Wooden houses have long established themselves as environmentally friendly and long-lasting housing. The proof of this is the buildings, which are about 100 years old. For erection, a bar is more often chosen, it can be unprofiled, profiled and glued.
For floors, the same wood is selected that was used during construction, a metal channel is less commonly used. Each material has both advantages and disadvantages. The long-term operation of the house depends on the quality and method of laying the floors. The following information will help you understand the specifics and nuances.
Overlapping is a structure that separates:
Thus, the upper part of the ceiling serves as the basis for the floor, and the lower part for the ceiling. For houses made of timber, a beam structure is used, since not a single wooden structure can withstand the weight of solid reinforced concrete slabs.
The ceiling must meet certain strength requirements, that is, withstand the load, which is played by people, furniture and other interior items. In addition, the structure must also be rigid, preventing deflection of the beam elements.
Metal floor beams
Metal beams are reliable and durable. Due to their increased strength and correspondingly smaller thickness, they save space. I-beam structures, channels or corners can be used here.
Advantages:
Disadvantages:
To install metal beams, special equipment is used, which is not advisable when erecting low-rise individual buildings.
Wooden floor beams
In most cases, when building houses from various materials, floor beams from a bar are used. More often they are harvested from coniferous trees, less often there is a beam from a hardwood massif.
Advantages:
Disadvantages:
However, processing with special preparations increases resistance to fire and biological influences.
For the construction of attic structures, logs are often used, which, depending on the diameter, are characterized by high bending strength.
It is worth noting separately glued timber beams, which, due to its special structure, significantly increases the span width limitation. Such elements withstand increased load. The beam has a beautiful appearance, which makes it possible to leave them open, creating an accent when creating an interior in country style.
The span is covered with beams along a short wall. First, the end bars are laid, then the distance between them is evenly distributed. The step directly depends on the section of the beams used, usually the thickness of the cross member should be 1/25 of its length. So, for example, if you need a floor beam 4 m long, then its width should be at least 160 mm.
For intermediate floors
For attic floors:
If it is not possible to purchase a floor beam of the desired size, then it is allowed to replace it with two boards, where the total thickness is equal to the cross section of the beam. Lumber must be fastened together with nails or screws in increments of 20 cm in a checkerboard pattern, this design will withstand a double load.
| Log diameter, mm | Span width, mm | |||||||||
| 3 000 | 3 500 | 4 000 | 4 500 | 5 000 | 5 500 | 6 000 | 6 500 | 7 000 | 7 500 | |
| 170 | 1 000 | 800 | 600 | --- | --- | --- | --- | --- | --- | --- |
| 210 | --- | --- | 1 000 | 800 | 600 | --- | --- | --- | --- | --- |
| 250 | --- | --- | --- | --- | 1 000 | 800 | 800 | 600 | --- | --- |
| 290 | --- | --- | --- | --- | --- | --- | --- | 1 000 | 800 | 800 |
| 310 | --- | --- | --- | --- | --- | --- | --- | --- | 1 000 | 800 |
| 330 | --- | --- | --- | --- | --- | --- | --- | --- | --- | 1000 |
The moisture content of lumber should not exceed 14%.
General rules for laying floor beams:
Having correctly calculated the technical characteristics of the beams, and following simple rules, the construction of individual elements of the house, in particular floors, will not create any difficulties.
The main element of attic and interfloor ceilings in many private houses is a wooden beam.
One of the elements that can withstand the entire load of the floor is the beam. The integrity and durability of the floor between floors will depend on how correctly it was installed and the bearing capacity was calculated.
A beam made of wood remains popular when equipping floors between floors. But they, like any building material, are endowed with their positive and negative qualities. Consider the characteristics.
The positive characteristics of wooden beams include the following:
Timber beams in homes are often the most economical option. The disadvantages of this building product include the following:
When installing wooden beams, a number of requirements must be met. Violation or failure to comply with these requirements may lead to negative consequences. The requirements state that:
When planning to mount a wooden floor, you need to calculate the required number of beams and their dimensions.
For this you need:
Installation of wooden floor beams The size of the beam is the sum of the total values. These quantities include:
The span is determined using measuring accessories, such as a tape measure. Depending on the material from which the wall is made (wood, concrete, brick, etc.), the depth of laying the beams will depend.
