Interfloor overlapping on wooden beams: calculation of prefabricated loads and allowable deflection. Ceilings between floors of a private house

Interfloor ceilings in a private house

An obligatory element of any structure is an interfloor overlap. This is a loaded part of the building that performs a number of tasks. Overlappings between floors in a private house divide the space inside the building into independent zones. The interfloor structure not only performs a separating function, but also heat-insulates the living space, absorbs noise, and also ensures the rigidity of the building frame. For the construction, various building materials are used, which differ in characteristics and installation technology.

Interfloor overlapping of the house

What should be the overlap between floors in a private house

Ceilings between floors are a critical element of the structure, to which a number of requirements are imposed. The overlay host must have the following properties:

• be durable. Under the influence of its own weight and loads from equipment, interior items, cracks should not appear and the rigidity of the structure should decrease. The level of perceived loads per 1 square meter varies from the functional purpose of individual rooms and is for attic space- 110 kg, and for the basement and interfloor base - 210 kg;
• have high rigidity. Overlapping structures connect the main walls of the building box into a common power circuit, providing elevated level building stability. Under the influence of efforts, a minimum deflection arrow is allowed, which is 1/200 for the foundations of attic spaces and 1/250 for floors located above the basement;
• securely soundproof the room. The base must prevent the access of external noise. The use of effective sound-absorbing materials and sealing of gaps in the docking areas can reduce the negative impact of noise factors and create favorable conditions in room;
• reduce heat loss. The use of heat-insulating materials allows to reduce the coefficient of thermal conductivity. By reducing heat loss, the cost of maintaining a favorable temperature is reduced. An increased layer of insulation should be installed above the basement, as well as at the level of the attic;
• resist open flame and high temperature. In the event of a fire hazard, the ceilings in the house between floors should not allow the spread of fire, temporarily localizing the source of ignition. Fire resistance depends on the material used and is 15 minutes for plastered wood structures, 1 hour for reinforced concrete. Metal constructions have a maximum fire resistance threshold.

Ceilings between floors are a critical element of the structure

Overlappings between floors also allow maintaining an individual microclimate in each room, inhibit the penetration of moisture and functionally divide the building into zones.

Ceiling ceilings in the house between floors - classification and varieties

The classification provides for the division of protective structures according to the following criteria:

• location;
• main purpose;
• constructive performance;
• construction method.

By placement, protective structures are divided into types with the following purpose:

• attic. Thermally insulate the residential part of the building, creating a reliable barrier with a cold attic. They are constructed using heaters that do not collapse under conditions high humidity and temperature fluctuations. Include a layer of vapor barrier;
• interfloor. share inner space a residential building into independent premises, each of which has its own purpose and is distinguished by a stable microclimate. They do not require the use of moisture-proof and heat-shielding materials and fulfill their main purpose associated with sound insulation;
• basement. Reliably isolate the basement of the building, which is not heated, and living rooms. The insulation layer prevents heat loss.

Basement floors

Depending on the design features, the floors are divided into the following groups:

• beam. They are made in the form of horizontal crossbars, a filler placed in the space between the beams, and a material that forms the floor or ceiling;
• beamless. They are made of independent reinforced concrete panels made at the enterprises, or separate slabs reinforced with steel reinforcement;
• combined. This is a prefabricated version of the supporting base, made of power bars, between which solid blocks are placed.

Let's stop at design features various overlaps, we will analyze their advantages and weaknesses.

In beam-type structures, the supporting element is the bars installed at an equal distance, made of various materials:

• wood;
• metal;
• reinforced concrete.

Let's consider each option.

Beam ceilings between floors made of wood

Ceilings in the house between the floors of wooden beams

Using beams from coniferous and deciduous wood, it is possible to build a wooden supporting structure. The strength of wood imposes certain restrictions on the size of the span:

• for interfloor bases - the maximum distance is 5 m;
• for attic spaces - span up to 6 m.

Wood flooring includes the following elements:

• bearing bars;
• flooring;
• heat insulator;
• ceiling material.

Advantages of a wooden base:

• ease of installation;
• ease of installation;

Wood flooring

• acceptable level of costs;
• small mass.

Disadvantages of timber beams:

• combustibility;
• hygroscopicity.

Impregnation with special compounds can reduce fire hazard and reduce sensitivity to moisture.

