Ceiling installation on wooden beams. We build wooden floors between floors, construction technology. Wood flooring technology

Private low-rise construction in last years is becoming more and more popular.

country houses and country houses, erected with their own hands, occupy an increasing share in the total volume of housing put into operation.

The most demanded material in private construction is wood, due to its affordable cost and ease of processing. But not all individual developers have sufficient experience and knowledge to independently carry out the entire range of construction work. So, the question often arises of how to properly lay the floor of the second floor in compliance with all building codes and technologies.

Construction requirements for wooden floors

In order to mount a durable and safe wooden floor between the 1st and 2nd floors with your own hands, you must strictly comply with the technical requirements for them.

Thermal insulation layer

Thermal insulation of the floor will improve the temperature in the room on the second floor

If the wooden floor will separate the upper and lower rooms with a temperature difference between them of more than 10 ° C, it will be necessary to build a heat-insulating layer.

This is necessary, for example, when arranging ceilings between the first floor and the underground, basement or between the first / second floor and an uninsulated attic.

Beam strength

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

When constructing the floor of the second floor according to wooden beams special attention should be paid to the strength of load-bearing structures. The safety of the operation of the building depends on how durable the wooden beams of the floors are.

According to building codes for wooden low-rise buildings, the maximum load on the floors of the first floor should not exceed 210 kg per sq.m., the pressure on the wooden floor of the second floor should not exceed 180 kg / sq.m., and for attics and attics this figure should be less than 105 kg/sq.m.

Maximum deflection

In addition, building codes also impose requirements on the deflection of wooden floor beams. According to SNiP, this coefficient should not exceed 1 to 250. That is, the maximum deflection of wooden supporting structures during operation should be less than 4 mm per meter of beam length.

According to this standard, the deflection of a beam structure 4 m long in the center should not be more than 1.6 cm (4 m: 250 = 0.016 m). If it is planned to place massive furniture in the room and household appliances, flooring as flooring tiles etc., then the requirements for structural rigidity increase to 1 to 400.

That is, the deflection should not exceed 2.5 mm per meter. For non-residential attics and attic spaces, a larger deflection coefficient is allowed - 1 to 200 (5 mm per 1 meter).

Soundproofing

Fifty-millimeter mineral wool will not only insulate the floor, but will also become a good sound insulator

According to building codes, the sound insulation threshold for interfloor floors of residential buildings should be 50 dB.

To ensure this requirement, it will be enough to cover the floor of the second floor under the finish coat with mineral wool 50 mm thick.

The length of the beam should be no more than 5 m

The maximum allowable length of the free sag of wooden beams should not exceed 5 m for interfloor and 6 m for attic floors. If the design length of the room is more than 5 m, it will be necessary to install an additional support under the bearing beam. The fact is that the optimal length of the supporting wooden structure is 4 m.

With a further increase in its length, the rigidity and strength of the supporting structure are sharply reduced and the requirements for the thickness of the beam section increase disproportionately. So, in order for the deflection indicators for an 8 m beam to “fit” into the SNiP standards, its thickness should be about 40 cm. For example: the same deflection indicator shows a 4 m beam with a cross section of only 15 x 15 cm.

Wood is a material quite vulnerable to external influences, primarily dampness and fire, therefore, before proceeding with the construction of load-bearing structures, all wooden elements must be treated with antiseptic materials and flame retardants.

Construction material

Before proceeding with the installation of the floor on the second floor on wooden beams, you should make a list of all the necessary materials. This will allow during work to avoid unforeseen downtime and delays caused by the need to purchase some building materials.

beams

A beam section of 15 x 15 will be enough

The basis of the entire structure of interfloor wooden floors is beams. They play the role of load-bearing elements, and the strength of the structure depends on them. For them, a bar or gun carriage with a section of 15 x 15 cm, or 18 x 18 cm is usually taken.

This section is usually enough to provide sufficient rigidity for a specific load of 400 kg per sq.m. In this case, it is necessary to observe the parameters recommended by building codes: the span is 4 m, and the step between the beams is 60 cm. Based on these parameters, you can also calculate the required amount of timber.

№	Span length (mm)	Beam cross section (mm)
1	2000	75×150
2	2500	100×150
3	3000	100×175
4	3500	125×175
5	4000	125×200
6	4500	150×200
7	5000	150×225

However, in the absence of a beam and small values of the expected loads on the floor, it is quite possible to use boards 50 or 40 mm thick, knocked together in pairs and placed on the edge. This option is suitable for flooring in the attic or in a small country house.

For the first floor of a residential building, this option is not suitable due to the low bearing capacity of the boards: to ensure the necessary rigidity, the step between the plank beams will have to be significantly reduced, which will lead to unjustified waste of material.

The most commonly used material for beams is pine. This the best option according to the "price-quality" criterion: its wood is quite affordable and at the same time has good technical characteristics.

Bars made of wood of stronger species (larch, oak) can rarely be found on free sale, and their price is incomparably higher, and pine wood after appropriate treatment with antiseptics will not be inferior in terms of durability to the same larch.

When buying a bar, you should choose a material with dry wood. Otherwise, after mounting the beams, their deformation during the drying process is possible - bending and twisting.

Flooring

Wooden flooring laid on beams will be a rough base under flooring

Usually, the flooring of interfloor ceilings is made in two tiers: from below there are rough floors, on which insulation is laid, and from above - pre-finishing flooring, mounted on top of the bearing beams. A decorative floor covering is laid directly on it.

To determine the nature and amount of material for flooring, you should clearly consider the design of the floors.

In the device of the subfloor, either 5 x 6 cm bars stuffed onto the supporting beams or grooves made in the beams can be used as a support for the floorboards. The latter option is quite laborious, so most often 5 x 6 cm bars are used to create a support.

To calculate the required number of bars, it is enough to count the number of beams and multiply them by the length of each of them. The resulting footage (the total length of all beams) is multiplied by two more (since the bars will be stuffed on both sides of each beam).

A wide range of materials can be used for finishing flooring. It can be boardwalk, plywood, chipboard, MDF, OSB, etc. Each of these materials has its advantages and disadvantages, after reading which you can choose one of them. To calculate the required amount of material, it is enough to simply calculate the area of \u200b\u200bthe room.

When purchasing building material, you should always purchase it with a margin of 10 - 15%, since unforeseen material overruns are inevitable during construction.

This will save you from having to interrupt work and buy the missing part.

Impregnation

Antiseptic will extend the life of the tree

To maximize the service life of wooden structures, they must be treated with antiseptic materials.

It will also be useful to treat wood with fire retardants, which increase its fire safety.

To calculate the required amount of impregnation, you should read the instructions for its use - it always indicates the approximate consumption of the mixture per sq.m.

waterproofing

Since wood is afraid of moisture, hydro is always used in construction. insulating materials.

It could be roll waterproofing used to create a water-repellent layer between wooden structures floors and topcoat, or between wood and brick (stone, cinder block, etc.).

To protect the tree from moisture, you can also apply a coating waterproofing based on polymers or liquid bitumens.

Heat and sound insulation

If it is necessary to create a barrier to noise or cold, insulating materials are used in the construction of floors. Most often, for these purposes, use a minplate or foam. Their total number in area should be approximately equal to the area of \u200b\u200bthe room. For more information about floor insulation, see this video:

Expanded clay or ordinary slag mixed with sawdust can also be used as an insulating material.

Fastening materials

To fasten wooden floor elements, you should purchase self-tapping screws, nails, steel corners, anchor bolts and other consumables. When purchasing screws and nails, attention should be paid to their length.

According to the standards for a strong connection, the nail should be 2/3 longer than the thickness of the attached element (board, bar). For self-tapping screws and screws, this figure can be reduced to 50%.

Those. for reliable fastening to the beam of the “magpie” board, you will need 120 mm nails or 80 mm self-tapping screws.

After everything necessary materials purchased, and all preparations are completed, you can proceed directly to construction work. The construction of interfloor ceilings can be divided into several main stages.

The part of the beam inserted into the wall is wrapped with three layers of waterproofing material

The installation of load-bearing beams is most often carried out at the stage of erecting the walls of the building. Before laying the bearing bars, their surface is treated with all the necessary impregnations.

Then their ends are cut at an angle of 60 ° and that part of them that will be walled up in the wall is wrapped in 2-3 layers of rolled waterproofing.

