How to cover a rough wooden floor. Making a subfloor in a wooden house

Longevity and excellent aesthetic characteristics of the finish flooring provides a subfloor in wooden house, which is done using different methods.

A rough base is understood as a special structure necessary to form the most level area for the finishing floor covering. Its second task is to ensure uniform distribution of the load on the floor. The rough foundation can be arranged in two ways:

1. Dry - logs are used.
2. Wet - the leveling structure is created using a concrete screed.

Rough subfloor

Among other things, the subfloor in a wooden house is installed in order to increase the thermal insulation performance of the home. In wooden buildings, the wet method of arranging a leveling base is used very rarely. Usually it is created using lag. In this case, the rough floor area is mounted on the base or on the ceilings (their function is performed by thick beams or reinforced concrete slabs). Next, we’ll talk about how to properly make a preliminary floor using wooden elements.

Before you begin arranging the rough foundation, you must choose the method by which it will be installed and determine the amount of materials required. After this, a series of holes should be made in the corners of the residential building made of wood. round shape. They will ensure effective ventilation of the subfloor and increase the service life of both the subfloor and the finished floor. The holes will not spoil the appearance of your home. Upon completion of all the planned work, you will simply disguise them with decorative ventilation grilles.

Then it is necessary to treat the entire underground space and the logs directly with an antiseptic composition. Laying a rough foundation on an untreated site is not permitted. You need to understand that various microorganisms can appear on the elements of the subfloor during the operation of the building. If wooden joists If not treated, they will very quickly be destroyed by mold and mildew. And it is almost impossible to repair the preliminary foundation - access to it is either completely impossible or very difficult.

• hot resin - it protects against negative influence moisture, and from a variety of insect pests;
• solutions VVK-3, HCP or MCHC;
• ammonium fluoride;
• chlorophos - it is most often used as protection against insects;
• sodium fluoride.

Wood processing products

All these compounds are safe for humans. They don't highlight harmful substances and at the same time have the required indicators of waterproofing of wood. Processing with their help should be carried out strictly according to the manufacturer’s instructions.

Note! Boards for the subfloor need to be processed only on the back side. But on the logs themselves, crowns and beams protective compounds applied from all sides.

Additionally, it is recommended to treat the rough base with fire retardants. Specialized stores now sell universal compounds that simultaneously protect wood from fire, moisture and the effects of microorganisms.

For installation of a platform under the floor finishing coat stock up on the following materials:

1. Wooden blocks of the third or second grade - logs. In most cases, such products are characterized by a not very smooth surface. Therefore, they need to be slightly corrected. Your job is to make them front side(the one on which the laminate will then be laid, parquet board or other coating) more or less flat. This operation is performed with an ax. Naturally, nothing needs to be done with logs made from first grade wood. Such products themselves are very smooth.
2. Bricks for the construction of support pillars. The height of the finished supports should be at the level of 20–25 cm, and their dimensions are usually 40x40 cm. The number of brick pillars is determined by geometric parameters wooden house and its floor base. The supports are mounted on cement mortar.
3. Plywood or boards. With their help, the first and second rough layers are laid.
4. Polyethylene film or other waterproofing material. It is needed to protect the logs from rotting.
5. Heat and vapor barrier material.

Installation of a platform for finishing floor covering

Also, laying the structure we describe is impossible without the use of fasteners. Wooden logs are most often connected to brick supports with 4x5, 5x5 cm bolts and steel corners.

How to make a floor correctly - instructions for beginners

The design discussed in the article can have two or one layer. If beams are attached to the walls of a wooden residential building, the installation of logs is mandatory. IN similar situation the distance between individual beam products is quite large. If the distance between the beams is minimal, the leveling base can be made directly on them.