How to install wooden floors

The installation technology provides for the following operations:

• Installation of bars impregnated with an antiseptic composition.
• Fastening wooden boards.
• Laying vapor barrier material and insulation.
• Fixing the finished floor and ceiling finishes.

To perform installation operations, you must first calculate the need for materials.

Wooden beams have a small mass

Rolled steel, used as beams, surpasses wood in terms of reliability, strength properties and durability, and also has a lower cross-sectional height compared to wood.

Advantages of rolled metal, which allows to form increased spans:

• biological stability;
• durability;
• temperature resistance.

Weak sides:

• susceptibility to corrosion;
• reduced thermal insulation;
• low soundproofing properties.

Concrete panels made of porous material or wood panels can be laid in the intervals, followed by concreting.

Ceilings between floors from a metal profile

The main advantages of reinforced concrete beams:

• increased strength;
• the ability to form spans up to 7.5 m long;
• increased soundproofing properties;
• effective soundproofing.

Disadvantages of reinforced concrete elements:

• the need to use lifting equipment;
• shipping costs.

The installation includes the following operations:

• Laying elements at a distance of up to one meter.
• Placement of finished blocks in the interbeam space.
• Sealing gates with cement mixture.
• Implementation of measures for thermal and sound insulation.

At the final stage, a fine finish is performed.

Ceilings between floors in a private house made of reinforced concrete

Beamless floors between floors

According to the manufacturing method, beamless structures are classified into the following groups:

• composite. They are assembled from separate parts, manufactured mainly in an industrial way;
• monolithic. Solid bases are concreted directly at the work site into a specially installed formwork;
• monolithic prefabricated. They are constructed from individual beams, the space between which is filled with reinforced concrete.

Consider the advantages and disadvantages of each option.

Prefabricated variant

Beamless ceilings between floors are formed from solid or hollow panels.

Advantages:

• increased load capacity;
• resistance to a humid environment;
• durability.

fill monolithic floor between floors

Disadvantages:

• installation only with the use of lifting equipment;
• dependence of the dimensions of the building on the dimensions of standard slabs.

When installing the plates are installed on the cement mortar. The size of the supporting surface is 10–15 cm.

Monolithic construction

They are made in the form of a solid reinforced concrete slab, 10–15 cm thick.

Advantages of a monolithic base:

• increased strength;
• performance of work without lifting equipment;
• lack of seams;
• pouring concrete into formwork of any shape.

The only negative is the complexity of the formwork installation operations and the cost of its construction.

Monolithic reinforced concrete floors

Prefabricated monolithic base

The combined option involves the use of porous or polystyrene concrete panels, followed by a screed.

Advantages:

• increased thermal insulation;
• reduced mass of the base;
• installation without the use of lifting devices;
• accelerated pace of work.

Disadvantages:

• increased labor intensity of laying the heat insulator;
• reduced span length;
• increased level of spending.

In order to increase the margin of safety of the insulated base, a reinforcing cage is placed before the concrete is poured.

Conclusion

Ceilings between floors can be constructed from various materials. It is important to choose the right option design, depending on the characteristics of the building and the requirements of the project. Properly installed ceilings in the house between floors can be used for a long time, providing comfortable conditions in room.

Many participants in my design training still have uncertainty with the choice of floors. I will describe in this article how I approached their choice. I considered wooden floors, factory reinforced concrete slabs, and monolithic reinforced concrete, poured on the spot. In the end, I chose wood. What I was thinking when I chose:

Strength

If in a simple way - what can the ceiling withstand: a small light fireplace, a solid fuel boiler, a piano, a huge aquarium ... horses have not walked around the house for a long time. In fact, there are certainly no really heavy things, weighing more than a ton, for example, in most houses, and the calculated configuration of the wooden floor is quite reliable. If the span is less than 5 meters, then usually beams of standard sizes can be dispensed with as beams.

If more, it is advisable to already use trusses, or glued beams. Ready-made ones are more expensive and not every construction market can buy them. But in low-rise individual construction, spans of more than 5 meters are still rare.

I sent a program to my subscribers in the mailing list for calculating single-span wooden beams, it just considers both the maximum breaking load and the calculated deflection. Let me give you a few examples ready-made options mminimum section of beams.

