Wooden floors. Attic floors on wooden beams: an overview of the best designs and tips for choosing beams Flooring at home on wooden beams

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- scaffolding, wood is a 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.

It 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 appropriate 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.

* 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 it can carry with it. warm air from the premises. 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 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, protects it well from 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 cover the entire niche around the beam with tar-soaked boards (since you can’t get tar in the modern world, 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.

It 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.

It 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 of 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 outer wall from 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. This is clear. To prevent the sound insulation layer from crumbling, some kind of rolled material is laid on the wooden flooring ( PVC film, roofing material, glassine, roofing felt, sack paper, etc.). 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 lag; 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 ceiling with lags and shield run-up: a - type of overlap; 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: by increasing the height of the inter-beam space, more or thicker layers of soundproofing material fit. 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 the 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 columns.

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.

It 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 of the wall; 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 with wooden logs 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 particular example); 12 - bar of shield rolling, based on the shelves of an I-beam; 13 - rolling boards; 14 - ceiling trim; 15 - logs connected end-to-end 16 - the same, overlapped; 17 - plywood gusset; 18- spacer.

Sections of I-beams when using wooden shields

* 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 good decision for the device of overlappings in sanitary knots 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*

The step of the beams cannot be taken arbitrarily, as in the case of a wooden deck: 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 beam ceiling the load falls on the beams, therefore, as an inter-beam filling, we can put the slabs with the ribs up.

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).

* 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.

With a warm attic, insulation is laid in the roof structure (for more details, see 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 the question of the wrong constructive solution, which reduces the durability of the overlap.

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 ventilation around the perimeter of the house, giving air access to the basement for ventilation, if the basement is not completely buried in the ground ( smallest size products - in 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. It's up to the question engineering equipment house, which is not discussed in this book.

Beam ceiling finish

Finishing the ceiling 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 etc.

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 capital houses this method is apparently not suitable, but is good for temporary or low-key building purposes.

If the construction of a two-story or one-story house, but with a basement or attic, it is necessary to correctly calculate and build interfloor ceilings. Consider the stages and nuances of the implementation of the overlap on wooden beams and calculate the sections of the beams that provide sufficient strength.

Device floors needs special attention, because made "by eye", they may not withstand the loads on them and collapse, or require unnecessary, unreasonable costs. Therefore, one or more options. The final decision can be made by comparing the cost or availability of acquiring materials.

Requirements for interfloor ceilings

Interfloor ceilings must withstand constant and variable loads, that is, in addition to their own weight, withstand the weight of furniture and people. They must be sufficiently rigid and not allow the maximum deflection to be exceeded, provide sufficient noise and heat insulation.

Specific loads from furniture and people for living quarters are taken in accordance with the standards. However, if you plan to install something massive, such as a 1000 l aquarium or a natural stone fireplace, this must be taken into account.

The rigidity of the beams is determined by calculation and is expressed in the allowable bending per span. Permissible bending depends on the type of flooring and the flooring material. The main limit deflections determined by SNiP are shown in Table 1.

Table 1

Please note that flooring in the form of ceramic tiles or concrete screed, prone to cracking, can further tighten the requirements for allowable deflection, especially with sufficiently long spans.

To reduce the loads on the beams, if possible, they should be placed parallel to the short walls, with the same pitch. The maximum span when covered with wooden beams is 6 m.

Types of floors

According to the purpose of the overlap are divided into:

• interfloor;
• attic;
• basement (basement).

The features of their design are in the permissible loads and the device of steam and heat insulation. If the attic is not intended for living or storing massive objects, variable loads can be reduced to 50-100 kg / m 2 when calculating the deflection.

Thermal insulation between two residential floors may seem redundant, but sound insulation is a desirable parameter for the majority, and this is achieved, as a rule, with the same materials. It should be taken into account that attic and basement floors need a thicker layer of thermal insulation material. Film material for vapor barrier in the attic floor should be located under the insulation layer, and in the basement - above it. To prevent the occurrence of dampness and damage to structures by a fungus, all rooms must be equipped with ventilation.

Floor options: 1 - plank shield; 2 - vapor barrier; 3 - thermal insulation; 4 - sparse flooring; 5 - boards; 6 - flooring

The design of the floors can also be different:

• with open and hidden beams;
• With various types bearing beams;
• With different materials filling and lining of the floor.