Wooden beams are structural elements with load-bearing functions If the building is brick, then the margin for wooden beams should be more than 10 cm. If the building is built of wood, then specific grooves are made under the beam span for the second floor, which have a depth of 6-10 cm. In the case when wooden structures are intended to become the basis for truss system, they should be 5-7 cm longer than the span of the building.
Important!
The overlap with wooden beams should be between 2.5 and 4 m. The maximum span should not exceed six meters. If the overlap exceeds this value, then glued beam structures are installed.
Installation of floor beams is an important and crucial stage of construction The load, like the size of the beams, consists of the sum of several elements. This is the total mass of span elements and interior details that will be located in the upper floor room. The elements that are included in the overlap between floors include logs, insulation, floor and ceiling coverings, vapor and waterproofing. Interior elements include furniture, household appliances. This also includes the possible number of residents who will constantly use the floor. Often, the calculation of loads is carried out by special institutions.
For self-calculation of the bearing capacity, the following scheme is used:
Wooden floor construction Having decided on the magnitude of the load that will fall on the beam and, having calculated its length, you can calculate the installation step and the size of the section (or diameter). These quantities are related relative to each other and are designated according to established standards:
To increase the rigidity of the floor, wooden beams are reinforced with spacers. Regardless of the material from which the flooring will be made, logs must be installed in the inter-beam space. What is it and what are they for? They can be called cross beams. Logs are installed perpendicular to the main beam ceilings. Serve to increase the rigidity of the overlap between floors and reduce the load. Ceiling and floor coverings are attached to them.
The advantages of using lag are obvious:
Logs are the transverse beams of the floor along which the floor covering is laid. The production of logs is carried out from wooden beams with a rectangular section. The cross section of the lag is in the ratio of width and height, like 2 to 3 or 1 to 2. In other words, the height of the lag should exceed its width by 1.5-2 times. For the production of logs, cheap coniferous wood is often used. For example, a pine tree or a Christmas tree. The bar is cut to the required length and a lag is obtained.
Important!
Wood for logs must be dried, without defects, treated with a special refractory solution, liquid from pests and fungal diseases.
Material for lag The installation of the lag must be carried out in a direction perpendicular to the direction in which the floor covering will be laid. It is important to correctly calculate the installation step of the lag. If the step is chosen correctly, then the strength of the flooring will be quite high. But, with a smaller step, the performance of work and the cost of the material will be more expensive. If the laying step is large, then the floor will sag and creak. To choose the right option, you must first take into account how thick the flooring will be. The thinner the coating, the closer to each other the installation of the log should be carried out. If the thickness of the floor covering (boards) is about 2-2.5 cm, then the installation step of the log should be within 30-40 cm. With an increase in the thickness of the coating to 5 cm, the step can be increased to 1 m.
When laying logs on wooden floors, it is better to attach them to the sides of the beams. Logs are attached directly to the beam, to its side. This makes it possible to carry out their adjustment without using additional linings. Their slope is checked by a special level. Having achieved the required position, the logs are attached to the beams with nails or screws.
In addition, the fastening of logs and beams to each other can be carried out using iron corners. One part of the corner is mounted on the beam with screws, logs are attached to the second parts of the corners. In addition to the corners, brackets in the form of the letter P, which are commercially available, can be used for mounting the log.
Laying a wooden floor on logs has a lot of advantages: simplicity of the process, ease of replacing individual elements When building your own house or cottage, wooden beam floors will be a good substitute for concrete floors. Work on their installation can be performed independently, without the involvement of special equipment. The presence of a lag in the interfloor overlap will increase the rigidity of the floor. Their presence will give the reliability of the entire structure. If everything is calculated and executed correctly, then the interfloor overlap on wooden beams will last a long time.
Interfloor ceiling in aerated concrete house
Wooden floors in a house made of timber: how not to do it
Ksenia Skvortsova. Chief Editor. Author.
Planning and distribution of responsibilities in the content production team, work with texts.
Education: Kharkov State Academy of Culture, specialty “Culturologist. Lecturer in History and Theory of Culture. Experience in copywriting: From 2010 to the present. Editor: since 2016.