The ends of the beams are usually also coated with waterproofing compounds, but some experts advise leaving them open to allow the moisture contained in the wood to freely escape.

The depth of the beams to the depth of the wall should be at least 15 cm. The step of laying the beams is usually taken at 0.6 m, but depending on the expected load on the floors, as well as on the thickness of the beam section, this indicator can be reduced or increased.

The choice of the interval between the beams is also influenced by the technical indicators of the material used for the finished floor.

If the top flooring is supposed to be made of inch boards, plywood or chipboard, then the distance between the beams should not exceed half a meter, otherwise the floors will sag when walking. For more information about the installation of beams, see this video:

Floor joists must lie in the same plane

The installation of load-bearing beams starts from the two extreme walls, while the beams should be located at a distance of 5 - 10 cm. After installing the two extreme beams, we mount the rest, observing the required interval.

When laying beams, special attention should be paid to the horizontal slope: all floor beams must lie in the same plane. To do this, a cutting board is placed on the edge between the two extreme bars, or the twine is pulled tightly.

If the base on which the beams are laid is uneven, then mortgages should be installed under the ends of the beams to level the horizontal level. For mortgages, material is used that is resistant to decay and physical stress - metal plates, pieces of tiles, etc.

It is not recommended to use wooden wedges to adjust the level of the beams, as they can quickly rot, which will cause the lowering of individual floor beams and the curvature of the floor line.

The bearing bars are attached to the wall with anchor bolts and steel corners.

Fastening of support bars

After all the floor beams are exposed, bars with a section of 5 x 6 cm are attached to them (the so-called "cranial" bars). They serve as a support for laying the subfloor and are attached along the entire length. load-bearing beam, on both sides.

They should be nailed in such a way that their bottom is flush with the bottom of the beams.

Most often, the draft floor is made from an inch board.

For the device of the subfloor, edged boards are taken and laid across the beams on the support bars. Since the distance between the beams usually does not exceed 0.6 - 0.8 m, then an inch or thirty board is quite suitable for subfloors: the pressure on them will be limited only by the weight of the insulation.

Also for these purposes, you can use a cut slab. You can also combine the draft floors of the second floor with the finished ceilings of the first floor or basement. In this case, edged boards are hemmed from below, from the side of the first floor to the beams. For more information about the draft field, see this video:

Thermal insulation flooring

After the installation of subfloors, compartments are formed between the beams, which, if necessary, can be filled with heat-insulating materials.

To do this, a hydro- or vapor barrier (roofing material, isospan, etc.) is laid on top of the subfloor boards, and then mineral wool, polystyrene, slag with sawdust, etc. are laid.

In this case, the entire space between the bars should be densely filled. We fill the gaps between the beams and foam sheets with sealant.

It is also desirable to lay waterproofing on top of the insulation, which will protect it from moisture leaks from above.

The final stage will be the flooring of the finishing floors, which is mounted on top of the supporting beams with self-tapping screws or nails.

To do this, the material (boards, OSB, plywood) is cut in such a way that their joint falls in the middle of the timber. The finished floor is the basis for the finishing coating - laminate, linoleum, parquet.

The elements are interconnected in a certain way, and the design works as a whole.

Beam ceilings are classified according to the material of the beams. In modern low-rise housing construction, wooden, steel and special beams for cellular floor blocks are used - for a precast-monolithic version.

Option for the location of floor beams: a - type of floor; b - transfer of loads from floor beams to the wall; 7 - floor beams; 2- bearing wall; 3 - non-bearing wall; 4 - plank floor or base for a clean floor (black floor boards); 5 - transfer of loads to the load-bearing wall

Interfloor ceiling on wooden beams

In our country, where there are many natural material- woods, wood is traditional building material. In stone houses, floors are often made on wooden beams. Of course, wood is an environmentally friendly material, especially not treated to increase fire and bioresistance.

Contrary to popular belief about the fragility of wood, wooden floors with proper construction and proper operation last a long time.

This is interesting. An example is the houses of St. Petersburg, which were built when he was the Russian capital. Wooden floors have not only low-rise estates, but also six-, seven-story houses in the center of St. Petersburg, former tenement houses. For 200 years, in a damp climate, the houses have been standing without reconstruction and are a residential historical fund.

You can also use Moscow as an example. True, here the number of storeys of houses is mostly smaller, but the houses are also much older than the houses in St. Petersburg. So, in the old central districts of Moscow (for example, in the area of Rozhdestvenka St. and Kuznetsky Most, on the Boulevard Ring and other streets), houses are 300 or more years old, and not all of them have been reconstructed.

Of course, in those distant times, it was not timber that was laid, but logs, which, in comparison with timber, are a stronger and more durable building material.

Wooden beams are easy to manufacture and do not require complex mechanical equipment.

Material and parameters of wooden beams

As wooden beams, as a rule, timber is used. A beam is a log sawn from four sides. Made from coniferous wood. On small spans up to 2 m, boards 25, 32 or 40 mm thick can be laid, placed on edge and knocked together with nails - 2 or 3 boards each. Of course, logs can also be used as the most durable material: but in modern life this is justified only with a special design of the room, or with an appropriate finish of the ceiling and floor construction for such a ceiling.

The parameters of the beam sections depend on the size of the spans to be covered and the steps with which the beams are laid, as well as on the magnitude of the permanent and temporary loads perceived by the ceiling. Roughly, you can use the data in the table.

Name of material, parameters bxh*, mm	Span P, mm	Pitch W (no more), mm***	Name of material, parameters bхh*, mm	Span P, mm	Pitch W (no more), mm***
Beam 50x150			Beam 100x200
Beam 100x150			Beam 150x200
Beam 150x150			Beam 175x200
Beam 150x175			Beam 200x200
Beam175x175			Beam 200x250

* Data of the current range of lumber in accordance with GOST 24454-80*; timber length from 1 to 6.5 m with a gradation of 250 mm.

** In the section parameters, the smaller parameter b is the section width, the larger h is its height.

*** The calculation of the step includes a payload on the ceiling of 200 kgf/m 2 , the mass of wooden beams and a soundproofing layer of mineral wool boards with a density of 100 kg/m 3 . In the case of backfilling with expanded clay, the step is reduced by 20% (this approximation can only be taken for educational purposes, in practice a competent calculation is needed).

A feature of wooden beams is the fact that on large spans they guarantee the strength of the floor, but do not ensure the rigidity of the floor: the floor becomes "unsteady". In principle, the "unsteadiness" of the floor is checked by calculation, which is not always possible to do. Therefore, in order to eliminate the possible "fluctuation" of the floor, the beams are laid with a small step - 500 ... 600 mm, even if the strength calculation of the beams shows the possibility of a larger step. Otherwise, you need to apply lags (see below).

Laying out floor beams and embedding them into the wall

The length of the beams is selected depending on the size of the overlapped span. Beams, as a rule, are laid along the smallest span if the overlapped room is rectangular. If the room is square, then the direction of laying the beams does not matter. The fact is that all the walls of a stone house can be classified as load-bearing, as they are strong enough to withstand the load from wooden beams.

The figure shows an example of the layout of wooden floor beams. The parameters of the beams are selected depending on the spans and steps. The section between the coordination axes A/2 and B is interesting. To form the floor, two auxiliary beams with a section of 150x150 mm are introduced here, on which beams with a section of 100 x 150 mm are supported. To reach one floor level, the auxiliary beams are embedded in the load-bearing walls below the rest to the height of their section, i.e. by 150 mm.

Also, perhaps, it is necessary to explain why a small span between axes 3 and 4 is covered with beams 150x150 mm? In fact, these beams cover a six-meter span between axes 1 and 4, and the load-bearing wall along axis 3 serves as an additional support for the beams. But, of course, you can also prepare separately beams for spans 1-3-4.

The attentive reader, of course, noticed that the step of the beams is not always subject to the modulus. Why this subordination is not necessary, we will see when we study the composition of the layers of interbeam filling. In addition, here the steps are shown without regard to the specific material of the walls in which the niches for the beams will be arranged, and this may somewhat, slightly, affect the size of the steps.

