What beam to use on the logs. Lags in floor construction

The device of even and durable floors is considered one of the main issues when renovating a residential building or building a new home. The owners of houses in modern conditions there are many options for flooring, based on new technologies in production building materials. There are many for sale construction compounds on a synthetic or mineral basis. However, as before, many homeowners still prefer to make floors by laying wooden flooring on logs, according to the old, time-tested technology.

Of course, the technologies of modern manufacturers of building materials have also touched the floors on the logs, but the principle of construction itself has remained unchanged. Exactly reliability and simplicity make such a flooring device in demand and popular and at present. Such flooring is able to do it yourself House master Not good highly qualified, showing care, patience and accuracy, using the necessary control and measuring and working tools.

What are floor joists and the benefits of using them

Cross beams, which are the basis for installing wooden floorboards or other floor sheeting in the house, are called logs. Modern technologies construction allow the use of concrete, metal and polymer materials for the construction of structures, but still wood remains the traditional material in the manufacture.

Wooden logs for the house can be different designs and thickness. The most convenient to use is wood even beam required size. The use of a beam greatly simplifies setting the level required for a given surface, and the process of assembling the structure is more accurate. Used for the manufacture of structures and boards, if you install them on the edge. Required thickness logs are obtained by connecting several parts together. Sometimes the beams are made of round timber, and at least one side must be trimmed to ensure a snug fit between the battens or floorboards.

Of course, wood is inferior in strength to cement coating, but still floor construction using a log has its advantages:

The construction with lags is much lighter than a concrete floor, with an equal floor height.
If the assembly is done correctly, then the floor on the logs is well ventilated, which serves an important factor such coverage.
It is very easy to place various hidden communications between the lags ( electrical wiring, pipes). If it is necessary to eliminate the accident and carry out work on the prevention of communications, access to them is much easier.
It is very easy to make floor insulation in the house, even if there are communications. Almost any kind of insulating material easily fits into the niches between the lags.
Almost without changing the consumption of the material used, with the help of a log it is very easy to level the surface under the ideal horizontal, even with big difference level. Application concrete pavement, in such cases, becomes a more time-consuming process.
You can also highlight more high level floor noise absorption on joists.
The distribution and transfer of loads (dynamic and static) occurs evenly, which has a positive effect on the strength of the foundation.
Repair work is very easy to do using the floor on the logs. It is enough to dismantle and replace the damaged areas of the coating.
The design feature of the use of lags involves mounting any type floor covering. It can be not only wood, but also almost any rolled material, and even ceramic tiles, if the necessary manufacturing technologies are followed.
Modern technologies of building materials allow, even on wood flooring, to fix the base heating system.

Choice of wood

The optimal material used in the manufacture of floor logs is timber, which is cut into special machine in accordance with the size. Usually, for the manufacture of timber, not very expensive wood is used - spruce, fir, pine. hardwood trees are used much less often, because they have a high cost, although they have better performance.

The use of wood of the first and highest grade is inappropriate, it is enough to use second-class wood. The use of third-grade timber timber should be treated with caution, as it contains knots that adversely affect the strength of the material.

The cross section of the beam must be strictly rectangular shape . Deformed, bent or twisted beams are very difficult to level. The timber must be dried to a moisture content of 12%. It is undesirable to use a wetter material, as it can warp after complete drying.

The usual height of the timber should be 1.5–2 of its thickness.

The following types of wood are used for flooring:

Flooring made of pine, spruce and fir is used in rooms with low traffic, because these types of wood are considered soft and mechanical damage easily remains on them.
by the most durable material is oak. It can be used in any premises, even in industrial and office buildings. But here is not very frequent use of this material due to high cost his.
Siberian larch, due to the presence of resins, does not rot, so it is often used for floors in the bath. It has the same solid structure as oak.
Alder and aspen are good to use in children's rooms and bedrooms, because this wood is considered good for health.

The type of wood is often selected depending on the planned coating of the boards. We were going to paint the floor - you can take the second grade of boards. For varnishing it is necessary to use boards of the first grade. And in the ancillary or technical rooms you can lay the floors with boards of the third grade.

To ensure wooden structures from mold, fungi, bugs, decay, it is necessary to pre-treat them with an antiseptic.

Floor lag dimensions

The reliability of the entire coating system directly depends not only on the material you have chosen for the manufacture of the floor, but also on the dimensions of the timber. Therefore, even before addressing the issue of buying timber, you need to calculate the size of the desired material:

The length of the lag directly depends on the area of \u200b\u200bthe base itself. At the same time, it is desirable to choose the size taking into account the technological gap, the distance from the wall to the beam should be about 3 cm. This gap is arranged to avoid deformation of the frame when thermal expansion material.
The logs have a rectangular cross section and are laid on edge during installation. Therefore, the size of the width should formally be half the height.

