Attic flooring using wooden beams: a review of the best designs and tips for choosing beams. How to make a wooden floor between floors with your own hands Interfloor flooring using wooden beams

Insulation of interfloor ceilings according to wooden beams– an important part of the work: it is required to create a barrier to the cold and reliable sound insulation of the premises, while simultaneously preventing the possible formation of drafts and mold on the ceilings.

Thermal insulation is required for the ceiling between a cold basement and the first floor living spaces or between the living spaces and an unheated attic. Floors between living spaces require sound insulation, and therefore the approach to solving problems will be different.

How to insulate the interfloor ceiling to prevent drafts, dampness and mold? From the point of view of building thermal physics, the insulation of the interfloor ceiling using wooden beams will be correct when the thermal insulation is located on the cold air side.

The correct arrangement of layers in the ceiling structure repeats the principle of façade insulation: on the side where cold air enters, a vapor barrier is placed, then insulation, another vapor barrier, then a slab or other load-bearing structure. The arrangement of the layers must ensure the release of water vapor to the outside.

But when it comes specifically wooden structures in a private house, difficulties of a constructive nature arise.

When insulating an attic floor, there are two of them: thermal insulation, sound insulation and waterproofing of the structure are required at the same time. In addition, it will be necessary to walk on the ceiling for periodic inspection and roof repairs. The “pie” of the interfloor ceiling in this case will look like this:

1. A layer of material that can withstand occasional foot traffic.
2. Vapor permeable waterproofing.
3. Insulation.
4. Vapor barrier.
5. Basic structure.
6. The ceiling of the room.

Insulating wooden floors over a cold basement requires placing the layers in the reverse order:

1. Clean floor.
2. Vapor barrier.
3. Insulation.
4. Vapor barrier.
5. Basic structure.

ATTENTION: If there is no basement and there is a ventilated underground under the house, which often happens when constructing pile foundations, the insulation from below must be protected with a moisture- and wind-proof membrane.

In order to fulfill all these conditions, a competent choice of materials is necessary.

Selection of materials

Insulation of floors using wooden beams can be done with any type of heat-insulating materials:

1. Bulk (slag, expanded clay gravel).
2. Monolithic laying (lightweight concrete - expanded clay concrete, aerated concrete, etc., foam).
3. Slabs (slabs and mats made of various materials of mineral and synthetic origin - Velit porous concrete, mineral wool, foam glass, expanded polystyrene).
4. Film.

In order to choose insulation, it is necessary to analyze their thermal insulation properties, volumetric weight and the supporting structure of the building itself.

As a rule, bulk and monolithic insulation with high thermal conductivity have an impressive weight and, in order to ensure the required heat transfer resistance of external enclosing structures, a thickness of, for example, expanded clay concrete backfill of 0.5 m is required with a minimum volumetric weight of the material of 200 kg/m3, which is the same as wooden beams may not be able to stand it. These insulation materials are often chosen for interfloor ceilings on concrete slabs in brick houses.

The materials in greatest demand for insulation are mineral wool slabs (made of stone, basalt or glass wool) and expanded polystyrene. These materials have excellent characteristics:

• thermal conductivity indicators from 0.33 to 0.42 W/(m×K);
• low volumetric weight – from 10 kg/m3;
• low water absorption;
• high vapor permeability;
• compressive density from 70 kPa.

These indicators indicate the following:

• insulation of the interfloor ceiling using wooden beams will not require a thick layer of heat-insulating material;
• supporting structures will not be overloaded;
• insulation, if there is proper vapor and waterproofing, will not accumulate moisture, and, therefore, will last a long time and will
• maintain comfortable conditions in the home;
• during repairs it will not collapse from the weight of a person.

The choice of vapor barrier materials is no less important for the durability of the structure. There are a significant number of them offered on construction markets. Before purchasing, you need to find out how this material works, and in the case of multilayer membranes, which side should be adjacent to the insulation.

IMPORTANT: Polyethylene films, due to their short service life, fragility and inelasticity, are unsuitable for use as vapor and waterproofing when insulating floors in a wooden house.

We insulate the attic floor using wooden beams

Insulating the attic floor using wooden beams can be done in several ways. The choice depends on the distance between the beams and financial capabilities.

First way

The flooring scheme using mineral wool slabs is as follows:

Work algorithm:

1. Preparation of beams - impregnation with fire retardant and fungicide, reinforcement if necessary.
2. Attach a layer of vapor barrier to the bottom edge of the beams with lathing.
3. Place a layer of soft insulation – mineral wool mats – between the beams.
4. On the upper edge of the floor beams, lay a second layer of insulation - rigid mineral wool slabs with a laminated surface that can withstand limited foot traffic.
5. Apply a layer of waterproofing overlay to the slabs roofing material(Technoelast, Krovlyaelast, Bikrost, etc.) using a hair dryer.
6. Attach a suspended ceiling (plasterboard, OSB, chipboard, lining, etc.) along the sheathing.

Second way

Work algorithm:

1. Preparing beams.
2. Using lathing, we attach a vapor barrier to the beams.
3. We lay the first layer of thermal insulation.
4. We install wooden logs along the beams.
5. We lay a second layer of thermal insulation material between the joists.
6. We install the flooring from moisture-resistant chipboards, OSB or other material.

When laying the insulation boards, they are fixed to assembly adhesive or glue foam. According to the second method, mineral wool boards can be replaced with expanded polystyrene or penoplex.

We insulate the ceiling of the first floor

Insulation of the floor in this case can also be done in several ways, the choice depends on design features Houses. If there is a ventilated space under the ceiling, insulation can be done according to the attic principle, changing the alternation of layers.

First way

Insulation of the first floor floor along joists, with a cold subfloor, looks like this:

Work algorithm:

1. Preparing beams.
2. We attach a cranial block along the bottom edge.
3. We fasten the subfloor (boards, plywood, OSB, DSP, etc.) to the skull blocks with nails.
4. We lay a moisture- and windproof membrane on top, attaching it to the beams through counter slats.
5. We lay insulation in the space between the beams.
6. We lay a clean floor.