An example of the layout of floor beams

The beams are laid in niches specially prepared during the laying process in the wall. To ensure reliable and durable support, the depth of embedding the beam in a brick or any other stone wall must be at least 150 mm. The depth of the niche is determined in such a way as to ensure the depth of the beam embedded in the wall and leave a certain air gap (20 ... 30 mm), which excludes the contact of the tree with the stone back wall of the niche. In addition, an air gap will help prevent wood decay if air is allowed into the niche.

The niche is not filled with anything if the wall structure contains an insulating layer on the outside. In the event that no insulation is included in the wall structure (for example, the wall is built of ceramic stone, and the thermal protection of such a wall is provided), the niche can be a conductor of cold, since the remaining wall thickness is not enough here. Then in a niche we can get freezing and moisture condensation. To prevent this, the niche is filled with heat-insulating material. Expanded polystyrene is preferred as such a material, since, having closed pores, it is not saturated with moisture, which warm air from the room can carry with it. Of course, expanded polystyrene refers to combustible materials, but we are talking about wooden floors, in which, anyway, you need to be especially careful in terms of fire safety.

Embedding wooden beams into a wall: a - blind embedding of beams into an insulated wall; b - the same, into a wall without insulation and with the possible occurrence of cold bridges in a niche under the beam; c - open embedment of beams in the inner wall; g - type of anchor; 1 - mounting foam (preferably) or mortar; 2- anchor; 3 - wooden beam; 4 - beam antiseptic zone; 5 - the end of the beam wrapped with roofing felt; 6 - antiseptic board 32 mm thick (preferred) or several layers of roofing; 7- effective insulation.

Do not wrap the insulation with a film or place, say, in a plastic bag. This can lead to condensation in the closed space of the bag and, subsequently, to poor performance of the insulation; as a result - freezing of the wall.

The ends of the beams before laying on the wall are sawn off at an angle of about 60 ° ... 70 ° and treated with an antiseptic material. It will be reliable to wrap the ends of the beams with roofing felt or roofing material (roofing felt is preferable), but the ends of the beams are not covered to provide air access to the tree through its end part. A less reliable solution is not to wrap the beam with roofing paper, but then it is necessary to lay the beam on an insulating substrate: the same roofing felt, roofing material or a piece of antiseptic board to prevent contact between wood and wall stone. Otherwise, the wood will rot. Even more reliable option- combine the wrapping of the beam and the substrate, as shown in the figure.

It is well known that wood lasts a long time if it remains dry and ventilated. To keep the tree dry, it is advisable to seal the gaps formed around the beam with mounting foam. Mounting foam, "closing up" the upper pores of the tree, well protects it from the effects of moisture from the room, but, at the same time, allows air to penetrate through the micropores into the niche. If you are not too lazy and put the boards not only in the lower part of the niche, but also overlay the entire niche around the beam with boards soaked in tar (as in modern world you can’t get tar, then an antiseptic will do), then the beams will stand for more than one century. This is how niches are prepared in Moscow houses built 300 years ago and still pleasing us.

This is interesting. And how did they cope with the decay of the tree in ancient times? After all, then there were no modern antiseptic compounds. It turns out that soot is an excellent natural antiseptic, as well as a specific “lacquer” that protects wood from moisture and fungus. She processed the beams.

A niche sealed with one or another material is called a blind seal, this is a common solution. Less commonly, they make an open seal, which involves not filling the gap between the beam and the wall with anything. Here, the savings in materials and labor costs are small, but the sound insulation of the floor suffers.

When supporting the beams on the inner wall, the insulation under them must also be laid, and the ends of the beams must be antiseptic.

To connect the walls with the ceiling, as well as to ensure the rigidity of the building, the beams in the niche must be fixed. The point is that the walls two-storey houses reach a height of seven or more meters, connecting only in the corners. If rigidity is not provided, the wall can go out of its plane with all the ensuing consequences. Anchoring beams into the wall will help to make the spatial system of "wall-floor" rigid - the creation of horizontal disks of floors. This can be done using T-anchors cut from flat steel. One end of the anchor is nailed to the beam, the other end is driven into the masonry. The anchor is nailed to the top or bottom of the beam. Anchors are attached to each or through one beam.

The ends of the beams resting on the internal walls are interconnected by steel strips nailed on both sides of the beams.

This is interesting. Puffs have always been used for beam ceilings, even in large buildings. For example, today on the building of the Trekhgornaya Manufactory factory, built at the end of the 18th century, you can see how the puff anchors go out onto the facade.

The figure shows the developed solution for the support unit of wooden beams on walls erected from aerated concrete or gas silicate blocks. As in the case with ceramic stone, the heat-shielding properties of aerated concrete make it possible not to insulate the wall. Therefore, a heater is laid in a niche.

Supporting wooden floor beams on the outer wall of aerated concrete blocks: 1 - aerated concrete main blocks; 2 - additional blocks; 3 - mineral wool insulation; 4- U-shaped blocks; 5- wrapped with roofing felt (preferably) or roofing felt end of the beam; 6 - wooden floor beam; 7- steel plate - connector (anchoring); 8 - dowel-screw; 9 - monolithic reinforced concrete belt.

Since the strength of aerated concrete blocks is lower than that of bricks, a monolithic reinforced concrete belt is prepared under the beam - it will take the load from the ceiling. Insulation and reinforced concrete belt are laid in a cavity formed by special U-shaped blocks. The end of the beam entering the niche is antiseptic and wrapped with roofing material, roofing felt, etc.

Beams are anchored using a sheet strip bent at a right angle - a connector, which is fixed to the beam and reinforced concrete belt with dowel screws.

This solution can be supplemented with those actions and elements that we spoke about in such detail when considering the figure.

Inter-beam filling in the design of the ceiling without the use of logs and with logs

Inter-beam filling is inherently enclosing and contains layers and elements, each of which performs certain functions.

Floor construction without the use of lag

The floor structure without the use of a log is suitable only if the beam spacing does not exceed 500 ... 600 mm. Otherwise, with a larger step, the rigidity of the floor will not be ensured, the floor becomes “unsteady”, bends.

The layout plan for beams and subfloor boards is shown in the figure. Let's dissect the overlap and analyze the purpose of each layer.

The main one, of course, is the soundproofing layer. Sound-absorbing material is suitable for it, which is also used as a heat-insulating material: polystyrene foam, polystyrene, etc. or mineral wool. I must say that mineral wool is preferable: it belongs to non-combustible materials. The advantages of mineral wool include the fact that rodents are afraid of it, and in foam plastics they easily and with pleasure gnaw through passages and make holes. However, all these materials are not particularly effective as soundproofing, since their mass is small: for example, the mass of a layer of mineral wool or polystyrene foam 10 cm thick is only 4 ... 10 kg / m 2. And we remember that by gaining mass of the structure, the issue of sound insulation is solved.

Things are better if you fill up with environmentally friendly material - expanded clay: it is not combustible, non-toxic. But even his mass is small: a layer of expanded clay with a thickness of 10 cm has a mass of 70 kg / m2. Sound insulation increases significantly when sand is used: the mass of a layer of 10 cm is 200 kg / m 2. We will achieve the greatest effect if we fill the inter-beam volume as follows: pour sand down, and put mineral wool or polystyrene foam on it. To separate the layers, we put geotextiles. In this way we will create a layered structure, and all layered structures absorb sound better than single-layer ones.

Soundproofing material is placed on a wooden flooring, fixed on cranial bars, lined with beams. Section of bars, 30x40, 40x50 and 50x50 mm; it depends on the mass of the soundproofing material: the heavier it is, the larger the cross section. It's clear. To prevent the sound insulation layer from crumbling, some kind of rolled material (PVC film, roofing material, glassine, roofing paper, sack paper, etc.) is laid on the wooden flooring. Types of flooring are shown in the figure.

The design of the interfloor ceiling on wooden beams without the use of logs: a - layout of beams and subfloor boards; b - type of overlap; in-e- composition beam overlap layers; c - floor structure with a soundproofing layer of effective insulation; g - the same, from expanded clay; d - the same, from sand; e - two-layer sound insulation; g - shield reel; h, i - views decking; 1 - clean floor construction; 2 - black floor boards; 3 - soundproof elastic layer (for example, three layers of roofing material); 4 - rolled material that protects the inter-beam filling from scree, debris (for example, glassine); 5- effective insulation (mineral wool, expanded polystyrene); 6- expanded clay; 7- sand; 8- geotextile; 9-beam ceiling; 10-skull bar 30x40, 40x50 or 50x50 mm; 11 - ceiling decoration; 12 - floor boards; 13 - rolled material (roofing felt, roofing material, PVC or polyethylene film, etc.); 14 - rolling boards; 15- rolling bar; 16 - flooring slab; 17-plinth.