Installing a log for the floor

A floor device using a log can be made on various grounds. In this case, it is imperative to take into account the properties of the base, the magnitude of the load on the surface and some features of the installation of the structure.

Installation on wooden floors

When installing a floor with such ceilings, the logs are mounted on wooden beams. Due to the fact that the beams may not have a perfectly even level, they are attached to the sides of the beam. With this installation, the use of linings is not necessary. The horizontal is checked by a level control rail. It is better to fasten the logs with screws with a diameter of at least 6 mm, and a length of 2–2.5 times the width.

To prevent cracking of the logs and beams, you must first drill holes with a drill with a diameter of 2.5 mm less than the diameter of the screw.

Installation on concrete

There are two ways to install structures on a concrete base:

Before installing the logs on a concrete base, you need to do several preparatory operations:

Since concrete perfectly absorbs moisture, it is necessary to put a layer of waterproofing on the base.
Then lay a layer of sound insulation, which is necessary to eliminate impact noise.
Perform a screed either dry or cement.

Insulation must be laid strictly between the lags, preventing material from getting under them.

Ground installation

First you need to make leveling the surface of the soil and compacting it. This work is mostly done by hand. Then it is necessary to mark the distance for the columns under the logs. The distance from the wall to the first log is from 3 to 20 cm.

After marking the location of the supporting pillars, it is necessary to make a foundation for these pillars.

The foundation for the pillars is done as follows:

After the concrete has completely dried, we carry out waterproofing with pieces of roofing material. Then we lay the bricks directly on the roofing material. Usually the foundation is calculated so that two rows of bricks are enough, and the top row should be perpendicular to the length.

Then we carry out waterproofing on a brick from pieces of roofing material. Lay a pad on top soundproofing material, fasten it so that it does not move out.

For the device of the floor, it is necessary to achieve a perfectly flat surface, for which we carefully align the horizontal lag. First you need to install the lags extreme from the walls and at a distance of two meters from each other. Then we lay all the intermediate logs and fasten them.

Floor device

Previously, before laying the finished floor, you need to make Painting works on the walls of the room to prevent contamination of the boards.

After installing the lag need to perform floor insulation operations. insulating material must be laid between the lags. The insulation is laid directly on a solid base. And if the logs are arranged on the ground, then the insulation must be laid on the subfloor.

The floor begins to creep in from the farthest corner of the room from the door. The first row of boards is laid at a distance of 10 mm from the wall, with a tongue to it, so that the expansion of the tree during operation can be compensated. We fix the boards to the joists with screws.

If the size of the floorboards is less than the length of the room, then we lay the next row with an offset. Paste floorboard into the groove of the previous row and fasten it with a screw so as to hide its hat. So, sequentially, all the boards are tightly pressed against each other and are necessarily fixed to all the lags. The last row floorboards are fastened with screws so that later their caps can be covered with a plinth.

The device of a floor on logs is one of the most widespread. Such wooden floor easily repaired. If you carefully control the correctness of the lag laying process, then this design will turn out to be strong and durable in operation.

Owners of private housing continue to willingly opt for multi-layered wooden structures despite not being too long terms their operation. After all, they are characterized by environmental friendliness, low weight and relatively low cost. But if, when building walls with a tree, various artificial materials(brick, foam concrete, gas silicate blocks), then when arranging the floors, the predominant material for the log floor is still wood. However, during the manufacture multilayer structures from wood, not only wooden logs are now used, but also made from durable polymers.

What are lags?
Functions performed by lags
The choice of material for the lag
Wood floor impregnation
Cross section and dimensions of the lag
Step between lags

What are lags?

This term refers to transverse or longitudinal beams placed on the base of the room. Boards are already fixed on them, forming a horizontal, even floor surface.

Logs can be used regardless of what material the base of the floor is made of:

concrete slab;
floor beams;
even ordinary soil.

In all variants, approximately the same design is used, the differences are only in the methods of attaching the lag.

Functions performed by lags

Create a flat horizontal surface for the floor.
More evenly distribute the load on the foundation.
leave air layer between the base of the floor and its finish. This space is usually used for laying communications, and sometimes even for storing some items.
Most often, the space between the lags is filled with sound and heat-insulating material making the room noticeably warmer and quieter.
A rotten or cracked log can be quickly replaced with a new one without affecting the base of the floor.

The choice of material for the lag

When deciding which logs to choose, you need to remember what properties their material should have:

evenness;
strength;
minimum deformation at rated load.

