6 meter floor beams. Removal of formwork when constructing concrete and reinforced concrete structures. Section and pitch of wooden floor beams

Installation of wooden beams in the floors of houses is not uncommon. Their main purpose is to evenly distribute the load on the walls and foundation of the building. To beam structure performed its functions, it is necessary to select the right material for it, calculate the length and cross-section.

All wooden beams are divided among themselves according to their purpose and the type of material from which they are made. According to their purpose, they can be: interfloor, attic, basement and basement. Depending on the type of material, beams can be made of solid wood or laminated wood.

wooden floors in aerated concrete house

The interfloor span must be strong and reliable. Sound and vapor barrier fillers are placed in the internal volume between the ceiling and floor. The ceiling part is sewn up necessary material, the floor is laid on top.

The attic floor can be installed as a roof element, being part of its rafter structure. Can be installed as a separate independent element. In order to preserve heat, it must be equipped with steam and thermal insulation.

The ceiling of the basement and ground floor must be great strength and withstand high loads. These spans are equipped with heat and vapor barriers to prevent the penetration of cold from the basement.

Beams differ in types, which have their own advantages and disadvantages.Hardwood is used to make solid beams. A significant disadvantage of solid wooden beams is the length limitation, which cannot exceed 5 meters.

Laminated timber beams combine high strength and aesthetics. Their use significantly increases the maximum length, which can be up to 20 meters. Considering that glued floors look beautiful, they are often not covered with a ceiling and serve as a design element.

They have several more significant advantages, which include:

• ability to cover large spans;
• ease of installation;
• small weight;
• long period of operation;
• high level of fire safety;
• cannot be deformed.

The wooden parts of the floor beams may have rectangular section, which is typical for timber or boards, or round, made from logs.

Requirements for wooden floor beams

Installation of wooden beam floors entails a number of requirements that must be taken into account. They are as follows:

1. Beam products must be made coniferous species wood, which have a high margin of safety. At the same time, the moisture content of the wood should be no more than 14 percent, otherwise the logs under load will have a large deflection.
2. It is prohibited to use wood that is susceptible to fungal diseases or damaged by insects to make beams.
3. Before installation, beam elements must be treated with an antiseptic.
4. To ensure that the ceiling or floor does not sag even under load, it is necessary to perform a construction lift. The ceiling of the lower floor will receive a slight rise in the center, which will become even under load.
5. If the beams are planned to be laid with great frequency, then instead of them you can use boards that need to be installed on the ribs.

The procedure for calculating wooden beams

Before installation wooden floor, it is necessary to carry out calculations in which to determine the number and dimensions of beams. To do this you need:

• determine the length of the span on which they will be installed;
• calculate the possible load they will bear after installation;
• Having the specified data, calculate the cross-section of the beams and the step with which they will be installed. For this, special tables and programs are used.

Beam length consists of the length of the span that needs to be covered and the stock of the beam that will be mounted into the wall. The span can be determined using any measuring device. The supply of beams that will be mounted in the wall depends on the material from which the wall is made.

Important!

If the building is built of brick, then the margin for beams made from boards should be at least 10 cm and at least 15 cm for beams made from timber. IN wooden buildings special grooves are made, with a depth of 7 cm or more, for laying beams. If the beams serve as the basis for the roof rafters, then they are made 4-6 cm longer than the span.

The most used span, which is covered with beams, ranges from 2.5 to 4 meters. The maximum length of beams made of timber or boards cannot exceed 6 meters. If the span length exceeds this size, then it is recommended to install beams made of laminated veneer lumber. In addition, to cover spans longer than 6 meters, you can install a wooden truss.

Load carried by a wooden beam consists of a mass of span parts (beams, internal filling, ceiling and floor coverings) and a mass of temporary elements (furniture, Appliances, people present in the room).

Accurate calculations of the load-bearing capacity of beams are usually carried out by specialized organizations. At independent execution The following system is used for calculation:

• an attic floor with a lining, in which the insulation is mineral wool, carries a constant self-load of 50 kg per square meter. With such a load, according to SNiP standards, standard load will be 70 kg per square meter with a safety factor of 1.3. Finding out the total load is not difficult: 1.3x70+50=130 kilograms per square meter;
• if a heavier material than cotton wool is used as insulation, or thick boards were used as lining, then the standard load will be 150 kg per square meter. And the total load will have a different value: 150x1.3+50=245 kg per square meter;
• if the calculation is carried out for attic room, then the weight of the material from which the floor is laid and the objects located in the attic is taken into account. The load in this case will be 350 kg per square meter;
• in the case where the beams serve as interfloor spans, the calculated load is 400 kg per square meter.