Hidden beams are sewn on both sides and are not visible. Open - protrude from the ceiling and serve as decorative elements.

The figure below shows what the structure of the attic floor can be with a shield roll and with a filing of boards.

a - with a shield roll; b - with filing from boards; 1 - plank floor; 2 - polyethylene film; 3 - insulation; 4 - vapor barrier; 5 - wooden beams; 6 - cranial bars; 7 - shield reel; 8 - finishing; 9 - filing from boards

Types of fastenings and connections of wooden beams

Depending on the design and material of the load-bearing walls, wooden beams are attached:

• in the nests provided in the brick or block masonry, deepening the beam or log at least 150 mm, and the board at least 100 mm;
• on the shelves (ledges) provided in the brick or block masonry. It is used if the wall thickness of the second floor is less than the first one;
• into cut grooves in log walls to a depth of at least 70 mm;
• to the top rail frame house;
• to metal supports-brackets fixed on the walls.

1 - support on brick wall; 2 - solution; 3 - anchor; 4 - roofing felt insulation; 5 - wooden beam; 6 - support on wooden wall; 7 - bolt

If the length of the beam is not enough, you can lengthen it by connecting (joining) along the length using one of the known methods using wooden pins and wood glue. When choosing the type of connection, be guided by the direction of application of the load. It is desirable to strengthen the spliced ​​beams with metal plates.

a - compression; b - stretching; c - bend

About wooden beams

In construction, beams of rectangular, round or partially round section are used. The most reliable are rectangular lumber, and the rest are used in the absence of timber or for reasons of economy, if such materials are available on the farm. Glued wood materials have even greater strength. Beams made of glued beams or I-beams can be installed on spans up to 12 m.

The most inexpensive and popular type of wood is pine, but other types of conifers are also used - larch, spruce. Floors are made of spruce in summer cottages, small houses. Larch is good for building premises with high humidity (bath, swimming pool in the house).

The materials also differ in grade, which affects the bearing capacity of the beams. Grade 1, 2 and 3 (see GOST 8486-86) are suitable for floor beams, but grade 1 for such a design may be unnecessarily expensive, and grade 3 is best used on small spans.

Calculation of load-bearing beams

To determine the section and step of the beams, it is necessary to calculate the load on the ceiling. The collection of loads is carried out according to the methodology and taking into account the coefficients set forth in SNiP 2.01.07-85 (SP 20.13330.2011).

Load calculation

The total load is calculated by summing the constant and variable loads, determined taking into account the standard coefficients. In practical calculations, they are first set by a certain design, including the preliminary layout of beams of a certain section, and then corrected based on the results obtained. So the first step is to sketch all the layers of the "pie" overlap.

1. Own specific gravity of the overlap

The specific gravity of the floor is the sum of its constituent materials and is divided by the horizontal total length of the floor beams. To calculate the mass of each element, you need to calculate the volume and multiply by the density of the material. To do this, use table 2.

table 2

For wood-based materials and waste, the density depends on the moisture content. The higher the humidity, the heavier the material.

Permanent loads include partitions (walls), specific gravity which is taken approximately 50 kg / m 2.

The decor of the room, people, animals - all this is a variable load on the floor. According to Table. 8.3 SP 20.13330.2011, for residential premises, the standard distributed load is 150 kg / m 2.

The total load is not determined by simple addition, it is necessary to take the reliability factor, which, according to the same SNiP (clause 8.2.2), is:

• 1.2 - with a specific gravity of less than 200 kg / m 2;
• 1.3 - with a specific gravity of more than 200 kg / m 2.

4. Calculation example

As an example, let's take a room with a length of 5 and a width of 3 m. Every 600 mm of length we put beams (9 pcs.) Of pine with a section of 150x100 mm. We will block the beams with a board 40 mm thick and lay linoleum 5 mm thick. From the side of the first floor, we will sew the beams with plywood 10 mm thick, and inside the ceiling we will lay a layer of mineral wool 120 mm thick. Partitions are absent.