During the construction of any private house, it is always necessary to produce various types of floors. These can be interfloor or attic structures, but in any case, their installation must be approached responsibly, and the most suitable materials must be chosen for this.
We can say that these structures are the same integral element of any home as walls, foundations or roofs.
Depending on the type of buildings and the planned costs for their manufacture, the following can be used:
During the construction of most private houses, developers make the floor of the second floor from a bar. This is a relatively inexpensive, but at the same time quite reliable material that has been used for such purposes for several centuries. The only necessary condition is the correct calculation of the cross section of such cross members installed in the span as a lag.
In order to more accurately determine the cross-section of the beam for overlapping, special formulas are used, which, among other things, take into account the resistance of the wood used and its moisture content. These parameters are defined in SNiP II-25-80, with which any developer or private master must be familiarized without fail.
You can also find the necessary formulas and tables there, with the help of which the parameters of the beams for specific interfloor structures are determined.
When calculating wooden floors, it is also necessary to take into account the span width, the distance between the beams, and the shape of their section. When calculating each cross member to be laid, it must be remembered that the value of its deflection under load should not exceed 1/250 of the span length.
Since it is quite difficult for a technically untrained person to correctly calculate the lag parameters using formulas and tables, special calculators can be used to independently select beams. In such a program, it is enough to enter a few basic quantities, and as a result, you can choose the correct dimensions of the bearing lag.
As an example, using one of these calculators, we will try to calculate which beam to use to cover 5 meters.
For data entry we need to know:
In order to make the correct calculations, we substitute the span width equal to 5m to the input values, and set the beam type to the beam type. We will select the height and width empirically in the parameters “bar dimensions for floor beams”. Be sure to take into account such values as the load per kg / m, and the step between the crossbars.
For interfloor structures, the load value should not be less than 300 kg / m, since it is necessary to take into account not only the weight of furniture and people, but also the weight of the materials themselves from which the floor is made. This includes floor beams, rough and finishing floors and, of course, insulation and sound insulation.
Advice. For non-residential attic structures, a load value of 200 kg / m will be quite sufficient.
In almost all bases that sell lumber, floor beams are sold mainly in several sizes. As a rule, these are beams from 100x100 mm to 100x250 mm, and from 150x150 mm to 150x250 mm. In order not to waste too much time and money on searching for logs with non-standard sizes, the price of which can be much higher than the standard ones, we substitute into the program those parameters that are commercially available.
To do this, you must first find out on the basis of lumber what sizes they sell. Thus, we obtain that for interfloor structures the minimum size of the beam should be approximately 100x250 mm, and for attic structures 100x200 mm will be quite enough, with a step between them equal to 60 cm.
If you do not trust software calculators and want to independently calculate the size of the floor beam, then you will have to use the formulas and tables given in the relevant technical documentation. Or you can use the general rule, which says that the height of each log should be 1/24 of the length of the opening, and its width is 5/7 of the height of the crossbar.
Interfloor ceilings in a house made of timber begin to be mounted by laying a log. To do this, a prepared beam is placed on the walls, which is pre-wrapped with roofing material. This will protect the wood from moisture penetration, and as a result, from decay.
The extreme beams should be laid no closer than 5 cm from the wall, and the distance between adjacent crossbars should not exceed the previously calculated values, which in our case are 60 cm.
An important condition is that the logs must be laid over the entire thickness of the walls, having maximum support and stability. The gaps between the lags on the wall are laid with bricks or building blocks, after which the draft floor is stuffed from the top of the edged boards 150x25 mm.
Ceiling ceilings made of timber are almost completely identical to interfloor ones, with the only difference being that the thickness of the beams can be less, and the step between them is several centimeters larger.
Let's say you need logs of 150x250 mm in size, but there are no such sizes on sale, but there are always plenty of boards with dimensions of 50x250 mm at any lumber base. In order to get a beam of the desired size, it is enough to buy 3 of these boards and fasten them together.
As fasteners, it is better to use not nails, but wood screws, because over time the wood dries out, and the nails do not hold the boards together so firmly.
As the instructions for self-manufacturing prefabricated logs advise, if you use them for basement or basement floors, then before tightening with self-tapping screws, it is worth treating each board with an antiseptic.