Scheme self-execution installation work is this:

1. Install brick pillars(they act as a support for the black base) or make a frame of boards around the perimeter of the room. If supporting elements made of bricks are used, roofing felt must be laid on top of them.
2. Attach the joists to the base of the house. Fix them with bolts and metal corners (to brick supports) or (to wood frames).
3. When installing joists, leave 20 mm gaps near all wall surfaces. It will be possible to place in these slots heat insulating material. If the support distance of the logs to the base of the house is short (less than 10 cm), they are installed in the same way. And then they press it with a fairly massive beam. It is fixed tightly in the walls of the building. The walls of the house and the sections of timber joints are measured, after which the corresponding cut is made. It is advisable to take its dimensions a couple of centimeters larger than those that you get as a result of measurements. Do not forget that the joists will expand slightly when exposed to moisture.
4. Install cranial blocks at the bottom of the supports for the rough foundation. Then connect them to the joists on the sides. The geometric parameters of such bars are always taken to be smaller than the dimensions of the main elements.
5. Mount the boards on the beams. There is no need to attach them. Wood will expand during use. Loose placement of the boards will not interfere with this natural process.
6. On floor base lay a layer of waterproofing. The selected moisture-proof material (for example, polyethylene film) should be fixed to the wall surfaces. On them, the waterproofing agent reaches a height that is equal to the height of all available levels of feasible floor base(this figure includes finishing floor). Fasten the areas where the pieces of film are connected to each other with a construction stapler.
7. Lay a layer of thermal insulation. The height of the logs should be slightly greater than the thickness of the heat-shielding material. For wooden buildings it is permitted to use any materials for

   Subfloor thermal insulation layer

   Next, cover the made pie with a vapor barrier material. It is also fixed to the walls of the building with a stapler. The joints of vapor barrier products are glued together using construction tape. If the thermal insulation material was laid exactly according to the height of the logs, thin slats should be mounted on their sides. They will hold the insulation in place. As a result, you will have a gap under the floor for ventilation.

   The final work is laying plywood, boards, OSB boards on the rough base. Installation of the second layer of the base is carried out in the same way as you installed the first part of the structure (leave gaps at the walls, place heat-insulating material in them, and so on). Fastening of boards, slabs and sheets is done in increments of 10–14 cm using stainless self-tapping screws.

   As you can see, it is not difficult to arrange a rough foundation with your own hands. Good luck in this matter!

The subfloor, as a base, can be made of wood and concrete houses. The preliminary floor must be perfectly level. Installation of such a coating is a labor-intensive process, and it is best to trust the professionals.

Of course, you can make a subfloor in a wooden house with your own hands.

Before proceeding with installation, we will discuss with you the types and purposes of subfloors.

Types of subfloors

Flooring directly on the joists. In this case, we use chipboard, OSB, plywood or boards, which in turn are laid on logs.

This type of subfloor is well suited for surfaces with low load-bearing properties, which allows you to distribute the load over the entire floor area. It is recommended to use coatings such as laminate, linoleum or parquet boards.

Flooring directly under the joists. It is also called double layer. The space from joist to joist is filled with waterproofing, thermal insulation, and vapor barrier.

Subfloor directly on load-bearing beams. This flooring option should be used when designing a house.

In order to reduce the step between the beams from 1.2-1.5 m, as is usually accepted, to 0.6-1 m, then the beams will replace the logs. We discard the extra layer. In terms of everything Consumables, it turns out that we also save about 30%.

Plus we get an increase in the height of the room. But, in case you have already purchased ready house, don’t be upset, the subfloor boards can be thrown diagonally across the beams, this will ensure high strength of the floor surface.

Types of subfloor:

The wet base is a screed ( concrete base), under the space on which the wooden floor will be installed.

Since the concrete base is not level, an additional leveling layer will be required. The finishing coat can be applied only after the rough base has completely dried, approximately 7-8 days.

Dry is the flooring lag. They are laid on the ground covered with sand. When installing the log, use a ruler and level. Unlike a concrete base, a floor on joists is difficult to bring to a perfectly level state.

Protecting the subfloor from moisture

All subfloor components must be treated by special means against mold and rot. Processing of all wooden elements is carried out after drying - this is very important point, the less moisture in the wood, the better and more deeply it absorbs antiseptics.

Impregnation is done at least 2 times, do not forget about the cross sections of wood, they must be processed. It is not recommended to lay the boards first and then process them, because the ends will be open to mold and water vapor.

Natural ventilation of the underground, the most important Organizing time, when installing a subfloor. If it is not organized correctly, then not a single antiseptic will help you, and after a while you will have to change the entire floor covering.

Vents are made at a height of 30-40 cm, and 90 cm from the corner of a wooden house, so that the air does not stagnate.

To protect small rodents, you can install a metal grill on the vents. In winter, you can close the vents to preserve the heat of the first floor, but be sure to open them as the weather gets warmer.

