Design

An example of a floor structure on wooden beams. Interfloor overlapping on wooden beams: calculation for prefabricated loads and allowable deflection

The advantage of a multi-storey building is obvious - a large living area with the same external dimensions. Figuratively speaking, putting the floor on the floor, you can double the usable space.

This is actually not difficult, the only thing that needs to be thought out in advance is the design of the floors. Concrete creates an excessive load on the walls, steel is difficult to process.

Wooden floor between floors the best choice for a country house. It is only important to accurately calculate its parameters and choose high-quality materials.

Wooden flooring device

Perhaps this best view floors, it compares favorably with ease of manufacture and availability of materials. In addition, only wood is used to create it, which ensures environmental cleanliness with sufficient reliability. The device for overlapping on wooden beams is not particularly difficult, its main components are:

bearing beams;
guide bars;
draft ceiling;
floor base top floor;
insulation;
waterproofing;
decorative coating.

The necessary strength and reliability of the entire structure will give the timber. It can be solid or glued from several layers. A good replacement for timber is solid logs of small diameter. Boards can also serve as the basis for the structure, but such floors have significant limitations in terms of span length and load.

In principle, the beam can be made of any wood, but it is better to choose larch or pine. Hardwood has a slightly different structure and less resistance to bending. Such an overlap may not withstand constant load.

On the supporting structure of parallel beams, the base of the future floor and ceiling is mounted, respectively. It can be a prepared board or wood-based sheet material. Lay on the finished base flooring(on the second floor), and from below they make a full-fledged ceiling.

feature similar design is free inner space to be used. It is filled with any material with heat-insulating or sound-absorbing properties. This will help keep the heat in the rooms and provide a sufficient level of sound insulation.

Material selection

First of all, this design is functional, therefore, the interfloor overlap on wooden beams should be reliable. It is important to understand that it must not only support its weight, but also the weight of the furniture located on the top floor, and the weight of the people there. Consequently, high quality requirements are placed on the material used, especially on the beams.

As already mentioned, best material for the beam is a coniferous tree. The choice of wood should be taken with all possible responsibility. Basic material requirements:

minimum humidity, its value should not exceed 14%;
minimum knots per unit length;
there should not be a pronounced oblique layer;
absence of cracks, rot, darkening, traces of pest activity.

To ensure the durability of the floor, all wooden surfaces are pre-treated with an antiseptic and impregnated with special compounds that reduce the combustibility of the material. This guarantees the durability of the structure and protects against fires.

Varieties of floors according to the method of fastening

Bearing bars are securely fixed to the walls. There are two main ways to attach them: installing them in a socket or using additional fasteners.

Installing the bars in the grooves

This method is great for brick houses, cinder block buildings and similar materials. To fix the beam, you need to make a selection (groove) in the wall. The dimensions of the groove should exceed the thickness and width of the beam by 2-3 cm, the depth varies in the range from 100 to 150 mm. It is not difficult to provide waterproofing of the connection with the help of a conventional roofing material; they wrap the ends of the beams recessed inside the wall.

Using metal clips

If it is not possible to sink the beams into the wall, external steel fasteners can be used. Technically, this method is simpler, but it provides less strength, therefore, the wooden floor will withstand less load. Such a hinged mount can be used to create small ceilings or between the first floor and the attic (attic) of a garden house.

Fasteners for sale different shapes, some are designed for wall mounting, others are mounted on internal or external corners. With the choice of the optimal configuration of the supporting elements, there will definitely not be any problems.

The main parameters of the beam for beams

The parameters of the beams directly depend on the geometric dimensions of the premises of the lower and upper floors, their intended purpose. The calculation of parameters is an important stage in the creation of an interfloor overlap, the reliability and durability of the entire structure largely depends on it.

Shape and section

A rectangular beam is seen as the optimal material for the manufacture of beams. Installed on the edge, it has a sufficient margin of safety, high reliability. Sometimes round timber or lumber of specific profiles, for example, an I-section, is used as load-bearing structures.

The exact parameters of the beam directly depend on the expected load, the span length and the distance between adjacent beams. By the way, it is not at all necessary to calculate all the parameters yourself; you can use ready-made tables and diagrams.

Length calculation

Calculating the length of the beam is simple - this is the width of the span plus the tolerances for embedding in the grooves. Regardless of the section, it is not recommended to make spans more than 6 m wide, this will inevitably cause sagging, which can result in an accident. If it is necessary to make a larger wooden floor, you can get out of the situation by installing supports and props in the form of columns from the same beam.

Material quantity

For ease of calculating the amount of material, it would be useful to sketch out a diagram of the future overlap. It should be borne in mind that the distance from the extreme beams to the wall will be approximately 50 mm, and the rest will be evenly laid between them at the same interval (0.5–1.0 m).

Stages of manufacturing an interfloor ceiling

After the calculations are completed, the material is purchased, you can proceed directly to the installation of the wooden floor. The process of its manufacture is not a very complicated matter, but in order to facilitate the work, it is advisable to do everything with an assistant, this is especially true when making large-width ceilings.

Beam installation

The best option for a residential building with a full-fledged second floor can be considered the installation of beams in grooves. You can make grooves both at the construction stage, which is much easier, and after the construction of the building. Work begins with the extreme beams, which will be located in close proximity to the side walls.

A blank of the required length is cut out of the timber, the ends are cut circular saw or a hand saw at an angle of about 60 degrees. Special accuracy is not needed, it is important to create conditions for the wood to breathe.

