Construction of the subfloor: what is hidden under the floor covering. Subfloor in a wooden house: arrangement options, insulation, stages of work How to install a subfloor

To privately wooden house to obtain, it is necessary to make a multilayer structure. This will ensure a cozy microclimate in the room and save money on heating.

But, in order to properly equip your own hands with an even and high-quality final coating, you must first make a subfloor. The structure and complexity will be dictated by the type heating elements, which are planned to be installed in the house.

A subfloor is needed, first of all, to level the surface on which the final coating will be laid. That is why during installation it is necessary to maintain the horizontal position of the laid logs and beams, because they will be the base.

Also, a subfloor is necessary to create high-quality thermal insulation in a wooden house. Its thermal insulation layer is different thicknesses, which depends on the specific insulation used, and it is mounted on waterproofing.

Each element consisting of wood in such a floor must be impregnated with a special moisture-resistant mixture to prevent them from rotting in the future.

In the first few years after laying, log houses can shrink significantly, in some cases up to 17 cm within 3 years. To prevent this from causing deformation finishing coating, a system of fastening subfloor elements directly to the walls of the room is used.

In such structures they are rarely used concrete screed, to create a flat surface. The entire load during the use of the house falls on the subfloor, which is why for installation it is advisable to choose dried logs and timber with a thickness of at least 5 cm.

In order to correctly distribute the load on the base, it is necessary to correctly select the step for installing the logs and the thickness of the boards.

During the construction of a home, the subfloor will determine what type of subfloor should be used.

Typically installation occurs on:

• special floors (either beams or reinforced concrete slabs);
• directly to the ground.

To create a high-quality subfloor in any wooden house, the following materials are used:

1. Brick pillars, the size of which is 40x40 cm and at least 20 cm in height. They will be installed with cement mortar. To determine the required number of them, you need to carry out a calculation based on such parameters as the size of the log, as well as total area premises.
2. Waterproofing. It can be as usual polyethylene film increased density, as well as other materials with such properties. Such material is necessary to prevent rotting of wooden elements.
3. Lags. They will be attached to the installed brick pillars. The distance between them is determined by the size of the boards, and their length will be equal to the corresponding characteristics of the room.
4. Fastening elements such as corners and bolts.
5. The material that will be used to apply the rough coating. It can be like boards or plywood.
6. Elements that will be used as insulation and waterproofing materials.

To choose the right material, you need to give preference to those types that meet stringent requirements. When choosing, you should take into account: the presence of good thermal conductivity, strength, as well as fire safety of the material, complexity of installation and weight.

Among the insulation materials, the following have optimal qualities: expanded polystyrene, glass wool, and also basalt wool.

• The first option is a very expensive pleasure. Typically, its use is advisable in cases where the insulation needs to be placed in a layer of minimal thickness.
• Basalt wool is average in terms of price/quality ratio. It is quite dense, non-flammable and has good moisture-resistant properties.
• Glass wool is very sensitive to dampness, so good waterproofing is necessary for its installation.
• Isoplast, polyethylene, as well as PVC membranes and ordinary roofing felt are used as waterproofing. These products have good basic properties to protect the insulation from possible penetration of moisture.

Installation of the subfloor is step by step process laying different layers:

1. First you need to nail the skull blocks to the joists in the lower side part. For this purpose, boards are suitable whose width is 8 cm greater than that of the joists. ;
2. The boards are laid on top of the bars and are not fixed. They will act as the basis for the next layer of thermal insulation;
3. Various film options act as waterproofing. During installation, it is worth remembering that this material should go slightly onto the walls, where it will be fixed with a stapler;
4. After waterproofing, insulation is laid between the beams. If the height allows, it can be laid in several layers, and on top of it is a vapor barrier, which should also extend onto the walls. Fixation can be done using a stapler and tape. If the logs are the same height as the insulation, counter battens are used to create ventilation. They need to be nailed along the joists and you will get the required clearance;
5. The last layer is a covering of boards or chipboard sheets. During installation, a gap of 2 cm must be left between them and the wall. It must be sealed with thermal insulation, after which the subfloor will be ready.

The load from the structure falls on its foundation. The structure that precedes the final coating and serves as the basis for the insulation is the “subfloor”. The temperature regime of your room depends on how it is installed. If there are cracks left in it, cold air will begin to flow in from below, dampness and a rotten smell will appear in the house.