Distance between beams 0.5 m

Span, m

Height of beams with thickness, cm

Distance between beams 1 m

Span, m
	Height of beams with thickness, cm

For floors from factory reinforced concrete slabs, the strength is known and high, for a monolithic, self-poured one, it is calculated, but the calculation from reality can be very different. It affects the human factor, and the quality of the ingredients.

Deflection, or "fluctuation"

For iron concrete floors deflection is minimal, but can also be noticeable on large spans.

For a tree, there were tables above with the minimum allowable beam section. It is the minimum, in terms of strength. To take a section, especially the height of the beam, of course, you need more, because the deflection also depends on it, or if it is simpler, the “unsteadiness” of the floor.

Those. the larger the section of wooden beams, the less your floor will look like a trampoline. I remember from childhood how in the house where I grew up, in the living room there were spans of about 4-4.5 meters, and the beams were made of logs 20-25 cm, the distance between them was about a meter, and on top of the usual batten. With this configuration, it was possible to walk without problems. But jumping and dancing - no, because all the dishes in the cupboard began to jingle. And if the fun is in full swing, then the doors begin to clap slightly)))

This did not happen immediately, but after the house had stood unheated for several years, and the beams had dilapidated during this time. To remedy the situation, I had to cut an opening in the floor, crawl under the floor and put supports made of bricks and wooden spacers under the beams.

At the same time, in the older house of the grandmother, there were approximately the same spans, but the board on the floor was 50-60mm, and people lived in the house all the time, so this problem was not observed.

Another property of the overlap has already been touched upon here -

Durability

On the one hand, wooden floors in Stalinist houses have been standing for more than 60 years, and in some houses for more than 100. But on the other hand, wood is wood, it is not eternal, alive, and reacts strongly to external conditions.

Compared to wooden floors, the durability of concrete floors is, of course, much higher.

fire resistance

For me personally, this parameter was not very important, because in my opinion the main thing is to leave the building on time and not get poisoned by combustion products. More important here is the 30 second rule when designing a house. And it is very unlikely to oversleep or not notice the fire when the ceilings are already burning with might and main.

Soundproofing

How audible vibrations are when walking overhead, and noise - for example, conversation, music ... Depends on the floor pie, floor and ceiling arrangement. Mineral or basalt, in my opinion, is a weak sound insulator, sawdust, for example, noticeably surpasses it in this property. Here I'm talking about the usual thermal insulation wool, has not yet had an acoustic case.

So that vibrations when walking on the second floor are not transmitted to the ceiling, I made the floor and ceiling beams separate, and then I was convinced of the correctness of my choice.

ABOUT soundproofing properties hollow core slabs you probably know well the overlaps from your experience of living in an apartment - how much music is heard from the neighbors from above, or you can hear how small children run along the ceiling.

Installation cost

Wood flooring is much cheaper than concrete. And you can save even more on it, because. it's easy to do it yourself. What can not be said about pouring or laying slabs.

Casting a reinforced concrete floor on their own is cheaper for many than factory slabs, but I would not say unequivocally that this is always the case. It has to be calculated on a case-by-case basis. Depends on the height and the need to call a concrete pump, on the cost work force, formwork - will you apply it further.

In addition, if speed is important to you - let's say you plan to bring everything under the roof and finish the heating circuit in a season, and start finishing in the winter, then it might be better to overpay a little than lose half a year in winter. When calculating the total budget, this option can turn out even cheaper.

Mounting speed

Given the finish, wooden floors are assembled faster. Monolithic ceilings require much more time for installation than others. It is necessary to set up the formwork, tie the reinforcing cage, pour it, wait for time to required set strength, disassemble the formwork.

But from the point of view of speed, there may be some “discounts” here - often for a monolithic floor you can not make a separate armored belt, while under the pits of the floor, as a rule, you need to.

Risks associated with violation of technology by unskilled workers

This point is very important to me. It is difficult to make a mistake with a tree - except that it is incorrect to calculate the required section and configuration. Factory plates are predictable and reliable. And the quality and reliability of self-poured floors depends on the quality of their calculation, the reinforcement performed, the quality of the concrete, the evenness of the pouring both from below and from above, and the conditions for drying the concrete.

Additional features

For example, will you have a warm floor, and which one. What material for the floor, ceiling, and how does it all fit with different types floors.