Note! The part of the beam that will be hidden in the wall is impregnated bituminous mastic(with the exception of the butt) and wrapped with roofing material.

The beam is inserted into the groove, a board 20–30 mm thick is placed under it. With the help of the level, the correct installation is controlled, the beam must lie strictly horizontally. The first and every fifth beam is additionally fixed with anchor bolts or steel plates.

This procedure is repeated with the other extreme beam. To control the plane, a board is temporarily laid between the extreme beams, on top of it - the usual building level. Thanks to this simple design, it is easy to choose the thickness of the lining for each subsequent timber.

skull bar

Cranial bar - slats with a cross section of approximately 50 x 50 mm, which are attached to both sides of the beam. Its task is to hold the roll used as a draft ceiling. It is advisable to use a bar only when the ceiling is mounted from above.

The slats are cut along the length of the beam, fixed with self-tapping screws. A roll is attached to them. This method is simple and does not require excessive physical effort, there is no need to keep the details of the draft ceiling on weight, but it significantly reduces the space inside the ceiling, which can be used for laying insulation and sound insulation.

If the ceiling is mounted from below, the work technology can be significantly simplified, without a cranial bar, then the roll will be attached directly to the beams using self-tapping screws.

Creating a draft ceiling

In most cases, it is convenient to use wood-based sheet material to create the base of the ceiling. It's easy to attach and is durable. To work, it is enough to arm yourself with a screwdriver and self-tapping screws.

When using a cranial bar, the material is cut into strips equal to the span in width, laid, fixed with self-tapping screws. If the cranial bar is not installed, you can use a material of any size, the only condition is to ensure that adjacent plates converge on the beam.

Thermal insulation and vapor barrier

Even if an overlap is created between residential floors, it is worth laying heat-insulating material inside, mineral wool is best. It will completely fill the space, save heat and become a good protection against noise.

Under the insulation, especially if the kitchen, bathroom or other room with high humidity, you need to lay a layer of vapor barrier. It will protect the ceiling from steam, protect the tree from moisture that will condense inside. The sheets are overlapped, the joints are additionally fixed with construction tape.

Waterproofing

A waterproofing film is laid on top of the finished insulating cake. Its task is to block the path of moisture from above, to prevent it from seeping into the sealant. The edges of the film must overlap each other by at least 10 cm on each side. Additional protection against possible leaks, as in the case of vapor barrier, will be provided by construction tape.

Draft floor of the next floor

To create a base for flooring, a board, plywood, OSB sheets, chipboard of sufficient thickness can be used. Fasteners are selected for the selected material, for plates these are self-tapping screws, for boards nails are suitable. When working with sheet material, as well as when creating a draft ceiling, you need to ensure that the plates are joined only on the beams.

Finishing floor and ceiling

Actually, the work is almost finished, only the skin remains. Here the technique depends solely on the selected material. The floor of the upper floor can be covered with budget linoleum, elite parquet, or choose the golden mean - laminate. The material for the ceiling can be drywall with subsequent painting, plastic ceiling panels, lining.

Wood flooring is the best choice for a country house. It is easy to install, strong and durable. This is exactly the overlap that you can do with your own hands. It will last a long time, does not require special care, and thanks to exclusively natural materials it perfect solution for a children's room, it can be done both on the top floor and on the bottom.

When planning the construction of a country cottage, the owner has to solve the difficult issue of choosing floors. Some contractors advise him to use reinforced concrete panels, others insist on using wooden beams as a ceiling.

We decided to help beginners get out of a difficult situation. In our article you will find an overview of the advantages and disadvantages of wooden floors.

Useful tips for their installation and important nuances doing this work will also not be superfluous. We hope that the information received will be useful to you at the construction site and help you avoid serious mistakes.

There is a stereotype in the minds of citizens that precast concrete panels are the only possible solution for any building. It is not difficult to overcome it.

It is enough to list the advantages of wooden beam floors:

Minimum cost (1 m3 of timber is several times cheaper than 1 m3 of hollow core panels);
The load on the walls is 2-3 times less than from the panels. This allows you to significantly reduce the consumption of reinforcement and concrete when laying the foundation;
On small spans (up to 4 meters), wooden beams can be laid manually using the simplest devices (winch or lifting block). Mounting heavy slabs without a powerful crane is an unrealistic task;
Low labor intensity and high speed of work (compared to pouring a monolithic reinforced concrete floor);
Environmental friendliness (granite gravel is used in concrete, the radiation background of which can significantly exceed the norm).

As you know, there are no advantages without disadvantages. There are few of them for wood floors:

Increased deformability. It manifests itself in the effect of vibration during walking and the formation of cracks at the junction of plasterboard partitions;
Low fire resistance (without special impregnation);
Relatively small length (does not exceed 6 meters). For reinforced concrete panels, it reaches 7.2 meters.

Among the shortcomings of these designs, some authors of feature articles include the formation of cracks in the plaster of the ceiling and poor impact sound insulation. However, with a competent approach to installation, these two problems are solved simply and reliably. To do this, a number of less thick beams are laid below the load-bearing beams, specially designed for filing the ceiling (drywall, OSB, lining, board).

The hemming beam, like the main one, is placed on the wall, but lower, and the ceiling cladding is attached to it. This solution is not common, although it is competent and its history dates back more than one century, in addition to cutting off the structural noise of the second floor, this option eliminates cracks in the ceiling. They appear in the case when the beam serves as a support for the floor of the second floor and at the same time the ceiling of the first floor is hemmed to it. From vibration and shock load, cracks appear in the finish.