When deciding which logs to use for the floor, you need to keep in mind that they can be used to make them. various materials, the most traditional of which is wood, although the choice of floor lag can also fall on reinforced concrete, metal or plastic. Adjustable structures made from metal channels or reinforced concrete are also found, although infrequently. With the help of especially strong logs, the permissible load on the floor can be increased several times. Most often, such elements are used in the construction of industrial buildings or public premises.

Under lags can be used:

bars hewn from logs minimum diameter 160 mm;
logs with a diameter of 150 mm, which are simply cut off;
a board for a log floor can also be used, if several of these boards are stacked in a stack 200 mm high, pulled together and placed on the ends;
rectangular wooden beam, the section of which satisfies the design loads on the floor;
the most convenient to use ready-made adjustable logs.

The choice of wood for the log:

Since when choosing which timber to use for the floor log, the quality of the wood plays a lesser role, then most often preference is given to the cheapest pine or spruce. However, the use of these materials requires the preparation of appropriate floor waterproofing.
Logs made of larches for the floor, which are not afraid of exposure to water, but they immediately lead to a significant increase in the cost of this engineering solution.
It is also moisture resistant aspen, therefore, it is more expensive than spruce and pine.

In any case, when thinking about what kind of wood it is best to choose logs from, you should not spend extra money on sawn timber of the first and highest grade, since the second will be enough. But at the same time, you should not go down to the third grade, which has a large number of knots, because the logs remain load-bearing elements, and if for them appearance doesn't matter, the durability should still be high.

Therefore, the presence of cracks, blue and rotten areas should not be allowed - such materials will not last the allotted time.

Also, great attention should be paid to the geometry of the beam so that it is not bent, twisted or otherwise deformed, since it will be extremely difficult to level products from it, especially if the lag length is significant.

It is best if you can buy dried special technology lumber, after which they will have a residual moisture content of only 12%. But such material at home, before it is installed, must be stored in dry conditions.

Do not use timber for floor logs with residual moisture above 15-18%, because after the final drying they can lead, and this threatens with a general deformation of the entire floor structure, the appearance of unstable zones on it and the appearance of an unpleasant creak.

If the timber is required to be laid on a reinforced concrete base, then polyethylene foam must be placed under it. If the lags rest on support pillars from brick, then polyethylene should be laid between them, as well as between the soil and the pole. In addition to polyethylene, it is possible to waterproof wood from bricks using roofing material.

Wood floor impregnation

If lumber is used, it is strongly recommended that the floor logs be impregnated with various antiseptic compounds and flame retardants, which protect structural elements from being eaten by grinders and rodents, fungus and mold, and also for the purpose of fire safety. Many such compositions have been invented, there are even those that have a double effect. They not only give wood antiseptic properties, killing various biological animals, but also significantly increase its resistance to fire, since they contain fire retardants.

The composition must be diluted to the required concentration, although more often they are sold ready-to-use. Impregnation can be applied either with a brush or by spraying it in the form of an aerosol, and small items, such as floor joists, can simply be dipped into this solution. Antiseptic treatment requires the consumption of approximately 100 ml of solution per square meter surfaces.

It is better to carry out such a treatment twice - let the first layer soak and dry, which will take about an hour at a positive temperature, and then repeat the treatment.

Before processing, the bars must be thoroughly cleaned of dirt, traces of paint, lime, etc. It makes no sense to process wet wood for the following reasons:

the composition is much worse absorbed into wet wood;
after impregnation, the drying process of the material slows down significantly.

That is, wood with a moisture content above 25% cannot be processed, although this humidity will no longer allow you to get an ideal result.

Cross section and dimensions of the lag

The reliability of the design will depend not only on the choice of material, but also on how to choose the logs for the floor, correctly calculating them. Even before buying a bar, you need to calculate its length and cross section:

The length of the floor lag should correspond to the dimensions of the room in which the floor will be installed, but at the same time be 20-30 mm less to prevent deformation from temperature changes.
Bars are used for lag rectangular section with an aspect ratio of 1.5 x 2. If the floor is supported by wooden floor beams, then the section of the log will depend on the length of the span between adjacent elements on which the log will rest.

When insulating the floor

In case of floor insulation with heat-insulating material, it is necessary to leave between the insulation and finish coating ventilation gap having a thickness of at least 2 cm, and even better - 3-4 cm. Therefore, the beam in this case must be taken taking into account this additive for the ventilation gap.

When installing lags on the ground

And if the logs rest directly on the ground, then it will be necessary to additionally take into account the thickness of the roll, which is laid on the cranial bars attached to the logs. It is best to buy a bar, the section of which has some margin.

