Wooden floors on logs are one of the oldest methods of arranging floors and the only one used in the northern regions of our country. Modern materials have only improved the old technologies, due to which the scope of application has significantly expanded and performance has improved. Before proceeding directly to the consideration of various options, you should familiarize yourself a little with the engineering requirements for calculations.
Technical characteristics of the lag and requirements for their installation
Logs are distinguished from beams by their smaller size and mobility. If the beams after installation cannot be moved, the repair is very long and labor-intensive, then the logs are a mobile architectural element. They are much easier to mount, if necessary, repairs are made faster.
Before proceeding with the construction of the floor, you need to study the requirements of regulatory documents for the dimensions of the log and the distance between them, taking into account the thickness of the floorboards.
Log section table with a step of 70 cm
Table of the distance between the lags depending on the thickness of the board
In order to learn how to independently make calculations based on tables, it will be useful to consider the simplest example. Initial data: the length of the room is 10 m, let's take a floorboard 30 mm thick.
Method of calculation
According to the table, with such a board thickness, the distance between the lags is 50 cm, with a room length of 10 m, 20 lags will be needed. The removal of the lag from the walls cannot exceed 30 cm. This means that we will have to increase their number by one piece, the distance between the rest will decrease to 45 centimeters.
Important note. During calculations, all rounding must be done only downwards, thus creating an additional margin of safety.
There is no need to calculate dimensions and distances to the nearest millimeter, no one is engaged in such measurements. By the way, during construction, the vast majority of architectural elements and structures are measured in centimeters, the highest accuracy is half a centimeter. Millimeters are almost never used during measurements.
Floor base options
These types of floors can be placed on a wooden and concrete base or on the ground. Each option has its own technological features that must be kept in mind during the production of work. As for the specific purpose of the premises, taking into account this parameter, the floor base and its performance characteristics are selected. The device technology itself remains almost unchanged. There are, of course, options for warm and cold floors, but these features also have a common construction algorithm.
The device of a wooden floor on logs on wooden bases
Such floors can be made both in wooden and brick buildings, they can have several varieties. It is necessary to think over the features of floor coverings at the design stage of the building. Not only the purpose of each room and its dimensions are taken into account, but also the climatic zone of residence, microclimate requirements and the financial capabilities of the developer. Below are step-by-step recommendations for the construction of this type of floor.
Depending on the specific conditions, the algorithm can be changed somewhat, but all the main construction operations are mandatory. Moisture-resistant OSB boards or plywood sheets can serve as the base. The design of the floor coverings provides for the possibility of laying insulation, it is allowed to use rolled and pressed glass wool or polystyrene. If there are heaters, then be sure to put hydro and vapor barrier.
Step 1. Take the dimensions of the room and calculate the number of lags, taking into account the above recommendations. Prepare materials and tools, markup. Do the work slowly, the mistakes made at this stage have extremely negative consequences. Removing them will take a long time.
Step 2. Start installing logs from the extreme wall. If the room has black floors, then the logs can be fixed directly to them. To facilitate the work, it is better to use perforated metal squares, such elements significantly speed up the work and increase the stability of the lag. According to the mark on the wall, taking into account the thickness of the floorboards, set one end of the log, fix its position.
Practical advice. During the installation of the extreme lags, do not fix them immediately; at first, the screws should only be baited. This will enable final fine adjustments to be made.
Do the same actions at the second end of the log, constantly monitor its position in terms of level. When the log lay down normally, you can firmly fix the ends and proceed with the installation of intermediate fasteners. The distance between them depends on the thickness of the boards that are used for the logs, it is about 70 centimeters.
Step 3 Between the extreme lags you need to pull the ropes, set all the remaining lags along this line. Constantly check the level, the installation accuracy should be ± 1–2 mm. There is no point anymore, it takes a lot of extra time. A small difference in height will be removed during the finishing of the front surface of the floorboards.