Calculation of wooden floor beams

Determination of the section and pitch of wooden beams

By calculating the load and length of the beams, you can determine their pitch and cross-sectional dimensions or diameter.

These indicators are interrelated and are calculated according to established rules:

1. The width and height of the beams should be in proportion 1:1.,4. In this case, the width of the beams should be in the range from 4 to 20 cm, and the height from 10 to 30 cm, taking into account the thickness insulation material. Logs for floors should have a diameter in the range from 11 to 30 cm.
2. The installation step should be in the range from 30 to 120 cm, taking into account the insulation and lining materials that will be in the space between the beams. If the structure is frame, then the step should correspond to the distance between the frames.
3. The cross-section of wooden beams is determined using developed tables or using certain programs. When calculating sections, it is necessary to take into account that the maximum bending attic beams should not exceed 1/200, and between floors 1/350.

Application of wooden trusses, advantages and disadvantages

Floor trusses made of wood look like two parallel logs or bars located above each other, which are connected to each other by supports located at an angle or vertically in relation to these logs or bars. The main task that trusses solve is covering long spans, if the installation of additional support posts impossible.

For the manufacture of trusses, developed tables and programs are used, which take into account the type of connections, installation pitch, cross-section of structural parts and its overall dimensions. Often, trusses are manufactured industrially using high-precision equipment. Along with this, you can make a farm with your own hands.

By comparing wooden beams and floor trusses, you can determine the advantages and disadvantages that the trusses have. The advantages include:

• the ability to cover a span of significant size without additional support posts;
• insignificant mass, which entails a small load on the load-bearing elements of the building;
• high strength and resistance to deflection, which entails long-term operation of lining and flooring materials;
• ease of installation on any load-bearing elements of the building, regardless of the material from which they are made;
• the ability to change the width of the truss laying step;
• possibility of installing internal communication lines;
• excellent sound insulation;
• beautifully made trusses can be left unsewn and used as a decorative element.

In addition to advantages, farms have some disadvantages, which include the following:

• due to design features, the thickness of interfloor ceilings increases significantly;
• significant labor costs when making a farm with your own hands, the need for special equipment;
• high price for a finished structure.

Wood truss design

Beams in a house usually belong to rafter system or overlap, and to get reliable design, the operation of which can be carried out without any fear, must be used beam calculator.

What is the beam calculator based on?

When the walls have already been brought under the second floor or under the roof, it is necessary to make, in the second case, smoothly turning into rafter legs. In this case, the materials must be selected so that the load on the brick or log walls did not exceed the permissible limit, and the strength of the structure was at the proper level. Therefore, if you are going to use wood, you need to choose the right beams from it, make calculations to find out required thickness and of sufficient length.

Subsidence or partial destruction of the ceiling may be caused by different reasons, for example, too large a pitch between the joists, deflection of the cross members, too small cross-sectional area or defects in the structure. To eliminate possible excesses, you should find out the expected load on the floor, be it basement or interfloor, and then use a beam calculator, taking into account their own weight. The latter can change in concrete lintels, the weight of which depends on the density of the reinforcement; for wood and metal, with a certain geometry, the weight is constant. The exception is damp wood, which is not used in construction work without pre-drying.

On beam systems in floors and rafter structures load is exerted by forces acting on section bending, torsion, and deflection along the length. For rafters it is also necessary to provide snow and wind load, which also create certain forces applied to the beams. You also need to accurately determine the required step between the jumpers, since too many crossbars will lead to excess weight of the floor (or roof), and too little, as mentioned above, will weaken the structure.

You may also be interested in the article about calculating the amount of unedged and edged boards cubed:

How to calculate the load on a floor beam

The distance between the walls is called a span, and there are two of them in the room, and one span will necessarily be smaller than the other if the shape of the room is not square. Interfloor or attic floor lintels should be laid along a shorter span, the optimal length of which is from 3 to 4 meters. Longer distances may require beams non-standard sizes, which will lead to some instability of the flooring. The best solution in this case would be to use metal crossbars.