Second way

Insulating the floor above a cold basement differs from the previous method in small nuances; accordingly, the algorithm for performing the work does not change.

IMPORTANT: Before carrying out work, the wood must be protected from rotting with antiseptic impregnations and fire retardants to impart fire resistance.

Conclusion

Properly performed insulation of the floor between floors using wooden beams is guaranteed to ensure comfortable living, eliminate drafts and the formation of fungus and mold. All work will not be difficult to perform for any homeowner who knows how to use a drill and building level.

If we consider the wooden floor between floors, then in general it consists of beams, inter-beam filling, roll-up forming the subfloor, and the finishing layer of the ceiling. The main structural element is the beams. Most often they are made from coniferous species tree. This is the kind of wood that should be used, since hardwood material works worse in bending. Besides solid timber you can use beams knocked down from those placed on edge wide boards. Moreover, the final cross-section of the elements in such a case can be reduced by 20-30%, since the strength of such a beam is slightly higher than that of a solid beam.

Also suitable as a material for flooring are: glued beams, made from lamella boards up to 12 meters long. Such beams are much stronger than solid wood elements. It is possible to manufacture them according to individual orders in accordance with the agreed dimensions. In this case, installation is simplified due to the absence of additional adjustment manipulations. When using laminated veneer lumber, you should remember that most often these elements undergo additional processing and are covered with a thin layer of wax. Wax makes the surface of the bars slippery. Therefore, immediately after installation on the walls or foundation, temporary flooring must be laid on top of them to prevent possible injury.

Selecting the cross-section of wooden floor beams

For floors between floors with a span of 3 - 4.5 meters, beams with a cross section from 140 × 100 mm to 200 × 120 mm should be used. For spans of 4.5 - 6 meters, beams from 200 × 120 mm to 240 × 160 mm will be needed. For attic floors, you can use elements with a cross-section that is 20 - 30% smaller. These are all general recommendations, of course. To more accurately and correctly determine the required section and pitch between the beams, a calculation is needed. To calculate the cross-section, the span length, the distance between the beams and the amount of load exerted on them are taken into account. As an alternative to calculating parameters yourself, you can use

General parameters for selecting beams for interfloor and attic floors:

Section of a wooden beam, mm	Distance between beams for a given span width in a wooden floor between floors, m					distance between beams for a given span width in the attic floor, m
	3,0	3,5	4,0	4,5	5,0	3,0	3,5	4,0	4,5	5,0
50×160	0,8	0,6	0,45			1,2	0,9	0,65	0,5	0,4
60×200	1,25	0,8	0,7	0,55	0,45	1,85	1,35	1,05	0,8	0,65
100×100	0,6	0,45	0,35			0,9	0,7	0,5	0,4

Installation of wooden floors between floors

Wood beams are laid at a distance of 0.6; 0.8; 1.0 or 1.2 meters from each other (table for selecting beams for interfloor and attic floors). The larger the span width and beam cross-section, the smaller this gap should be. An exception may be attic floor, where the distance between elements can be increased to 1.5 meters. The beams (logs) are mounted along the short side of the room perpendicular to its length, maintaining parallelism to each other as much as possible. First of all, the outer beams are fixed, the correct position of which is checked by the building level. Then the elements are laid from the edges to the center, maintaining the distance between them. You also need to check the horizontality of the beams and, if necessary, place cuttings of boards protected by waterproofing under their ends.

It is necessary to leave special niches in the structures of external walls 150-200 mm deep, into which beams are subsequently laid. The length of the supporting part must be at least 120 mm, but not more than 180 mm, so that there is a 20-30 mm gap between the wall and the beam in the niche. When laying in walls made of brick or other block materials, every third beam must be secured with masonry. Before laying, the ends of the beams on the side of both internal and external walls are wrapped with two or three layers of roofing material or covered with bitumen mastic. This reduces the likelihood of wood rotting. The remaining voids in the niche are filled with insulation ( mineral wool or polystyrene foam) and sealed.

Installing a wooden floor in a wall groove:

Inter-beam filling It is made of two layers: rolling (flooring) and thermal insulation. For the first layer use wooden boards and boards. The roll is attached to bars with a cross-section of 50 × 50 mm, which are nailed to the sides of the beams. From below, the interfloor ceiling is hemmed with boards, particle boards (chipboard, OSB) or plasterboard slabs. All these materials play the role of a rough or finished ceiling. If you want to leave the beams natural and visible, finishing hemming should be done to the frame (beam) attached to the inside of the beam above the lower plane of the floor.

Wooden floors between floors in section:

A vapor barrier and slabs of mineral wool, extruded polystyrene foam, polystyrene foam, and perlite are laid on top of the roll. The insulation boards should be laid as closely as possible to each other. The thickness of the layer of any material for interfloor coverings should be at least 100 mm, and for attic and basement floors - 200-250 mm. A more accurate calculation of the required insulation and its required thickness can be performed in

If there is a need to strengthen the wooden floor between floors with a large span, then it is recommended to lay the beams in a cross pattern, perpendicular to each other. However, this method will increase the labor intensity of the work, because you will not only have to install more beams, but also make cuts in them (at the intersection nodes), then tighten them with clamps or wire. True, the beams themselves in this case, both in the longitudinal and transverse directions, can be laid less frequently. And yet it is much easier to reduce the pitch of the beams and lay more of them, reducing the space between the beams. Another way to solve the problem is to choose elements with a large cross-section or strengthen the beams on the sides with additional overlays from boards.

The elements are connected to each other in a certain way, and the structure works as a single whole.

Beam floors are classified according to the material of the beams. In modern low-rise housing construction, wooden, steel and special beams are used for cellular floor blocks - for the prefabricated 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 - load-bearing wall; 3 - curtain wall; 4 - plank floor or base for a finished floor (subfloor boards); 5 - transfer of loads to the load-bearing wall

Interfloor ceiling on wooden beams

In our country, where there is a lot of natural material - forests, wood is traditional building material. In stone houses, floors are often made using 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 it was the Russian capital. Not only low-rise estates, but also six- and seven-story buildings in the center of St. Petersburg, former apartment buildings, have wooden floors. For 200 years, in a damp climate, the houses have stood without reconstruction and are a residential historical stock.