Applications and calculation of wooden floors

in buildings built of wood (frame and chopped);
in country houses designed for summer operation;
in outbuildings(sheds, bathhouses, workshops);
in prefabricated prefabricated houses.

In addition to the listed options, wooden structures for interfloor ceilings can be used in cottages intended for year-round use. Only in this case, you need to use the two-row beam installation system, which we described above.

We do not recommend selecting the cross section of the timber according to the principle “the thicker the better”. There is a simple calculation method taken from building codes.

According to it, the height of the wooden beam should be at least 1/25 of the span to be covered.. For example, with a 4-meter distance between the walls, you need to buy a sawlog with a section height (H) of at least 400/25 = 16 cm with a thickness (S) of 12 cm. To create a margin of safety, the found parameters can be increased by 2-3 cm .

The second parameter that you need to choose correctly is the number of beams. It depends on their pitch (the distance between the central axes). Knowing the cross section of the beam and the size of the span, the step is determined from the table.

Table. Beam spacing selection

The calculated load of 350-400 kg / m2 indicated in the table is the maximum for the second floor. If it is not residential, then its value will not exceed 250 kg / m2.

When planning the layout of the beams, you need to take into account that the two extreme ones should recede from the end walls by at least 5 cm. The remaining beams are distributed evenly along the walls (in accordance with the selected step).

Stages and features of installation

Technologically, the device for overlapping wooden beams cannot be called complicated. The main attention should be paid to the alignment of the beams horizontally and the quality of embedding their ends into the wall array. You can’t just put the bars on the masonry and lay them with bricks. It is necessary to provide them with a reliable connection with the walls and qualitatively protect the wood from decay.

Options for sealing beams, depending on the material of the masonry, the type of wall structures (external, internal, chimney) and the methods of their fastening are shown in the figures.

The length of the supporting part of the beams in a brick and block wall should be at least 16 cm (in a wooden 7-8 cm). If paired boards placed on edge are used instead of timber, then they are embedded in the masonry by at least 10 cm.

The side parts of the beams in contact with the wall are wrapped with 2 layers of glassine or 1 layer of roofing material. Experienced craftsmen cut the ends of the beams at an angle (60-70 °) and leave them uninsulated, while not forgetting to treat them with an antiseptic composition on a par with the rest. This ensures the "breathing" of wood wrapped with waterproofing.

When installing the ceiling on the sides of each beam, small gaps (3-5 cm) are left, filled with mineral wool or tow. A heat insulator is also placed in the space between the end of each beam and the wall. This eliminates the "cold bridge" that occurs by reducing the thickness of the masonry.

When constructing ceilings in walls made of aerated concrete and wood concrete blocks, it is recommended to use an open seal. In this case, the ends of the beams are also cut at an angle, antiseptic and pasted over with roofing paper on mastic, leaving the ends free.

The outer wall of the nest is insulated with felt or mineral wool and a box made from pieces of an antiseptic board is inserted into it. Its height is chosen such that an air gap (2-3 cm) is formed above the beam. Through it, water vapor accumulated in the wood will exit into the room in the plinth area. This solution protects the supporting part of the beam from decay.

In practice, developers most often use a simpler method of embedding without the use of insulation and a wooden box, closing the logs with block cuts or just a raster.

The floor bars are supported on, which is used to increase the spatial rigidity of the block masonry.

In internal bearing walls beams close up in a closed way. To increase the rigidity of the overlap, they are connected to each other through three steel anchor plates.

The section of the beam adjacent to the smoke channel is insulated with asbestos or other non-combustible material. The main protection against fire here is brick cutting (thickening of the pipe masonry) 25 cm thick.

IN wooden houses installation of beam ceilings is performed in two ways:

Cutting into log crowns;
Through a steel shaped plate (high chair), fixed to the wall with threaded studs.

Installation of the ceiling by cutting into the walls

The option of installing beams on "chairs"

If the upper floor or attic is not residential (heated), then it is necessary to insulate the wooden floors. To do this, a heater (mineral wool, ecowool) is laid in the space between the beams, having previously spread a layer of vapor barrier over the ceiling filing.

Styrofoam should not be used for this work for three reasons:

It does not allow water vapor to pass through, and the wood rots under it;
Does not isolate impact noise;
It is problematic from an environmental point of view.

The design of the insulated floor is shown in the diagram.

Similarly, the insulation of the floor of the first (basement) floor is performed. The difference between them is that it is quite difficult to hem beams from below from a shallow underground. In this case, the builders act differently. To the side faces of the beams, they knock out a cranial bar (5x5 cm). An antiseptic boardwalk is laid on it. It serves as a support for slab insulation, placed in the gaps between the bars. A vapor barrier is placed under the mineral wool. A vapor barrier is also laid on top of the beams. After that, logs are attached to them and a finishing floor is already mounted on them.

The mineral wool slab should be placed between the bars as tightly as possible to prevent blowing through the floor. For better insulation, all joints of the insulation are treated with mounting foam.

The control of the horizontal installation of the bars is carried out using a bubble level laid on a flat long board. For leveling use cutting boards, protected by bituminous mastic. They are placed under the ends of the bars.

Vapor barrier sheets should be laid with an overlap of at least 10 cm and all joints should be glued with construction tape.