Regarding the section wooden beam, there is a certain standard that requires that the sides of the beam be in a ratio of 7:5, that is, the height is divided into 7 parts, and 5 of them must make up the width of the profile. In this case, deformation of the section is excluded, but if you deviate from the above indicators, then if the width exceeds the height, you will get a deflection, or, if the opposite discrepancy occurs, a bend to the side. To prevent this from happening due to the excessive length of the beam, you need to know how to calculate the load on the beam. In particular, the permissible deflection is calculated from the ratio to the length of the lintel as 1:200, that is, it should be 2 centimeters per 4 meters.

To prevent the beam from sagging under the weight of logs and flooring, as well as interior items, you can grind it from below a few centimeters, giving it the shape of an arch; in this case, its height should have an appropriate margin.

Now let's turn to the formulas. The same deflection mentioned earlier is calculated as follows: f nor = L/200, where L is the span length, and 200 is the permissible distance in centimeters for each unit of beam subsidence. For reinforced concrete beam, distributed load q which is usually equated to 400 kg/m 2, the calculation of the limiting bending moment is performed using the formula M max = (q · L 2)/8. In this case, the amount of reinforcement and its weight is determined according to the following table:

Cross-sectional areas and mass of reinforcing bars

The load on any beam made of a sufficiently homogeneous material is calculated using a number of formulas. To begin with, the moment of resistance W ≥ M/R is calculated. Here M is the maximum bending moment of the applied load, and R – design resistance, which is taken from reference books depending on the material used. Since most often beams have rectangular shape, the moment of resistance can be calculated differently: W z = b h 2 /6, where b is the width of the beam, and h– height.

What else should you know about beam loads?

The ceiling, as a rule, is at the same time the floor of the next floor and the ceiling of the previous one. This means that it needs to be made in such a way that there is no risk of combining the upper and lower rooms by simply overloading the furniture. This probability especially arises when the step between the beams is too large and logs are abandoned (plank floors are laid directly on the timber laid in the spans). In this case, the distance between the crossbars directly depends on the thickness of the boards, for example, if it is 28 millimeters, then the length of the board should not be more than 50 centimeters. If there are lags, the minimum gap between the beams can reach 1 meter.

It is also necessary to take into account the mass used for the floor. For example, if mineral wool mats are laid, then a square meter of the basement floor will weigh from 90 to 120 kilograms, depending on the thickness of the thermal insulation. Sawdust concrete will double the mass of the same area. The use of expanded clay will make the flooring even heavier, since the load per square meter will be 3 times greater than when laying mineral wool. Further, we should not forget about the payload, which for interfloor ceilings is at least 150 kilograms per square meter. In the attic it is enough to take permissible load 75 kilograms per square.

In order to build a reliable wooden floor, it is necessary to select the correct dimensions of the beams, and for this it is necessary to calculate them. Wooden beams ceilings have the following main dimensions: length and cross-section. Their length is determined by the width of the span that needs to be covered, and the cross-section depends on the load that will act on them, on the length of the span and the installation pitch, that is, the distance between them. In this article we will look at how to independently make such a calculation and select the correct beam sizes.

Calculation of wooden floor beams

In order to determine how many wooden beams and what sizes will be required for the floor installation, you must:

• measure the span that they will cover;
• decide on ways to secure them on the walls (to what depth they will go into the walls);
• make a calculation of the load that will act on them during operation;
• using tables or a calculator program, select the appropriate pitch and section.

Now let's look at how this can be done.

Length of wooden floor beams

The required length of floor beams is determined by the size of the span that they will cover and the margin required to embed them in the walls. The length of the span is easy to measure using a tape measure, and the depth of embedding in the walls largely depends on their material.

In houses with brick or block walls, beams are usually embedded in “sockets” to a depth of at least 100 mm (board) or 150 mm (timber). IN wooden houses They are usually placed in special notches to a depth of no less than 70 mm. When using a special metal fastening(clamps, angles, brackets) the length of the beams will be equal to the span - the distance between the opposite walls on which they are attached. Sometimes, during installation rafter legs roofs directly onto wooden beams, they are released outside, beyond the walls by 30-50 cm, thus forming a roof overhang.

The optimal span, which can overlap wooden beams, is 2.5-4 m. Maximum length beams made of edged boards or timber, that is, the span that it can cover is 6 m. When longer length span (6-12 m), it is necessary to use modern wooden beams made of laminated veneer lumber or I-beams, and you can also rest them on intermediate supports (walls, columns). In addition, to cover spans longer than 6 m, wooden trusses can be used instead of beams.