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

Of course, in those distant times, it was not timber that was laid, but logs, which, compared to 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 a rule, timber is used as wooden beams. A beam is a log sawn on four sides. Made from coniferous wood. On small spans of up to 2 m, you can lay boards with a thickness of 25, 32 or 40 mm, placed on edge and nailed together - 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 finishing of the ceiling and floor structure for such an overlap.

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

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

* Data on the current assortment of lumber according to GOST 24454-80*; timber length from 1 to 6.5 m with gradation of 250 mm.

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

*** The calculation of the step includes payload for flooring 200 kgf/m2, mass of wooden beams and a soundproofing layer of mineral wool slabs with a density of 100 kg/m3. In the case of filling with expanded clay, the step is reduced by 20% (this approximation can only be accepted for educational purposes; in practice, proper calculation is required).

The peculiarity of wooden beams is the fact that over large spans they guarantee the strength of the floor, but do not provide 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 possible “unsteadiness” 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 use 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 span to be covered. Beams, as a rule, are laid along the shortest span if the room being covered is rectangular. If the room is square, then the direction in which the beams are laid does not matter. The fact is that all the walls of a stone house can be classified as load-bearing, since they are strong enough to withstand the load from wooden beams.

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

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

The attentive reader, of course, noticed that the pitch of the beams does not always obey the modulus. We will see why this subordination is not necessary 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 located, and this may slightly, slightly, affect the size of the steps.

Example of floor beam layout

The beams are laid in niches in the wall that are specially prepared during the laying process. To ensure reliable and durable support, the depth of embedding of a 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 embedding of the beam into the wall and leave a certain air gap (20...30 mm), which prevents contact of the wood with the stone back wall of the niche. In addition, an air gap will help prevent the wood from rotting 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 case when insulation is not included in the wall structure (for example, the wall is built from ceramic stone, and the thermal protection of such a wall is ensured), the niche can be a conductor of cold, since the remaining thickness of the wall is not enough. Then in the niche we can get freezing and condensation of moisture. 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 that it can carry with it. warm air from the premises. Of course, expanded polystyrene is a flammable material, but we are talking about wooden floors, for which you already need to be especially careful from the point of view of fire safety.

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

The insulation should not be wrapped in film or placed, say, in a plastic bag. This can lead to condensation in the enclosed space of the bag and subsequently to poor performance of the insulation; As a result, the wall freezes.

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

It is well known that wood lasts a long time if it remains dry and ventilated. To keep the wood dry, it is advisable to seal the cracks formed around the beam with polyurethane foam. Polyurethane foam, “sealing” the upper pores of the wood, 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 boards not only in the lower part of the niche, but also cover the entire niche around the beam with boards impregnated with tar (since modern world if you can’t get tar, then an antiseptic will do), then the beams will last for centuries. This is exactly how niches are prepared in Moscow houses built 300 years ago and which still delight us today.

This is interesting. How did they deal with wood decay in ancient times? After all, there were no modern antiseptic compounds then. It turns out that soot is an excellent natural antiseptic, as well as a specific “varnish” that protects wood from dampness and fungus. The beams were treated with it.

A niche sealed with one material or another is called blind sealing; this is a common solution. Less often they do 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 beams on an internal wall, insulation must also be laid under them, 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 secured. The point is that the walls two-story houses reach a height of seven or more meters, connecting only at the corners. If rigidity is not ensured, the wall may go out of its plane with all the ensuing consequences. Anchoring beams into the wall will help make the spatial “wall-floor” system rigid - creating horizontal floor discs. This can be done using T-shaped anchors cut from strip steel. One end of the anchor is nailed to the beam, the other end is inserted 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 connected to each other by steel strips nailed to both sides of the beams.

This is interesting. Tightenings have always been used for beam floors, even in large buildings. For example, today on the building of the Tryokhgornaya Manufactory factory, built at the end of the 18th century, you can see how the tie-down anchors extend onto the façade.

The figure shows the developed solution for supporting wooden beams on walls built 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, insulation is installed in the niche.

Supporting wooden floor beams on outer wall from aerated concrete blocks: 1 - aerated concrete main blocks; 2 - additional blocks; 3 - mineral wool insulation; 4- U-shaped blocks; 5- the end of the beam wrapped in roofing felt (preferably) or roofing felt; 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 brick, a monolithic reinforced concrete belt is prepared under the beam - it will take the load from the floor. The insulation and reinforced concrete belt are placed in a cavity formed by special U-shaped blocks. The end of the beam entering the niche is antiseptic and wrapped with roofing felt, roofing felt, etc.

Anchoring of beams is done using a sheet strip bent at a right angle - a connector, which is secured to the beam and the reinforced concrete belt with dowel screws.

This solution can be supplemented with those actions and elements that we talked about in so much detail when looking at the figure.

Inter-beam filling for floor construction without the use of joists and with joists

The interbeam filling is inherently enclosing and contains layers and elements, each of which performs specific functions.

Floor design without the use of joists

A floor structure without the use of joists is only suitable if the pitch of the beams does not exceed 500...600 mm. Otherwise, with a larger step, the rigidity of the floor will not be ensured, the floor becomes “unsteady” and bends.

The layout plan for the 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 sound insulation layer. It is suitable for sound-absorbing material, which is also used as heat insulation: expanded polystyrene, polystyrene foam, etc. or mineral wool. It must be said that mineral wool is preferable: it is a non-combustible material. The advantages of mineral wool include the fact that rodents are afraid of it, but in polystyrene foam they easily and happily gnaw passages and make holes. However, all these materials are not particularly effective as soundproofing materials, since their mass is small: for example, the mass of a layer of mineral wool or expanded polystyrene 10 cm thick is only 4...10 kg/m 2. And we remember that adding weight to the structure solves the issue of sound insulation.