Description

When choosing a material for load-bearing beams floor structure as a whole, consider the area of ​​the room for which it will be intended. The larger it is, the thicker they are. This factor is explained by the fact that fine coating and all materials that are involved in the process installation work, should be evenly distributed on them.

How to make a subfloor in a wooden house

There are several options for its formation, but the “dry” method is more often used.

The subfloor is formed according to the following principles:

• According to the lags.
• “Prefabricated”, using dry screed.
• “Adjustable” (on plywood and chipboard).

"Prefabricated" subfloor

"Adjustable" subfloor

If the boards are laid on logs, then they are laid on the following base:

• Beams.
• Iron concrete slab.

The adjustable floor is formed on the following bases:

• Lags.
• Plywood.

What do you need to know?

It is laid on the main floor using less hard wood. These include coniferous varieties. These are the following types:

• Edged board.
• Gorbyl

In order to achieve the expected results from the installation, you need to know the following:

• The basis of the entire floor structure is a beam, which is laid on a layer of waterproofing (two layers of roofing felt).
• Rolled protective material or 2 layers of polyethylene are spread on it high density.
• Logs are attached to the beam, which serve as a frame for installation. They are not brought to the walls, leaving a gap of up to 30 mm. This distance will be insurance against possible soil shrinkage (change temperature regime and level groundwater in the soil) and natural fluctuations in the moisture content of the log during its operation.
• The artificially created free area between the wall must be filled with mineral wool.
• The entire tree must be treated with antiseptics and fire retardants. If materials that are ready for use are purchased, then the cuts made must be protected from moisture and bark beetles.

Do-it-yourself subfloor in a wooden house

To carry out the work, use a board with a thickness of 15 to 20 mm. Properly prepared for milling machines the original material will create grooves and shoulders on its side. This option will eliminate the need to work with a hammer and nails, which will speed up the assembly process and the tightness of the connection. The rigidity of the structure will not create creaking.

The thickness of the subfloor board affects the distance (step) between the joists. The larger it is, the wider this gap. For example:

• With a board thickness of 40 mm, the step between the lags can reach one meter.
• With a thickness of 35 cm, the step between the logs should not exceed 850 cm.
• If the thickness is less than 35 cm, the step between the lags should not exceed 60 cm.

The correct location of the foundation pillars is of great importance. They are located around the entire perimeter and in the central part of the building.

The thickness of the log is directly related to the spacing of the foundation pillars, since the main beam is attached to them.

The following relationships should be observed between the dimensions of the logs and the pitch of the foundation pillars, expressed in centimeters:

• The logs are 40 thick with a pitch of no more than 900.
• Logs thickness 50 at a pitch of 1100.
• Logs thickness 60 at a pitch of 1300.

Installation of subfloor using plywood

The sequence of work is as follows.

• The beams are placed on a layer of waterproofing.
• They lay on them roll material, providing protection from moisture.
• They fix the logs.
• They are lined with plywood sheet 10 mm thick or moisture-resistant boards (MDS, VAT).
• The seams of the connection are covered with construction tape or sealant is poured.
• Cover the subfloor with a layer of vapor barrier.

To insulate against condensation from the room side, the following materials are used:

• Cement mortar.
• Thick cellophane in 2 layers.
• Rolled foamed polyethylene on a foil base (lay with foil to the room) and other materials.

An air barrier must remain between the vapor barrier and the floorboards. The subfloor must be ventilated through holes in the foundation (vent).

Before application, insulate pipes and meters with construction tape. Apply in layers using a brush, roller or rubber spatula. Please pay attention Special attention hard to reach places. After the first layer, self-adhesive tape must be applied to all joints and joints. It will be covered with the second layer. The composition should be partially applied to the wall (its lower part).

There are other materials for carrying out similar work. Rolled foil insulation can be used, which will simultaneously help insulate from noise and retain heat in the room. They are laid overlapping with the metal part towards the room.

Video: Correct installation subfloor

Conclusion

This type of “dry subfloor” can serve as the basis for the formation of the main coating. In some cases for installation parquet board or laminate, the finished structure is covered with a layer of waterproof plasterboard.

Video: How to make a subfloor from plywood?