Determination of the load acting on the floor

The load acting on the floor along wooden beams consists of the load from the own weight of the floor elements (beams, inter-beam filling, lining) and permanent or temporary operational load (furniture, various household devices, materials, weight of people). It usually depends on the type of floor and its operating conditions. The exact calculation of such loads is quite cumbersome and is carried out by specialists when designing the floor, but if you want to do it yourself, you can use its simplified version given below.

For an attic wooden floor, which is not used for storing things or materials, with light insulation (mineral wool or others) and sheathing, the constant load (from its own weight - Rown) is usually taken within 50 kg/m2.

The operational load (Rexpl.) for such an overlap (according to SNiP 2.01.07-85) will be:

70x1.3 = 90 kg/m2, where 70 – normative meaning load for this type of attic, kg/m2, 1.3 – safety factor.

The total design load that will act on this attic floor will be:

Rtot.=Rown.+Rexpl. = 50+90=130 kg\m2. Rounding up we take 150 kg/m2.

In case the design attic space heavier insulation, material for inter-beam filling or lining will be used, and if it is intended to be used for storing things or materials, that is, it will be used intensively, then the standard load value should be increased to 150 kg/m2. In this case, the total load on the floor will be:

50+150x1.3 = 245 kg/m2, round up to 250 kg/m2.

Using attic space to construct an attic, it is necessary to take into account the weight of floors, partitions, and furniture. In this case, the total design load must be increased to 300-350 kg/m2.

Due to the fact that an interfloor wooden floor, as a rule, includes floors in its design, and the temporary operating load includes weight large quantity household items and the maximum presence of people, then it should be designed for a total load of 350 - 400 kg/m2.

Section and pitch of wooden floor beams

Knowing the required length of wooden floor beams (L) and determining the total design load, you can determine their required cross-section (or diameter) and laying step, which are interconnected. It is believed that the best is a rectangular section of a wooden floor beam, with a ratio of height (h) and width (s) of 1.4:1. The width of the beams, in this case, can be in the range of 40-200 mm, and the height 100-300 mm. The height of the beams is often chosen so that it matches required thickness insulation. When using logs as beams, their diameter can be in the range of 11-30 cm.

Depending on the type and cross-section of the material used, the pitch of the wooden beams the ceiling can be from 30 cm to 1.2 m, but most often it is chosen within the range of 0.6-1.0 m. Sometimes it is chosen so that it matches the size of the insulation boards laid in the interbeam space, or ceiling sheets. In addition, in frame buildings, it is desirable that the pitch of laying the beams corresponds to the pitch of the frame posts - in this case the greatest rigidity and reliability of the structure will be ensured.

You can calculate or check the already selected dimensions of wooden floor beams using reference tables (some are given below) or using online calculator"calculation of wooden floor beams", which is easy to find on the Internet by typing in the corresponding request in a search engine. It is necessary to take into account that their relative deflection for attic floors should not be more than 1/250, and for interfloor floors - 1/350.

Table 1

table 2

Table 3

Table 4

Among the many structural elements In a private house, the ceiling is one of the most important and difficult components to design and install. This is where inexperienced builders make, perhaps, the most dangerous mistakes; it is about the arrangement of this system that the most questions are asked.

1. Why choose a tree

In any building, the ceiling is a horizontal structure that serves as the basis for creating the floor. In addition, being connected to the load-bearing walls of the house, it provides lateral stability to the structure, evenly distributing possible loads. Therefore, the highest demands are placed on the reliability of this design.

Regardless of what material is used in the construction of a house, wooden floors are most widespread in the private sector. They can often be seen in various stone cottages, and it is quite obvious that in wood construction(logs, beams, frame and frame-panel technology) there is no alternative to such a solution. There are many objective reasons for this. Let's look at the advantages and disadvantages of wood floors.

In private low-rise construction ceilings are mounted in several options:

• Ready reinforced concrete slab,
• Monolithic reinforced concrete slab,
• Ready-made reinforced concrete beams,
• Beams and trusses made of rolled metal,
• Flooring made of lumber.

pros

Or why wooden floors are so popular.