The situation is better if you fill it with environmentally friendly material - expanded clay: it is not flammable, non-toxic. But its mass is also small: a layer of expanded clay 10 cm thick has a mass of 70 kg/m2. Sound insulation increases significantly when using sand: the mass of a layer of 10 cm is 200 kg/m2. We will achieve the greatest effect if we fill the inter-beam volume like this: pour sand down, and put mineral wool or polystyrene foam on it. To separate the layers, we will put geotextiles. 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, secured to cranial blocks, 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 is laid on the wooden flooring ( PVC film, roofing felt, glassine, roofing felt, sack paper, etc.). Types of flooring are shown in the figure.

Construction of an interfloor floor on wooden beams without the use of joists: a - layout diagram of beams and subfloor boards; b - type of overlap; v-e- composition beam floor 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 roll; h, i- views flooring; 1 - clean floor design; 2 - subfloor boards; 3 - soundproofing elastic layer (for example, three layers of roofing material); 4 - rolled material that protects the inter-beam filling from scree and debris (for example, glassine); 5- effective insulation (mineral wool, expanded polystyrene); 6- expanded clay; 7- sand; 8- geotextile; 9-floor beam; 10-skull block 30x40, 40x50 or 50x50 mm; 11 - ceiling finishing; 12 - flooring boards; 13 - rolled material (roof felt, roofing felt, PVC or polyethylene film, etc.); 14 - reel boards; 15- knurling block; 16- deck slab; 17-plinth.

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

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

Next, subfloor boards are laid along the beams, which will subsequently serve as the basis for the finished floor structure. For the subfloor, low-grade boards are used, their thickness is 25 or 32 mm. To eliminate the sound bridge that arises from the shock wave, a soundproofing lining is placed between the beam and the subfloor boards, for example, several layers of roofing felt, roofing felt, or other elastic material. It is possible to lay bare floor boards over the beams, but this option is not suitable for expensive floor finishing.

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

Floor construction using joists

As can be seen from the table, the pitch of the beams and their cross-section are interrelated quantities: the more powerful the beams, the larger the pitch they can be laid. This is good because it reduces the labor intensity when embedding beams into niches. However, if the beam pitch exceeds 600 mm, the rigidity of the floor will not be ensured.

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

Floor design with logs and panel roll: a - type of floor; b - type and parameters of the shield roll; 1 - subfloor boards; 2 - logs laid flat; 3 - soundproofing layer; 4 - rolled material; 5 - shield roll bar; 6 - panel boards; 7- nails for fastening the skull block; 8 - cranial block; 9 - beam; 10 - elastic material to eliminate sound bridge.

The filling between the beams is the same as in the structure without joists. At the same time, the logs have another purpose: by increasing the height of the interbeam space, it fits large quantity or thicker layers of soundproofing material. Soundproofing layers are laid on the flooring or panel roll.

The logs are placed in increments of 400...600 mm; in this case, a regularity is observed: the larger the beam pitch, the smaller the lag pitch.

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

Supporting wooden beams on vertical supports

With a frame or combined structural system, floor beams rest on separate supports: racks, columns, pillars.

If it is necessary to connect the beams, the joining point must be above the vertical support. If the supports are wooden, then the beams are attached to the supports with nails driven at an angle and connected with staples. Fastening can be done using plywood overlays, which are fastened on both sides of the beams being butted. Various metal fasteners are also used, for example, those shown in the figure. For round racks, the supporting area of ​​the beams may not be enough, then the lower edges of the beams connected end-to-end are bolted to a metal plate.

The logs are also joined above the supports.

Supporting wooden beams on free-standing supports and methods of connecting them: a - supporting the beam on a support; b - connecting beams using plywood gusset; c - the same, using metal parts; g - supporting the beam on a round stand; 1 - beam; 2 - support; 3 - plywood gusset; 4 - detail metal fastening; 5- metal platform columns.

Interfloor ceiling on steel beams

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

This is interesting. In Moscow's Stalinist high-rises, and, as you know, there are seven of them, the floors are reinforced concrete and use steel beams. As examinations have shown, time has not damaged the ceilings, and they will last for a very long time.

For steel beams, rolled profiles are suitable - I-beams, channels, angles.

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

Embedding steel beams into a wall

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

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

Embedding steel beams into the wall: a - uninsulated niche, anchoring the beams using a steel strip or rod; b - insulated niche, anchoring beams using corners; c - embedding beams into a niche in the inner wall; d - type of 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 for the same purpose; 6 - section of an I-beam; 7- I-beam; 8 - anchors - corners; 9 - effective insulation

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

The niche is finished for the same reasons as in the case of wooden beams. If the construction of a niche violates the heat-shielding properties of the wall, then insulation is laid between the rear 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 cement-sand mortar. Unlike wooden beams, steel beams “feel good” when in contact with mortar.

Anchoring a beam into a wall is done using a metal anchor welded to the beam on one side and inserted 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 at the top and bottom and inserted into the masonry are also suitable.

Supporting the beams on the internal wall, anchoring them and finishing the niche is done in the same way as in the case of external walls.

Inter-beam filling

The pitch 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. The shields are first knocked down on the ground. Boards are tacked to the bars from below, leaving the ends of the bars free. Then the bars with their free ends rest on the lower flanges of the I-beams, which play the role of cranial bars. The bars in places where they rest on the beams are antiseptic.

Based on the characteristics of the wood from which the flooring is made, the pitch of the beams cannot exceed 2 m; The beam pitch does not obey the module.

All other layers of inter-beam filling are the same as for 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 avoid contact with metal beams subfloor boards must be insulated with wooden joists or some other insulating material. The logs are installed flat or on edge. The connection of the lags to the edges is done end-to-end using a plywood gusset. For rigidity, a spacer is inserted between the joists. When connecting with an overlap, the logs extend somewhat beyond the planes of the upper flanges of the beams. Spacers may also be needed here. The logs must be protected from contact with the metal of the beams; Roofing felt, roofing felt, etc. are suitable for this.