Many novice builders who have just started building their home are already wondering what kind of linoleum or laminate they will lay in their future room.

And soon, they are faced with the question - How and on what to lay this linoleum. Of course, we all understand that first you need to make a so-called subfloor - a base on which you can subsequently lay any floor covering you like. But how to properly make a floor “from scratch” so that it is reliable, smooth and, most importantly, warm. You will find the answer in this article.

To make a subfloor with your own hands, you do not need any professional skills or special tools. The main thing you need is good physical strength and a head on your shoulders, as well as some very ordinary tools. But more on that later, first you need to decide which construction material will need to be purchased for the construction of a subfloor. Choice of flooring materials construction market is now huge, but we will consider the most common option - no less reliable and at the same time not expensive.

We use the following lumber:

— wooden beam with dimensions 100 by 150 mm (or 150 by 200 mm) and length 6000 mm;
— wooden block with dimensions 50 by 50 mm (or 60 by 60 mm) and length 3000 mm;
— planed boards 50 mm thick and 6000 mm long;
- OSB sheets with dimensions 1250 by 2500 mm and minimum thickness 12 mm.

It is advisable to use it as insulation basalt insulation(simply glass wool). To protect lumber from mold and rot, you need to purchase a special solution (antiseptic). You may also need cement mortar during the construction of the floor. Now let's look at all the lumber used separately, as well as what role they play in rough floor.
Lumber used.

Wooden beams with dimensions of 100 by 150 mm are used as load-bearing logs, on which the entire floor in the room will subsequently rest.

Bars with dimensions of 50 by 50 mm are intended for placing insulation in the floor.

The cost of timber averages about 6,500 rubles per cubic meter. To calculate the total cubic capacity of all beams, you will need to calculate the volume of one beam and multiply by required amount bars The volume of any beam is calculated as the volume of a parallelepiped.

Choose correct board
The board is playing important role, therefore, it is better to use planed larch as the base of the subfloor. The cost of one cube of such a board is approximately the same as that of beams. The cubic capacity is calculated similarly.

All lumber listed must be made primarily from coniferous species trees, such as larch, it is less afraid of moisture and dampness, which means it will last longer. By the way, the whole of St. Petersburg, which is already more than 300 years old, was built from it!

When purchasing beams and boards, you will need to take into account that the drier the lumber, the better and more expensive it is. After all, dried boards will no longer warp and will not fly (by helicopter), for example, during the heating of a house. Therefore, we select lumber based on the following criteria:
— the lower the humidity level, the better, you can take it straight from the dryer;
- timber or boards must be smooth, the surfaces without significant defects, cracks and delaminations.
OSB sheets (plates)

These so-called OSB boards are used to complete the construction of the subfloor. Subsequently, OSB panels will serve as the final basis for the floor covering. Translated into Russian, OSB is translated as OSP - oriented particle board. The material itself is a board pressed from sawdust.

Behind recent years 5, OSB boards have become increasingly used for finishing walls and floors and are considered a fairly good basis for almost all types of finishing materials.

The main advantages of OSB boards:
— high moisture resistance;
- high mechanical strength;
- the material is easy to install.

One OSB sheet with dimensions of 1250 by 2500 mm and a thickness of 12 mm will cost you about 700 rubles. Many Russian manufacturers They sell OSB boards that cost less than 500 rubles apiece. You should not lean towards a cheaper option; it is cheap OSB panels that have received bad reviews due to their low level of environmental safety.
We've sorted out the materials, now we'll find out what tool you'll need to install the subfloor. Prepare or buy next tool, with which you will simplify your work as much as possible:

- hammer;
— electric jigsaw;
- hacksaw or electric saw;
- roulette;
— level 1.5 meters long;
- stationery knife;
- nails 50-100 mm long.

Stages of subfloor construction

Let's first figure out how to properly position the logs. Before you understand correct location Okay, let's go back in time a little. It is advisable to take care of the construction of the floor even before the construction of the main walls of the house, that is, immediately after preparing the foundation. After all, then it will be impossible to correct anything in the location of the lags.

First, we treat all the beams (for the first floor) with a special solution (antiseptic) against mold and rot. The fact is that the logs are located near the ground, under the house and will always be subject to humid environment.