• Small mass. When using a board or beam, we do not overload load-bearing walls and foundation. The weight of the ceiling is several times less than that of concrete or metal structures. Usually no technology is required.
• Minimum deadlines for completing work. Minimum labor intensity among all options.
• Versatility. Suitable for any building, in any environment.
• Possibility of installation at sub-zero and very high temperatures.
• No “wet” or dirty processes.
• Possibility of obtaining any level of thermal insulation and sound insulation characteristics.
• Possibility of using cavities for gaskets engineering communications(power grid, heating, water supply, sewerage, low current...).
• Relatively low price of prefabricated frame floor from lumber, both in terms of the cost of parts/components and the contractor’s wages.

Minuses

The disadvantages of a wooden ceiling system made of wood are quite conventional.

• Difficulty in choosing the cross-section of materials and constructive solutions to ensure the calculated load-bearing capacity.
• The need to carry out additional fire prevention measures, as well as provide protection from moisture and pests (antiseptic treatment).
• The need to purchase soundproofing materials.
• Strict adherence to technology to avoid construction errors.

2. What material to use for assembly

Wooden flooring always consists of beams. But they can be made from a variety of lumber:

• Rounded log up to 30 cm in diameter.
• The beam is four-edged.
• Large section board (thickness from 50 mm, width up to 300 mm).
• Several boards of relatively small thickness, twisted face to face.
• I-beams, top and bottom belt which are made of edged planed boards/bars, and the vertical wall is made of OSB-3, plywood or profiled metal (wood-metal product).
• Closed boxes made of sheet materials (plywood, OSB).
• SIP panel. In essence, these are separate sections in which the beams are already sheathed and have an insulator inside.
• Various truss designs, allowing to cover large spans.

The easiest options for installation, as well as the cheapest and most convenient for subsequent operations, are those where the floor beams are made of edged lumber.

Due to the very high requirements for load-bearing capacity, durability and geometric deviations, first-grade lumber must be considered as blanks. It is possible to use products classified as second grade according to GOST, which do not have critical geometric deviations, defects and processing defects that can reduce strength characteristics and service life finished parts(through knots, twists, cross-layers, deep extended cracks...).

In these structures, the use of dead wood (dead wood, dead wood, burnt wood) is excluded due to insufficient strength and multiple damage to wood-destroying diseases and insects. Also big mistake will buy a beam or board “with air”, “with Armenian size”, “TU” - due to the reduced sections.

This should be exclusively healthy material from green spruce or pine, since needles, due to their resin content and solid structure, can withstand bending loads and compression much better than most hardwoods, and having a relatively low specific gravity.

Anyway edged lumber must be freed from remnants of bark and bast fibers, treated with an antiseptic and fire retardant. Dry planed lumber will perform best here, but the material natural humidity(up to 20 percent) during normal processing are also actively (and most importantly - effectively) used, especially since the price edged timber or boards of this type are noticeably lower.

3. How to choose the size of beams and at what step to arrange them

The length of the beam is calculated in such a way that it covers the existing span and has a “margin” to provide support on load-bearing walls (read below for specific figures for permissible spans and wall penetration).

The cross-section of the board/beam is determined depending on the design loads that will be exerted on the floor during the operation of the building. These loads are divided into:

• Permanent.
• Temporary.

Temporary loads in a residential building include the weight of people and animals that can move along the floor, moving objects. TO constant loads include the mass of the lumber of the structure itself (beams, joists), floor filling (insulation/noise insulation, insulating sheets), hemming (rolling), rough and finishing flooring, finishing flooring, partitions, as well as built-in communications, furniture, equipment and household items...

Also, you should not lose sight of the possibility of storing objects and materials, for example, when determining the load-bearing capacity of the floors of a non-residential cold attic, where unnecessary, rarely used things can be stored.

The sum of the dead and live loads is taken as a starting point, and a safety factor of 1.3 is usually applied to it. Exact figures (including the cross-section of lumber) must be determined by specialists in accordance with the provisions of SNiP 2.01.07-85 “Loads and Impacts”, but practice shows that the load values ​​in private houses with wooden beams are approximately identical:

• For interfloor (including under a residential attic) and basement floors total load is about 350 - 400 kg/m2, where the share of the structure’s own weight is about 100 kilograms.
• For covering an unloaded attic - about 130 - 150 kg/m2.
• To cover the loaded non-residential attic up to 250 kg/m2.

