After laying the foundation and constructing the lower harness, it becomes necessary to attach the log to the timber. How does this happen? Depending on the type of foundation and base, heavy beams can be attached both to the wall and to the first strapping crown. In the article we will consider the main methods of installing beams, as well as the types of fasteners that would ensure reliable fixation of heavy logs.
What is the bottom harness?
The floor frame of the house includes such important components:
- beam;
- main beams (logs);
- secondary beams.
In the process of building a house, a pile, strip or monolithic foundation can be laid under the structure. In the case of assembling the first two, it is planned to install a lower trim from a bar, which would serve as the basis for the subfloor beams. At the same time, the complexity of the installation of beams lies in their weightiness. They are able to create a large load on the fasteners, which will lead to deformation of the base.
That is why a special cut is made in the wall or strapping beam, into which the beam is inserted. To fix it, you can use different kinds fasteners. However, in the process of choosing them, it is very important to take into account the degree of their strength and durability.
When installing a subfloor in a house, it is very important to choose only high-quality strapping timber. During the operation of the coating, it is he who will experience the heaviest load. And if the quality of wood or fastening is mediocre, the base can easily be deformed. In the process of assembling a strapping from a bar, experts pay attention to such points:
- The beam must be accurately calibrated and sized;
- To exclude the possibility of wood decay, the timber must be treated with an antiseptic;
- When assembling the harness in frame house it is desirable to give preference to logs made of coniferous wood (they are less hygroscopic);
- The strapping of the timber must be laid clearly horizontally, otherwise some of the parts of the structure during operation will experience a large load;
- You can fasten the strapping logs to the support poles using clamps, metal brackets, anchors and U-shaped galvanized profiles.
Ways to install a lag in the house
Installation of lag in wooden house opens up a fairly wide range of options for attaching beams to a bar. According to the method of installation, they can be divided into two types:
- Wall mount. This method is often used when installing a log on the second floor of a house. The device of the floor involves laying the beams "in the spacer". A special cut is made in the wall along the width of the beam, after which they are inserted into the grooves formed and fixed with fasteners. The advantage of this method is that the beam itself lies completely on the beam and does not create a large load on the anchors and brackets with which it is fixed. That is why fixing the log in the wall is optimal when arranging the floor of the second floor of the house;
- Fastening to the beam. In this case, the elements can be attached to the first crown of the strapping "butt" using fasteners. At the same time, the beam is not sawn, but simply docked with lags and fixed with anchors or horseshoe-shaped profiles. Also, for the installation of the floor of the first and second floors of the house, for fastening to the strapping, a cut is made in the beam itself. Technically, it is quite difficult to embed logs into the strapping material, however, such designs have a long service life.
Design Benefits
Why is a subfloor device with beams so popular? Despite the fact that the process of attaching wooden crates to the base is very difficult, it is still in demand. Why? The beam base provides the floor with the following technical advantages:
- Improves heat and sound insulation performance;
- Provides a more even distribution of the load on the floor, which ensures a long service life of the subfloor;
- The timber does not contain synthetic substances and therefore can be used to equip the floor in residential premises;
- When arranging a non-ground floor of a high-rise building, it is more expedient to use wooden elements for finishing the floor base, which do not create a large static load on the interfloor ceilings;
- An air gap can be formed between the strapping and the beams, which will create optimal conditions for underground ventilation;
- Via wooden beam you can not only equip the warm floor, but also level it if necessary.
Beam mounting options
When repairing the floor of the first and second floors of a private house, various types of fasteners can be used. Each of them has its own advantages and disadvantages. To assess the feasibility of using each of them, consider the most popular types of fasteners in more detail:
- Perforated brackets. This type of fastener is made of sheet steel coated with anti-corrosion compounds. They can have a different design depending on the place where the beam is fixed. Corner versions of perforated brackets are L-shaped. They are fixed in the logs with the help of powerful self-tapping screws with a cross section of at least 3 mm;
- Steel corners. The fasteners reliably tighten the beams and beams together, however, in the absence of at least some kind of support under the logs, they can experience a large load, as a result of which they can be deformed. You can attach the corner to the harness and beams using anchors or self-tapping screws;
- U-shaped holders. Holders are horseshoe-shaped overhead grooves into which beams are inserted. They are mounted only in a strapping beam, imitating a standard cut, but at the same time they do not violate the integrity of the strapping logs;
- Drank. This method of fastening the lag is one of the most budgetary, albeit time-consuming. The beam is specially sawn, making cuts along the entire length of the log. A beam is laid in the formed cut and fixed either simply with self-tapping screws or with the fasteners that were listed above.
Features of mounting a lag for the floor
An example of connecting bars of dovetail locks When arranging the floor of the first floor of the house, you need to take care not only of the high-quality assembly and fastening of the harness, but also the processing of the wooden components of the floor base. The work of attaching the beams to the first crown of the strapping includes such features.
The article provides a table for calculating loads on wooden beams made of coniferous wood.
Floor beams or floor/ceiling joists
Ceiling beams or ceiling logs are the supporting structure of the house, therefore, before you start to mount the floor logs in a log cabin at home or baths on your own, we strongly recommend that you take special care approach the choice of material and correctly calculate roof structure.