1 - beam; 2 - board; 3 - insulated linoleum 5 mm

The calculation of the constant specific load on the area of ​​​​the room (5 x 3 \u003d 15 m 2) is shown in table 3.

Table 3

Design load on the beam (qр) - 250 x 0.6 m = 150 kg / m (1.5 kg / cm).

Allowable deflection calculation

We accept the permissible deflection of the interfloor ceiling - L / 250, i.e. for a three-meter span, the maximum deflection should not exceed 330 / 250 = 1.32 cm.

Since the beam lies on the support at both ends, the calculation of the maximum deflection is carried out according to the formula:

• h = (5 x qp x L4) / (384 x E x J)

For our example:

• h \u003d (5 x 1.5 x 3304) / (384 x 100000 x 2812.5) \u003d 0.82 cm

The result obtained in comparison with the allowable deflection has a margin of 60%, which seems excessive. Therefore, the distance between the beams can be increased by reducing their number and repeat the calculation.

In conclusion, we suggest watching a video on calculating the floor on wooden beams using a special program:

Growth in private housing construction testifies to the improvement of 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.

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. In case of violation of technology thermal insulation 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 that this information will help you make the best decisions 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.

1. . 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. Disadvantages: high price, relatively large 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.

   

   

2. . 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 distributed 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 is that modern polystyrene does not support open combustion, this is a very important characteristic of all building materials. Of course, foam plastic is much inferior to mineral wool in terms of fire safety, 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 follow in without fail impregnate with modern antiseptics, all places of contact between wood and concrete or masonry building materials are waterproofed. And most importantly - the presence of constant and effective ventilation of the space under the floor. This is the only way to ensure optimal conditions operation of load-bearing 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, building codes and regulations 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, while choosing a specific one, it is recommended to take into account the maximum number of 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. First, they react extremely negatively to high temperature and are bound to 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 with a thickness of 20 mm.

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 that 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. It makes no sense to talk about the negative consequences of 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.

1. 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.
2. 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.

   

3. 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 weakest point 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 number 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

Comments:

There are interfloor, basement, basement and attic floors. over wooden beams is a system in which logs are stacked in the right position and at a certain distance from each other.

Advantages and disadvantages of the design

The installation of wooden floor beams is intended for private houses that have only one floor, or for buildings erected along frame technology. The maximum span for such a device is 5 m.

Concerning positive aspects, then the following can be distinguished:

1. To install a wooden floor, you do not need to spend a lot of time, because in this case, equipment is not needed due to the light weight of the wood.
2. Although the tree is natural material, it has a low cost unlike reinforced concrete slabs.

But there are also disadvantages in this arrangement:

1. So that wooden beams do not succumb to rot, mold and moisture, before installation, it is necessary to impregnate the beams with special means.
2. In terms of fire hazard, wood has a high rate for this characteristic.

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How to make calculations correctly?

Pine, spruce or larch beams may be suitable for arranging a wooden floor. But, regardless of what kind of wood will be used for these purposes, you need to know that the moisture index should have a maximum rating of 14%. Otherwise, the elements will have insufficient strength, during installation and further operation, the structure will sag.

The distance from the laid elements should not exceed 1 m, so that the strength indicator is optimal. For additional reinforcement, metal beams or thick boards are used, but these elements will increase the load on the walls of the house and on its foundation.

You should know that if you compare a beam with a round log, then the second one is more tolerant of loads, although the beam itself does not bend so much. If two beams are fastened together with a bolt, then they will be more reliable than two elements simply placed next to each other.

The installation of a wooden floor comes with the expectation that each beam has a deflection, the minimum indicator of which can be 1/300 of its length. Therefore, a construction lift is used, which allows to compensate for such deformation. In this case, the beam structure will have an upwardly curved middle, which will later level out under the influence of loads.

The correct beam should have a thickness of not less than 1/24 of its length.

If necessary, replace one wooden beam two boards are used, which are fastened together. Only their total cross section should be equal to the cross section of the beam.

To fasten the elements, nails and self-tapping screws are used, which have a step of 20 cm and are arranged in a checkerboard pattern.

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Creating a slab

Before making a wooden floor, it is necessary to treat the ends of the beams with an antiseptic. They are also tarred and wrapped with roofing material in two layers.

The ends of the beams are attached to the walls.

