Installation of logs on a concrete base. Laying joists on a concrete floor How to attach joists to the floor in an apartment

Today there are a huge number of technological possibilities for arranging a concrete floor in an apartment or private house. You can use a variety of insulating, insulating, and flooring materials, apply “warm floor” technology, and level the concrete surface with self-leveling solutions.

If a moisture-proofing membrane is spread on the floor, then the logs are laid on it without a gap.

However, such an option as laying on a concrete floor does not lose its relevance. This option of flooring over a concrete floor is especially in demand in the construction of private houses, where the ceiling height allows it. In addition, laying on a concrete floor makes it quite easy to use inexpensive types of insulation materials.

For logs, dried coniferous trees are most often used.

When attaching a particular building material to concrete, different fasteners and tools can be used. Mounting is quite simple. Today, even an option that involves the absence of fastening the joists to the floor is becoming popular.

With this option, the floor structure is strengthened by bonding floor boards or other flooring material to the joists. However, in this case there is a high risk of shifting and sliding of the flooring. Therefore it is better to use classic version when the logs are attached to the concrete floor with self-tapping screws or anchors.

Choice

It is also important to choose the right logs themselves. In this sense, attention should be paid to the following criteria:

suitable type of wood;
section dimensions;
price.

It is most advisable to use not very expensive coniferous wood (pine, spruce, fir). In this case, wood of 2-3 grades, dried to a moisture content of 20%, is quite suitable.

The cross-sectional size of the beams is selected depending on the type of insulating layer that will be laid between them. In addition, you need to take into account the height of the ceiling.

If it is not very large, then you cannot raise the floor too much, so as not to compress it at all inner space rooms.

Tools for work

The specificity of the work associated with fastening to a concrete floor is that you will need tools both for processing wood and for drilling the concrete base. To perform standard manipulations you will need:

When installing logs, make sure that they are level.

perforator;
self-tapping screws with a diameter of 6 mm and a length depending on the size of the beams, with polypropylene dowels, which should enter the concrete by 6 - 8 cm;
metal anchor fastenings (selected depending on the size of the beams);
carpentry tools: hacksaw, plane, circular saw, etc.

Choose between self-tapping screws with dowels and anchors metal fastenings should take into account the planned financial costs. The first option is much more economical, the second is more reliable. Most often, a dowel fastening is sufficient, especially since inexpensive self-tapping screws can be screwed in at smaller increments. The advantage of anchor fastenings is that they will not only fix the position of the beams, but also press them against the concrete base, which is very important in cases where the finished flooring will be quite massive and often subject to strong mechanical external influences.

You will also need waterproofing material, which must be laid on a concrete floor before installation. Here you can use dense construction polyethylene or roofing felt. You will also need mixtures for priming and antifungal treatment of wood. These mixtures must be pre-treated with wooden beams. If concrete base is not entirely level, then you need to stock up on material to create linings. Boards, chipboard, and plywood can be useful here.

Fastening process and features

Having prepared everything necessary materials and tools, you can proceed directly to fastening to the concrete floor. They are not difficult to attach and are quick enough. All work can be carried out independently, without the help of an assistant. Standard option such fastening goes through the following stages:

Flooring on joists is ideal if the house has high ceilings.