For the manufacture of floor lags, it is best to use dry, first-grade material impregnated with a fire-retardant composition.
Beams are most often embedded:
How to ensure the strength of floors and easy installation
Having previously marked the places for tie-in beams, cuts are made in the log and tight beams are inserted into them at a distance of about 600 mm from each other. Such a distance between the beams provides the necessary strength of the floors. Most types of insulation are produced exactly 600 mm wide, which provides convenient installation of heat and sound insulation. With this method of mounting the log, there is no need to attach them additionally to the wall.
Floor logs can also be mounted after assembling the log house by fixing them to the wall using special brackets and self-tapping screws. The construction market now has a huge variety of fasteners. But more correct reliable installation method - the first!
Questions arising during the construction process
During construction log house, log saunas Naturally, questions arise: What section should be cut into the floor beams (floor, ceiling)? What load can wooden logs (beams) withstand? What is the maximum length of the beam possible for what section of the board, beam, log?
Based on the table below, it is easy to calculate the cross section of the log, depending on its length. The data are given for standard spans with a width of 2 to 6 meters, with a lag set frequency of 600 mm (the distance between the lags is 600 mm) The estimated load is 300 kg per 1 sq. meter. The table shows the breaking loads for these lags in kg per square meter.
Simply put, the numbers on a colored background are the load in kilograms per 1 m2, at which the ceiling will simply break. But in order for the floor not to “spring”, there is also an indicator of the bending of the beam. Blue background - the floor will not “spring”, yellow is the maximum allowable, and red background the floor will sag at a load of 300 kg more than the allowable norm.
Table for calculating the breaking load (kg / m2) on the logs (beams) of the floors of a log house.
log length m
2,0
2,5
3,0
3,5
4,0
4,5
5,0
5,5
6,0
log cross section mm
Board 100x50
733
587
489
419
367
326
293
267
244
Board 150x50
1650
1320
1100
943
825
733
660
600
500
Board 200x50
2933
2347
1956
1676
1467
1304
1173
1067
978
Beam 200x100
5867
4693
3911
3352
2933
2607
2347
2133
1956
Beam 200x200
11733
9387
7822
6705
5867
5215
4693
4267
3911
Log 200
6912
5529
4608
3949
3456
3072
2765
2513
2304
Hello! Tell me please. In the log house for the floor device there are logs made of logs. I want to align them by installing counter beams (that is, cut beams from a bar, for example, 100x150 across the log logs). Does this method have any disadvantages? Thank you.
Boris, Vyborg.
Hello Boris from Vyborg!
Yes, this method of leveling the floor logs of a log house made of logs with uneven surfaces on their top is one of the options.
Although usually experienced cutters of log cabins, already during the initial assembly of the log house, these logs are laid in such a way that after transporting the log house to a permanent place and its final assembly, they have the same level at which you can lay the finishing floor.
In the same cases, when the floor logs from logs are not at the same level, then they are cut off along the upper surfaces either with an ax or an electric planer. Then they check how correctly they lie in the plane. Why nails are nailed at intervals of about a meter along all four walls of the log house (the places of clogging are determined by a liquid tubular building level at least 10 meters long). A cord is attached to the nails and then it is clearly visible where there is still a need to hew the logs of the sex logs.
This method is good because you do not need to use additional material which costs money.
Therefore, all other options where it is necessary to use lumber are obviously more expensive.
Sometimes a different method is used, namely, even edged boards with a thickness of 40-50 millimeters and a width of 100 millimeters and above are attached to the side surfaces of the lag logs (also in terms of level). They are placed, of course, on the edge for greater structural rigidity. Fastening is carried out with sufficient strength (metal forged staples, large nails, self-tapping screws up to 150 millimeters long with a gap between fasteners from 0.5 to 1 meter.
But you can do it the way you want. But a section of 100/150 is probably too big. It is enough to use not such beams, but the edged board already mentioned above with a thickness of 40 - 50 millimeters and a width of 100 -120 millimeters. With a step of distances between the boards of this second row, the lag (counterlag) is from 600 to 900 millimeters. And installation on the edge for greater rigidity. This will be enough so that later the floors have a solid foundation and do not sag during operation.
As for cuts in log logs for installation of counter logs, it should be remembered that any such cut is a stress concentrator and weakens the floor structure. And the deeper he washed down, the weaker the design. Therefore, such cuts should be approached with caution. They should be minimal.
Much depends on how large your log house is, it is one thing if its size is 6/6 meters and quite another if it is 9/12. And what is the distance between the log lags - a meter or a half.
At large sizes and distances, it is preferable to make cuts not in the logs themselves, but in counterlags. Since they will certainly be located closer (600 -900 millimeters, as mentioned above) to each other than log logs. In addition, sometimes a 90-degree cut is smoothed out. That is, a sharp angle is hewn with an ax and a fillet is obtained. This also reduces stress concentration.
In short, everything is in accordance with the strength of materials and the course of building structures.
Ask a question to Semenych (the author of the materials)
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