It is obvious that unconditional safety is of paramount importance. Here a good margin is taken into account and the option is considered not so much of distributed loads on the entire floor (in such quantities they are practically unrealistic), but rather the possibility of a local load that can lead to deflections, which in turn caused:

• physiological discomfort of residents,
• destruction of components and materials,
• loss of aesthetic properties of the structure.

By the way, certain deflection values ​​are allowed regulatory documents. For residential premises, they can be no more than 1/350 of the span length (that is, 10 mm at 3 meters or 20 mm at six meters), but provided that the above limiting requirements are not violated.

When choosing the cross-section of lumber to create a beam, they are usually guided by the ratio of the width and thickness of the beam or board in the range of 1/1.5 - 1/4. Specific figures will depend, first of all, on: loads and span lengths. When designing yourself, you can use data obtained from calculations using online calculators or publicly available tables.

Optimal average cross-section of wooden floor beams, mm

As we can see, to enlarge load-bearing capacity ceilings - it is enough to choose lumber with a larger width or greater thickness. It is also possible to assemble a beam from two boards, but in such a way that the resulting product has a cross-section no less than the calculated one. It should also be noted that the load-bearing properties and stability of a wooden floor increase if logs or various types of subfloors (sheet flooring made of plywood/OSB or edged boards) are used on top of the beams.

Another way to improve the strength properties of a wooden floor is to reduce the spacing of the beams. Engineers in their projects of private houses determine different conditions the distance between the beams is from 300 mm to one and a half meters. IN frame construction The pitch of the beams is made dependent on the spacing of the posts, so that there is a post under the beam, and not just a horizontal frame run. Practice shows that the most appropriate from the point of view of practicality and cost of construction is a step of 600 or 1000 mm, since it is best suited for the subsequent installation of insulation and noise insulation by surprise ( insulation materials slabs and rolls have just such a form factor). This distance also creates optimal distance between support points for mounting floor joists installed perpendicular to the beams. The dependence of the cross section on the pitch is clearly visible from the numbers in the table.

Possible cross-section of floor beams when changing the pitch (total load per square meter is about 400 kg)

4. How to properly install and secure beams

We have decided on the step - from 60 centimeters to a meter will be the golden mean. As for spans, it is best to limit yourself to 6 meters, ideally: four to five meters. Therefore, the designer always tries to “lay” the beams along the smaller side of the house/room. If the spans are too large (more than 6 meters), then they resort to installing load-bearing walls or support columns with crossbars inside the house. This approach makes it possible to use lumber of a smaller cross-section and increase the spacing, thereby reducing the weight of the floor and its cost for the customer with the same (or better) load-bearing characteristics. As an option, trusses are created from lighter lumber using metal perforated fasteners, for example, nail plates.

In any case, the beams are placed strictly horizontally, parallel to each other, maintaining the same pitch. The wooden beam must rest on load-bearing walls and purlins by at least 10 centimeters. As a rule, use 2/3 thickness outer wall from the side of the room (so that the end of the beam does not go out onto the street and remains protected from freezing). IN wooden walls they make a cut, in stone ones they leave openings during laying. In places where the beams of supporting structures touch, it is necessary to lay insulating materials: damping elastic pads made of rubber/felt, several layers of roofing felt as waterproofing, etc. Sometimes they use firing of sections of the beam that are subsequently hidden or coating them with bitumen mastics/primers.

Recently, special perforated brackets “beam holders/supports” have been increasingly used to create floors, which allow the beam to be mounted end-to-end with the wall. With help of this type brackets are also assembled assemblies with transverse crossbars and beams truncated in length (opening for flight of stairs, chimney passage, etc.). The advantages of this solution are obvious:

• The resulting T-shaped connection is very reliable.
• The work is done quickly (there is no need to make cuts, it is much easier to set a single plane).
• No cold bridges are formed along the body of the beams, because the end is moving away from the street.
• It is possible to buy lumber of shorter length, since there is no need to insert the timber/board inside the wall.

In any case, it is very important, after adjusting the lumber to size, to thoroughly antisepticize the end of the beam.

5. What insulating layers should be used inside wooden floors

To answer this question, first of all, it is necessary to divide the overlapping structures (in a year-round habitable house) into three separate types:

• Basement ceiling,
• Interfloor,
• Attic.

In each specific case, the set of pie will be different.