After laying the beams, check that they do not touch the ground (the distance from the bottom of the beam to the surface of the ground must be at least 20 cm). That is why all the space inside the foundation is always cleared in advance.

So, we place the beams perpendicular to the direction of the longest side of the future room with a step of 80-100 cm. The more often the step is maintained, the less the floor will wobble and play, but this will require more building materials, and therefore more costs.
We place all the beams with an “edge” to increase the rigidity of the floor and make it as high as possible from the ground level. Agree, a room on the ground floor with too low windows is not the best option. We place all the logs, strictly in horizontal position, checking them with a level from the edges, in the middle and between adjacent beams. If necessary, the edge of the beam can be raised using cement mortar.

The beams should rest with their edges on almost the entire width of the foundation, and their ends should be covered with cement mortar or closed from the street. There is no need to specially attach the logs to the foundation - we simply lay them, but so that they are firmly adjacent to the surface of the foundation and do not wobble.

It is advisable to lay all the boards, even before erecting the walls, on joists and cover them with the same anti-mold solution. You can also adjust them to size and trim the boards that are too long a little, so that later, indoors, it will be more convenient to work with them.

Finally, we make the base of the floor after the walls are erected. We measure all the boards so that at the end there is a gap of 3-5 mm between the wall and the board. This gap is needed so that the board does not rest against the walls during the shrinkage of the house. We lay the boards perpendicular to the direction of the lag.

We nail each board with “weaving” nails, one or two logs every other. You should not hammer three nails into each beam - you will not gain anything by doing this. The boards should also not be pressed too hard against each other. The first board is placed at a distance of 3-5 mm from the wall, the last one is adjusted to size. You may have to adjust the last board and saw it lengthwise.


To insulate the floor we use bars and basalt insulation. To insulate the floor, it is necessary to build something like a frame in the form of a lattice of 50 by 50 mm beams. You will place insulation 50-60 mm thick into the cells of this frame. Insulation in our case comes from slabs, but if you don’t like it, you can insulate it with soft wool, just keep in mind that for the same soundproofing effect as from slabs, you will need twice as much soft wool. For example, if you open up a wooden floor in a Soviet apartment, you will see a similar lattice, and in rare cases, even with insulation.

The bars must be distributed in increments equal to: width OSB boards divided by two, that is, approximately 620-630 mm. The bars are also laid across; here you determine the step at your discretion.

Try to place all the bars in horizontal level. This can be achieved using small wooden wedges. It won't be difficult to make the wedges yourself.
Important! We nail the bars to the boards, as in the previous case.
We lay the insulation in small rectangles, cutting out right size stationery knife.
Important! When working with insulation, be sure to wear goggles and a mask.

A small digression.
There's another one that's pretty bad bad way floor insulation. Although it is used primarily for insulating the floor of the second floor, it is also suitable for the first floor. Here, the insulation is placed in the space between the joists. To keep the insulation in place, boards 80-100 cm long are nailed to the joists from below; you must agree, this is not very convenient. Moreover, you should try to nail the boards tightly to each other so that the insulation does not crumble over time and does not fall to the ground inside the foundation. However, in this case, you can lay the insulation in a thicker layer, and the floor will be better insulated as a result. With this method of insulation, the installation of bars 50 by 50 mm will not be necessary.

Construction technologies are constantly changing. Modern methods often more effective, but not always cheap. In particular, one of the most affordable flooring technologies is a subfloor with joists. Yes, it's not perfect, but so far it's the most cheap way make the floor In any case, in those regions where the price of timber is still low.

In floor construction, subflooring can serve two functions. The first is to serve as a basis for laying heat, hydro, soundproofing materials. The second function is to serve as a support for finishing flooring or floor screed under the floor covering. Moreover, insulating materials can also be used to improve performance.

One of the options for heated floors and tiles using

Is it possible to make a finished floor without a subfloor? Basically, it is possible, but in this case it is more difficult to achieve the required characteristics. If the requirements are not too high (dacha, summer or guest house, technical building) and it is important to get only minimum required, you can do without a subfloor.