The design of the interfloor ceiling on wooden beams using a log: a - a diagram of the layout of beams, logs and subfloor boards; b - type of overlap; c - overlapping lag connection; g - butt joint; e - floor construction with a soundproofing layer of effective insulation; e - the same, from expanded clay; g - the same, from sand; h - two-layer sound insulation; 1 - clean floor construction (conditionally shown); 2 - black floor boards; 3 - lag 50x75 mm, laid flat; 4-roll material that protects the inter-beam filling from scree, debris (glassine, roofing paper); 5 - effective insulation (mineral wool, expanded polystyrene); 6- expanded clay; 7- sand; soundproof elastic layer; 9 - geotextile; 10- floor beam; 11- ceiling decoration; 12 - cranial bar 30x40.40x50 or 50x50 mm; 13 - flooring boards; 14 - roll material (roofing felt, roofing material, PVC or polyethylene film, etc.); 15 - plywood or plank lining.

To support the inter-beam filling, a shield roll is also suitable. Fragments of the shield roll are prepared in advance, and then they are laid with support bars on the cranial bars; what it looks like is shown in the figure.

Further, subfloor boards are laid along the beams, which will subsequently serve as the basis for the construction of a clean floor. For the subfloor, low-grade boards are taken, their thickness is 25 or 32 mm. To eliminate the sound bridge that occurs from the shock wave, a soundproof lining is laid between the beam and the subfloor boards, for example, several layers of roofing material, roofing felt, or other elastic material. On the beams, flooring from clean floor boards is possible, but this option is not suitable for expensive flooring.

The figure shows another material - glassine, tar paper, laid on top of a layer of sound insulation. Its functional purpose is to protect the inter-beam filling from debris or damage during construction.

Floor construction using lag

As can be seen from the table, the step of the beams and their cross section are interrelated values: the more powerful the beams, the greater the step they can be laid. This is good, because the labor intensity decreases when embedding beams in niches. However, with a beam spacing exceeding 600 mm, floor rigidity will not be ensured.

Logs will help to increase the rigidity of the floor - boards with a section of 50x75 or 50x100 mm. Logs are laid flat across the beams or placed on edge, and black floor boards are laid on them, perpendicular to them. The connection between the logs should be made at the point of support on the beam - overlap or butt. The fastening element is a plywood or metal lining.

The design of the floor with lags and shield roll: a - type of floor; b - type and parameters of shield run-up; 1 - black floor boards; 2 - logs laid flat; 3 - soundproofing layer; 4 - roll material; 5 - bar of shield rolling; 6 - shield boards; 7- nails for fastening the cranial bar; 8 - cranial bar; 9 - beam; 10 - elastic material to eliminate the sound bridge.

The inter-beam filling is the same as in the design without a lag. At the same time, the lag also has another purpose: due to the increase in the height of the inter-beam space, it fits large quantity or thicker layers of soundproofing material. Soundproofing layers are laid on the flooring or shield roll.

Logs are arranged in increments of 400 ... 600 mm; at the same time, the regularity is observed: the larger the step of the beams, the smaller the step of the lag.

The logs are adjacent to the wall, but they are not embedded in the wall.

Supporting wooden beams on vertical supports

With a frame or combined structural system, floor beams are supported by free-standing supports: racks, columns, poles.

If it is necessary to connect the beams, it is necessary that the docking point is above vertical support. If the supports are wooden, then the beams are attached to the supports with nails hammered at an angle and connected with brackets. Fastening can be done using plywood pads, which are fastened on both sides of the butt-joined beams. Various metal attachment points are also used, such as those shown in the figure. For round racks, the support area of \u200b\u200bthe beams may not be enough, then the lower faces of the butt-joined beams are bolted to a metal plate.

Logs are also joined above the supports.

Supporting wooden beams on free-standing supports and methods for their connection: a - supporting the beam on the support; b - connecting the beams with a plywood gusset; c - the same, with the help of metal parts; g - beam support on a round post; 1 - beam; 2 - support; 3 - plywood gusset; 4 - detail of the metal fastening; 5 - metal platform of the column.

Interfloor ceiling on steel beams

Steel beams are stronger and more durable than wood beams. It is also fair to attribute to their advantages the ability to cover large spans - up to 7 ... 8 m. Such circumstances make steel beams more and more attractive in low-rise private housing construction, where there is a need for spacious rooms. Steel beams are widely used in the reconstruction of buildings.

This is interesting. In the Moscow Stalinist skyscrapers, and there are seven of them, as you know, the floors are reinforced concrete and with the use of steel beams. As surveys have shown, time has not damaged the floors, and they will stand for a very long time.

For steel beams, a rolled profile is suitable - I-beams, channels, corners.

The location of steel beams on the building plan is made from the same considerations as wooden beams. Therefore, the scheme shown in the figure is quite suitable for studying the nodes for embedding steel beams into the wall and inter-beam filling.

Embedding steel beams into the wall

Embedding beams in niches is similar to that in the case of wooden beams, but with some features.

Steel beams are embedded in niches specially prepared in the wall with a depth of 250 mm. To evenly distribute the forces, steel plates are laid under the beams, or the beams are laid on a distribution concrete pad. This technique also protects the wall of bricks or cellular blocks from crushing in the area where the beams are supported.

Embedding steel beams into the wall: a - an uninsulated niche, anchoring the beams with a steel strip or rod; b - insulated niche, anchoring beams with corners; c - embedding beams into a niche in the inner wall; g - view of an I-beam; 1 - symbol walls; 2 - cement-sand mortar; 3 - anchor - steel strip or rod; 4 - steel sheet to distribute the load from the beam; 5 - nabetonka with the same purpose; 6 - section "an I-beam; 7- I-beam; 8 - anchors - corners; 9 - effective insulation

The support depth of the steel beams must be at least 200 mm.

Finish a niche for the same reasons as in the case of wooden beams. If the niche device violates the heat-shielding properties of the wall, then a heater is laid between the back wall of the niche and the beam. In this case, the depth of the niche is calculated depending on the required thickness of the insulation.

The niche cavity is sealed with a cement-sand mortar. Unlike wooden beams, steel beams “feel good” when in contact with the mortar.

The beam is anchored into the wall using a metal anchor welded to the beam on one side and driven into the masonry on the other. In this case, the length of the bend must be at least 200 mm. For anchoring, corners welded to the beam from above and below and brought into the masonry will also fit.

The support of the beams on the inner wall, their anchoring and finishing of the niche is carried out in the same way as in the case of the outer walls.

Inter-beam filling

The step of the beams depends on the material of the inter-beam filling, namely the flooring on which the soundproofing layer is located.

Flooring - wooden shields. Shields are knocked down on the ground beforehand. Boards are knocked to the bottom of the bars, leaving the ends of the bars free. Then the bars with their free ends rest on the lower shelves of the I-beams, which play the role of cranial bars. The bars in the places of support on the beams are antiseptic.

Based on the characteristics of the work of the tree from which the flooring is knocked together, the step of the beams cannot exceed 2 m; the step of the beams is not subject to the module.

All other layers of inter-beam filling are the same as with wooden beams; the choice of the type of filling remains with the customer, who needs to be told all the pros and cons of this or that material.

To exclude contact with metal beams, subfloor boards must be insulated wooden lags or some other insulating material. Logs are installed flat or on edge. The butt joint of the lag on the edge is made using a plywood gusset. For rigidity, a spacer is inserted between the lags. When overlapping, the logs go beyond the planes of the upper shelves of the beams. Spacers may also be needed here. Logs must be protected from contact with the metal of the beams; roofing felt, roofing felt, etc. are suitable for this.

Lags laid flat will allow you to slightly reduce the height of the ceiling.

The cross-sectional parameters of steel beams, as well as wooden beams, depend on the overlapped spans, steps, and loads. Approximate parameters of the section can be taken from the table.