Interfloor ceilings in the vast majority of cases separate rooms in which temperature regime similar or close in value (if there is room/floor/zone adjustment heating system). These also include the attic floor, which separates the residential attic, since this room is heated, and the insulation is located inside roofing pie. For these reasons, thermal insulation is not needed here, but the issue of combating noise, airborne (voices, music...) and shock (steps, rearranging furniture...) becomes very relevant. As sound insulation, acoustic fibrous materials based on mineral wool are laid in the ceiling cavity, and sheets of sound-proofing membranes are also laid under the sheathing.

The basement design assumes that under the ceiling there is soil or a basement, cellar, or ground floor. Even if the room below is equipped for use, this type of floor requires full insulation, characteristic of the enclosing structures of a particular climate zone and a specific building with its unique thermal balance. According to standards, the average thickness for the Moscow region modern insulation With good performance thermal conductivity will be about 150-200 mm.

Similar thermal insulation requirements apply to attic floor, above which there is no heated attic, because it will be the main barrier to heat loss through the roof of the building. By the way, due to the greater heat flow through top part at home, the thickness of the insulation here may be required more than in other places, for example, 200 mm instead of 150 or 250 mm instead of 200.

They use polystyrene foam, EPS, mineral wool with a density of 35 kg/m3 in slabs or cut into mats from a roll (one that is allowed for use in non-load-bearing areas is suitable horizontal structures). Thermal insulation is laid between the beams, usually in several layers, with the joints bandaged. The load from the insulation is transferred to the beam through the rough hemming (often it is attached to the beams using cranial bars).

Where watt insulation/sound insulation is used in structures, it should be protected from moisture. In the basement, moisture can rise in the form of evaporation from the ground or from the basement/cellar. IN interfloor ceilings and attics, water vapor can enter, which always saturates the air in residential premises during human daily activities. In both cases, underneath the insulation you need to lay construction material vapor barrier film, which can be ordinary or reinforced polyethylene. But, if thermal insulation is performed using extruded polystyrene foam, which does not have any significant level of water absorption, then a vapor barrier will not be needed.

Insulation and fiber on top soundproofing materials protected with waterproof sheets, which can be membranes or non-perforated waterproofing.

A reliable water barrier is especially relevant in rooms with high humidity: kitchen, laundry room, bathroom... In such places it is spread on top of the beams, always with the strips overlapping by 100-150 mm and gluing the seam. Canvases around the entire perimeter of the premises in mandatory placed on the wall - to a height of at least 50 mm above the finishing coating.

The ceiling, which will later be lined tiles, it makes sense to supplement with a rough flooring made of waterproof sheet materials - various types cement-containing slabs, preferably tongue-and-groove. On such a continuous flooring you can carry out additional coating waterproofing, perform thin-layer leveling of the plane with a leveling compound or lay the tiles immediately.

You can choose another option - assemble a continuous flooring from edged boards, lay a hydraulic barrier, pour a thin-layer screed (up to 30 mm), and install tiles.

There are also modern adhesive compositions(and elastic grouts) allowing tiling wooden bases, including movable and heated ones. Therefore, tiled floors are often sold here on moisture-resistant plywood or OSB.

Important! Taking into account the increasing loads (general or local - a large bathtub, a Jacuzzi bowl, a floor-standing boiler...), the calculation of the cross-section and pitch of beams under such rooms must be performed individually.

If desired, floors in the bathroom or kitchen wooden house can be equipped with a heating cable or pipes of the water circuit of the heating system. They are mounted both in screeds and a layer of tile adhesive, and between joists in a deliberately created air gap. With any chosen option, the ceiling must be well insulated so as not to heat the ceiling of the room from below, preferably equipped with waterproofing with a reflective foil layer.

01.10.2010, 11:47

calculation:
1) beam 200*200*6000 through 0.5M = 22 t.r (deflection 20 mm)
2) I-beam 20B h/w 1.2 m = 27 tr. (deflection 20 mm)

By weight 1) -90 kg timber, 2) - 120 kg beam

In theory, the solutions are very similar. I'm interested in practice, which is better?

Green Cat

01.10.2010, 11:55

Beam.
You shouldn't do any work with iron at all. bearing structures for in a fire, wood holds out to the last, and iron is grunted and ready.

01.10.2010, 15:55

The temperature at which the I-beam will deform is incompatible with life. Especially if the bottom is covered with plasterboard.