This will prevent the appearance of wood pests and significantly increase the life of the entire floor. If you use prefabricated timber for interfloor ceilings, then no pre-treatment of the boards is required.
The admissibility of using this type of lag is obvious and not questioned. This material is also environmentally friendly, like conventional timber, since no adhesives are used during assembly.
Attention!
The load-bearing capacity of prefabricated timber is even higher than that of solid lumber, while the cost is somewhat lower.
From the foregoing, it becomes clear that in some cases the use of prefabricated elements is even more preferable than solid ones.
This type of lumber is an acceptable alternative if the desired solid logs cannot be found, or their price is high enough for you, and it is not possible to make a prefabricated structure yourself.
Beams for floors in a wooden house made of glued beams are distinguished by good strength and resistance to loads, but they also have some disadvantages.
It is quite possible to build wooden floors in the house with your own hands. This design is considered one of the traditional options. They arrange such floors during the construction of residential buildings from almost any material: brick, foam concrete, expanded clay blocks, and, of course, they will be relevant in a wooden house. How to make them with your own hands? A detailed answer to this question can be found in this article. Installation, insulation, sound and vapor barrier: we will consider the most important aspects of the work.
Interfloor, as well as attic wooden floors in the house, made of wood, practically do not differ in their design features. They consist of wooden beams, as well as inter-beam filling, which is a roll-up made of shields or wood. Wooden beams are load-bearing structures, which are usually made from softwood. It can be, for example, hewn logs, boards or bars.
The cross section of the beams is determined depending on the length, as well as on the load that will fall on them. Approximately, the ratio will be as follows: the height is 1/24 of the length, and the width is approximately half the height.
As for the distance between the beams (or, as they say, the size of the laying step) - it is determined based on the data on the cross section of the material, as well as on the span length. For convenience, this distance can be determined from the corresponding table.
After you have decided on all the sizes and distances, it is time to perform the installation of beams. In order to use thinner and shorter beams, load-bearing partitions should also be arranged. This is also necessary in order to minimize the total thickness of the floor made of wood.
The ends of the beams are cut obliquely, then it is necessary to carry out their antiseptic treatment, use special compounds that will protect the tree from a wide variety of damage for a long time. Then the beams must be wrapped with waterproofing material - in two layers and, finally, embedded in the partitions and in the outer walls of the residential building. What should be the depth of the beams? According to the standard, at least 180 centimeters. At the same time, the length of the supporting part will be about 150 centimeters, and the width of the gap between the wall and the end of the beam will be about 3 centimeters. When the emphasis of the beams on the internal walls is created, it is necessary to put roofing material or other waterproofing materials under them in two layers. The ends of the beams, equipping a wooden floor, must be left open, they cannot be covered with bitumen or roofing material, since they must "breathe".
From the sides, “cranial” bars are stuffed onto the beams, the cross section of which is 4x4 cm or 5x5 cm.
https://www.youtube.com/watch?t=1&v=F6cn3B0ehos
1 - Wall; 2 - Waterproofing; 3 - Beam; 4 - Mounting foam; 5 - Insulation; 6 - Anchor; 7.8 - Roll forward; 9 - Skull bar. The roll-up of wooden floors is equipped either from an ordinary board, or from two boards (shields) knocked down perpendicular to each other next to each other. Starting the reel device, you should pay attention to the fact that the bottom of the reel is located in the same plane with the bottom surface of the beams. An exception can only be the case when you decide to make antique styling, and the beams in your house turned out to be somewhat protruding. Do not forget that any wooden elements that you use in the construction of your home must be carefully treated with antiseptic compounds. Next, the roll should be covered with a material for waterproofing, for example - roofing material. Its device is carried out in such a way that the waterproofing covers the beam at half the height. Then insulation is performed: a layer of thermal insulation - expanded clay, foam plastic, stone wool and other materials is laid on the waterproofing.
1 - Beam; 2 - Cranial bar; 3 - Reel with filing; 4 - Vapor barrier; 5 - Insulation How well the insulation is carried out affects not only the level of heat loss in the building, but also how long the truss system will last, as well as the durability of the roofing. Good thermal insulation should also be combined with good ventilation of the attic space of a residential building.