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

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

Construction of an interfloor floor on steel beams using panel rolling: a - composition of the layers of the floor structure; b - butt lag connection; c - the same, overlapped; 1 - clean floor design; 2 - subfloor 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; 8 - soundproofing elastic layer; 9 - geotextile; 10 - roll material (roof felt, roofing felt, etc.); 11 - steel I-beam No. 12 (only for this specific example); 12 - panel-beam block resting on the I-beam flanges; 13 - bevel boards; 14 - ceiling finishing; 15 - butt-joined joists 16 - the same, overlapping; 17 - plywood gusset; 18- spacer.

Sections of I-beams when using wooden panels

Beam profile no.*	Section hxb, mm**	Span, mm	Step, mm***	Beam profile no.*	Section xb, mm**	Span, mm	Step, mm***
No. 10B1	100x55			No. 16B1	157x82
No. 12B1	117x64			No. 18B1	177x91
No. 14B1	137x73			No. 20B1	200x100

* Data from the current assortment of rolled profiles GOST 27772-88*.

*** The calculation of the step includes a payload on the floor of 200 kgf/m2, the mass of wooden panels and a soundproofing layer of mineral wool slabs with a density of 100 kg/m3. In the case of filling with expanded clay, the step is reduced by approximately 20%.

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

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

It is more convenient and modern to use small-sized reinforced concrete slabs as flooring - PRTM. This will be an especially good solution for installing floors in sanitary facilities where leaks are possible. The type of PRTM slabs is shown in the figure, and the name and their parameters are given in the table.

Parameters of small-sized 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 pitch of the beams cannot be taken arbitrarily, as in the case of wooden flooring: it will depend on the length of the slabs. Since the smallest slab has a length of 1170 mm (PRTM-1), the correspondingly smallest pitch of the beams will be 1.2 m. The mass of such a slab is only 65 kg, so laying 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 interbeam filling are shown in the figure. Here the slabs are placed on the lower flanges of the beams. In this case, they are located with the ribs up. Areas that are not multiples of the width of the slabs are monolithic.

The slabs can also be placed on the upper shelves - edges down.

Strictly speaking, PRTM slabs are capable of withstanding a significant load, as is clear from their name (designed for heavy loads). And to absorb the load, they are designed to be positioned with the ribs down. However, in beam floor the load falls on the beams, so we can place the slabs with their edges up as filler between the beams.

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

The cross-section parameters of 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 - layout plan for beams and PRTM slabs; b - type and parameters of the PRTM slab; 7 - I-beam No. 18 (only for this specific example); 2- plate P RTM-1; 3 - monolithic section; 4- channel No. 18; 5 - construction of a clean floor; 6- subfloor boards; 7-joists 50x75, laid flat; 8 - rolled material protecting the space between the beams from debris; 9 - effective insulation; 10 - expanded clay; 11 - sand; 12 - soundproofing elastic layer; 13- geotextile; 14-roll material (roof felt, roofing felt, PVC film, etc.); 15- ceiling finishing; 16 - metal mesh (when finishing the ceiling with plaster).

Beam profile no.*	Section hxb, mm**	Span, mm	Step, mm***	Beam profile no.*	Section hxb, mm**	Span, mm	Step, mm***
No. 12B1	117x64			No. 18B1	177x91
No. 14B1	137x73			No. 20B1	200x100
No. 16B1	157x82			No. 23B1	230x110

* Data from the current assortment of rolled profiles GOST 27777-88.

** The larger value h is the height of the profile, the smaller value b is the width of the I-beam flange.

*** The calculation of the step includes a payload on the floor of 200 kgf/m 2 , the mass of PRTM slabs and a soundproofing layer of mineral wool slabs with a density of 100 kg/m 3 . In the case of filling with expanded clay, the step is reduced by approximately 20%.

When laying the slabs on the upper flanges of the beams, they are placed with the ribs down. There is no need for joists or subfloor boards here: the floor structure is built as if on a reinforced concrete slab (see the “Floors” section). Undoubtedly, this is an advantage of such a solution, but its imperfection is low sound insulation compared to large-sized slabs: after all, the mass of the PRTM is small. We can improve sound insulation qualities if we fill the inter-beam volume appropriately. To form the inter-beam volume, either wooden panels are laid on the lower flanges of the beams, if there is no more than 2 m between the beams, or gypsum-fiber, glass-magnesia, calcium sulfate and other slabs offered by the construction market. The soundproofing layer can be chosen in any way - from environmentally friendly sand and expanded clay to synthetic effective insulation.

This option does not require graphical explanation, therefore, by compiling all the above solutions, you can independently develop a cross-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 installed over steel beams. In this case, the steel beam is either concreted or remains open. In the second case, the beams must be hidden suspended ceiling, in the first - at the request of the customer.

In both options, it is necessary to install formwork on which concreting is carried out. The 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 it is the strongest floor. In low-rise residential construction, it is used, as a rule, for large spans in frame structural systems.

Attic ceiling in a cold attic

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

Measures to combat the appearance of condensation are different. First you need to reduce and, if possible, cut off the flow of steam into the attic volume. This is done using vapor barrier materials laid on 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 sound insulation and high-quality floor finishing, so some elements of the attic floor may not be included in it. How one of the large Moscow design firms 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 just any rolled material under the insulation (remember that in a regular interfloor floor it played the role of a barrier against the fall of soundproofing material), but rather a vapor barrier.

If steam does penetrate through leaks in the structure or other paths, which most often happens, then constructive measures are taken: for example, vents are installed to ventilate the roof, which will be discussed in the “Roofs” section.

With a warm attic, insulation is installed in the roof structure (more details about this are discussed in the “Roofs” section), but the attic floor is not insulated.

Basement (basement) ceiling above the 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 beams will become covered with rust; this is about the question of the wrong constructive 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 on the side of the warm above-basement (above-basement) room, i.e. above the insulation;
• make vents around the perimeter of the house, allowing air to enter the basement for ventilation if the basement is not completely buried in the ground (the smallest size of vents is one brick). The vents are sealed with nets, and in the winter, if necessary, they are covered with something, for example, bricks or special plugs.