If you still decide to make it with wood, then I recommend 200x60x6000 with a step of 600 mm.

01.10.2010, 16:55

“it’s a mess and it’s done” - but it won’t matter anyway)))

It can be deformed in one place and fly to another, where there are still conditions for life... :) but in general you are right.
+Wood itself will support combustion, but iron will not...

Green Cat

01.10.2010, 17:41

The temperature at which the I-beam will deform is incompatible with life.
Wrong.
It’s one thing when he’s on his own, and another when he’s under load.

Until recently, it was generally prohibited to use meth as rafters. profile, now I see they are doing it with all their might.

I recommend 200x60x6000 with a pitch of 600 mm
It will be too small, too small - let's look at the cuckulator.

01.10.2010, 20:32

In one room I had a span of 5.7 meters, the overlap between the 1st and 2nd floors. I chose an I-beam 20B at 1.3 meters, it seems that according to calculations the I-beam was stronger than wood. It is worth considering that a tree can be found 6.5 meters long, and the length of an I-beam is 11.7 meters or 12 meters (to cover a span of 6 meters you need at least 15 cm on one side). It would have been better to lay the slabs, but I didn’t succeed. The difference between the tree and the I-beam was somewhere around 10-12%. When laying the walls, I installed 3 cm of foam between the cutout in the gas block and the I-beam.
Regarding the fire, you need to take precautions.

02.10.2010, 00:47

And I laid a 5.8 meter reinforced concrete slab on the 6 m span and don’t think about anything else. Doesn't burn, doesn't melt, doesn't bend...

02.10.2010, 09:00

Thanks to everyone, I’m still leaning towards an I-beam, since it’s stronger, I want to install 100 cm internal walls made of foam block for the ceiling. (although it was probably possible to put 2 beams under the wall)
then wawan001 the span is 6M along the axes of the walls, that is, there will be 15 cm of support on each side.
then Cat, I guess if you fall asleep non-flammable insulation ala expanded clay, then there will be nothing to burn there at all (the house is made of foam block).

And another question, if you cover it with an I-beam, is it possible to use, say, a 50 piece of wood attached to the side walls instead of the outer beams??

02.10.2010, 18:30

There is another option.

02.10.2010, 19:12

There is another option.
You make a load-bearing beam (albeit from an I-beam), on which you lay simple wooden floor beams. It will be much cheaper.
You will need one or two I-beams, but powerful ones. The price will still be cheaper.

I did it to myself

02.10.2010, 20:01

dengt, this idea came to my mind from the point of view of the manufacturability of installing floors in the future, if wooden floors are installed inside the I-beam, and a counter-lattice is made on top (beams according to calculations). The distance from the edge of the beam to the I-beam is 40 cm - reliable. After all, according to calculations, the load on the outermost beams is 2 times less than on the adjacent one, you can put a 150x200 beam or take 2 pieces of 50x200 boards and between them install pieces of boards of the same size 1.5 meters long, and I think 50 is flimsy, although if to It can be attracted to the wall and it will be fine. If you are confident in the fasteners, then probably yes.

04.10.2010, 05:57

I covered the span with a 5m beam of 150*150, folded in half and tied with pins, i.e. The result is a beam 150*300. It turned out pretty tough, but I would still make it out of concrete if possible :(

05.10.2010, 09:32

[
I did it to myself
the span is 11 by 6, divided into three parts by two I-beams and laid wooden beams, and in order not to increase the thickness of the ceiling, laid them inside the T-beam. I first welded the corners to the tee and secured the beams with bolts.

As I understand it, the I-beams were 6 meters high?
here you need at least 25B2, it’s a 5 cm thicker covering, it doesn’t seem to be fatal.

What worries me about attaching the side beams to the walls is that all the other beams will sag, but the outer ones will not, then the floor will bend in a “bubble”? What will this lead to?

05.10.2010, 10:11

6-measure I-beam 20B1 - two pieces across the length, it turned out 3 zones, two with beams resting on one side on the wall, and the other on the I-beam, and one zone with beams sandwiched between the I-beams. I didn’t notice any flexing; the I-beam doesn’t work at that length.

06.10.2010, 13:06

06.10.2010, 13:47

depending on how you load it, if according to theory it’s 400 kg/m then in your case the 20B1 will bend by 77 mm

I wonder how you calculated this?