If the requirements are high (for a residential or heated building), as a rule, the design without rough flooring requires more money. Why? For subfloor use inexpensive materials. The main selection criterion is strength. On appearance no attention is paid and this allows the use of inexpensive materials. For example, unedged board(after appropriate processing), construction plywood, lean concrete slab. Other materials are laid on the rough base and the claims to their strength are minimal. The main emphasis is on “protective” characteristics. After all, the load falls on the floor structure and rough flooring, and not on these materials. And as a rule, they are relatively inexpensive.

All rough foundations can be divided into two large groups: dry and wet. All types or are considered wet. But we are not talking about them here. We will talk about dry ones, and in terms of joists and beams.

Today there are more modern technologies, but the subfloor remains the cheapest in terms of joists. This traditional version, which has been modified in order to adapt it to modern requirements of comfort and efficiency. But even with changes, it is difficult to achieve those parameters that are considered the norm today. In particular, sound insulation and thermal insulation cannot be ideal. You can only get closer to the norm. But the solution will not be the cheapest.

Floors on wooden beams

Beams in a floor structure are wooden or metal elements that rest on the foundation and serve to transfer the load. Since wood is still the cheapest tool for us, most often our beams are wooden. They are made from timber - solid, glued, or spliced ​​beams (from several boards) are used.

Beams can rest only on the foundation and may have intermediate supports. In houses with a subfloor, piers serve as intermediate supports; in the absence of a subfloor, brick columns are stacked or pillars are made of reinforced concrete. Two layers of waterproofing (roofing felt or something like it, but not film) are laid on these supports, and beams or joists are supported on the waterproofing.

Beams and logs - the difference

How do beams differ from joists? In short, beams are load-bearing structures, but joists are not.

A beam is a linear element of load-bearing structures, supported at both ends (unlike a console) and working primarily in bending. As a rule, the cross-section of the beam is rectangular or square. In wooden houses they are also made from hewn logs. The installation step of the beams and their cross-section are considered when developing the project. Logs are also prescribed, but they are not so critical, so their characteristics can be changed during the construction process.

Lags are not elements load-bearing structure and they are simply made from a thick board, which is often placed “standing” - resting on the narrow part. With this installation, it is convenient to lay insulation between the joists - when choosing the step for installing the joists, the width of the insulation is also taken into account. The subfloor along the joists can also have insulation on top. This type is called a floating floor, since the finishing coating does not have direct contact with the base (in this case, the rough flooring).

There are two important points. The first is when using mineral wool as insulation, you need to measure the actual width of the roll or slabs. It does not always coincide with what is stated. Second, the distance between the logs should be 3-4 cm less than the width of the insulation. Then it can be placed in a spacer and it will hold on due to the force of elasticity. This makes installation easier. But there is one more advantage of this solution. Even if the insulation shrinks a little or dries out during use, gaps will not appear between the wool and the joist, since the material will straighten out.

When laying insulation, the main thing is not to leave any gaps and minimize cold bridges

When using polystyrene foam, polystyrene foam, or polyurethane foam as insulation, the pitch of the logs (and their cross-section) is also better to select. But in this case, “compressing” it will not work. The slabs are cut into pieces slightly smaller than the distance between the joists, and the cracks are filled with polyurethane foam.

Lag installation step

The installation step depends on the board from which the logs are made:

• for a board 40 mm thick, the distance between the centers of the support is 80-90 cm;
• 50 mm - distance 100-110 cm;
• board thickness 60 mm - 120-130 cm.

The subfloor is the basis for the finishing floor, so it must be leveled to the horizon. The smoother the base, the less problems when laying other materials. Therefore, already when installing the logs, their edges are brought out at the same level.

One of the possible options

If the pitch of the beams is small - up to 80 cm, the rough flooring can be laid immediately, without logs (40 mm board). At big step Logs are laid across the beams, and a subfloor is laid on them.

A couple of comments about the wide board. If your budget is limited, you can save money by making prefabricated joists. Two 25mm thick boards cost less than one 50mm wide board of the same length. We buy two boards, stack them one on top of the other, connect them with nails or self-tapping screws (nails are preferable). We install the fasteners on both sides in a checkerboard pattern. The logs are placed “on edge”, so that they are even stronger than the board – there is less chance of cracks appearing along the wood layer. There is one more nuance that will help to avoid “torsion” of the prefabricated log: we arrange the boards so that the annual rings are located towards each other.