The design of the interfloor ceiling on steel beams using shield roll: a - the composition of the layers of the floor structure; b - butt lag connection; in - the same, overlap; 1 - clean floor construction; 2 - black floor boards; 3 - logs 50x75, placed on edge; "/-roll material that protects the inter-beam filling from debris, scree; 5 - effective insulation; 6- expanded clay; 7- sand; 11 - steel I-beam No. 12 (only for this case study); 12 - a bar of shield rolling, based on the shelves of an I-beam; 13 - rolling boards; 14 - ceiling decoration; 15 - logs connected end-to-end; 16 - the same, overlapped; 17 - plywood gusset; 18- spacer.

Sections of I-beams when using wooden shields

beam profile number*	Section hxb, mm**	beam profile number*	Cross section xb, mm**
№10B1	100x55	№16B1	157x82
№12B1	117x64	№18B1	177x91
№14B1	137x73	№20B1	200x100

* Data of the current range of rolled profile GOST 27772-88*.

*** The calculation of the step includes a payload on the ceiling of 200 kgf/m 2 , the mass of wooden panels and a soundproof layer of mineral wool boards with a density of 100 kg/m 3 . In the case of backfilling with expanded clay, the step is reduced by about 20%.

The advantage of this method is the use of wood - an affordable and inexpensive material. In addition, it is possible to lay beams with a small step, in which lags are not necessary to increase the rigidity of the floor. This will reduce the height of the overlap section.

However, this method is distinguished by high labor intensity and, as a result, an increase in construction time.

It is more convenient and more modern to use small-sized reinforced concrete slabs - PRTM. Especially it will be a good solution for the installation of ceilings in sanitary facilities, where leaks are possible. The type of plates PRTM is shown in the figure, and the name and their parameters are given in the table.

Parameters of small size slabs PRTM*

product name	Parameters lxbxh, mm	product name	Parameters lxbxh, mm	product name	Parameters lxbxh, mm	product name	Parameters lxbxh, mm
PRTM-1	1170x390x90	PRTM-4	1770x390x90	PRTM-7	2370x390x120	PRTM-10	2970x390x120
PRTM-2	1370x390x90	PRTM-5	1979x390x120	PRTM-8	2570x390x120	PRTM-11	3170x390x120
PRTM-3	1570x390x90	PRTM-6	2170x390x120	PRTM-9	2770x390x120	PRTM-12	3370x390x120
						PRTM-13	3570x390x120

The step of the beams cannot be taken arbitrarily, as in the case wooden flooring: it will depend on the length of the slabs. Since the smallest slab has a length of 1170 mm (PRTM-1), then, accordingly, the smallest step of the beams will be 1.2 m. The mass of such a slab is only 65 kg, so the laying of these particular slabs is practiced in low-rise construction if it is not possible to use lifting and transport equipment.

An example of the layout of beams and slabs, as well as the composition of the layers of inter-beam filling are shown in the figure. Here the slabs are laid on the lower shelves of the beams. In this case, they are located ribs up. Plots that are not a multiple of the width of the slabs are monolithic.

Plates can also be laid on the upper shelves - ribs down.

Strictly speaking, PRTM slabs are able to take a significant load, which is clear from their name (designed for a heavy load). And to take the load, they are designed to be located with the ribs down. However, in a joist slab, the load falls on the beams, so we can put the slabs with the ribs up as an inter-beam filling.

A soundproof layer is laid on the PRTM boards. Then, since the step of the beams does not provide the rigidity of the subfloor, it is necessary to lay the logs. The lag step is the same as in the case of overlapping on wooden beams, i.e. 400...600 mm.

The parameters of the cross-section of the beams in the case of filling with PRTM slabs depend on the overlapped spans, steps and, of course, loads. Approximate parameters of the section can be taken from the table.

An example of a floor arrangement on steel beams using PRTM slabs: a - plan for laying out beams and PRTM slabs; b - type and parameters of the PRTM plate; 7 - I-beam No. 18 (only for this particular example); 2- plate P RTM-1; 3 - monolithic section; 4- channel No. 18; 5 - clean floor construction; 6 - black floor boards; 7-lags 50x75 laid flat; 8 - rolled material protecting the space between beams from scree; 9 - effective insulation; 10 - expanded clay; 11 - sand; 12 - soundproof elastic layer; 13- geotextile; 14-roll material (roofing felt, roofing material, PVC film, etc.); 15- ceiling decoration; 16 - metal mesh (when finishing the ceiling with plaster).

beam profile number*	Section hxb, mm**	beam profile number*	Section hxb, mm**
№12B1	117x64	№18B1	177x91
№14B1	137x73	№20B1	200x100
№16B1	157x82	№23B1	230x110

* Data of the current range of rolled profile GOST 27777-88.

** Large value h - profile height, smaller b - I-beam flange width.

*** The calculation of the pitch included the payload on the ceiling of 200 kgf/m 2 , the weight of the PRTM boards and the soundproofing layer of mineral wool boards with a density of 100 kg/m 3 . In the case of backfilling with expanded clay, the step is reduced by about 20%.

When laying the slabs on the upper shelves of the beams, they are placed with the ribs down. No logs or black floor boards are needed here: the floor structure is arranged as if on a reinforced concrete slab (see the "Floors" section). Undoubtedly, this is the advantage of such a solution, and its imperfection is low sound insulation, compared with large-sized slabs: after all, the mass of the PRTM is small. We will be able to improve the soundproofing qualities if we fill the inter-beam volume accordingly. To form an inter-beam volume, either wooden shields are laid on the lower shelves of the beams, if there is no more than 2 m between the beams, or slabs - gypsum fiber, glass-magnesium, calcium sulfate and others offered by the construction market. Any soundproofing layer is chosen - from environmentally friendly sand and expanded clay to synthetic effective heaters.

This option does not require a graphical explanation, therefore, by compiling all the above solutions, you will be able to independently develop a section of the interbeam space.

Monolithic reinforced concrete slabs on steel beams

Instead of prefabricated technology - laying PRTM slabs - a monolithic reinforced concrete floor can be arranged on steel beams. In this case, the steel beam is either concreted or remains open. In the second case, the beams must be hidden false ceiling, in the first - at the request of the customer.

In both options, it is necessary to install the formwork on which concreting is carried out. Reinforcement and thickness of the slab section are determined by calculation. The resulting ribbed slab has rigid reinforcement in the ribs in the form of steel beams, and therefore this is the most durable floor. In low-rise housing construction, it is used, as a rule, for large spans in frame structural systems.

Attic floor in cold attic

The attic can be warm or cold.

In a cold attic, the roof is not insulated, and heating is not provided. To prevent cold air from such an attic from penetrating into the room under the attic, the attic floor is insulated.

However, from a residential warm attic space, to a greater or lesser extent, warm air still diffuses (penetrates) into the attic, carrying water vapor with it. The steam rises higher and, colliding with the cold inner surface of the roof, turns into condensate. Sometimes the drops of condensed moisture are so plentiful that, gathering in streams, they flow along the walls. Dampness, mold, fungus and other phenomena appear that worsen not only the humidity and sanitary conditions of the house, but also destroy the structures of walls and roofs. It is clear that this is unacceptable.

Measures to combat the appearance of condensate are different. First you need to reduce, and if possible, cut off the flow of steam into the volume of the attic. This is done with the help of vapor barrier materials laid from the side of the attic warm room, i.e. under the insulation. An attic that is not used as a living space does not require complete soundproofing and high-quality flooring, so some elements of the attic floor may not be laid in it. How one of the large design firms in Moscow solves this issue is shown in the figure.

If you want to make the attic floor the same as the interfloor one, you need to lay not any rolled material under the insulation (recall that in the usual interfloor floor it played the role of a barrier against scree of soundproofing material), namely vapor barrier.

If steam nevertheless penetrates through leaks in the structure or other ways, which most often happens, then constructive measures are taken: for example, air ducts are arranged to ventilate the roof, which will be discussed in the "Roofs" section.

At warm attic insulation is laid in the roof structure (more on this in the "Roofs" section), and the attic floor is not insulated.