To reduce impact noise, soundproofing tape 5 mm thick is laid on the beams before installation of the second floor floor joist. A waterproofing film under the logs is placed only if the second-level room is residential. It will protect the insulation from water ingress when washing the floor. The technology of its installation is similar to the laying of vapor barrier.

The final stage of the wooden floor device is the installation of a subfloor from boards, plywood or OSB boards using self-tapping screws. After the completion of this work, a fine coating of laminate, linoleum, parquet is laid and the ceiling is finished.

It is possible to independently perform the installation of a wooden floor between floors, subject to significant experience in carpentry and general construction work. Interfloor floors made of wood are critical structures in residential buildings and require careful observance of installation instructions.

Do-it-yourself wooden flooring - advantages and disadvantages

Any overlap between floors, including wood, must meet the following characteristics:

Static and dynamic strength. The design must withstand the weight of the expected load with a large margin;
Rigidity sufficient for a high-quality basis for the arrangement of floors (upper floor) and ceilings (lower floor);
Durability comparable to the life of the entire structure. Replacing interfloor floors in an old building is a complex and expensive repair procedure; at the stage of capital construction, it is much easier to make floors between floors from durable wooden beams;
A good floor must have decent heat and sound insulation.

Floors made of wood satisfy all the listed qualities and are distinguished by additional advantages. They are easily mounted by two people and do not require the involvement of heavy construction equipment. A span of up to 100 m 2 can be laid in one day, if we talk about load-bearing structures, and not their finishing. Wooden beams are many times cheaper reinforced concrete slabs or steel floors - and their service time is tens (or even hundreds) of years.

The potential dangers of using wood as a load-bearing interfloor structure include the danger of its decay and ignition in case of fire. These factors are minimized by appropriate processing of the beams prior to installation. Equally important is the consideration of the minimum allowable deflection. Coniferous wood is used for interfloor beams due to durability and resistance. But it is quite plastic - therefore, the maximum the size of the beam span made of wood is limited to a size of 5 meters. If it is necessary to block a large room, additional supports (columns, crossbars, etc.)

Overlapping of the second floor on wooden beams - design calculation

From the correct calculation and competent general construction preparation, it largely depends on how high-quality the device of the wooden floor between the floors will turn out. According to convenient seats with the help of optimally prepared beams, interfloor openings are covered quickly and easily. First of all, the direction of installation of floors is always chosen according to the short size of the room. The installation step is interdependent on the cross-section of the base of the floor, but is usually equal to 1 meter, since a smaller step will lead to great labor intensity when arranging seats. It is wiser to buy wood of a larger section than to spend money on a palisade of weak floors.

For an installation step of 1 meter, subject to the habitability of the second floor, it is necessary to acquire such load-bearing bars that can withstand a load of at least 400 kg / m 2:

With a span of up to 2.2 meters - 75x150 mm;
With a span of up to 3.2 meters - 100x175 mm;
With a span of up to 3.2 meters - 125x200 mm;
With a span of up to 5 meters - 150x225 mm.

Overlapping of uninhabited attics is carried out with the same step, but with a material of a smaller section. For example, for half the load (that is, 400 kg / m 2), bars 50x160, 50x180, 70x180 and 70x200, respectively, will be enough. Just keep in mind that you will then have to crawl in the attic with such an overlap, and not walk ... As you can see from the calculations, load-bearing beams with a ratio of 1.5: 1 height to width are considered optimal. For attic space, on the contrary, a narrow tree of an elongated profile is used due to a small load in the future.

Overlapping between floors - preparing for installation at the construction stage

When erecting walls made of bricks, silicate blocks, aerated concrete, they provide openings for floor elements. The step of these openings is 1 meter, the depth is at least 30 (and preferably 40) centimeters, the width is the same. The beam must enter the wall by at least 20 cm, plus free space will be required for its ends. The end part of the ceilings is not filled with any building mixtures in order to natural ventilation and inhibition of decay.

The more accurately the seats in the walls of the house are displayed in height, the easier it will be to lay the beam structure. In houses made of wood, it is possible to embed beam structures directly into the walls, here the implementation of the future overlap preparation at the stage of wall construction is not required. It is important to take into account the inadmissibility of installing load-bearing bars close to a parallel wall, no closer than 10 cm, and it is imperative to maintain a strict constancy of the installation step - the allowable “run-up” from the nominal value of 1 meter should not exceed ± 5 cm.

Overlapping of the second floor on wooden beams - installation stages

The walls with landing nests are ready, the wood and auxiliary materials are purchased, the tools are ready - we begin the installation of floors:

One day before installation, the tree is smeared with antiseptic mixtures and fire-resistant compounds - with the exception of the ends, no “chemistry” can be applied to them. The choice of such compositions is now very large, you can name brands Finesta, Seine well, Neomid, Pinotex etc. with wide choice antiseptics and flame retardants. All primer should dry well;
We measure the beams and saw off with a sharp wood saw with a margin of 35-45 centimeters from the size of the room for reliable support on the walls. The cut should be at an angle of 60˚, so that when viewed from the side, the overlap element looks like a trapezoid with a wide lower part. The ends recessed into the walls are coated with resin and wrapped with roofing paper after it dries;
Installing the end beams. We work from a high, wide and reliable "goat", it will not be possible to manage with ladders alone. Carefully set them in level and on the horizon. As linings, wide sections from the same floors are used, and in advance with antiseptic and fire-fighting compounds. Make sure that the ends of the beams do not rest against the walls, there should be a gap for ventilation of at least 3-5 cm in depth;
When there is no doubt about the accuracy of the installation of the side beams, they are fixed with dry gravel in the landing nests. Lines are pulled tightly between the extreme beams. On these auxiliary fishing lines, other elements of the beam frame of the floor are installed;
The installed beams are once again carefully measured and adjusted, after which the landing nests are concreted with a solution of cement and crushed stone.

