a table of distances between floor joists, based on the thickness of the boards.

To more accurately determine the step between the lags, you will need to carry out the calculations.

Calculation example

1. Let the length of the room be 11 m.
2. The width of the beam will be 0.15 m.
3. We choose floorboards with a thickness of 25 mm (0.025 m) for flooring. Therefore, the gaps between the lags should be from 40 to 50 cm. Let's average these figures up to 45 centimeters, that is, 0.45 meters.
4. Let's denote the number of lags as x.
5. The width of all our lags will be 0.15∙x .
6. The first bars will be installed at a distance of 30 mm (0.03 m) from the walls. Based on this, the step between the lags will be: x-1. The distance between all lags will be equal to 0.45∙(x-1).

To find out the distance between the lags for the floor, we create the equation:

room length \u003d beam width + gap between all lags + indent from the walls.

1. We substitute the values: 11=0.15∙x+0.45∙(x-1)+0.06.
2. We solve the equation:

11=0.15∙x+0.45∙x-0.45+0.06;

11=0.6∙x-0.39;

1. The number of lags must be an integer, based on this, we round the value up to 19.
2. The sum of all the gaps between the lags will be equal to 11-0.06-19∙0.15=8.09 meters.
3. We divide this figure by the number of distances - 8.0919-1=0.4494.
4. The resulting result: the exact distance between the sexual lags should be 44.94 centimeters.

Frame installation

The floors along the logs can be equipped both on the floors of the house and on the ground base.

Installing a lag on a wooden floor

1. Logs need to be fixed to the strapping beams. It should be taken into account that they are unlikely to have an absolutely even level. Therefore, the beam is best attached to the sidewalls of the beams.
2. In this case, determine the horizontal position of the lag with a control rail; linings can be omitted.
3. Fix the lags with screws with a diameter of 6 mm. They should be 2/2.5 times longer than the beam width.
4. So that the lumber does not crack, drill holes in the logs and beams. When doing this, use a drill that will have a diameter 2.5 mm smaller than the size of the screw.
5. When the beams are placed far apart, you need to mount double logs. First, lay the first row of logs on the beams, on top of them, with a smaller step - one more.

Laying timber on the ground

1. First level with your hands and tamp the soil. This work can be done with a large log. Nail a board to it from below and, moving the rammer along the ground with a partner, compact it. The board should be at least 5 cm thick and slightly larger than the log section.
2. Next, markup for the support pillars for the log. When the supports for the frame are the beams of the lower trim, marks can be left directly on the bars. If the support is a grillage covered with roofing material, put marks on the waterproofing material.
3. The indent from the initial logs to the walls should be 3/20 cm.

Before installing the support posts, you need to make a foundation for them. It can be poured separately under each support or laid under a series of columns.

The dimensions of the foundation for the column, at least - 0.4 × 0.4 m, height - 0.2 m, 5 cm of them should protrude from the soil.

The instructions for arranging the foundation are as follows.

1. From the axis marked on the strapping beams, set aside 0.2 m in both directions.
2. Pull the string between the marks.
3. Do a similar operation in a plane perpendicular to the lags to mark the corners of the columns located at the intersection points of the cords.
4. Drive stakes into the corners. Next, remove the cords.
5. When the foundation is laid under a row of supports, only the edges of the row are marked with cords.
6. In the marked areas, remove the top layer of soil. Tamp them, pour rubble and compact it.
7. Assemble the foundation formwork with a height of 0.1 m.
8. For waterproofing concrete, lay a film of polyethylene in the pits. If the soil is clay, then you can not do this.
9. Reinforce the foundation with a frame welded from reinforcement with a diameter of 0.8 cm. You need to lay it slightly below the center of the layer of future concrete.
10. Next pour in the solution. Its composition should be the same as for the foundation of the house.
11. Wait for the concrete to set for 2/3 days.
12. After that, lay the waterproofing. For this purpose, cut pieces of roofing material according to the size of the supports, in other words, 40 × 40 cm each. You can also make laps of 1 centimeter. Lay the insulation directly on the mortar, it is not necessary to coat it with bitumen.
13. Now you can start laying bricks. Enough of their two rows in height, the top of them should be perpendicular to the length of the beam. To fasten the material, use a sand-cement mortar, use a brick grade, not lower than m-100.
14. Lay the waterproofing over the bricks.
15. Place soundproof pads on top of it. So that they do not move out, secure them.

First, lay the logs-beacons, the first from the walls. Fasten them with a gap of 2 meters from each other.

Note! Check the horizontal position of the material in relation to the ground, as well as each other. If the logs lie unevenly, the protruding sections can be removed with a planer, and linings can be installed under the bending parts. It should be noted what maximum deviation is permissible - it should be one millimeter per 1 meter of timber.

Conclusion

The strength and reliability of the construction of all floors depends on the step of the lag, their section and the wood used. Therefore, the choice of these parameters must be taken seriously. In the presented video in this article you will find additional information on this topic.