The weight of the floors, for concrete ones, as a rule, is rather big, should be reflected in the design of the foundation, and the bearing capacity of the walls.

The choice of the type of flooring must be made already during the design, in order to plan the places for supporting the floors in the project, take into account the standard sizes of the plates, and do not have to cut them later, which costs a lot of money. And if we are talking about wooden floors - so that you immediately understand whether you can get by with a standard beam with standard sizes, or special beams must be ordered. Trusses, glued beams - usually have a greater height, this must also be taken into account in the project.

Interfloor ceilings for constructive principle practically the same. Whether it is the ceiling of the basement in the garage or the ceiling of the last floor.

However, the device technology of each of them will be different, and performance will depend on the correct manufacture.

According to the constructive principle, overlapping devices are divided into 4 main types:

• monolithic reinforced concrete floors;
• slab ceilings made of prefabricated reinforced concrete;
• ceilings are often ribbed (prefabricated-monolithic);
• wooden ceilings.

Consider the two most common ways to organize floors - wooden and monolithic

Wood, unlike other bases (reinforced concrete slabs, monolith) used for floors, is an environmentally friendly material. Besides wooden ceiling or the floor gives the room a distinctive look and retains heat well. Previously, the tree was used for these purposes all the time. Now interfloor floors made of wood, as a rule, are made only in wooden houses, although there are exceptions.

Comments:

The interfloor overlap is one of the main components of the construction of a private house, therefore, the strength of the entire structure depends on how high quality it is. When working on a floor, the builder must understand that it must be strong enough to easily support its own weight, as well as the weight of all internal partitions and all the furniture on the floor, the weight of the owners of the house. It must be strong and in no case sag in order to avoid the risk of collapse.

The stability of the entire structure as a whole depends on the reliability of the interfloor overlap.

However, sometimes deflections still cannot be completely avoided, so there are standards under which the design is considered safe. If the floor is wooden, then the maximum deflection should not be more than 0.6%. If we are talking about steel floors, then this maximum number is 25%. This design is responsible for the rigidity and stability of the construction of a private house, so the transverse rigidity of the interfloor ceiling should also be as large as possible. Based on all the requirements, it is worth concluding that a specialist or a very well-informed person should do it on their own.

But the functions of overlapping do not end there! Having made it, you must be sure that it is not only strong, but also completely fire resistant and temperature changes in the rooms or the presence of a fireplace will not create a fire. Also, at your request, the overlap can be added such beneficial features like sound insulation, heat insulation, waterproofing.

Work on the floor structure should take place in accordance with the design and structure of your house, its walls, partitions and foundations. It is very important to take this into account and, if possible, consult with experts in this field if you decide to do the work yourself.

For example, if your walls have a frame structure, and the foundation is columnar, then the building will collapse if you use reinforced concrete floors.

You should definitely know such features of work as this before starting work.

What are the general design requirements?

Perhaps, for a start, we should figure out what general requirements and rules exist regarding the design floors from the foundation to the roof. Let's consider them in the order in which a building is usually built. House designs are completely different, so for example, we will consider the most common one. Many houses have a basement available, so the first interfloor floor will be the basement. It separates the basement from the very first floor of your private house.

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basement floor requirements

As you probably already guessed, it is this design that accounts for heaviest weight and load. First of all, this is the weight of all internal partitions, and if they are load-bearing, then the weight of all objects that rely on these bearing walls. And the first floor itself will obviously contain very heavy furniture elements (many people have a fireplace and a kitchen on the first floor). Although during the construction of the lower floor there are positive points, facilitating the work: the weight of this particular structure, no matter how heavy it may be, helps to support the foundation itself, unlike interfloor and attic floors.

It should not be forgotten that if your basement does not have heating, then you should do quality insulation heat and steam. The vapor barrier should be placed on the insulation, on top of it, since the diffusion of water vapor will move from the heated, warm room on the first floor directly to the lower, cold basement room. With a warm basement with heating, the instructions for its construction are no different from the usual interfloor ceiling. If the premises in question have high humidity or provides for the presence of leaks, this room should be equipped with waterproofing.

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Interfloor floors

The floors that separate the living rooms from each other are called interfloor. Here a very important role is played by what kind of floor design you choose. A fine balance must be struck between the self-weight of the floor and the bearing strength of the walls. This should be given Special attention, since there are often cases when it is necessary to install additional load-bearing walls in order to significantly shorten the span. Also, you may need to refuse to purchase too heavy furniture.