The base of the wooden interfloor ceiling with your own hands is ready. After curing cement mortar you can proceed with the thermal insulation of the floors, laying the waterproofing film and laying the floors on the new floor. If the floors of the upper floor are laid on additionally installed logs, then the ceiling of the lower one can be fixed directly to our beams.

The growth in the volume of private housing construction indicates an increase in the well-being of our compatriots. The younger generation can hardly believe that not so long ago it was necessary to be on the waiting list for 30-40 years for housing, and the result of the waiting was still unknown. Even those who had the opportunity to immediately pay for cooperative housing had to sign up as members of these communities through a large pull, the volumes of such construction were scanty. This is a reference for those who idealize the times of the USSR too much, but did not live then.

Today the situation has changed dramatically, a large number of our compatriots can buy ready-made apartments in high-rise buildings, and those who do not want to breathe city smog are being built outside the city. The building materials and technologies that exist on the market make it possible to create unique projects that architects could not even dream of before. But not all developers have enough knowledge to choose correct option On the second floor. Let's try to figure it out.

Depending on the features of the building project, there are two types of floors on the second floor on wooden beams.

SNiP 2.03.13-88 of 01.01.1989 Floors. Thickness, floor coverings, interlayer, screed and subfloors(click on the link to open the PDF file in a new window).

Table. Types of floors on the second floor on wooden beams.

floor type	Description of technical and operational features
	Such floors are currently almost never used, but in vain. Below we will consider options for when it is advisable to install non-insulated floors. In terms of cost, they are the cheapest, laying them is not difficult even for beginners.
	The design is complex from an engineering point of view, consists of several layers, each of which has a noticeable effect on the overall performance. It is much more expensive than cold ones, but can significantly reduce heat loss. Due to this, an expensive design quickly pays off and begins to bring direct profit. But this is possible only under one condition - warm floors are laid in strict accordance with existing building codes and regulations. Otherwise, they quickly lose their original properties and require complex and expensive repairs.

floor type

Description of technical and operational features

Such floors are currently almost never used, but in vain. Below we will consider options for when it is advisable to install non-insulated floors. In terms of cost, they are the cheapest, laying them is not difficult even for beginners.

The design is complex from an engineering point of view, consists of several layers, each of which has a noticeable effect on the overall performance. It is much more expensive than cold ones, but can significantly reduce heat loss. Due to this, an expensive design quickly pays off and begins to bring direct profit. But this is possible only under one condition - warm floors are laid in strict accordance with existing building codes and regulations. Otherwise, they quickly lose their original properties and require complex and expensive repairs.

In what cases is it recommended to lay cold floors on the second floor

To convincingly answer this question, we must recall a few elementary rules of heat engineering.

Most professional builders strongly do not recommend making insulated floors on the second floor if its premises are used as residential. You need to know that in addition to unnecessary losses of money and thermal energy, another problem may appear. If the technology is violated, the heat-insulating material increases its humidity, all wooden elements are operated in very difficult conditions. Heat plus moisture is an excellent environment for the development of fungi and rot on load-bearing wooden elements, and no state-of-the-art impregnations can protect them for a long time. Over time, we have to deal with very unpleasant premature repairs. We hope this information will help you optimal solutions in each specific case.

General requirements

Regardless of the specific features of the floor, building codes put forward for all structures General requirements. Only their implementation guarantees long-term and efficient operation of structures.

insulation

Among the many types, two are most often used: mineral wool and. Which to choose? The answer to the question should be sought by each developer on their own, we only give our recommendations.

. It can be rolled or pressed, it has replaced traditional glass wool. It has two real advantages: it does not burn and does not release harmful chemical compounds into the air. Cons: high price, relatively big weight and hygroscopicity. The last drawback requires special attention. The fact is that cotton wool absorbs moisture very quickly and dries for a long period of time. This means that wooden floor structures are constantly operated in conditions of high humidity, and this has an extremely negative effect on durability. Another problem of hygroscopicity - wet cotton wool dramatically increases the thermal conductivity, the efficiency of insulation decreases markedly.
. Many consumers are wary of this material, the consequences of anti-advertising of competitors are affecting. Like, it burns and emits aggressive chemical compounds. Such anti-advertising is spread by manufacturers of mineral wool, they have their own personal economic goals. What is real? Modern foam plastic is manufactured using innovative additives, due to this, the amount of harmful substances emitted has decreased to a normalized permissible level. According to these parameters, there are no strict restrictions for polystyrene foam; by the way, it is less toxic than some varnishes used to make furniture. Another little-known quality modern foam does not support open combustion, this is a very important characteristic of all building materials. Of course, in terms fire safety polystyrene is much inferior to mineral wool, but this is not as critical as it might seem. In practice, no one has yet seen the whole house burn down, and the floor with mineral wool remained safe and sound. And vice versa, firefighters did not observe a situation when only one floor with foam insulation burned down, and all other structures were not affected by the fire. In case of fire, there is no big difference with what material you insulated the floor of the second floor, the house will completely burn down anyway. But at the cost of manufacturability and durability of operation, floors with foam insulation are much superior to designs with mineral wool.