If the floor is laid over an earthen base, then you can save on expensive large-section timber. It can be replaced with a thinner beam laid on shorter spans and supported on brick posts dug into the ground. The distance between the pillars should be 120 cm, and they themselves are made of red brick, since silicate can only be used in cases where the aquifer is deeper than two meters.

Of course, reinforced concrete or metal logs for the floor will have a smaller cross section, because they are much stronger than wood and bend less.

Step between lags

The distance between adjacent lags depends on the thickness of the upper deck: the thicker it is, the greater the step between the supports, since the thick coating will sag less under load. To know the exact ratio, you can use a special table, which indicates that:

for boards with a thickness of 20 mm, the required support pitch is 30 cm;
for boards 25 mm - 40 cm;
for boards 30 mm - 50 cm, etc.

Instead of a table, you can use the rule - an increase in the thickness of the beam by 5 mm allows you to increase the pitch by 100 mm.

Logs for the floor under plywood are calculated somewhat differently, which is more resistant to bending. In this case, plywood 15-18 mm thick can rest on logs spaced 40 cm apart. Plywood is attached to the logs in several places at once. The logs are laid so that the plywood sheets are fixed on them in the corners and in the center. That is, the edge of the sheet should be located in the middle of the beam.

Which lags do you prefer: wood or metal? What kind of wood? Tell us about it in the comments - your experience is important to us.

There are many DIY floor leveling solutions. An exception is not laying the floor with the help of wooden logs. This method of floor installation is very popular due to its environmental friendliness and practicality, and the naturalness of the materials creates warmth, comfort and a welcoming atmosphere. The wooden floor has always been valued both for arranging in country houses as well as in apartments. And if the choice fell on a wooden floor on logs, you should decide what kind of wood to choose, how exactly to install the logs for the floor in a particular room, their size, amount of material, and so on.

Scheme of the device of a wooden floor on the ground on logs (with heaving soil)

The main purpose of the lag is to obtain a flat surface for subsequent finishing works in the house. In addition, they help to maintain a full ventilation mode of the lower part of the floor, which prevents wood decay. This is especially important if the floor is laid on the ground, from which dampness appears. The space between the base of the floor and the flooring prevents dampness and improves sound insulation. In addition, there are other functions:

Communications can be placed in this space, which spoil the view if they remain on the floor;
Logs ensure uniformity of the load on the foundation;
There is an opportunity for, the types of which are many. Expanded clay, sawdust, mineral wool and etc.;
It is possible to adjust the height of the floor;
The beam allows you to get a solid floor due to the support points;
Mounting on joists guarantees a quick and easy installation that even a novice can do.

Logs are a wooden beam that is laid on any base or directly on the ground. Most often you have to use a beam with an aspect ratio of 1:1.5 and 1:2, but there are other section sizes. It all depends on the characteristics of the overlap and load.

Pine timber and the section used for the floor log

It is better to buy a ready-made timber, but making it yourself is also not excluded, the main thing is to choose the right wood. Its ideal moisture content is 18-20%. With more high values there will be deformation of the finished floor after drying.

The most popular material is pine. You can also use spruce and fir. There are no special requirements for the very quality of the tree; the beam can be made of material of the second or third grade.

There are options for making logs from simple boards, which are connected with self-tapping screws and installed on the edge. If very long bars are needed, they are spliced together by creating a lock joint or butt-to-butt. And at the joints, a support is installed, for example, columns of bricks.

The choice of material for the lag

When choosing a base material, it should be remembered that it must be strong, even and have a low rate of deformation in the event of a load. It can be plastic, metal, reinforced concrete, etc. But the most popular material is a wooden beam.

Since there is no need for high quality wood for timber, the choice usually falls on spruce and pine, which are very popular due to their low price. But when installing such a tree in a house, it is better to think over a waterproofing system.

Larch and aspen are more expensive, but indispensable when it comes to high humidity. Larch is considered the best option if you need strength and resistance to rotting of the floor in the house.

Logs on brick posts and a full floor cake on the ground

If the beam is mounted on a reinforced concrete base, then a layer of foamed polyethylene is preliminarily laid. And if the logs are installed on brick support posts, then polyethylene is placed between the beam and the post, as well as between the post and the ground. Roofing material is suitable for laying between wood and brick.

Before installation, the logs must be treated with an antiseptic to protect yourself from various pests. This is especially true for wooden houses where carpenter beetles can start.

Determination of section and dimensions

How reliable the design will be depends not only on what material is used, but also on the correct calculations. Before purchasing a timber, it is necessary to determine its length and thickness. The length must match the length and width of the house in which the floor is to be installed. But it is better to leave a gap, and choose a bar 20-30 mm less. This is done in order to prevent deformation in the event of changes in temperature and humidity.