The preliminary floor does not have to be continuous. For flooring, you can use any material that can withstand this load.

Waterproofing is mainly used over subfloors. But it can also be used before, or crushed stone can be used as a material.

Roofing felt is used as waterproofing on top of the floor. We lay a layer of insulation on top of the waterproofing ( mineral wool, Styrofoam).

After the insulation layer, you can begin installing the finished floor, but professionals recommend applying another layer of waterproofing on top of the insulation layer, and then final coating floor.

Laying a subfloor on a concrete base

The most important condition is that the screed is perfectly level.

There are two options for installing a subfloor on the surface of a concrete base:

Reiki are used when it is necessary to carry out communications, install additional insulation or the screed has significant differences, more than 2-3 mm.

Between the slats and the screed we lay a layer of waterproofing, usually roofing felt. We align the slats with pads and secure them with dowels. If necessary, we additionally insulate or install communications. Subsequently, we install the floor using boards or slabs.

Remember that two slabs will be joined in the middle on one rail. We lay out the slabs as brickwork, thanks to this we get an even distribution of the load on the slats. We fasten the slabs or boards with nails or self-tapping screws.

Laying a subfloor on a concrete base is used on a perfectly flat surface. To obtain a smooth surface, auxiliary compounds are used, usually construction adhesive. The glue is applied in an even layer, the slabs are laid one after another.

The glue under the slab removes all the unevenness and the subfloor becomes a monolith with concrete surface. The heads of nails and screws are recessed using a screwdriver or hammer. The holes from the caps are puttied with a special compound.

It is important to always leave a distance of approximately 1 to 2 cm between the walls and the floor. Do not forget to cover this distance with any insulation. If you plan to lay linoleum on top, then it must be sanded with special machines. Mainly the joints of the slabs.

Price of work performed

• Rough floor work for 1 sq.m. - on average 150-200 rubles.
• Finishing floor work for 1 sq.m. - on average 150-200 rubles.
• Completely rough floor, for 1 sq.m - on average 1200-1500 rubles.
• Completely finished floor, per 1 sq.m. – on average 2400-2800 rub.

Every person knows that it is not possible to live fully in an apartment or house without a furnished floor. It is simply necessary. Is it worth doing it in a wooden house? This is a question that worries many. Their logic boils down to the fact that why spend money on an additional subfloor, it might be easier to just lay a finished floor right away. Everything is ambiguous here.

You can, of course, get by with a clean one, but in this case you won’t be able to get a reliable and beautiful coating. But the main thing that a floor should stand out for is reliability, strength, Smooth surface, as well as some other parameters that are extremely difficult to achieve without a subfloor. Changing the finished floor every year if there is no rough floor is an unaffordable luxury.

Photo: subfloor in a wooden house

Subfloor - what is it?

A subfloor is a special base for a finished floor, which forms a flat horizontal plane for it. The subfloor ensures the distribution of the load that acts on the floor covering.

In a wooden house, the subfloor can be made in several ways:

• wooden on joists;
• plywood flooring;
• pouring concrete.

Wooden subfloor on joists

In a wooden house, the installation of a subfloor on joists is practically no different from its installation in monolithic or brick houses. The main difference is in the fastening of the lags.

General scheme devices

Attaching the log

Floor joists should not be attached to wooden wall, and you don’t need to crash into it. It is advisable to fasten the logs to the base or grillage of the foundation, retreating from the wall a few centimeters. At the same time, the distance of the support that falls on the foundation must be maintained at least 10 cm on either side of the log.

The logs are attached to the base

Before laying logs on the foundation, they must be laid bottom trim, made of long thin boards, to which logs will be attached using metal anchors (corners).

The logs should not be rigidly attached to the frame - they only need to be fixed so that they do not move while laying other layers of the subfloor. The created structure will have a distance of several cm from each wall, where thin insulation can be installed.

Waterproofing of logs is required

If the distance to the foundation is less than 10 cm, then it is better to crash into the walls, but you will need to first lay the logs on the foundation, and then attach a log or timber to them. Measure the contour of the cutout and then cut out the necessary grooves in the wood with the dimensions required for the support distance (for subsequent expansion of the lag, approximately 2 cm should be added).

We must not forget that the laying of beams and joists is carried out on the plinth or grillage only after laying the waterproofing layer.