These are objective comparative characteristics two heaters, analyze the information and draw your own conclusions.

floor beams

Depending on the planned loads, boards 50 × 200 mm, 50 × 250 mm or bars of at least 150 × 150 mm can be used. It is necessary to choose only high-quality lumber not lower than the first grade. During calculations, it should be taken into account that the load per square meter of the floor can reach 210 kg, and the maximum deflection should not be more than 1/250 of the length. For example, if the length of a room on the second floor is 5 m, then the deflection in its center cannot be more than 2 cm. This is the maximum value, in some cases the deflection cannot exceed 1/400 of the length.

Beams and ceilings must withstand up to 180 kg / sq. m load

A beam section of 15x15 will be enough

Beams should be impregnated without fail with modern antiseptics, all places where wood contacts concrete or masonry building materials are waterproofed. And most importantly, the presence of a constant and effective ventilation spaces under the floor. This is the only way to ensure optimal operating conditions for carriers. wooden structures.

Soundproofing

Existing regulations prescribe that the sound insulation threshold of interfloor ceilings should not exceed 50 dB. It is known from physics that the greater the density of a material, the better it conducts vibrations. Sound is air vibrations, air waves of various lengths and intensities. All insulation materials perfectly extinguish them; to achieve the required standards, it is enough to make a layer of mineral wool or polystyrene 50 mm thick between floors.

Maximum length of wooden beams

The floor can not be laid on fragile bases, and lumber has its limitations. Modern wooden channels can cover spans up to ten meters, unfortunately, beams cannot be used in such situations. They are allowed to be used with a span of no more than 5 m for interfloor floors and no more than 6 m for attic floors. But the length of 4 m is considered optimal, with a further increase in the distance between the stops, the deflection under its own weight increases significantly. In connection with such features, the beams must be laid across the width of the room, the step between them depends on several initial data: in the first place is the load per square meter, in the second place is the convenience of laying heat-insulating materials. To facilitate the selection process in building codes and the rules have tables with recommended beam sizes, taking into account the span of the floor.

Type and materials of flooring

There are several options for arrangement, when choosing a specific one, it is recommended to take into account maximum amount individual factors.

Natural boards or soft coatings can be used as finishing materials. But there is one limitation. If underfloor heating is planned, then wooden materials should not be used for two reasons. Firstly, they react extremely negatively to high temperatures and will definitely crack. Secondly, the tree has a low thermal conductivity, which impairs the heating efficiency.

Video - Draft floor. Floor device in a wooden house

Waterproofing materials

They should only be used when laying underfloor heating with mineral wool. Where exactly and what kind of waterproofing is used?

If the room has underfloor heating, then the installation process is even more complicated. between insulation and heating element there is an additional reason. It greatly complicates the process of natural ventilation and worsens the operating conditions of wooden structures. This must be remembered before starting work with the floor, it is necessary to foresee the consequences of the decisions made.

Step by step instructions for building a floor

For example, we will take a complex option - a floor insulated with mineral wool. Floor beams from boards 50 × 200 mm, according to calculations, such elements fully withstand the planned loads and have a safety margin of approximately 40%. The reserve is obligatory for all critical architectural elements of buildings, the ceiling is included in the list of such structures. For vapor barrier, modern membrane coatings will be used, a subfloor made of edged boards 20 mm thick.

Practical advice. In order to reduce the cost of construction, OSB or plywood boards, used boards of the same thickness or various substandard segments can be used for the subfloor. The decision should be made taking into account personal financial capabilities and the type of finish flooring.

Step 1. Lay the floor beams on the load-bearing walls. We have already said that in order to reduce the deflection force, they should be laid along the width of the room, and not along the length. Be sure to wrap the ends of the beams with roofing felt, there must be at least two layers. The boards themselves are recommended to be impregnated at least twice with an antiseptic. The specific brand does not matter, they all do their job quite effectively, except for obvious counterfeit products. The distance between the beams corresponds to the width of the mineral wool sheets. Standard materials have a width of 60 cm, which means the distance along the axes of the beams is also 60 cm. Thus, a clean niche of 55 cm wide is obtained, this allows you to tightly insert mineral wool and eliminate the appearance of cracks. Slots are undesirable not only because they cause heat loss. There is another problem - condensation is constantly present in these places, the tree gets wet and begins to rot. ABOUT negative consequences there is no point in describing such a process.

Options for fixing floor beams to wooden walls

There are quite a few ways experienced builders make the final decision on site. Beginners can be recommended to use one of the listed methods.

At the ends of the beams, recesses are made for the dimensions of the logs.. Advantages - the beams lie firmly on the wall, in many cases additional fixation is not required. Disadvantages - the trimmed elements lose their strength, it takes quite a lot of time to prepare each beam. During the calculations, it is necessary to take into account not the total width, but only in the place of the undercut. And there it is significantly reduced, due to which the consumption of lumber increases.
The ends of the beams lie on the log line, special openings are made under them. A very simple and time-tested method, universal application. Professional builders always try to use this method of mounting the second floor floor beams.
With the help of metal special fasteners. They are matched to the size of the beam and screwed or nailed to the inner surfaces. facade walls. Beams are inserted into seats. The advantages of the method are simplicity and ease of installation. Disadvantages - the bearing capacity is reduced, the mount is the most weakness and cannot withstand the same loads as the beam.