With the determination of the dimensions of the cross section of the beam, the situation is much more complicated. The thickness depends on the lag material and on the calculated characteristics of the future floor. The maximum possible load on the floor and the size of the spans between the lag support points are taken as the basis. IN residential buildings taken for maximum load an indicator of 300 kg per sq. m.

There is a table that displays the relationship between the thickness of the beam and the length of the span between its supports. Usually, with a length of 2 m, a beam with a section of 110x60 mm is used, with a length of 3 m - 150x80 mm, and for a four-meter span, a beam with a section of 180x100 mm is used. You can trace the pattern: the larger the span, the thicker the beam.

Dimensions of the lag section depending on the span of the room

The shape of the section itself is usually rectangular. The beam is installed on the edge so that the logs can withstand high pressure. This achieves maximum rigidity of the beam.

But do not get hung up on the ratio table, since the thickness of the lag can be greater if necessary. For example, if you plan to lay a thick layer of insulation.

Consideration should be given to the fact that for non-residential premises load level indicator more than 300 kg per sq. m. And it will have to be calculated first and only then select the appropriate lags, based on the data obtained.

If the beams are not made of wood, but of metal or reinforced concrete, a smaller thickness is allowed. This is due to the fact that such materials are more resistant to stress, they bend less.

The distance between the lags is selected depending on the thickness of the coating that will be used for the flooring. After all, the thicker the flooring, the bigger step can be between lags, since a thick coating is less susceptible to deflection when exposed to loads. To establish such a ratio, there is also a special table. With a board thickness of 20 mm, the step is 30 cm; 25 mm - 40 cm; 30 mm - 50 cm, etc. And you can use the following formula: with an increase in the thickness of the beam by 5 mm, the step length increases by 100 mm.

The distance between the lags depending on the thickness of the floorboard

When used or calculations are slightly different. This is due to the higher bending stiffness. Here, for a beam with a thickness of 1.5-1.8 cm, a distance between the lags of up to 40 cm can be allowed. And such materials are attached to the lags in several places. The logs are arranged in such a way that the flooring can be fixed at the edges and in the middle. In this case, the edge of the sheet is laid only up to half the beam, and not over its entire width.

Log laying

Wooden logs can be installed on any base, subject to the installation rules. For the crate you will need:

bars,
Level,
screwdriver,
jigsaw,
fasteners.

When installing the floor on the logs can be used as simple design, so and . IN adjustable design screws are able to align the logs. The bars can not be attached to the base of the floor, but there is a risk of destruction of the entire structure due to the displacement of the lag.

In addition to these tools, you may need others. To install a log on concrete or soil, you need a manual puncher. First, supports are installed, for which holes are made up to 10 cm deep, covered with sand and filled with water. A film is placed on the sand, and a brick support is placed on the film, which is covered with roofing material. Bars can be installed on these supports, fixing them to the walls with the help of galvanized corners.

If wooden beams act as a base, it is important to determine the direction of the timber. If the timber is laid across the beams, it is better to fasten the logs with self-tapping screws, treat the beams with an antiseptic, and drill the holes to avoid splitting. With a parallel fastening of the beam relative to the beams, the logs are installed both on top and on the sides.

For the concrete floor, polyethylene foam with a foil layer is used, which creates waterproofing and reduces heat loss. The beam is distributed over the entire surface with a certain step. Next, the base is leveled and the lags are fixed. You can also install the beam using stands. First, the supports are fixed to the ceiling, and the logs are already attached to them with the help of self-tapping screws.

The floor in the house plays a huge role. And in order for it to be even and beautiful, preparation should be taken seriously before installation. When installing the floor along the logs, it is important to correctly calculate their size, the amount of material, the distance between the bars and the parameters of the house itself. If you strictly follow the instructions for laying the floor along the lags, the surface will not sag and creak, but will only bring joy and comfort to the residents of the house. After all, despite the ease of installation, the process of installing such a floor is very responsible. And it is better to constantly monitor all actions in order to avoid mistakes. If you have something to add, or you want to leave your opinion about the article, write in the comments!

Modern technologies in construction are unique opportunities. For many, such words as bridging and polymers, tape floor, GOST, cabinets, column connections, dimensions 100x200, or 150x50 do not say anything. But those who have already encountered the repair know that we are talking, most likely, about the field on the logs. Someone just wants to reinforce the floor, while someone needs to lay a new, durable and beautiful one. And very often the technology of arranging the floor on the logs is used.

It’s worth saying right away that laying the floor on the logs is in many cases simple perfect solution. Indeed, this method has many advantages. It is very important that the floor is warm.

It is also worth making the floors on the logs as:

Noise from neighbors in the apartment below will not penetrate to you;
Installation can be completely done by hand;
The cost of the floor and work is quite acceptable;
Wires and pipes, not very attractive, but necessary, can be hidden under such a floor;
This is an eco-friendly floor.