Installation of flooring on wooden beams over a cold room and ventilation of the room: 1 - wooden floor beam; 2 - clean floor design; 3 - subfloor boards; 4- logs; 5 - vapor barrier; 6 - thermal insulation; 7-roll vapor-permeable material; 8 - boardwalk; 9 - cranial block; 10 - air; 11 - floor structure on the ground.

In the case of an underground floor, i.e. When the basement is completely buried in the ground, you need to remove the ventilation ducts. This is already a question engineering equipment home, which is not discussed in this book.

Beam ceiling finishing

The finishing of the ceiling is carried out depending on the design idea. Previously, we studied drawings in which the beams were hidden by some kind of finishing or filing. Suitable for finishing are plaster, profiled natural boards of the “lining” type, plasterboard sheets(“dry plaster”), special finishing ceiling tiles and so on.

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

However, wooden beams often want to be emphasized. In such cases, the cranial bars are tacked to the beams to the desired height. Moreover, the cranial bars can also be given curly shape. Ordinary bars are hidden by hemming.

When accepting this ceiling solution, we must not forget that the volume between the beams will decrease here, and, consequently, the sound insulation of the floor will suffer.

A very simple option is to not arrange the space between the beams 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 unpretentious buildings.

When constructing private low-rise houses made of wood, concrete blocks or brick, wooden floors are most often erected between floors. These designs, compared to alternatives concrete slabs, have a number of advantages. Wooden floors do not overload the walls and do not require the use of lifting equipment during installation. In addition, they have high strength, durability and reasonable price. The installation of such ceilings is quite simple, so many home craftsmen do it themselves.

Floor design

The basis of a wooden floor is beams that are supported on load-bearing walls and serve as a kind of “foundation” for the remaining structural elements. Since the beams will bear the entire load during operation of the floor, special attention should be paid to their proper calculation.

For beams, they usually use solid or laminated timber, logs, and sometimes boards (single or fastened in thickness with nails or staples). For floors, it is advisable to use beams made of coniferous trees (pine, larch), which are characterized by high bending strength. Hardwood beams perform much worse in bending and can deform under load.

Rough boards (OSB, plywood) are fixed to the floor beams on both sides, on top of which a facing covering is sewn. Sometimes the floor of the second floor is laid on logs, which are secured to beams.

It is worth remembering that the wooden floor on the side of the first floor will be the ceiling, and on the side of the second floor (attic, attic) will be the floor. Therefore, the upper part of the ceiling is sheathed flooring materials: tongue and groove boards, laminate, linoleum, carpet, etc. The lower part (ceiling) - clapboard, plasterboard, plastic panels, etc.

Thanks to the presence of beams, space is created between the rough boards. It is used to give the ceiling additional properties. Depending on the purpose of the second floor, heat-insulating or sound-proofing materials are laid between the floor beams, protected from moisture by waterproofing or vapor barrier.

In the event that the second floor is a non-residential attic that will not be heated, thermal insulation must be included in the ceiling structure. For example, basalt wool (Rockwool, Parock), glass wool (Isover, Ursa), polystyrene foam, etc. A vapor barrier film (glassine, polyethylene and polypropylene films) is placed under the thermal insulation layer (from the side of the first heated floor).

If EPS, which does not absorb water vapor, was used as thermal insulation, the vapor barrier film can be excluded from the “pie”. A layer of waterproofing film is laid on top of heat-insulating or sound-proofing materials that absorb and can deteriorate from moisture. If during finishing the possibility of atmospheric moisture entering the attic was excluded, the insulation does not need to be protected with waterproofing.

If the second floor is planned as a heated and living space, then the floor “pie” does not need additional thermal insulation. However, in order to reduce the impact of noise that will occur when people move along the floor, a soundproofing layer is laid between the beams (usually conventional thermal insulation materials are used).

For example, basalt wool (Rockwool, Parock), glass wool (Isover, Ursa), polystyrene foam, sound-absorbing ZIPS panels, soundproofing membranes (Tecsound), etc. When using materials that can absorb water vapor (basalt wool, glass wool), a vapor barrier film is laid between the first floor and the sound insulator, and waterproofing is placed on top of the sound insulator.

Attaching beams to the wall

Floor beams can be connected to walls in several ways.

In brick or timber houses, the ends of the beams are inserted into grooves (“sockets”). If beams or logs are used, then the depth of the beams in the walls should be at least 150 mm, if the boards are at least 100 mm.

Parts of the beams in contact with the walls of the “nest” are waterproofed by wrapping them in two layers of roofing material. The ends of the beams are cut at 60° and left uninsulated to ensure free “breathing” of the wood.

When inserted into a “nest,” ventilation gaps of 30-50 mm are left between the beam and the wall (on all sides), which are filled with thermal insulation (tow, mineral wool). The beam is supported on the base of the groove through an antiseptic and waterproofed wooden plank 30-40 mm thick. The sides of the groove can be covered with crushed stone or covered with cement mortar to a depth of 4-6 cm. Every fifth beam is additionally fastened to the wall using an anchor.

IN wooden houses the beams are buried in the grooves of the walls by at least 70 mm. To prevent squeaks, waterproofing material is laid between the groove walls and the beam. In some cases, beams are cut into walls, making dovetail connections, etc.

Beams can also be fixed to the wall using metal supports - steel angles, clamps, brackets. They are connected to walls and beams with self-tapping screws or self-tapping screws. This option fastening is the fastest and most technologically advanced, but less reliable than when inserting beams into wall grooves.

Calculation of floor beams

When planning the construction of a floor, you first need to calculate the design of its base, that is, the length of the beams, their number, optimal cross-section and spacing. This will determine how safe your ceiling will be and what load it can withstand during operation.

Beam length

The length of the beams depends on the width of the span, as well as on the method of fastening the beams. If the beams are fixed on metal supports, their length will be equal to the width of the span. When embedding walls into grooves, the length of the beams is calculated by summing up the span and the depth of insertion of the two ends of the beam into the grooves.