Step 2 Fix the steam protection to the lower planes of the beams with a stapler. An overlap of at least ten centimeters, all joints must be sealed with adhesive tape. We have already mentioned that it will not be possible to make a sealed cavity, moisture will find gaps in any case. But this does not mean that it is unnecessary to take measures to minimize this process.

Step 3 Nail slats or boards to the bottom of the beams. The finishing of the final ceiling will be fixed to them, the base must be strong. Thermal insulation material is laid on top of the rails. In our case, this is mineral wool, make sure that it fits snugly against the edges of the niche.

Practical advice. The thickness of the insulation is recommended at least ten centimeters. It is much more efficient to lay not one layer of insulation of this thickness, but two five centimeters each. Due to this, it is possible to make displacements of the joints and completely eliminate the likelihood of cold bridges.

It is very important that the mineral wool does not get wet, if the house does not have a roof, then it must be protected with a film. Wet material cannot dry on its own in a niche; it must be removed for drying. And this is not only unplanned loss of time, but also a large amount of unproductive waste. During dismantling, wet cotton wool is easily torn, some sheets must be completely replaced with new ones. As a rule, no one plans such losses and does not take into account when calculating the amount of insulation. As a result, a second visit to the building supplies store is required.

Step 4 Lay waterproofing on top of the insulation. We have already mentioned that for these purposes it is necessary to use only a special innovative membrane, it allows steam to pass through and retains water. The membrane is also overlapped and fixed with a stapler.

Step 5 Lay the subfloor. Laminate is chosen as the topcoat, and a solid base is required under it. Nail the boards tightly, but there is no need to specifically tighten with wedges. Gaps of no more than one centimeter are allowed. At least two nails must be driven into each board on each side, otherwise they will definitely bend during operation. This is a very undesirable phenomenon, especially for a laminate - a light coating rises, extremely unpleasant squeaks appear when walking.

It is not easy to eliminate them, you need to completely remove the laminate, level the subfloor boards and re-lay the coating again. As practice shows, it is much more profitable both economically and in time to follow the recommended technologies exactly than to eliminate the admitted marriage later.

The draft floor on the second floor is ready, you can continue the construction of the facade walls. Finishing covered is allowed only after the completion of the installation of the roof, finishing the ceiling and walls.

Prices for floor boards

floor boards

Video - Wooden floor insulation

Video - Laying the floor on wooden beams on the second floor

How the length of wooden floor beams is determined: FORUMHOUSE experts talk about the nuances of calculation and self-production.

The possibility of unsupported overlapping of large areas greatly expands the architectural possibilities when designing a house. A positive solution to the beam issue allows you to "play" with the volume of rooms, install panoramic windows, build large halls. But if it is not difficult to block a distance of 3-4 meters with a “tree”, then which beams to use on a span of 5 m or more is already a difficult question.

Wooden floor beams - dimensions and loads

They made a wooden floor in a log house, and the floor is shaking, bending, the effect of a “trampoline” has appeared; we want to make wooden floor beams of 7 meters; you need to block the room with a length of 6.8 meters so as not to rest the logs on intermediate supports; what should be the floor beam for a span of 6 meters, a house made of timber; what to do if you want to make a free layout - such questions are often asked by members of the forum.

Maxinova FORUMHOUSE User

My house is about 10x10 meters. I “threw” wooden logs onto the ceiling, their length is 5 meters, the section is 200x50. The distance between the lags is 60 cm. During the operation of the floor, it turned out that when children run in one room and you stand in another, there is quite a strong vibration on the floor.

And this case is far from the only one.

elena555 FORUMHOUSE User

I can’t figure out which beams for interfloor ceilings are needed. My house is 12x12 meters, 2-storey. The first floor is made of aerated concrete, the second floor is attic, wooden, covered with a bar 6000x150x200mm, laid every 80 cm. When I walk on the second floor, I feel shaking.

Beams for long spans must withstand heavy loads, therefore, in order to build a strong and reliable wooden floor with a large span, they must be carefully calculated. First of all, it is necessary to understand what kind of load a wooden log of one or another section can withstand. And then think over, having determined the load for the floor beam, what rough and top coat gender; what will the ceiling be hemmed with; whether the floor will be a full-fledged living space or a non-residential attic above the garage.

Leo060147 FORUMHOUSE User

The load from the own weight of all structural elements of the floor. This includes the weight of beams, insulation, fasteners, flooring, ceiling, etc.
operating load. The operating load can be permanent or temporary.

When calculating the operating load, the mass of people, furniture, household appliances etc. The load temporarily increases with the arrival of guests, noisy celebrations, rearrangement of furniture, if it is moved away from the walls to the center of the room.

Therefore, when calculating the operational load, it is necessary to think through everything - up to what kind of furniture is planned to be installed, and whether there is a possibility of installing a sports simulator in the future, which also weighs far more than one kilogram.

For the load acting on wooden beams of a long floor, the following values \u200b\u200bare taken (for attic and interfloor floors):

Attic floor - 150 kg / sq.m. Where (according to SNiP 2.01.07-85), taking into account the safety factor - 50 kg / sq.m - this is the load from the floor's own weight, and 100 kg / sq.m - the standard load.

If it is planned to store things, materials and other household items in the attic, then the load is assumed to be 250 kg / sq.m.