When you work, the smell in the room will be very pleasant. For many, by the way, the smell of processed wood is a real antidepressant, which by itself cheers up and sets you up for work.

Lags are called bars, which are needed as a support for a hard floor covering. Logs can be made of metal, polymers, reinforced concrete, but usually wooden logs are taken to be laid. Wood is easier to work with and cheaper.

Logs differ from beams in mobility and smaller sizes. Beams after installation, if given figurative example, you can’t move, but lags can. Yes, and it is much easier to mount them, and if repairs are needed, it will be simple and quick.

Installation tools: laying floors on logs in the house

To work, you will need a hammer, level, screwdriver or drill, knife. The following materials are taken for the manufacture of such a floor - pieces of chipboard or plywood, any insulation, self-tapping screws, corners or U-shaped fasteners.

To prepare the floor for installation, the entire floor area should be freed. Check the old screed, if the concrete floor is already deprived of integrity, it needs to be patched up. Then debris and dust are removed, everything should be clean. Then you need to eliminate the defect of the subfloor. The floor should be primed. No matter how much the pros say about the need for a primer, there is some kind of careless attitude to this procedure. The primer is right, it must be absorbed and dry, and only then the flaws are filled.

Then, the level is calculated maximum point surfaces in the room. You need to set a mark so that this is a guide for subsequent work. And then the work develops according to two possible scenarios: to make a screed, bringing the surface to one level, or to set the logs to the level with plywood gaskets big size.

Step-by-step instructions: do-it-yourself installation of a floor lag

It all starts with the fact that solid or connected bars are laid out across the width of the room. The first bar and the last will be located 20 cm from the wall. You need to calculate the step between the lags in advance.

It is necessary to bring the level of the floor, the quality of the finish coating will depend on this moment;
All bars must be placed in the same horizontal plane;
For lifting, linings of bars or plywood are used;
It is not enough to install, you need to fix the logs, for this, either self-tapping screws are used, or anchor bolts are installed;
The length of the fastening interval is 70-80 cm, you drill the timber, grabbing concrete foundation, tighten the screw.

There is an option to install a log and on adjustable fasteners, turning it, you will achieve the desired result. By the way, if the finish is not a wooden floor, but ceramic tile small size, then the distance between the bars will be 30 cm. Only in this situation there are also transverse logs, moreover, at the same distance. They need to be fixed at an equal level with longitudinal bars (a corner is used). Such reinforcement of the structure must be used, because the size of the tile is small.

Modern logs for the floor: the size of the timber

The reliability of the design depends not only on whether you use a board or metal elements, but also on whether the calculation is correct. First, the length and thickness of the beam is determined. Length is the length and width of the house. In this case, it is imperative to leave a gap, and the beam, respectively, is selected 20-30 mm less.

Such a ventilation gap is necessary - it prevents deformation if changes in humidity and temperature occur.

The cross section of the beam, its size is more difficult to calculate. Here, the potential load on the floor is important, as well as the size of the spans between the support points of these lags. There is a table that makes the calculations easier. The larger the span, the thicker the beam will be. For example, the span size is 3m, which means that the lag section is 150 by 80 mm. The sectional shape is usually rectangular. Install the beam on the edge so that the logs can withstand high pressure.

What is the distance between the floor joists

The lag step will depend on the thickness of the flooring. If you use flooring from durable thick boards, logs can be fixed relatively rarely. Well, a thin and not particularly durable coating requires more lag.

Dependence can be seen in a couple of examples. For example, the thickness of the floor board is 30 mm, which means that the interval between the lags is half a meter. Or a thickness of 40 mm, therefore, a step between lags of 700 mm.

You really don't need an exact calculation. It will be sufficient to take just the distance between our lags of the average value. And if at the end of the installation you saw that the distance was inaccurate, then make the step between these last lags smaller, and the structure will be strong.

Beam size: floor joists

The length of the beam should be approximately 3 cm less than the width and length of the room where the floor is laid. The length of the log must necessarily be less than the length of the room in order to avoid deformation of the structure if temperature changes occur. It is good to make logs from solid materials, but sometimes the bar needs to be lengthened.

Two elements are spliced according to the rules:

There should be supporting elements under the splicing point, for example, poles;
If adjacent logs are spliced, then the splicing points are positioned relative to each other with an offset.

The connection must comply with these conditions, otherwise there may be a threat of low floor stiffness in the very place where the timber is spliced. Neighboring logs are spliced with an offset of a meter. This fact affects the size of the bars taken.