If you like a calm, quiet environment, then in rooms such as the bedroom, if you wish, you can install soundproofing. In the bathroom, do not forget about waterproofing in order to avoid the accumulation of moisture in the ceilings.

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Attic floor

The work of such an overlap is to separate the living space from the attic. The most important thing you must do when building this floor is to take care of the presence of thermal protection. It should be remembered that the insulation may lose its heat-insulating abilities over time, so it needs to be protected from moisture. This will help the installation of a vapor barrier, which should be placed under the insulation. If your roof is made of metal, then a layer of insulation will help get rid of noise.

So, we figured out the basic rules and requirements, now we should move on to considering the types of interfloor ceilings and instructing on how to make the ceiling between floors with our own hands.

So, the types of floors:

• floors that are made of wood;
• interfloor ceilings from a monolith;
• reinforced concrete floors to be assembled.

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Interfloor wooden floors and method of their installation

The composition of interfloor wooden floors can be described as follows: support beams, a draft floor prepared in advance from below (optionally with heat-insulating material) and counter rails installed on top, along which the floor from the boards is laid. Maximum span width this species overlap - 5 meters. Having calculated what loads the wooden floor will have to withstand, you can choose the parameters of the beams. They can be from 135 mm to 240 mm high.

Thickness starts from 50 mm and goes up to 160 mm. The installation step is 60, 85 or 100 cm, depending on the selected beam dimensions.

The flooring device originates from the preparation of beams. The ends of all beams should be cut before starting work, observing an angle of 60 degrees. Further, these areas should be treated with bitumen, and then dried. The sequence of work is as follows: first, the outer, side beams are laid, then the intermediate ones. When working, the same step is observed. Do not forget that the entire structure must be flat on a horizontal level.

If a wooden beam must rest on a brick wall, this is possible only if there is a nest in the wall, specially left during the construction of the wall. The minimum nest depth is 170 mm. If during work there are empty spaces between the ends of the beams and the wall, they should be removed using cement mortar. In order to strengthen the ceiling, increase its bearing capacity, every third beam must be reinforced with anchors.

If the beam is attached to the wall of blocks, you need to make a reinforced concrete jumper. It is installed under the beam itself and inserted into the wall to a depth of at least 175 mm. The beam is inserted into the wall in the same way as the previous option. A heater is installed behind the box, the side of the beam is equipped with a gap designed to remove moisture. If the walls are made of logs, beams or shields, you should simply cut down the upper crown.

If you carefully look at the estimate for the construction of a typical private house (cottage), then such structural elements account for about 15-20% of all costs. It is with the help of increasing the number of storeys of any building that it is possible to solve the problem of more rational "development" even relatively small area earth. What types of overlaps are there, how they are characterized, when it is advisable to use one or another of their options, what will come out to do on their own is the topic of this article.

Main characteristics

Any private house, even in 1 tier, is conditionally divided into several levels. When arranging interfloor ceilings with your own hands, it should be taken into account that, depending on the location of these structural elements, different requirements are imposed on them. First of all, according to the main characteristics. These include:

1. bearing load. Sometimes they talk about the strength of the interfloor ceiling, that is, its ability to withstand not only its own mass, but also the weight of everything that is located above - furniture, Appliances etc;

2. resistance to deformation. First of all, break. This characteristic is interconnected with the previous one and determines the linear parameters of the samples (slabs, beams) that separate the floors of the cottage;

3. sound transmission. The lower this indicator, the lower the cost of arranging sound insulation;

4. thermal conductivity. This is especially true for the lower and top floors private house. From this characteristic of the material directly depends on how heat will be stored in its rooms.

5. fire resistance. Requirements fire safety for residential buildings it is much tougher than for ancillary buildings (storage, utility and others).

Classification

1. According to the place of installation.

• Attic.

The main criterion for assessing quality is minimal heat loss. Therefore, such interfloor floors need additional insulation. If the cottage has attic room, this stage finishing works is given increased attention. It is also taken into account that all vapors rise to the ceiling. Therefore, the correct arrangement of the vapor barrier of the uppermost floor of a private house is of great importance.

• Basement (basement).