For interfloor floors and ceilings of the attic floor, the total load is taken at the rate of 350-400 kg / sq.m.

Overlapping boards 200 by 50 and other running sizes

These are the beams on a span of 4 meters that are allowed by the regulations.

Most often, in the construction of wooden floors, boards and timber of the so-called running sizes are used: 50x150, 50x200, 100x150, etc. Such beams satisfy the standards ( after calculation), if it is planned to block the opening no more than four meters.

For overlapping with a length of 6 meters or more, the dimensions 50x150, 50x200, 100x150 are no longer suitable.

Wooden beam over 6 meters: subtleties

A beam for a span of 6 meters or more should not be made of timber and boards of running sizes.

You should remember the rule: the strength and rigidity of the floor to a greater extent depend on the height of the beam and, to a lesser extent, on its width.

A distributed and concentrated load acts on the floor beam. Therefore, wooden beams for large spans are not designed "end-to-end", but with a margin of strength and allowable deflection. This ensures normal and safe operation overlap.

50x200 - overlap for an opening of 4 and 5 meters.

To calculate the load that the ceiling can withstand, you must have the appropriate knowledge. In order not to delve into the strength of materials formulas (and this is definitely redundant when building a garage), it is enough for an ordinary developer to use online calculators for calculating wooden single-span beams.

Leo060147 FORUMHOUSE User

A self-builder is most often not a professional designer. All he wants to know is which beams need to be installed in the ceiling so that it meets the basic requirements for strength and reliability. This is what online calculators allow you to calculate.

These calculators are easy to use. To make calculations of the necessary values, it is enough to enter the dimensions of the lag and the length of the span, which they must cover.

Also, to simplify the task, you can use ready-made tables presented by the gurus of our forum with the nickname Roracotta.

Roracotta FORUMHOUSE User

I spent several evenings to make tables that even a novice builder will understand:

Table 1. It presents data that meet minimum requirements on the load for the floors of the second floor - 147kg / sq.m.

Note: since the tables are based on American standards, and the dimensions of lumber overseas are somewhat different from the sections adopted in our country, the column highlighted in yellow should be used in the calculations.

Table 2. Here are the data on the average load for the floors of the first and second floors - 293 kg / sq.m.

Table 3. Here are the data for the calculated increased load of 365 kg / sq.m.

How to calculate the distance between I-beams

If you carefully read the tables presented above, it becomes clear that with an increase in the length of the span, first of all, it is necessary to increase the height of the log, and not its width.

Leo060147 FORUMHOUSE User

You can change the stiffness and strength of the lag upwards by increasing its height and making “shelves”. That is, a wooden I-beam is being made.

Independent production of a wooden glued beam

One solution for long span spans is the use of timber beams in the spans. Consider a span of 6 meters - which beams can withstand a large load.

By type cross section long beam can be:

rectangular;
I-beam;
box-shaped.

There is no consensus among self-builders which section is better. If you do not take into account purchased products (prefabricated I-beams), then the simplicity of manufacturing in the "field conditions" comes first, without the use of expensive equipment and tooling.

Just Grandpa FORUMHOUSE User

If you look at the cross section of any metal I-beam, you can see that from 85% to 90% of the mass of the metal is concentrated in the "shelves". The bonding wall accounts for no more than 10-15% of the metal. This is done on the basis of calculation.

What board to use for beams

According to the strength of materials: the larger the cross section of the "shelves" and the further they are spaced from each other in height, the greater the load the I-beam will withstand. For a self-builder, the optimal technology for manufacturing an I-beam is a simple box-shaped design, where the upper and lower “shelves” are made of a board laid flat. (50x150mm, and the side walls are made of plywood with a thickness of 8-12 mm and a height of 350 to 400 mm (determined by calculation), etc.).

Plywood is nailed to the shelves or screwed with self-tapping screws (only not black ones, they do not cut) and must be glued.

If you install such an I-beam on a six-meter span in increments of 60 cm, then it will withstand a large load. Additionally, an I-beam for a ceiling of 6 meters can be laid with a heater.

Also, using a similar principle, you can connect two long boards, collecting them into a “package”, and then put them on top of each other on an edge (take boards at 150x50 or 200x50), as a result, the beam section will be 300x100 or 400x100 mm. The boards are planted on glue and pulled together with studs or planted on capercaillie / dowels. You can also screw or nail plywood to the side surfaces of such a beam, having previously lubricated it with glue.

Also interesting is the experience of a forum member under the nickname Taras174, who decided to independently make a glued I-beam to block a span of 8 meters.

For this, the forum member purchased OSB sheets 12 mm thick, cut them into five lengths equal parts. Then I bought a board 150x50 mm, 8 meters long. With a dovetail cutter, I chose a groove in the middle of the board with a depth of 12 mm and a width of 14 mm - so that a trapezoid with an extension downwards was obtained. OSB in grooves Taras174 glued with the help of polyester resin (epoxy), having previously “shooted” a strip of fiberglass 5 mm wide to the end of the plate with a stapler. This, according to the forum member, would strengthen the design. To speed up drying, the glued area was heated with a heater.

Taras174 FORUMHOUSE User

On the first beam, I trained "filled my hand." The second one was done in 1 business day. At a cost, taking into account all materials, I include a solid board of 8 meters, the cost of a beam is 2000 rubles. for 1 piece

Despite the positive experience, such a "squatter" did not escape several criticisms made by our experts. Namely.