Most often, the insulation of interfloor floors made of wood in a house is made using mineral wool slabs. The material is usually laid between the beams, or on the ceiling. The material with which the insulation is made is laid on a polyethylene film or other vapor barrier materials (for example, on the Polycraft material). For those materials that have a foil side, this side should be on the bottom. Further, the inter-beam space is filled with thermal insulation. Performing insulation with your own hands, in order to prevent heat loss through the so-called "cold bridges", an additional layer of heat-insulating material is also installed, it is placed on top of the beams.
After the roll is installed and the insulation is completed (the material is placed on the beams), the next stage begins - the installation of the ceiling filing. You can make a filing, for example, from gypsum boards of standard thickness (9.5 mm). Do-it-yourself such plates are installed easily and quickly, and the surface will be even. If you want to equip the mansard roof in your house with your own hands, the floor from the boards will be nailed to the beams. In this case, along with thermal insulation, it is important to make high-quality, sufficient sound insulation. To do this, special materials that create a soundproof gasket are placed under the floor boards. Additional protection against extraneous sounds and noise will also provide a good layer of insulation.
In those places where chimneys pass, corresponding holes will need to be left in the wooden floor: they are framed with additional shorter beams. These beams will lean against each other with the help of special clamps. When planning a device of this design, keep in mind: the distance from the unprotected outer surface of the chimney to the beam should be at least 40 centimeters. You can hold special events - arrange a "sandbox", thermal insulation or asbestos gasket at the intersection with the ceiling - then this distance can be reduced to 10-20 cm.
As you can see, it is quite possible to do-it-yourself wooden floors in a country house, their insulation, soundproofing and other related work. The main thing is to follow all these rules and use only high-quality materials in your work.
When planning the construction of a country cottage, the owner has to solve the difficult issue of choosing floors. Some contractors advise him to use reinforced concrete panels, others insist on using wooden beams as a ceiling.
We decided to help beginners get out of a difficult situation. In our article you will find an overview of the advantages and disadvantages of wooden floors.
Useful tips for their installation and important nuances of this work will also not be superfluous. We hope that the information received will be useful to you at the construction site and help you avoid serious mistakes.
There is a stereotype in the minds of citizens that precast concrete panels are the only possible solution for any building. It is not difficult to overcome it.
It is enough to list the advantages of wooden beam ceilings:
As you know, there are no advantages without disadvantages. There are few of them for wood floors:
Among the shortcomings of these designs, some authors of feature articles include the formation of cracks in the plaster of the ceiling and poor impact sound insulation. However, with a competent approach to installation, these two problems are solved simply and reliably. To do this, a number of less thick beams are laid below the supporting beams, specially designed for filing the ceiling (drywall, OSB, lining, board).
The hemming beam, like the main one, is placed on the wall, but lower, and the ceiling cladding is attached to it. This solution is not common, although it is competent and its history dates back more than one century, in addition to cutting off the structural noise of the second floor, this option eliminates cracks in the ceiling. They appear in the case when the beam serves as a support for the floor of the second floor and at the same time the ceiling of the first floor is hemmed to it. From vibration and shock load, cracks appear in the finish.
In addition to the listed options, wooden structures for interfloor ceilings can be used in cottages intended for year-round use. Only in this case, you need to use the two-row beam installation system, which we described above.
We do not recommend selecting the cross section of the timber according to the principle “the thicker the better”. There is a simple calculation method taken from building codes.
According to it, the height of the wooden beam should be at least 1/25 of the span to be covered.. For example, with a 4-meter distance between the walls, you need to buy a sawlog with a section height (H) of at least 400/25 = 16 cm with a thickness (S) of 12 cm. To create a margin of safety, the found parameters can be increased by 2-3 cm .
The second parameter that you need to choose correctly is the number of beams. It depends on their pitch (the distance between the central axes). Knowing the cross section of the beam and the size of the span, the step is determined from the table.
Table. Beam spacing selection
The calculated load of 350-400 kg / m2 indicated in the table is the maximum for the second floor. If it is not residential, then its value will not exceed 250 kg / m2.
When planning the layout of the beams, you need to take into account that the two extreme ones should recede from the end walls by at least 5 cm. The remaining beams are distributed evenly along the walls (in accordance with the selected step).