The logs are attached to the foundation grillage

The standard step between the lags is 40-60 cm. However, its choice depends on the width of the insulation, as well as the direct load. The cross section of the log is also selected from the current load. For a light section, choose 15×10 cm, for a medium one – 15×15 cm, for a heavy one – 15×20 cm.

If the beam has a small cross-section and the load is significant, then it should be placed at a distance of 30-40 cm - this is a fairly optimal option.

Installation of subfloor on joists

Upon completion of installation, the lag is made standard installation floors on joists. It looks like this:

A ventilation gap must be left between the insulation and the floorboard.

Important! Boards, bars and joists should be treated with an antiseptic to prevent them from exposure to various fungi and insects.

Plywood subfloor

A plywood floor will serve reliably for a long time. She has high strength. Plywood can even be used for the final floor covering, since if it is carefully sanded and varnished, it will look quite noble. However, it is more often used as a base for covering laminate, parquet and linoleum.

Laying plywood on an old floor

Plywood can be laid:

1. On a cement base, but it is necessary to ensure that the base is even and horizontal, or to use adjusting posts.
2. Fastening on logs. Here the difficulty is in placing the joists to ensure that the joints of the sheets fall on them. The logs must be positioned so that their upper surface provides one horizontal plane. Hiding in the logs engineering Communication, insulation and sound insulation are installed.

Laying plywood on joists

Important! When laying plywood in one layer, it is necessary that its thickness be at least 15 mm; if in two layers, then you need to choose at least 9 mm for the layer.

Before final installation of plywood, all dust and debris must be removed from the base. It is also advisable to perform priming, that is, treat with a special primer.

When building a new house or renovating an old one, it is very important to properly make the floor for laying the flooring. If you are going to make a subfloor in a wooden house with your own hands, then you should know how to construct it and the technology to choose from. optimal option. To choose the right subfloor option for a wooden house, you need to take into account the features of the floor covering, as well as the need for hydro- and thermal insulation.

Floor design

Regardless of the choice of method for constructing the subfloor, the following layers must be provided in the structural cake:

• Underlying layer. This Bottom part floor pie. The layer is needed to evenly distribute the loads from the elements laid above. Typically, this structure is made of floor slabs, beams (joists), rammed soil or concrete preparation.
• Intermediate layer needed to connect the lower and upper elements of the pie into one whole (it is not available in all designs).
• Insulation layer performs the functions of heat, hydro or sound insulation of the floor. The choice of materials for this layer depends on the design features, the purpose of the room and the type of floor covering.
• Rough leveling layer. The purpose of this part of the pie is to level out the unevenness of the previous layer. Sometimes at this stage the required slope of the floor surface is provided. The arrangement of this layer can be done using a dry backfill of sand or gravel or by installing a concrete screed.
• Final leveling layer. It is not always needed. Laying the finishing layer is required when arranging finishing floors with laminated boards, carpet or linoleum. Finishing leveling does not need to be done under ceramic tiles.

Two flooring options are suitable for a wooden house:

• arrangement of floors along logs;
• You can make a dry screed or pour a wet screed.

In turn, the arrangement of floors along logs in a private wooden house can be carried out on beams or a concrete base. By the way, such floors can be arranged in brick house or construction from foam blocks.

Subfloor on joists

Preliminary stage of floor installation using joists

If you decide to make a subfloor using joists with your own hands, keep in mind that the joists are a supporting element for laying subflooring made of plywood, boards, or OSB. In turn, depending on the design of a private structure, logs can be laid on pillars, beams or a mortgage element. They can be used not only in a private wooden house, but also in a house made of foam blocks.

If the room is large, then attaching the edges of the joists to the beams will not provide adequate strength to the base. In this case, it is necessary to use intermediate posts. Step support posts depends on the cross section of the lag. Usually the step is taken to be 0.8-1 m. The material of the columns is brick or concrete. Even in a house made of foam blocks, it is better to make columns from durable materials.

The post is installed on a shallow concrete foundation. The foundation is installed over a layer of compacted sand and crushed stone. The brick column is insulated from the joists and the foundation with rolled insulating material, for example, roofing felt.