Beam spacing

The distance between the axes of the beams is maintained within 0.6-1 m.

Number of beams

The number of beams is calculated as follows: plan to place the outer beams at a distance of at least 50 mm from the walls. The remaining beams are placed evenly in the span space, in accordance with the selected interval (step).

Beam section

Beams can have a rectangular, square, round, or I-section. But the classic option is still a rectangle. Frequently used parameters: height – 140-240 mm, width – 50-160 mm.

The choice of beam section depends on its planned load, the width of the span (along the short side of the room) and the spacing of the beams (step).

The load of the beam is calculated by summing the load of its own weight (for interfloor floors - 190-220 kg/m2) with the temporary (operational) load (200 kg/m2). Typically, for exploited floors, the load is taken equal to 350-400 kg/m 2. For attic floors that are not in use, you can take a smaller load, up to 200 kg/m2. A special calculation is required if significant concentrated loads are expected (for example, from a massive bathtub, swimming pool, boiler, etc.).

The beams are laid along a short span, the maximum width of which is 6 m. Over a longer span, sagging of the beam is inevitable, which will lead to deformation of the structure. However, in such a situation there is a way out. To support beams over a wide span, columns and supports are installed.

The cross section of the beam directly depends on the width of the span. The larger the span, the more powerful (and durable) beam must be chosen for the ceiling. The ideal span for covering with beams is up to 4 m. If the spans are wider (up to 6 m), then it is necessary to use non-standard beams with a larger cross-section. The height of such beams must be at least 1/20-1/25 of the span. For example, with a span of 5 m, you need to use beams with a height of 200-225 mm and a thickness of 80-150 mm.

Of course, it is not necessary to perform beam calculations yourself. You can use ready-made tables and diagrams that indicate the dependence of beam sizes on the perceived load and span width.

After completing the calculations, you can begin installing the floor. Let's consider the whole technological process, starting with fixing the beams on the walls and ending with the finishing cladding.

Wooden floor technology

Stage #1. Installation of floor beams

Most often, beams are installed by inserting them into the grooves of the walls. This option is possible when the installation of the floor is carried out at the stage of building a house.

The installation process in this case is performed as follows:

1. Beams are coated with antiseptics and fire retardants. This is necessary to reduce the tendency of wooden structures to rot and ensure fire safety.

2. The ends of the beams are cut at an angle of 60°, painted with bitumen mastic and wrapped with roofing felt in 2 layers (for waterproofing). In this case, the end must remain open so that water vapor can escape freely through it.

3. Installation begins with the installation of two outer beams, which are placed at a distance of 50 mm from the walls (minimum).

The beams are brought into the “sockets” by 100-150 mm, leaving a ventilation gap between the wood and the walls of at least 30-50 mm.

4. To control the horizontality of the beams, install a long board along their upper plane on the edge, and a bubble level on top of it. To level the beams, wooden dies of different thicknesses are used, which are placed in the lower part of the groove on the wall. The dies must first be treated with bitumen mastic and dried.

5. To prevent the beam from creaking and block the access of cold air, the gap is filled with mineral insulation or tow.

6. The remaining intermediate beams are laid out on the laid control board. The technology for inserting them into wall nests is the same as for installing the outer beams.

7. Every fifth beam is additionally secured to the wall using an anchor.

When the house has already been built, it is easier to install floor beams using metal supports. In this case, the installation process is as follows:

1. Beams are impregnated with fire retardants and antiseptics.

2. On the walls, at the same level, in accordance with the calculated pitch of the beams, fix the supports (corners, clamps, brackets). Fastening is carried out with self-tapping screws or self-tapping screws, screwing them into the holes of the supports.

3. The beams are laid on supports and secured with self-tapping screws.

Stage #2. Fastening the cranial bars (if necessary)

If it is more convenient to lay the “pie” of the floor structure from above, that is, from the side of the second floor, cranial bars with a section of 50x50 mm are filled along the edges of the beams on both sides. The bottom of the bars should be flush with the surface of the beams. Skull bars are necessary in order to lay rolling boards on them, which are the rough basis for the ceiling.

You can do without cranial bars if you hem the bevel boards from below, from the side of the first floor. In this case, they can be attached directly to the beams using self-tapping screws (nails are not suitable, since they are difficult to drive vertically into the ceiling).

Stage #3. Attaching the reel boards for the rough base of the ceiling

When installing from the second floor side, the boards are secured to the skull blocks with nails or self-tapping screws (it is possible to use OSB or plywood).

When fastening the roll-up from the side of the first floor, the boards are secured to the beams from below using self-tapping screws. If it is necessary to lay a thick layer of insulation or soundproofing material between the beams, the option of filing the boards from below is preferable. The fact is that the cranial bars “eat up” part of the space between the beams, and without their use the thickness of the floor can be completely filled with insulating material.

Stage #4. Laying vapor barrier (if necessary)

A vapor barrier is placed in the ceiling structure in front of the insulation (which can also serve as a sound insulator), if there is a risk of steam entering it or condensation occurring. This happens if the ceiling is arranged between floors, the first of which is heated and the second is not. For example, an unheated attic or attic is installed above the first residential floor. Also, steam can penetrate into the floor insulation from wet rooms on the first floor, for example, from the kitchen, bathroom, swimming pool, etc.

The vapor barrier film is laid on top of the floor beams. The canvases are laid with an overlap, bringing the edges of the previous canvas onto the next one by 10 cm. The joints are taped with construction tape.

Stage #5. Thermal insulation or sound insulation device

Between the beams, slab or roll heat or sound insulators are laid on top. Gaps and voids must be avoided, materials must fit tightly to the beams. For the same reason, it is undesirable to use scraps that have to be joined together.

To reduce the occurrence of impact noise in the ceiling (with a residential upper floor), sound insulator strips with a thickness of at least 5.5 mm are laid on the upper surface of the beams.