Technologically, the device for overlapping wooden beams cannot be called complicated. The main attention should be paid to the alignment of the beams horizontally and the quality of embedding their ends into the wall array. You can’t just put the bars on the masonry and lay them with bricks. It is necessary to provide them with a reliable connection with the walls and qualitatively protect the wood from decay.
Options for sealing beams, depending on the material of the masonry, the type of wall structures (external, internal, chimney) and the methods of their fastening are shown in the figures.
The length of the supporting part of the beams in a brick and block wall should be at least 16 cm (in a wooden 7-8 cm). If paired boards placed on edge are used instead of timber, then they are embedded in the masonry by at least 10 cm.
The side parts of the beams in contact with the wall are wrapped with 2 layers of glassine or 1 layer of roofing felt. Experienced craftsmen cut the ends of the bars at an angle (60-70 °) and leave them uninsulated, while not forgetting to treat them with an antiseptic composition on a par with the rest. This ensures the "breathing" of wood wrapped with waterproofing.
When installing the ceiling on the sides of each beam, small gaps (3-5 cm) are left, filled with mineral wool or tow. A heat insulator is also placed in the space between the end of each beam and the wall. This eliminates the "cold bridge" that occurs by reducing the thickness of the masonry.
When constructing ceilings in walls made of aerated concrete and wood concrete blocks, it is recommended to use an open seal. In this case, the ends of the beams are also cut at an angle, antiseptic and pasted over with roofing paper on mastic, leaving the ends free.
The outer wall of the nest is insulated with felt or mineral wool and a box made from pieces of an antiseptic board is inserted into it. Its height is chosen such that an air gap (2-3 cm) is formed above the beam. Through it, water vapor accumulated in the wood will exit into the room in the plinth area. This solution protects the supporting part of the beam from decay.
In practice, developers most often use a simpler method of embedding without the use of insulation and a wooden box, closing the logs with block cuts or just a raster.
The floor bars are supported on, which is used to increase the spatial rigidity of the block masonry.
In the internal load-bearing walls, the beams are sealed in a closed way. To increase the rigidity of the overlap, they are connected to each other through three steel anchor plates.
The section of the beam adjacent to the smoke channel is insulated with asbestos or other non-combustible material. The main protection against fire here is brick cutting (thickening of the pipe masonry) 25 cm thick.
In wooden houses, the installation of beam ceilings is carried out in two ways:
Installation of the ceiling by cutting into the walls
The option of installing beams on "chairs"
If the upper floor or attic is not residential (heated), then it is necessary to insulate the wooden floors. To do this, a heater (mineral wool, ecowool) is laid in the space between the beams, having previously spread a layer of vapor barrier over the ceiling filing.
Styrofoam should not be used for this work for three reasons:
The design of the insulated floor is shown in the diagram.
Similarly, the insulation of the floor of the first (basement) floor is performed. The difference between them is that it is quite difficult to hem beams from below from a shallow underground. In this case, the builders act differently. To the side faces of the beams, they knock out a cranial bar (5x5 cm). An antiseptic boardwalk is laid on it. It serves as a support for slab insulation, placed in the gaps between the bars. A vapor barrier is placed under the mineral wool. A vapor barrier is also laid on top of the beams. After that, logs are attached to them and a finishing floor is already mounted on them.
The mineral wool slab should be placed between the bars as tightly as possible to prevent blowing through the floor. For better insulation, all joints of the insulation are treated with mounting foam.
The control of the horizontal installation of the bars is carried out using a bubble level laid on a flat long board. For leveling use cutting boards, protected by bituminous mastic. They are placed under the ends of the bars.
Vapor barrier sheets should be laid with an overlap of at least 10 cm and all joints should be glued with construction tape.
To reduce impact noise, soundproofing tape 5 mm thick is laid on the beams before installation of the second floor floor joist. A waterproofing film under the logs is placed only if the second-level room is residential. It will protect the insulation from water ingress when washing the floor. The technology of its installation is similar to the laying of vapor barrier.
The final stage of the wooden floor device is the installation of a subfloor from boards, plywood or OSB boards using self-tapping screws. After the completion of this work, a fine coating of laminate, linoleum, parquet is laid and the ceiling is finished.