Floor structures on wooden beams

When installing a subfloor, a board is often used. Basically, it serves only as a basis for laying insulation. The load from the insulation is small, so you don’t have to knock down the flooring tightly, but leave a gap of up to 1 cm. But such a sparse installation is suitable for materials with sufficient density. When using bulk thermal insulation, you will have to make a continuous sheathing.

For long beams or joists, intermediate jumpers are also added for a more stable geometry.

Subfloor on joists under screed (floating floor)

If necessary, you can do it. The only question is whether the beams can withstand the load. This is calculated separately. What's good about this design? Because:

• An ordinary “cold” floor can be made warm. You can even heat it up (if the beams can handle it).
• You can lay tiles on top of a concrete slab, lay sheet material and lay coverings that are demanding on the base - laminate, PVC tiles, linoleum.

Using the same principle, you can make a subfloor using wooden joists without cement. As a top layer, you can lay plywood, OSB and other sheet materials that you consider suitable in two layers. Again, tiles and any other type of finishing coating can be laid on such a base.

What kind of logs and board should I use? You can/should be selected, since the thickness of the board depends on the step of installing the logs:

• the distance between the lags is 80 cm (up to 100 cm is permissible, but not under screed or tiles, under lighter coatings) - board 40 mm;
• installation pitch lag 50-60 cm, board 30-35 mm;
• for boards smaller than 30 mm, support is required with a distance of 35-40 cm (depending on the specific thickness).

In this case, the subfloor may not be continuous, but with gaps. Under a concrete slab, it is best to use extruded polystyrene foam or high-density polyurethane foam as insulation. You can use foam glass (foam glass), but it is very expensive. These materials can normally withstand the weight of a monolithic screed. By the way, since it is laid on an unstable base.

How to ensure long-term use

With this type of floor design wooden beams, it is important to protect the subfloor board as best as possible from rotting. If there is an underground floor below, you need to make sure that it is ventilated (vents) and that the humidity in the underground is as low as possible. You need a blind area around the house (preferably insulated), as well as a drainage system.

How additional measure film with sand is used. A thick sheet of paper is spread on the ground PVC film in two layers - glue the joints with tape, place them on the foundation and secure them there. A layer of sand is poured on top of the film (at least 5 cm, but more is better). Film most it does not let in moisture (if it is intact and the joints are well taped), and the sand adsorbs the excess and then slowly dries out. The same method is used when using any other subfloor along the joists.

Subfloor made of OSB (OSB). You can remove the rough flooring from the board and lay the slab in two layers

As already mentioned, the subfloor board can be edged or unedged. Required condition— operating humidity. Chamber drying Few people will lay it, but the board must be dry - at least 6-9 months of drying. If the floor of the first floor is being laid, the material must be processed protective compounds. The humidity in the underground will be high, so the quality of processing should be good. It is better to process several times. There are more than enough chemicals for wood today. You can select by properties. If needed folk remedies is a processed oil.

Ground floor above ventilated subfloor

The ceiling of the first floor above an unheated underground floor is different in that it must be well insulated. If you are not going to heat the floor, you need to make sure that it is comfortable even with working air. To do this, it is better to make two layers of insulation and place them in different directions.

In this design, the rough flooring is only a support for the first layer of insulation, so it makes no sense to take a thick board here. Usually they take 25 mm, process it and use it for filing. In the design shown in the figure, a cranial block is nailed to the bottom of the beams. Usually its cross-section is 25*25 mm. A roughing board is placed on the cranial block. The segments are short - the length is equal to the step between the lags. You can use substandard lengths for this flooring, but there is less waste if the length is a multiple of the joist pitch.

Waterproofing is laid on the rolling boards. Please note that if mineral wool is used as insulation, the material must be vapor permeable. It should make it possible to remove moisture from the insulation. If the insulation is polystyrene foam, polystyrene foam, foam glass, they themselves do not conduct steam and this layer is generally irrelevant.

The thickness of the insulation should be such that it top edge was 2-3 cm below the edge of the beam. This is necessary to provide a ventilation gap. Wood changes humidity and it is necessary to give this opportunity by leaving a ventilation gap.

A cross frame is laid across the beams. These are lags. Their height depends on the required thickness of the insulation, and the installation step depends on what kind of flooring you plan on top. The dependence of board thickness on lag pitch is described above. But this can be not only a board, but also any sheet material.