Basement (basement) ceiling above a cold room

A cold room can be an unheated basement or basement. Here the situation is similar to that with a cold attic. Water vapor, rushing into a cold room, condenses on the walls of the basement (ground floor) and the lower surface of the ceiling facing the basement room. A damp cold room will be completely unsuitable for any purpose. Another danger: in a damp room, wooden beams will quickly rot, and steel ones will rust; this is a question of an incorrect design solution, which reduces the durability of the floor.

Normal operating conditions in the basement (ground floor) will be ensured if:

lay a vapor barrier layer from the side of the warm basement (above basement) premises, i.e. above the heater
make vents around the perimeter of the house, giving air access to the basement for ventilation, if the basement is not completely buried in the ground (the smallest vent size is one brick). The vents are sealed with nets, and for the winter, if necessary, they are covered with something, such as bricks or special plugs.

The device for overlapping on wooden beams above a cold room and ventilation of the room: 1 - a wooden floor beam; 2 - clean floor construction; 3 - black floor boards; 4- logs; 5 - vapor barrier; 6 - thermal insulation; 7-roll vapor-permeable material; 8 - boardwalk; 9 - cranial bar; 10 - air; 11 - floor construction on the ground.

In the case of an underground floor, i.e. when the basement is completely buried in the ground, ventilation ducts must be removed. This is already the question of engineering equipment at home, which is not considered in this book.

Beam ceiling finish

Finishing the ceiling of the ceiling is made depending on the design idea. Before that, we studied drawings in which the beams are hidden by some kind of trim or filing. Suitable for finishing plaster, profiled natural board type "lining", gypsum boards ("dry plaster"), special finishing ceiling tiles and so on.

As for steel beams, they are almost always closed, because there is no beauty in them, unless, of course, the house is made in a certain style.

However, wooden beams often want to emphasize. In such cases, the cranial bars are knocked to the beams to the desired height. Moreover, the cranial bars can also be shaped. Ordinary bars are hidden by filing.

When accepting this option for solving the ceiling, one should not forget that the volume between the beams will decrease here, and, consequently, the sound insulation of the ceiling will suffer.

A very simple option is not to arrange the inter-beam space at all and fill the floor boards directly onto the floor beams. For floors of capital houses, this method, apparently, is not suitable, but it is good for temporary or unassuming buildings.

An example of an attic floor on wooden beams

Overlapping on wooden beams is a load-bearing structure that separates adjacent rooms: floors, attic, underground. During its construction, factors such as bearing capacity, sound and heat insulation, seismic resistance and heat resistance are taken into account. This structure is regularly exposed to stress and atmospheric influences, therefore, it must meet the criteria for strength and wear resistance. According to the purpose of the overlap, they are classified into basement, interfloor and attic.

Design work includes the planning of the supporting structure, as well as the calculation and selection of materials. For various floors, bars of the appropriate type are used. Most often, wooden beams are typed according to external characteristics: section, composition and bearing capacity:

board- a simple structural material used in the construction of the crate and subfloor;
I-beam- structural material with a section in the form of the letter H. I-beam allows you to reduce the total weight of the structure without loss in bearing capacity;
LVL-beam- a beam of glued veneer, made by gluing peeled softwood: pine, spruce, larch. Differs in high rates of durability at horizontal loading. Used in construction rafter legs, beams of interfloor ceilings, as well as ridge beams;
combined beam- glued laminated timber, which includes veneer from several types of wood;
four-edged beam- quadrangular lumber, having 4 processed sides, is most popular in the construction of floors of any type;
double edge beam(carriage) - lumber that has 2 processed sides opposite to each other. Despite the relatively low strength indicators, the carriage is often used in the construction of interfloor ceilings;
rounded log- milled lumber whole piece wood, characterized by the highest load-bearing capacity. Maximum load per 1 sq. m. beams of this type is 500 kg. However, due to their rounded shape, rounded logs are more often used in the construction of attic, rather than interfloor floors.

When harvesting beams, preference is given to coniferous species due to their increased strength and resistance to putrefactive processes. An analogue of spruce, larch and pine can also be acacia, oak or maple. These types of wood are characterized by low moisture content (from 12% to 14%). Over the years, the strength of beam ceilings increases due to the evaporation of moisture from their surface. After 5 years of shrinkage, the strength of the timber approaches the strength indicators of metal beams.

Horizontal supporting structures are of several types:

interfloor overlapping on wooden beams;
attic floor;
basement cover.

After the type and material of the beams are determined, the builders proceed to the calculation of the potential section. The choice of bars with one or another section directly depends on such indicators as:

per 1 sq. m. - the estimated mass, which will have a permanent / temporary effect on the supporting structure. You can calculate the load yourself using one of the online calculators;

span length (DP) ;

step - distance between adjacent beams (50 cm, or 1 m).

Mon	150	250	350	450
2 m	50×100	50×100	50×100	50×120
2.5 m	50×100	50×120	50×130	100×100
3m	50×120	50×140	50×160	100×120
3.5 m	50×140	50×160	50×180	100×160
4 m	50×160	50×180	100×160	100×180
4.5 m	50×180	100×160	100×180	100×200
5 m	100×160	100×190	100×210	100×190
5.5 m	100×180	100×190	100×200	100×220
6 m	100×200	100×200	100×250	100×220

Tab. 1 - Cross section of beams at a step of 0.5 meters

Mon	150	250	350
2 m	100×100	100×110	100×120
2.5 m	100×110	100×120	100×130
3m	100×120	100×130	100×150
3.5 m	100×140	100×160	100×180
4 m	100×160	100×190	100×200
4.5 m	100×180	100×200	100×220
5 m	100×190	100×210	100×230
5.5 m	100×200	100×220	100×240
6 m	100×220	120×230	120×250

Tab. 2 - Cross-section of beams at a step of 1 meter.

The calculation of the number of beams for the floor is made according to the following formula:

KB \u003d DP / W, where:

KB - the number of beams of the established section;
DP - span length;
W - step.

The total number of beams depends on the number of spans.

Floor covering technology on wooden beams

The maximum bearing load on the floor in residential premises is about 400 kg per 1 m 2. Based on this value, bars of the corresponding section are purchased.

In outbuildings, baths, garages and other non-residential premises, the load varies from 100 to 300 kg. per m 2. Based on these indicators, beams with a smaller section are selected (see Tables 1 and 2).

It is worth noting that each beam should have an allowance of 30 cm to the main length. This is necessary for mounting the beam into the wall. So, for example, for spans of 3 meters, beams with a length of 3.3 meters are used.

The technology of mounting beams has a number of features, among which are the following:

The step depends on the type of building. IN wooden buildings the bars are laid parallel to each other at a distance of 1 meter, in frame houses- at a distance of 50 - 60 cm;
The height of the beam should not be less than 1/24 of its length. Smaller indicators reduce the strength of the structure;
The optimal width of the beam is equal to its height, or half the height.
The distance from the nearest beams to the furnace must exceed 30 cm.

Basement ceilings are mounted according to the "pie" principle. The supporting structure consists of the following layers:

draft floor;
waterproofing;
insulation;
bearing beams;
lags;
floor boards.

Wooden beam floor construction

Floor arrangement technologies differ only in the type of fastening of the beams. When installing floor beams, hinged and recessed fastening methods are used. In the first case, metal canopies are mounted on opposite walls at an equal distance from each other - timber supports. After all the supports are placed, the floor beams snap into them. This type of fixture is suitable for rooms with strip foundation, brickwork, as well as in aerated concrete structures .. The canopy will provide the beam with maximum fixation in the groove.

With recessed mounting methods, a hole for beams is cut at the base of the walls. Before mounting the beam, this recess is laid with tow. In this case, the ends of the beams can be processed as a lock. So, for example, a spike and a hole are often ground down to a trapezoidal shape and fastened according to the dovetail principle.

This method is considered the most complex and effective.

Basement installation technology consists of several stages:

Marking and construction of nests. With the help of a building level and a measuring tape along the first beam (ordering) from the foundation, the step of the beams is set. After that, nests are drilled at the marks, or nests are cut through with a cross section of 5-6 cm more than the beam and a depth of 10 to 15 cm. The nests are laid with a heater.
Beam installation. Logs are mounted in recesses. The first and last beam fit snugly against the adjacent wall. The gaps between the nest and the beams are caulked with tow or other insulation. If necessary, fixing canopies are attached to the bars and the wall. In cases where it is impossible to drill nests, ceilings are installed only on sheds (brickwork), or fastened with side rails (wooden walls).
Floor screed. Boards are laid on the beams. The end of the first board is pressed tightly against the adjacent wall. Nails are driven in at an angle of 45 degrees. The end of the second board is pressed against the end of the first and attached to the beams using the same technology. Depending on the length of the span, 1 board can take from 4 to 10 nails. For floors in residential premises, a five-board and nails No. 12 are optimal.