Step 4 If the floors are warm, then it is necessary to lay thermal insulation between the lags; waterproofing and vapor barrier are used to prevent moisture from entering. The distances between the lags must be adjusted taking into account the length and width of the heaters. It can be either mineral wool or polystyrene, or bulk types of insulation. If all the preparatory work is completed, then you can start laying the floorboards.
There are options for mounting the log on the floor beams. These are the so-called ventilated floors, most often used for non-residential premises. It is not necessary to observe special accuracy, the alignment of dimensions is done by lags. Logs to the beams are attached with nails or self-tapping screws on the side. The work algorithm is the same. First, the extreme ones are placed, a rope is pulled between them and all the rest are fixed along it.
Ventilation is carried out through special vents in the foundations, the distance between the ground and the floor must be at least fifty centimeters. Otherwise, the air exchange rate does not meet the required indicators, and this causes damage to wooden structures.
Floor installation on wooden logs for concrete
Such floors are considered more complex, time-consuming and expensive; all wooden structures must be reliably protected from direct contact with concrete. Otherwise, the structures will quickly become unusable and they will have to be changed prematurely. There is a chemical way to protect the log from decay processes with the help of various impregnations. They are quite effective, they really prevent the process of wood damage. But unfortunately, impregnated wooden structures can no longer be considered environmentally friendly, and it is for the sake of this indicator that most developers install natural wooden floors.
If the logs are placed over the entire area on concrete, then waterproofing is required between them.
But they can also be fixed with the help of metal squares, which allows you to make a gap between the base and the lag. It must be borne in mind that in this case the bearing characteristics of the floor are somewhat reduced.
This method of fixation has its advantages. Firstly, direct contact of wooden structures with concrete structures is completely excluded. Secondly, logs can also be installed on a black screed. With the help of corners, you can eliminate irregularities of several centimeters, there is no need to make a final screed. This saves a lot of time and money.
The second way of laying on a concrete screed - logs are placed directly on it, material based on modified bitumen is used for insulation.
Laying log on the ground
The method is used for outbuildings, bathhouses, gazebos, verandas, etc. Wood must be treated with antiseptics. The foundation is better columnar, if you want to make a more durable tape, then it is necessary to provide ventilation for natural ventilation in advance.
Practical advice. It is much easier to make columns from ready-made blocks. Horizontal alignment must be done along the rope. After the extreme ones are set according to the hydraulic level, a rope is pulled between them. Deviations should not exceed ± 1 cm. This variation is eliminated during the installation of the log.
Step 4 Proceed to fixing the lag, you also need to start work from the extreme ones. Spacers can be used for precise horizontal alignment. It is undesirable to take wood wedges, over time they will dry out and wobble will appear: the floor will begin to creak unpleasantly while walking. Between wooden structures and concrete surfaces, it is imperative to put two layers of roofing material for reliable waterproofing.
Step 5 After the extreme logs are laid, a rope is pulled between them and all the rest are laid under it. Logs are fixed with metal squares on dowels and self-tapping screws. To increase stability, it is recommended to install them on both sides. Floor boards can be laid immediately on the logs or pre-laid with a subfloor. The final choice depends on the characteristics of the operation and purpose of the premises.
Wood preservative
Always select logs with a margin of safety, especially in cases where the installation method involves bending loads. It must be remembered that correcting mistakes made during the construction of floor coverings is always much more expensive than the production of work with quality materials and in compliance with the recommended technologies.
Choose your boards carefully. They must be absolutely healthy with no signs of rot. The presence of through cracks and rotten knots is completely prohibited. If there are large healthy through knots, then you need to install the logs in such a way that there is an emphasis under them.
Firmly fix the lags
Most lag wobbles cause very unpleasant floor squeaks while walking. To eliminate such phenomena, it will be necessary to remove the floor coverings, which is long and expensive, it is not always possible to keep the dismantled materials in a state suitable for reuse.
Video - Installation of a wooden floor along the logs