Stage #6. Laying waterproofing film

A waterproofing film is laid on top of the heat or sound insulating layer. It serves to prevent the penetration of moisture from the upper floor into the insulating material. If the upper floor is non-residential, that is, no one will wash the floors there and the penetration of atmospheric moisture will also be excluded, the waterproofing film may not be used.

The waterproofing film is laid in sheets, overlapping by 10 cm. The joints are taped to prevent moisture from penetrating into the structure.

Stage #7. Fastening boards (plywood, OSB) for the subfloor

A rough base for the floor of the second floor is sewn along the beams on top. You can use regular boards, OSB or thick plywood. Fastening is carried out using self-tapping screws or nails.

Stage #8. Covering the floor from below and above with finishing coatings

On top of the rough base below and above the ceiling you can lay any suitable materials. On the upper side of the ceiling, that is, on the floor of the second floor, coverings made of laminate, parquet, carpet, linoleum, etc. are installed. When arranging the floor of a non-residential attic, the rough boards can be left without covering.

On the lower surface of the ceiling, which serves as the ceiling for the first floor, sew ceiling materials: wooden lining, plastic panels, plasterboard structures, etc.

Operation of floors

If the design used beams with a large margin of safety, laid with a small step, then such an overlap will not need repair for a long time. But you still need to check the beams for strength regularly!

If the beams are damaged by insects or as a result of waterlogging, they are strengthened. To do this, the weakened beam is removed, replaced with a new one, or strengthened with strong boards.

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

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

Wooden floor beams - dimensions and loads

Made a wooden floor in timber house, and the floor shakes, bends, a “trampoline” effect appears; we want to make wooden floor beams 7 meters long; you need to cover a room 6.8 meters long so as not to rest the logs on intermediate supports; what should be the floor beam for a span of 6 meters, a house made of timber; what to do if you want to make an open plan - such questions are often asked by forum users.

Maxinova User FORUMHOUSE

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

And such a case is far from the only one.

Elena555 User FORUMHOUSE

I can’t figure out what kind of beams are needed for the interfloor floors. I have a house 12x12 meters, 2 floors. The first floor is made of aerated concrete, the second floor is an attic, wooden, covered with timber 6000x150x200mm, laid every 80 cm. The logs are laid on an I-beam, which rests on a pillar installed in the middle of the first floor. When I walk on the second floor, I feel shaking.

Beams for long spans must withstand heavy loads, therefore, in order to build a strong and reliable wooden floor with a large span, they must be carefully calculated. First of all, you need to understand what load it can withstand. wooden joist one section or another. And then think about, having determined the load for the floor beam, what rough and finishing floor coverings will need to be made; what the ceiling will be hemmed with; whether the floor will be a full-fledged residential space or a non-residential attic above the garage.

Leo060147 User FORUMHOUSE

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

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

Therefore, when calculating the operating load, it is necessary to think through everything - right down to what kind of furniture you plan to install, and whether there is a possibility in the future of installing a sports exercise machine, which also weighs more than one kilogram.

The following values ​​are taken for the load acting on long wooden floor beams (for attic and interfloor floors):

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

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

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

Flooring with boards 200 by 50 and other common sizes

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

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

For floors 6 or more meters long, the dimensions 50x150, 50x200, 100x150 are no longer suitable.

Wooden beam over 6 meters: subtleties

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

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

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

50x200 - overlap for openings of 4 and 5 meters.

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

Leo060147 User FORUMHOUSE

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

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

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

Roracotta User FORUMHOUSE

I spent several evenings to make tables that would be understandable even to a novice builder:

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

Note: since the tables are based on American standards, and the sizes of lumber overseas are somewhat different from the sections accepted in our country, you need to use the column highlighted in yellow in the calculations.

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

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

How to calculate the distance between I-beams

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

Leo060147 User FORUMHOUSE

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

Self-production of laminated wood beams

One solution for spanning long spans is to use wooden beams in the floors. Let's consider a span of 6 meters - which beams can withstand a larger load.

By appearance cross section a long beam can be:

• rectangular;
• I-beam;
• box-shaped

None among self-builders consensus, which section is better. If we do not take into account purchased products (factory-made I-beams), then the ease of production in “field conditions”, without the use of expensive equipment and accessories, comes first.

Just Grandfather User FORUMHOUSE

If you look at a cross section of any metal I-beam, you can see that from 85% to 90% of the metal mass is concentrated in the “shelves”. The connecting wall contains no more than 10-15% of the metal. This is done based on calculation.

Which board to use for beams

According to the strength of strength: the larger the cross-section of the “shelves” and the farther they are spaced apart in height, the greater the loads the I-beam will withstand. For a self-builder, the optimal I-beam manufacturing technology is a simple box-shaped structure, where the upper and lower “shelves” are made of boards laid flat. (50x150mm, and the side walls are made of plywood with a thickness of 8-12 mm and a height of 350 to 400 mm (determined by calculation), etc.).

Plywood is nailed to the shelves or screwed with self-tapping screws (not black ones, they do not work for cutting) and must be placed on glue.

If you install such an I-beam on a six-meter span with a step of 60 cm, then it will withstand a large load. Additionally, an I-beam for a 6-meter ceiling can be lined with insulation.

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

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

To do this, the forum member purchased 12 mm thick OSB sheets and cut them lengthwise into five equal parts. Then I bought a board 150x50 mm, 8 meters long. Using a dovetail cutter, I used a dovetail cutter to select a groove 12 mm deep and 14 mm wide in the middle of the board, so as to create a trapezoid with a downward expansion. OSB in grooves Taras174 glued it in using polyester resin (epoxy), having previously “shot” a strip of fiberglass 5 mm wide to the end of the slab with a stapler. This, according to the forum member, would strengthen the structure. To speed up drying, the glued area was heated with a heater.

Taras174 User FORUMHOUSE

On the first beam I practiced “pushing my hand.” The second one was done in 1 working day. In terms of cost, taking into account all materials, I include a solid board of 8 meters, the cost of the beam is 2000 rubles. for 1 piece

Despite the positive experience, such “squatter construction” did not escape several critical remarks expressed by our experts. Namely.