After installing the basement floor, the subfloor is lined with facing material: Fiberboard, laminate, linoleum and others.

The device of interfloor ceilings on wooden beams

The overlapping of the second floor on wooden beams is carried out according to the same technology as the installation of basement structures. The main difference between interfloor flooring and outdoor flooring is the presence of a double subfloor. At the same time, the lower draft floor is the ceiling of the 1st floor and is made of boards with a smaller section.

The construction of attic and interfloor ceilings is carried out according to the following technology:

Bearing beams are installed in the landing nests.
From below, with the help of a construction stapler, a windproof film is attached.
A draft floor is attached below.
A heater is lined in the niches between the beams. It can be mineral wool, expanded polystyrene, or ecowool based on split paper.
Boards are laid on top of the insulation and a screed of the upper subfloor is carried out.

Ways to reinforce wooden floor beams

Conventionally, beam reinforcement technologies can be divided into several types:

restoration;
reconstruction.

Restoration . This category includes such methods as reinforcement with wooden overlays, metal plates, carbon fiber wrapping, prosthetics. Let's consider each of the options in more detail.

Wooden lining

Damaged beams (rotten, brittle, potentially weak) can be reinforced with wooden overlays. To do this, the beam itself is cleaned with sandpaper or a planer and treated with an antifungal drug. On both sides lay out a beam with a smaller section. The structure is pulled together with cords and stitched through bolts.

metal plates

The bearing capacity of broken logs is restored using metal prostheses according to the technology described above. The hardware is applied to the cleaned and processed beam and tightened onto a series of through bolts.

Carbon fiber wrap

Carbon fiber glued to damaged timber.

The technology for restoring floors using carbon fiber is simple and easy. To do this, the damaged area is glued with several layers of carbon material.

Prosthetics

Prosthetics are used to increase the strength and wear resistance of the joints between the beam and the wall. This is where the effects of corrosion and wear most often appear due to the maximum pressure. Preventive measures are taken at the stage of initial installation of the structure. Metal linings are sewn with bolts to the bar spike. The reinforced structure is installed in the socket. An analogue of the overlays is a metal prosthesis. It is drilled into the body of the beam and installed in a small hole in the wall.

installation of supports (columns, vertical beams);
installation of additional beams.

Installation of supports

With insufficient bearing capacity of the beam, it is often reinforced with vertical supports. Installation of the pile allows you to redistribute the pressure from the beam to the support. This technology is most popular with repair work in attics and under floors.

Additional beams

With a meter step, you can increase the bearing capacity of wooden floor beams with the help of additional bars. To do this, the floor is completely dismantled and the beam is installed in increments of 50 cm.

Video instruction

When erecting hardwood floor for beams, each of the stages of work is important: from calculations to commissioning. The videos below demonstrate the technology for designing and erecting roof structures.

1. Calculation of materials for wooden floors.

2. Construction of the basement on wooden beams

3. Erection of floor slabs on wooden beams.

4. The construction of the attic floor.

5. Ways to strengthen wooden logs.

6. Installation of the subfloor of the ceilings.

In the construction of private low-rise buildings, wooden floors are mainly used.. The use of wood does not make the structure heavier and allows you to do without the use of equipment. Installation of wooden floors between floors in a brick house will help to significantly save on strengthening the foundation. In addition, the tree has good strength, durability, and also helps to maintain a favorable microclimate in the room.

Advantages and disadvantages of using wood

The positive aspect of using a wooden floor is the ease of installation and the excellent qualities of the material:

environmental friendliness;
thermal insulation;
decorative.

Among the disadvantages of wood can be noted:

tendency to damage by microorganisms, fungi, pests;
decay and destruction;
poor quality material can be deformed, sag, and if the installation rules are violated and the floor does not fit snugly, it will creak and oscillate.

Floor mounting materials

Popular cover option

For the manufacture of beams for the ceiling between floors, only coniferous types of wood are used.. They have higher flexural strength than rocks deciduous trees. Pre-bar or logs for beams are dried in the shade for outdoors. Wood that is completely ready for use should make a certain sound when tapped. Floor beams must be tightly fixed in the nests brickwork. Beams from a bar or a log with a section from 50 to 150 mm and 140 to 240 mm are used. The step of the beams corresponds to approximately 0.6-1.0 meters.

The ratio of the cross section of beams and the distance between them

Also used for overlays.:

planed tongue-and-groove boards for the floor on the second floor;
board for the subfloor of the second floor;
cranial bars 50x50 mm for attaching to the bottom of the beams;
insulation (fibrous thermal insulation);
hydro vapor barrier film;
decorative coating on the floor and ceiling;
wood preservative, bituminous mastic, ruberoid.

Wood floor device

The laying of floor beams in a brick house is carried out at the stage of its construction. The depth of the nest should be at least half the thickness of the wall. It can be made through with further sealing with insulation. All other work is carried out before the start finishing works. The load on the floor slab is calculated in advance, the laying step and the dimensions of the required beams are determined. The use of wooden beams for floors is possible only in a house where the span is no more than five to six meters..

Beam installation principle

You can also make the placement of beams by laying them on brick pillars. However, they should be installed at short intervals. This method is more often used when equipping the ceilings of the basement.

Laying beams

Laying begins with the extreme beams, leveling them with the help of linings treated with mastic and a long plank placed on edge. Intermediate elements are equal to the board laid on the extreme beams.

The wood is pre-treated with an antiseptic and dried thoroughly.. The wide sides of the beams when laying should be vertical - this increases their rigidity. The ends of the beams are cut at an acute angle, smeared with mastic and wrapped with two layers of roofing material.

Processed lintels are placed in niches, a layer of mineral wool is introduced into the formed recesses. Every third beam should be reinforced with anchors. With the help of a stretched cord, level maintenance is monitored. The step between the structural elements is no more than 1.5 meters.

Subfloor device

Hydro-vapor barrier (izospan) is overlapped on the ceilings and subfloor. The joints are sealed with tape. A fire-resistant insulation is laid on top of the film. It can be mineral wool, expanded polystyrene, ecowool, expanded clay. The material must not protrude beyond the surface of the beams.

Insulated floor

The floor joists of the second floor are installed on top of the floors. It is advisable to lay an additional layer of mineral insulation between the lags in order to isolate the floor and ceiling from noise. Then the waterproofing film is laid.

Top floor device

The floor of the second floor is covered with a finishing board, plywood or drywall, and also strengthened with self-tapping screws. Then the floor covering is laid in the form of laminate, linoleum, tiles.

To properly make a "warm floor", you should use a foil film as a vapor barrier.

Connection of beams in length

If there are not enough beams for the entire span, then you need to make a connection:

Splicing - joining in length.
Rallying - combining in width.
Knitting - corner connection.

The principle of joining beams

Basically a lengthwise connection is required. There are several ways to do this:

overlay- beams are cut at an angle and connected with bolts, brackets or a clamp.
back to back- connection of beams overlaid with an emphasis on the internal wall partition.
Lock fastening- a complex connection method that requires certain skills. Its essence is that recesses and protrusions are cut out in the beams, which are then connected, securely fixing the device to each other.

Improving the bearing capacity of the floor

There are several ways to improve the bearing capacity of beams. One of the most popular methods is the fastening of overlays from thick boards to them.. At the same time, their endings must be supported by supports.

It is also used to improve the bearing capacity by strengthening the U-shaped channels. They are attached to the beams from the side.

The most elementary method to strengthen the overlap between floors is to lay additional beams in the gaps between the existing ones.. This is the most time-consuming, but very effective way.

In the houses of the former development, they did not save on materials, so the wooden beams were installed with a small step. And they are more than adequate. But even in such a house, the ceiling between floors should be checked to determine the condition of the beams. This will allow timely strengthening of weakened areas and replacement of damaged areas. The damaged fragment of the beams is removed, and the healthy wood is lengthened and strengthened by fastening the overlays from thick boards.