Algorithm: laying the floor on the logs with your own hands

Lay wooden log needed from the corner of the room. Then, the first row is usually placed with a tongue and groove relative to the wall, and in this case, the gap between the wall and the lag should be 1 cm (to avoid wood deformation). Then a number of logs are laid offset relative to the first log, by about a few bars.

In order for the boards to be firmly attached to the base, you need to knock a little on the wood with a construction hammer. This is necessary for the reliability of fastening. Boards are attached along the wall, fixed with screws. The screws may be on the surface, it doesn't matter, the skirting boards will close them.

Hint: how to increase sexual lags

Everything is individual here, but some general rules There is. For example, if the floor lags and the strapping lower beam are at the same level, then you can fasten them together with forged brackets, or they will help perforated corners. If the logs are located below the strapping beam, then a metal bracket is used.

Roughly speaking, the main purpose of the reinforcement is the rigid fixation of the floor log and the bars. lower crown. In this case, when strengthening the floor, the floorboards will stop moving apart. Still, as an option, you can rally the floors until the cracks are eliminated, and the gaps are simply covered with skirting boards.

How to put logs on the floor (video)

Today, when the floor can be laid, poured, made polymer coatings, use plastic parts, brick inclusions, etc., from classical ways many refuse to repair. But sometimes, instead of complex and expensive designs, old and proven methods are required. The same floor on the logs, which will "make friends" with both a wooden and a brick house.

Despite the fact that wooden floors have a shorter service life and are subject to negative impact various factors, many consumers prefer them. After all, they are light weight, affordable and environmentally friendly. Floor lumber is one of the most popular options in suburban construction. The basis of this whole structure are floor logs, which are also made of wood. Although today some manufacturers offer logs made of polymeric materials, which are superior to wooden ones in many respects.

Why are lag floor structures so popular?

Reasons for the popularity of lag structures

They have a number of advantages:

This design is excellent thermal insulation properties. By the way, under it you can put an additional thermal insulation material.
The affordability of lumber and minimum expenses on them.
The load acting on the foundation, floor beams or concrete slab is minimal. At the same time, free space is formed under the wooden floor, which can be used for laying communication networks.
The ability to raise the floor plane to any level. Sometimes designers, using this, create multi-level floors.
Rapidity installation process when compared with setting cement-sand screed where you have to wait for it to dry. In addition, you can do the installation yourself, thereby saving a decent amount from the family budget.
Due to the wooden floor, you can create a certain microclimate inside the premises.

With the floor installed on the joists, you can avoid the high costs and time associated with leveling processes. After all this design itself performs the leveling function. The void under the plank floor is a peculiar ventilation duct guaranteeing long-term operation of the structure. But experts still recommend processing wooden materials antiseptic compounds.

Design and technical features

Immediately make a reservation that you can lay the floor on the logs, no matter what the foundation is in your house. This can be ordinary soil, floor beams or a concrete slab. The design in all variants is approximately the same with slight deviations, which mainly relate to the fastening of the log.

If we talk about what lags are, and what they are made of, then this cross beams, on which a wooden top coat. Currently, the most popular are logs made of wood or plastic. Less often - from metal or concrete products. wooden elements choose because of their low cost, and polymer - because of the speed of the installation process and ease of installation.

Attention! If for some reason it was not possible to purchase a wooden beam for a log, you can use double boards as this element. They are usually laid on edge. In terms of its strength characteristics, a double board is in no way inferior to a beam, and if you take boards of a large section, then their quality increases significantly.

Beginning of work

Out-of-town developers always face the question of the strength of the lag structure. How to choose the right section of the beam for the logs? Experts say that this will have to take into account several factors regarding the design of the floor as a whole. Here you will have to take into account the span, which means the size of the area of \u200b\u200bthe room, the thickness of the boards being laid, and so on. But one indicator must be unchanged - this is the ratio of the height and width of the beam itself. It should be 2x1.5. That is, the height of the beam should be a multiple of 2, and the width should be 1.5.

For example, a beam of 70 × 100 or 150 × 200 millimeters is selected. In the event that the floor is arranged according to wooden beams overlappings, then the wider the distance between the beams, the larger the logs in the section should be.

Pay attention to the location of the ventilation gap. The distance between the finished wooden floor and the heat-insulating material between the joists must be at least 2 centimeters. And it is better if this figure is 3-4 centimeters. So you need to purchase lags taking into account this gap. If the floor is mounted on logs that are installed on the ground, then you will have to take into account the size of the cranial bar, which is attached to the structure from below and creates the necessary roll.