Waterproofing flooring at a distance of 2-3 cm from the surface of the insulation

Vapor-waterproofing is laid on top of the insulation. This time the material should retain both vapor and liquid. In case of using mineral wool, it is better to use a membrane with one-sided vapor permeability (for example, Isover or other brands have it). It must be laid so that steam can escape from the insulation. This solution is better, as it makes it possible to maintain normal humidity in the floor cake.

There are also options with one layer of insulation (in the figure above). This method is convenient if, according to thermal calculations, the thickness of the insulation is not too large.

What is the subfloor made from?

The subfloor can be made from boards (edged or unedged without bark) and any sheet material, including plasterboard. TO sheet materials include:

Now we are not talking about the environmental safety of the listed materials. Here everyone makes their own decision. The point is that any of these materials can be placed on the logs. These materials fulfill their role as foundations. The thickness of each material depends on the installation step of the beams or joists. Once you decide on a specific material, choosing the thickness will be easy.

The subfloor is required as a reliable base for installation various coatings– parquet, laminate and other materials. A lot depends on the quality of the subfloor: squeaks when walking, service life, humidity and temperature in the house. Creating a subfloor at the stage of building a house differs from the same operation, which is performed during renovation by the method of attaching the joists. In this article we will talk about all the stages of creating a subfloor in a wooden house, so you can do this work yourself.

Mounting methods

All subfloors can be divided according to the method of fastening the supporting structure:

• attached to walls;
• installed on concrete base;
• ground mounted;
• combined.

Fastening the load-bearing structures of the subfloor to the walls is most in demand in houses installed on screw, column and strip foundation. More details about different types foundations, read the article -. This method of fastening allows you to create a rigid load-bearing frame gender, but requires high flow rate wood The most popular mounting methods are using corners and in a cut-out groove. The first method is simpler, but less reliable, the second method is more reliable, but involves cutting through one of the crowns.

When installing a floor on a concrete base, various supports are used that allow you to raise the logs above the concrete. Brick pedestals are used as supports and metal fastenings. It is also possible to lay the logs directly on concrete, but in this case you will have to spend a lot of time high-quality waterproofing. In some wooden houses, the floor supports are installed on the ground. In this case, brick pedestals are built as supports. Combined method fastening the supporting structure of the floor involves the use of the methods described above in any combination.

Subfloor design

The basis of the subfloor is the logs from which the supporting structure is assembled. In most cases, logs are laid in one row, but there are exceptions. If it is not possible to use a board of sufficient width and thickness, then the supporting structure is made double-row, placing the rows perpendicular to each other. I also use this design if the subfloor sheathing boards must be laid across the room, and for this it was necessary to lay the joists lengthwise, which increases the requirements for the width and thickness of the boards. Laying perpendicular supports under the top joists reduces the requirements for the width and thickness of the board. A rough flooring made of sawn, planed or profiled boards is laid on top of the supporting structure. This flooring not only creates a platform for laying the covering (finished floor), but also serves as a additional element load-bearing structure ligaments.

Tools for work

Whether you're installing flooring in a new home or renovating an old one, you'll need a variety of tools, such as:

• gasoline or electric saw;
• jigsaw;
• axe;
• chisels;
• screwdriver;
• drill;
• sander;
• hammer;
• level;
• a simple pencil;
• roulette.

Installation of the subfloor at the stage of wall construction

The easiest way is to make a subfloor during the construction of the house. To do this, it is necessary to cut through or non-through grooves in the timber or logs of the corresponding crowns, into which the logs will then be laid. Optimal distance between the logs - 60–80 cm. If the thickness of the board with which the logs will be sewn up exceeds 30 mm, then the distance between the logs can be increased to 90–100 cm. Lay the logs across the room. If the width of the room exceeds 4 meters, then it is advisable to install at least one support under each log or increase the thickness and width of the log by 1–2 cm. You can also use timber with a cross-section of 150x150 mm. This will reduce the likelihood of the floor sagging and squeaks.

Having chosen a board or timber to create a lag, measure its width and mark the corresponding crown for cutting grooves. If the wall is made of profiled or laminated timber, the width of which is equal to the width of the log, then cut through the entire beam, cutting pieces from it to fit the size of the log. If the wall is made of sawn or planed timber, then cut a groove ¾ of the width and thickness. After all, crowns made from such timber are not connected into a lock, so by cutting the timber, you will break the structure of the wall.