How to protect the floor between floors

It is not enough just to build a house correctly, it is necessary that no problems arise during operation. To do this, even at the design stage, all factors contributing to its durability and protection of building structures are taken into account. Of no small importance is the solution of two problems - fire protection and biological influence environment .

According to combustibility, materials are divided into five categories, ranging from highly combustible to non-combustible. Designs from various materials distinguished by their ability to prevent the spread of fire. Flame retardant properties - completely excluding the spread of fire and semi-flammable - capable of delaying its spread for some time. It should be noted that flammability is not the same as fire resistance. Fire resistance is understood as the property of a structure or material to preserve load-bearing and enclosing functions in case of fire.

Protection against fire, fungus and insects

For this purpose, the wood is treated with fire-resistant solutions to ensure fire resistance for at least 30 minutes under experimental conditions. In residential construction, the design of the second floor floor structure must have at least semi-fire-resistant properties.

When drafting ceilings, it should be borne in mind that the beams are exposed to fire not only from the bottom side, but also from the sides.

The burning rate of coniferous wood is 0.8 mm/min according to the resistance parameters. Considering fire resistance, choose a material with cross section 11 by 24 cm, because with a beam height of 24 cm and a span width of 5.8 to 5.85 m, their width is increased to 120 mm or more.

The problem of protecting wooden structures from biological influences is also very relevant.:

water, which violates the structure of the tree and is a breeding ground for microorganisms.
molds, rot.
insects that cause damage to the structure of wood and rottenness.
ultraviolet light, which softens and darkens the wood.

Unlike other materials, wood is an environmentally friendly product, which is important for a living space. In addition, the wooden floor retains heat well in the house. There is now a trend towards a return to natural materials which used to be widely used. Funds already created effective protection wood from harmful effects that impair its performance.

Beam ceilings are used in low-rise construction (in wooden and stone buildings), in the reconstruction of old buildings by replacing wooden beams with more durable metal or reinforced concrete ones.

According to the material, the beams are divided into wooden, reinforced concrete and metal.

Ceilings on reinforced concrete beams. Ceilings on reinforced concrete beams consist of beams laid on load-bearing walls with a distance in the axes of 600, 800, 1000 mm, inter-beam filling and floor (Fig. 5.5).

The depth of support of the ends of the beams on the walls or girders is taken at least 150 mm. The ends of the beams on the supports are anchored, and the gaps between the beam and the nest walls to a depth of 40-60 mm are sealed with mortar. Inter-beam filling (Fig. 5.6) consists of a run-up, which is a flooring of lightweight concrete slabs and a soundproof (heat-insulating) layer. The seams between the rolling elements and the beams are carefully filled with mortar or glassine is laid on top of the rolling. Soundproofing is usually performed from a layer of slag or sand with a thickness of at least 60 mm. From below, the roll and beams are rubbed with mortar. This design is used for plank floors along the logs. When installing other types of floors, such as cement, requiring a continuous gesture

Fig.5.5. Prefabricated reinforced concrete beams and details of their support:

a - plan for the location of floor beams; b - general view of the beam; 1 - beam;

2 - steel anchor; 3 - steel structure; 4 - mounting loop; 5 - concrete embedment

After some preparation, the space between the beams is filled with slag, along which a layer of cinder concrete with a thickness of at least 40 mm and a floor are laid (Fig. 5.6d). More appropriate in these cases are rolls of double-hollow lightweight concrete stones - liners that have sufficient soundproofing properties and require only careful filling of the joints with mortar (Fig. 5.6 e).

Ceilings on metal beams. Currently, metal beams are used only in exceptional cases in the repair and reconstruction of buildings.

Steel beams (usually I-beams) are located at a distance of 1-1.5 m from each other. The depth of support of their ends on the walls is 200-250 mm.

Fig.5.6. Prefabricated beam construction

reinforced concrete elements:

a - general view; b - lightweight concrete slab; c - lightweight concrete stone insert; d, e - floor options with mineral floors; 1 - reinforced concrete beam; 2 - reel from lightweight concrete slabs; 3 - waterproofing layer; 4 - sound insulation; 5 - soundproof gasket; 6 - log; 7 - plank floor; 8 - slag; 9 - slag concrete thickness

40 mm; 10 - cement floor 20 mm thick; 11 - grouting with mortar

To increase the area of pressure on the masonry in order to protect it from collapse, concrete pads or steel linings are placed under the ends of the beams. The ends of the beams are anchored into the masonry of the walls and, if necessary, insulated with felt, followed by sealing the gaps around the perimeter of the nest with concrete (Fig. 5.7).

Inter-beam filling can be made of reinforced concrete prefabricated or monolithic slabs, and in some cases from brick vaults.

Fig.5.7. Ceiling construction on steel beams:

a - supporting the ends of the beams on the walls; b - anchor fastening detail; c - overlap with filling with a reinforced concrete monolithic slab; g - the same, brick vaults;

1 - steel beam; 2 - steel anchor; 3 - concrete pad; 4 - bolt; 5 - termination cement mortar; 6 - reinforced concrete monolithic slab; 7 - lightweight concrete; 8 - ceramic tiles over a layer of cement mortar; 9 - brick vault; 10 - soundproof layer; 11 - two layers of roofing; 12 - plank floor along the logs; 13 - steel mesh; 14 - plaster with cement mortar

Ceilings on wooden beams. Currently, wooden floors are allowed to be used only in low-rise buildings and only in areas where wood is a local building material. Their advantages are the simplicity of the device and the relatively low cost. Disadvantages - combustibility, the possibility of decay and relatively low strength.

All wooden floor elements are made of coniferous forests (pine, larch, spruce, etc.). Beams are made mainly in the form of rectangular bars, the dimensions of which are established by calculation. (Fig. 5.8). The distance between the axes of the beams is taken from 600 to 1000 mm.

To support the inter-beam filling, bars with a section of 40 x 50 mm, called cranial, are nailed to the sides of the beams (Fig. 5.8). The depth of support of the ends of the beams in the sockets of the stone walls must be at least 150 mm (Fig. 5.9). The ends of the beams are antiseptic with a 3% solution of sodium fluoride or coated (except for the ends) with resin, and when embedded in the outer walls, they are additionally wrapped with two layers of roofing paper. On internal walls or runs under the ends of the beams, two layers of roofing felt on tar mastic are laid. The gaps between the walls of the nest and the ends of the beams to a depth of 40-60 mm are tightly sealed with mortar. The location of the wooden floor beams, as well as their anchoring, are similar to reinforced concrete beam-type floors (Fig. 5.1 c).

The filling between the beams (Fig. 5.10) consists of a shield board run, lubrication on the top of the run with a clay-sand mortar 20-30 mm thick and a soundproof layer of slag or calcined earth 60 mm thick. The floors are made of boards along the logs with the device in them at the corners of the premises of metal ventilation grilles. Ceilings are plastered with lime-gypsum mortar along the strips or hemmed with sheets of dry plaster.

Fig.5.8. Constructive decisions wooden beams:

1 - bar single beam; 2 - beam composite of two bars of solid wood; 3 - a beam of glued wood; 4 - cranial bar

Rice. 5.9. Details of supporting wooden floor beams on

stone walls:

a - on the outer wall; b - on the inside; 1 - external load-bearing wall; 2 - external self-supporting wall; 3 - internal load-bearing wall; 4 - wooden beam; 5 - thermal insert; 6 - two layers of roofing paper on tar mastic or antiseptic zone of the beam; 7 - an anchor made of strip iron; 8 - crutches or nails

Fig.5.10. Floor construction on wooden beams:

a - with a plank shield roll; b - the same, from hollow blocks; c - the same, from lightweight concrete blocks (slabs); d - floors in bathrooms; e - types of rollovers; 1 - beams; 2 - reel (shield); 3 - plaster; 4 - clay lubricant; 5 - backfill; 6 - log; 7 - soundproof gasket; 8 - plank floor; 9 - hollow lightweight concrete block; 10 - cranial bar; 11 - solution; 12 - gypsum board; 13 - ceramic tile floor; 14 - cement strainer 20 mm; 15 - concrete preparation; 16 - two layers of roofing material on mastic; 17 - plank floor; 18 - plates; 19 - boards; 20 - false ceiling