Much here depends on how the technological floor is equipped, and whether it exists at all. There are quite a lot of options for the bases on which cottages are being built, if we take into account the combined ones (for example, piles + shallow tape). In the presence of basement the main requirements for this type of interfloor overlap are the same as for the previous one. Another condition is added - reliable protection from dampness, especially if there is no heating circuit on the technical tier. In this case, there is a specificity in the installation of the vapor barrier layer - it is laid on top of the insulation material, since vapor diffusion will occur from the warm zone (room) to the cold zone (basement).

• Interfloor.

They have different requirements. Since the microclimate is, by definition, maintained at the same level in all rooms of the cottage, such a characteristic as the degree of protection from noise comes to the fore. For interfloor floors located above (and below) rooms with excessive humidity (kitchen, bathroom, laundry, etc.), reliable waterproofing is also important.

2. By appointment:

• Carriers.
• Enclosing.

3. By execution.

3.1. Beamless options:

• Monolithic.

According to the manufacturing technology and the final result, such interfloor ceilings are divided into ribbed, "with liners" and a number of other varieties. The common thing is that in the process of work it will not be necessary to use complex equipment, especially, to deal with the delivery of samples to the construction site. A horizontally oriented formwork is preliminarily prepared, into which the solution is poured. After curing artificial stone between the floors a monolithic dividing structure is obtained.

Perhaps the only drawback is the preparation time. We'll have to wait until the solution is fully strengthened. But there is also a big plus - this technology can be applied to individual segments. For example, if it is necessary to update the interfloor overlap in wooden house, without large-scale dismantling of any part of it.

• Prefabricated.

They are the most reliable, as they are mounted from reinforced concrete (hollow slabs). But this technology in relation to a private house has a number of limitations. Firstly, the increase in the cost of work due to the need to use lifting equipment. Secondly, the complexity of transportation and laying of plates. Them maximum length- 9 m, and it may not coincide with the design parameters of the cottage. Thirdly, the walls must support the weight of the reinforced concrete. Consequently, such interfloor ceilings in a house made of aerated concrete, for example, cannot be applied. As an option - for brick buildings.

• Prefabricated monolithic.

It is the best engineering solution for arranging interfloor ceilings between floors with your own hands, although it is still rarely used in the construction of private houses. Basically, due to the lack of awareness of developers about the benefits of this option. The main thing is that you can do everything yourself, and in the shortest possible time.

The name suggests that this is a combined technology, which includes elements of prefabricated and monolithic structures. The basis is beams on which hollow blocks are laid. In fact, they play the role of forms, and the solution is subsequently poured into them. One of the significant advantages is that it can be anything. For example, interfloor prefabricated monolithic ceiling from aerated concrete.

3.2. Beam:

The main difference is in the material of the blanks used.

• Reinforced concrete beams.

In the process of building cottages, they are practically not used. Large labor costs, installation complexity, increased load on the foundation - these are just some of the problems that will have to be faced. For example, such interfloor ceilings in a house made of foam blocks are not an option due to the fragility of the wall material. Separation of floors in individual buildings can be done in other, more acceptable ways.

• Metal blanks.

In the construction of private houses, interfloor ceilings based on I-beams or channels are used quite actively. But, as a rule, only to separate the first and technological floors. Pluses - high strength and small sections compared to wooden counterparts (with the same design load); the ability to do the installation on their own. Cons - susceptibility to corrosion and high thermal conductivity of metals. Therefore, when laying them, some protective technologies are used. For example, wrapping the end parts of the blanks with felt.

• By wooden beams.

There are many advantages - the cost of production makes it affordable, low thermal conductivity, ductility of the material to be processed with the simplest tool. In most cases - best option division of floors in a small cottage.

There are other varieties. For example, coffered, hipped, arched. In the private sector, they are practically not used. Unless in cottages, the roofs of which have a complex configuration. To make any of them, you need not only accurate engineering calculations, but also professional skills. Therefore, independent execution is questionable. As a rule, such structural parts with small area they are mounted on their own only in ancillary buildings located on the backyard territory.

The article gives general review options for dividing the floors of a private house. You need to understand that it is necessary to determine, first of all, the sections of the samples used, therefore, the services of a specialist will be needed. But the rest of the work on the installation of the interfloor ceiling in most cases will be done on its own.