If work is carried out with an attic floor, then the bars will be fixed on last crown log or timber wall, where openings are prepared in advance for the entire thickness of the surface.

Depending on the type of construction, several types of fasteners can be used:

You can also use the dovetail mount, using metal brackets.

This method is suitable for buildings made of timber. If the installation is in wooden house, then here the method of fastening to the crossbar using trapezoidal joints, which are reinforced with clamps, is more common. Both methods create a single level between the crossbar and the beam.

The easiest thing that can be done in fastening beams and crossbars is done as follows: cranial bars are mounted on the crossbars, and a beam is already installed on top of them. Such bars are needed with a section of 5x5 cm.

When wooden beams are laid in a panel house, the beams can be mounted directly on the wall itself or in pre-made nests in it.

The ends of the beams are placed in them. It is important to know here that each niche should be on the same level as the others, and its depth should be equal to 15-20 cm. As for the width, gaps of 1 cm are left here so that ventilation is carried out. This is done so that the beams do not rot. As soon as the beam is in its place, it is covered with tow.

There is another way to secure the beams in place: this is the use of metal anchors. This element one end is inserted into the socket, and the other end is mounted with screws to the crossbar. With this installation, the beam will not enter the wall.

For brick buildings, a wooden floor is installed on the walls or in special holes (nests).

It is also important to keep one level for such niches, for which the bottom is leveled with a concrete mortar. As soon as the mixture dries, the bottom is covered with a double layer of roofing material or roofing felt.

In this case, when creating nests for the beams, it is necessary that their width be 6-10 cm larger than the crossbar, so that after installation there are gaps of 3-5 cm. The depth of such a hole should be 20-25 cm, while the installation does not go up to the very end, and so that 3-5 cm remain to the bottom. The beams from the ends are treated with antiseptics, after which they are tarred and covered with hot bitumen. In this case, it is necessary that the end cut remains intact. Having wrapped the element with a two-layer roofing felt or glassine (with an open end), it is inserted into its place. At the end, the niches are filled with concrete-crushed stone mortar and leveled to the level of the wall.

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Roll-on flooring: features

To create the ceiling of the lower floor, it is necessary to roll up the floor. There are several ways to do this, but the simplest one will be discussed below.

Cranial bars (section 4x4 or 5x5 cm) are attached to the installed beam along the sides. Thus, the bottom of the bars will be flush with the bottom of the beam. For rolling, boards (1-2.5 cm) are used, which must be laid on the cranial elements with a transverse direction relative to the beams.

It is important that there are no gaps between them. Plywood or ready-made wood panels are also suitable for these purposes. To level the ceiling from below, you can use LGK or the same plywood 0.8 cm thick.

You can roll up using a slab or a beam with a cross section of 6 cm or more. In this case, you will need the same cranial bars as in the previous case. Against the direction of the beams, on top of the bars, a slab is spread, but so that it looks up with its rounded side. Further, the “quarter” method is used for the connection, for which grooves are made in the beam. When choosing a slab, you need to know that its thickness should help create one level between the bottom of the beam and the material, while contributing to a reliable connection with the cranial elements. In this case, the slab will play the role of not only rolling, but also filing.

Private low-rise construction has become increasingly popular in recent years.

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

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

When constructing the floor of the second floor on wooden beams, special attention should be paid to strength 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 a floor covering of 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 space a larger deflection coefficient is allowed - 1 to 200 (5 mm per 1 meter).

Soundproofing

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 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

The basis of the entire construction of interfloor wooden floors- 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.

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

The most commonly used material for beams is pine. it 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

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. Received footage ( overall length of all beams) we multiply 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

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, waterproofing materials are always used in construction.

It can be rolled 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

For fixing wooden floor elements, you should purchase self-tapping screws, nails, steel corners, anchor bolts and other consumable. 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 floors can be divided into several main stages.

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 spacing between beams is influenced by technical indicators material used for the finishing 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:

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 activity- 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 of the bearing beam, on both sides.

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

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 finishing ceilings ground floor or basement. In this case, edged boards are hemmed from below, from the side of the first floor to the beams. More about draft field see in 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 beam. The finished floor is the basis for the finishing coating - laminate, linoleum, parquet.