Technology for constructing a subfloor using joists

The subfloor in a wooden house with joists is done in the following order:

1. Before installing the logs, it is necessary to stretch the fishing line above the surface and mark the places where the beams are attached. This will allow the elements to be placed on the same level, which will facilitate further work on the floor installation.
2. If the installation of logs in a private wooden house will be carried out on a base made of concrete, foam blocks or bricks, then they must be protected with a layer of waterproofing. So wooden elements will not absorb moisture from the base. Thick polyethylene film can be used as insulation. In addition, logs must be treated with fire retardants and antiseptics.
3. The installation step of the joists depends on the load on the floor. For living room optimal step the log is 45 cm. The logs are screwed to the base using self-tapping screws and pre-installed in drilled holes dowels
4. All wooden structural elements must be treated with impregnations that protect the wood from rotting and burning.
5. If the floor of the first floor is being installed, the room must be protected from moisture and insulated. To do this, bars are nailed to the bottom of the side surfaces of the logs on both sides. You can use timber with a cross section of 50x50 mm.
6. Next, you need to make a backing of plywood or boards for laying in the gaps between the insulation joists. To do this, sheets of plywood are cut according to the width of the gap between the joists and laid on top of the bars. Plywood is nailed to the beams. As a result, you will get a structure made of wood, like the letter “W”.
7. Before installation warm insulating material it is necessary to make a waterproofing layer. To do this, the insulating material is laid on the joists so that it sag into the gaps between them. For these purposes, you can take membrane waterproofing or polyethylene film.
8. Now the insulation is laid in the gaps between the joists directly on top of the insulating material. Thermal insulation can be done using mineral or basalt wool. We attach the film to the joists with a stapler.
9. To properly make the floor, you need to remember about the vapor barrier. To do this, the film is laid over the logs and thermal insulation material. Be sure to overlap adjacent sheets by 15 cm. The joints are taped.
10. Now you can lay the rough flooring. It can be made from plywood, chipboard, boards or OSB.
11. Depending on the choice of floor covering, the finished floor can be laid next or final leveling for laying tiles, laminate or linoleum.

Video instructions - installing the floor along the joists:

Dry floor screed

Often the subfloor in frame house can be installed on the ground. Sometimes such a base near the floor is made in houses made of foam blocks or bricks without a basement. As a rule, a dry screed is laid on a specific base. In this case, the base of the floor will consist of the following layers:

• rammed soil;
• sand compacted cushion 100 mm high;
• crushed stone backfill 100 mm high is also subjected to compaction (for additional waterproofing crushed stone can be treated with cement laitance);
• This is followed by concrete preparation, which serves as the preparatory layer of the floor (filling height 7-10 cm).

Important: if difficult geological conditions are observed at the construction site (soil swelling, high level groundwater), then installation concrete preparation better to do with reinforcement.

For reinforcement concrete pouring use a rod with a diameter of 8 mm. A mesh with cells measuring 150x150 mm is made from it. Installation reinforcing mesh lead to mortar heaps so that after pouring the concrete preparation, the mesh is located in the thickness of the layer. On each side it should be protected with a two-centimeter layer of concrete. This must be done to protect the fittings from corrosion.

Dry screed technology for subfloors

After pouring the concrete preparation, further installation of the floor can be done after 28 days. Work on installing a dry screed in a wooden house is carried out in the following order:

1. To properly install a dry screed, you first need to make insulation. To do this, insulation from polyethylene film. Strips of material must be laid with an overlap of 150 mm and placed on the walls of the room to a height of 2 cm higher than the level of the screed. The joints of the film are taped with tape (see video).

Important: try not to damage the integrity of the insulating material. If cuts or punctures occur, patches must be applied.

1. Next, a damper tape is attached to the walls along the perimeter of the room. It is needed to compensate for deformation changes in the floor surface, as well as to protect against impact noise. The width of the tape should be slightly larger than the thickness of the screed (see video).
2. Now you can install the beacons. It is better to use drywall guides as beacons. They are laid on mortar heaps. The pitch of the beacons from the walls of the room is 30 cm, between themselves - along the length of the rule or 1 meter.
3. After the beacons are leveled, granular material, for example, expanded clay sand, is poured between them. Its surface is leveled using the beacon rule.
4. Next, sheets of plywood, OSB, chipboard or gypsum fiber board are laid. They will serve as a subfloor. Before laying the finishing surface, they must be treated with a deep penetration primer.