Some craftsmen advise purchasing a beam with a section margin so that it can be reduced as needed. But such an operation is beyond the power of a non-professional, so it is better to purchase material exact dimensions, and when leveling, use linings. If the lag structure is being built on the ground, then brick columns are suitable for leveling in the plane. But keep in mind that for this it is better to use red brick brand M100. Can also be used silicate material, but you will have to find information about how deep they lay ground water. If this figure is below 2 meters, then use it without problems.

A few words about laying the log on the columns. Most important point- this is the definition of the distance between the rows of stacked beams. Mandatory for every brick column you need to fill in a small foundation measuring 40x40 centimeters. Sometimes they fill strip foundation under one row of columns. The minimum number of bricks in a column of one layer is 2 pieces.

Installation step

Insulation between joists

This constructive indicator is one of the most important. It is on its basis that the calculations of the amount of materials are carried out. There is one contradictory feature here. If you choose the distance between the lags of a large size, then the deflection of the finished floor elements will be greater. He will not be able to withstand heavy loads. So, it is necessary to increase the thickness of the floorboards. And than less distance, the thinner the boards. This suggests that if you want to save on the number of beams, you still have to buy expensive boards.

For example, if you purchased boards with a thickness of 24 millimeters, then the distance between the lags should be 30–40 centimeters. If the thickness of the boards is 50 millimeters, then the distance between the lags can be made 1 meter. Traditionally, in private country houses, a board of 40 millimeters is used, hence the standard distance between the elements of the lag structure, equal to 70 centimeters. In any case, each developer must decide for himself what size floor elements he needs.

Attention! The distance from the wall to the first element should not exceed half the distance between the joists. Traditionally, this is 20-25 centimeters.

How to properly orient the installation

The orientation of the structure in space is an important component of the installation process. What do you need to know for those who assemble the floor with their own hands?

The direction of laying a finished wooden floor - boards - should be along the room, that is, perpendicular to the wall where the window is located. Thus, natural light should not create shadows that can be formed by the laid boards. Then the floor will seem monolithic.
In those rooms where the traffic is very high - a corridor, an entrance hall, a vestibule - the boards are laid along the direction of movement.

Accordingly, the lags are installed perpendicular to the boards.

Mounting methods

The creak of a wooden floor on the logs can be an unpleasant surprise.

More recently, lags to concrete floor fastened with ordinary nails. But this type of fixation was not the best and most durable. Today, more and more often began to use additional fasteners in the form metal corners various shapes. What does the instructions for this mounting method say?

For fixing wooden structures, only self-tapping screws are used.
The depth of penetration of the self-tapping screw into the wood is 3-4 centimeters.
If the lag is attached to a brick or concrete column, then dowels are used instead of self-tapping screws.
Sometimes instead of corners, "P"-shaped metal constructions, which are a strengthened version of the former.

The sequence of installation work

The lag structure can be built after raising the walls, but the boards themselves are mounted only after all the rough finishing work in the form of plaster and putty, as well as after the completion of the painting processes.

The sequence of erecting the floor on the ground is as follows:

First of all, the soil is compacted, and crushed stone is poured with a layer of 5 centimeters. This results in an incompressible foundation.
Formwork is installed under each support, and small foundations are poured. After they dry, brick columns are erected. Please note that between the column and the foundation there must be waterproofing - roofing material, roofing felt or bitumen. It is laid on the posts upper layer waterproofing. You can also install a soundproof gasket.
Lags are installed and fixed. Required condition- exposure in one horizontal plane. A cranial bar is attached along their lower edge. The draft floor is mounted along the bars, for which cheap lumber can be used.
A layer of waterproofing is laid, heat-insulating material, another layer of waterproofing roll material, and the boards are being installed as a finishing floor. Please note that the boards should be located two centimeters from the walls. This gap will compensate for the expansion of the lumber with changes in humidity and temperature inside the room.

Adjustable floors

If wooden floors are assembled on beams or on a floor slab, then many processes are eliminated, which reduces the time of work and the number of necessary materials. For example, brick columns will not be needed.

The modern approach to many construction processes, including the construction of a wooden floor, has led to the introduction of advanced materials on the market. For example, the logs were completed with special lifting mechanisms, with the help of which you can easily and quickly change their position in space. Such a mechanism is a core, which is based on threaded connection bolt nut. The rod has two support plates supporting the floor and the beam itself. By rotating it, you can raise or lower the edge of the log. According to many experts, this is a very convenient device, several times reducing the time for setting the log in one horizontal plane.

Conclusion on the topic

It may seem to many that it is not so difficult to properly lay a wooden floor. But this is only apparent simplicity. To install the logs for the floor correctly, you have to sweat. In addition, the complexity of the process will depend on the installation technology. If the structure is installed on the ground, then there will be a lot of work. In addition, the foundation poured under the supports must be dried, which increases the time of work.

Ruslan Vasiliev