If you do not want the logs to spoil the appearance of a house made of profiled or laminated timber, then cut the same grooves as on sawn timber.

Having prepared the grooves, cut the logs to length. If necessary, cut a lock on the joists to match the groove in the wall. Then cover the joists and wall cutouts with the protective substances you plan to use on your home. Read more about that. After the impregnation has dried, insert the joists into the wall and check their horizontalness using a level and a long, straight strip. If some joist protrudes above the others, trim it; if, on the contrary, it is lower than the others, put something under it. Immediately replace a crooked, twisted or cracked joist with a normal one.. If you cut the joists to create a castle, then to increase the strength of the house, install a support board under the joists that will take the weight of the floor. Attach this board to the wall using nails or self-tapping screws. Instead of boards, you can use steel and aluminum corners, which are sold at any hardware store. Attach these corners to the wall using thick long screws, and to the joists using bolts, washers and nuts.

Once all the joists are laid, leveled and secured, install the next crown, then cover them with the selected board. tongue and groove batten preferable because there is less heat loss through it. If you are insulating the floor, then first carry out all the insulation work, then sew it up with a board. Lay the board in such a way that the distance between the coating and the walls is 1–2 cm, this is necessary to compensate for the expansion of the coating due to moisture absorption. Also, do not push the covering boards all the way towards each other, leaving 1–2 mm between them, which will avoid swelling of the floor due to swelling of the boards. To attach the covering boards to the joists, use self-tapping screws 70–120 mm long. If you cannot screw in a self-tapping screw of this length, then first drill a guide hole with a diameter of 1.5–2 mm.

Replacing an old floor in a wooden house

If the old wooden floor has rotted or you decide to replace it for some reason, remove the finished floor and subfloor covering, this will allow you to assess the condition of the joists and walls. If the old joists are damaged, remove them completely by cutting them flush with the wall. Inspect the crown where the joists were cut into; it may need to be repaired or replaced. If the crown is in order, treat it with a grinder and cover it with protective compounds. Also treat joists and flooring boards with protective compounds.

To learn how to do this, read the material about. Mark the installation locations for the joists on the wall and draw a line along their bottom. At the bottom, close to this line, attach a support board on which you will lay the logs. Place the outermost logs at a distance of 10–15 cm from the walls, the remaining logs at a distance of 60–100 cm from each other (depending on the thickness of the covering boards). After installing the joist, fix it with a corner, as described in the previous section, or support it on both sides with bosses made from scraps of the support board or joist. This fixation will securely secure the logs and prevent squeaks. After this, cover the subfloor with boards as described above.

Subfloor with supports on the ground or concrete

The difference between this floor and those described above is that the main load falls not on the walls, but on the ground or concrete. This is true for old houses and for buildings standing on slab foundation. If you are replacing the floor, remove the old boards and clean and repair the walls as described in the previous section. Then determine where the joists will be installed and where the support pedestals will stand. If you place the cabinets on the ground, then dig a foundation for them, a square or rectangular hole with a cross-section of 1x1 meter and a depth of 20 centimeters. Compact the bottom of the pit and pour a 5 cm thick layer of sand on it. Pour a 5 cm thick layer of crushed stone on top, then pour a reinforced concrete pad 10 cm thick. After 5–7 days, place a brick support on this cushion on cement mortar. The height of the support should be such that there is a distance of 1–2 cm between it and the bottom side of the joist. Upper part the supporting pedestal is covered with bitumen and roofing felt to ensure waterproofing of the lag. Then the logs are installed as described in the previous section, after which wedges or spacers of the required thickness are inserted between the supports and the logs, which will raise the log by fractions of a millimeter. Covering the logs with floorboards is carried out in the same way as described above.

Floor insulation in a wooden house

Warming – required element creating a subfloor in any wooden house. Insulation reduces heat loss at home and increases the comfort of living in it. Without insulation, a wooden floor loses half of its positive qualities. Details different methods insulation of the subfloor in a wooden house is described in the article -. Do not neglect this procedure, thanks to which you will be able to walk around the house in winter even barefoot.