Before you start laying the final coating, you need to take care of the rough coating. This rule should never be neglected, because otherwise you risk your entire repair. Remaking the flooring and the floors themselves will require even more effort, expense and time. In addition, such a complex event can cause damage to the entire interior of an apartment or house. So experts recommend taking a close look at the subfloor issue once and forgetting about it for many years.

There are two main ways to create a subfloor, which are divided according to the method and materials used: wet and dry. For wet, concrete or concrete expanded clay is used, and for dry, installation on joists is used.

DIY concrete subfloor

This option is especially popular in standard city apartments, but if desired, it can also be used to furnish a private home. The only question is the foundation.

First you need to create high-quality waterproofing. This can be done using a special film of increased strength. If we're talking about about renovations in an apartment on the second and higher floors, we recommend that you pay special attention to insulation. Your manipulations with the floor can cause leaks and affect the repairs of the neighbors below. So be very careful when installing the film. Along the perimeter of the apartment it needs to be supplemented with penoflex with a thickness of 0.5 - 1 centimeter.

The next layer of the subfloor is responsible for the thermal insulation of the room. Previously, polystyrene foam was predominantly used as a material, but in Lately penofol, consisting of two layers at once, with very good characteristics. The foil layer reflects heat and prevents it from leaving the room, and the polyethylene foam itself is responsible for thermal insulation. Whatever material you choose, it also needs to be covered with a layer waterproofing film.

Next important stage- This is the pouring of the floor with concrete or concrete expanded clay. But you can’t just pour the solution onto the future subfloor. The thing is that this layer will not be able to level itself. That is why, before pouring, special beacons are installed, which will become the basis for leveling the floor. All beacons must be installed level. Only in this case will you be able to get a beautiful and smooth subfloor as a result.

If you want to increase sound insulation, as well as thermal insulation, then pay attention to concrete expanded clay. This material has excellent properties and outperforms conventional concrete in many respects.

Having mixed the solution and distributed it over the floor, carefully level it using the rule, placing the tool on the beacons. Remove excess solution, then leave the coating until completely dry. Your subfloor is ready.

DIY wooden subfloor

To make a subfloor out of wood, you will need some kind of base. If the house already has concrete, then logs can also be laid on it. Just make sure that concrete screed flat and has no elevation changes. Otherwise, your floor will turn out crooked and will creak. Experts do not recommend using wooden blocks as a support for joists in excavation areas. The problem is that over time the wood will shrink and the joists will lose their stability. And your floors will sag and creak.

To avoid this, you need to be careful preparatory stage. So, to begin with, the concrete base is leveled using a small layer of screed. The amount of solution is determined by the height difference in the room. After this, leave the resulting base until the solution dries completely.

The next point is laying the waterproofing film, all joints of which must be taped. On top of it, in the place where the logs will be laid, we lay a special soundproofing layer. Foamed polyethylene or cork material is usually used. Without this layer, the floors in your home will make noise with every step.

Now it's time to deal with the lags. But for this you will need timber. Professionals recommend not skimping on joists and using edged boards High Quality. Installation will take you much less time and effort, and your own subfloor will turn out much more impressive and faster. To install the subfloor you will also need edged board 25 mm x 100 mm. It can be used not only for installing joists, but also for installing roof sheathing and other general construction work.

The logs themselves are installed on a pre-prepared base so that the layer of soundproofing lining is strictly under them. The height and slope of the joists must be checked with a level.

Now they need to be attached to the base of the floor using corners so that the logs do not move anywhere and serve as the basis for the next layer.

As soon as all the logs are firmly fixed, insulation is laid between them. In no case should it go onto the logs themselves, only occupy all the free space between them.

A floorboard or plywood is laid on top of the joists. This is what the subfloor itself will look like. Working with plywood is much easier, but it has certain disadvantage- comparatively high price. Batten of the same quality will cost less, but installation will require more effort and more time.

The thickness of the plywood sheet should be at least 22 millimeters, otherwise your subfloor will sag under the weight of a person. In addition, the distribution of furniture throughout an apartment or house can cause a change in the topography of the subfloor. Experts recommend using thicker plywood if you plan to place heavy objects in the room: a wardrobe, a refrigerator, a sideboard with big amount dishes and more.

Sheets of plywood should be laid in a checkerboard pattern to prevent joints from being aligned. Screw the plywood to the joists using self-tapping screws, not forgetting to leave a distance of 2-3 centimeters from the wall for shrinkage and ventilation.