First you need to cover the concrete base of the floor with roofing felt or other selected vapor barrier material. The joints of roofing felt or polyethylene sheets are glued together with construction tape.
Next we distribute it over the floor surface. Two of them will be laid along opposite walls. The rest are located between them with a certain step, which is calculated taking into account the density and rigidity of the material that will be laid on top. The stiffer the material, the larger the step between the joists. On average, this step ranges from 40 to 80 cm.
If the length of the room is greater than the length of the beams, then the latter can be laid joint to joint. When using high joists or with large expected loads on the floor, it is necessary to make end cuts to connect the joists to each other.
First, two parallel ones are laid along the walls. Using a level and wooden plank their height is equalized. A cord is stretched between them, along which all other beams will be laid.
The logs are attached to concrete very simply: a hole is drilled in the block and a corresponding hole in the concrete base. A polypropylene dowel or spacer piece of a metal anchor is placed in the latter. Then screws or screws are screwed in. Two or three anchors are required per beam. Self-tapping screws can be screwed in increments from 50 to 80 cm.
If necessary, leveling pads are placed under the joists, which are made of boards, chipboard, plywood or other rigid material. The pads must hold firmly after installing the timber so that the floor does not sag or squeak later. It’s better, of course, to do without gaskets. In some areas it may be necessary to plan out a small area of the joist if there is a slight bulge in the concrete base.

After the logs are installed, one or another can be laid between them. insulation material. Then, before laying the flooring, it is advisable to stretch the vapor barrier layer over the joists. This insulation system is quite effective, and the floor is durable and warm. Thus, the concrete base of the floor can be very successfully equipped using a technologically simple procedure for attaching wooden joists to the concrete floor.

Wood may not seem the most the best solution for decorating a subfloor in terms of strength and reliability, but in some cases it justifies itself in terms of other performance qualities. For example, if you need to correct deficiencies in the concrete base, create a niche for laying an insulator, or create channels for communications. At the same time, the technology for attaching joists to a concrete floor is not as simple as in the case of conventional wooden planks. Rough flooring is a critical structural element, the quality of which directly determines its durability. decorative covering.

Joists in the floor system

The floor frame consists of several levels, starting from the foundation with a grillage and ending with the base, on which the finishing coating in the form of tiles, laminate, parquet, linoleum, etc. is laid. The material for the base is usually concrete screed. It is used less frequently in wooden houses, but, for example, city apartments and private brick cottages they cannot do without such a platform. The screed can serve as both the final layer of the frame and the load-bearing layer in relation to the upper part of the base. The logs form a kind of superstructure over this structure. They are not laid on a concrete floor in a continuous manner, but with indentations similar to a lathing. The methods of fastening may be different, but the basic quality of the structure will be determined by the characteristics of the tree itself. The joists must be well dried, free from minor flaws and, if necessary, treated with special impregnations. These can be fire-resistant agents to prevent fires, or ordinary drying oil, which extends the service life of the material.

What tools and materials will be required for the work?

Large-format logs will be difficult to process at home, so it is better to calculate and order elements with the required parameters in advance. If this was not possible, then Preliminary processing lag will require the use of a jigsaw, circular hand saw and grinders. Already in the process of attaching the joists to the concrete floor, you will need an electric screwdriver or an electric drill with bit-type attachments. It is advisable to prepare a more powerful tool - at least with a 1500 W drive. As fasteners you will need metal fastening fittings - anchor elements, bolts, angles, screws, etc. The choice of one or another group of hardware depends on the installation technique.

Regarding auxiliary Supplies, then there will be few of them. At a minimum, you will need pads for the joists. In this capacity, you can use plywood sheets or bars of the appropriate format. Also, do not forget about the possibility of installing insulating coatings. The classic design of the floor on joists makes it possible to lay both thin vapor and waterproofing insulators and thick insulation in the form of slabs mineral wool.

Types of floor joists

The most common format of floor joists is a beam with a rectangular or square cross-section, having length and thickness parameters suitable for specific application conditions. Especially for worm flooring, it is recommended to use rectangular joists as the optimal design option. A beam with such a cross-section occupies less space in an underground niche, but at the same time provides sufficient coverage in segments along the width of the installation. Accordingly, attaching the joists to the concrete floor is simplified, since shorter and stronger hardware is required to fix the element.

There is also a division according to the method of manufacturing beams. Planed logs undergo special treatment in order to reduce hygroscopicity. This material more resistant to moisture, therefore can be used in the construction of baths and saunas. An alternative to planed beams is sawn timber. This is a rough material with less attractive technical and operational qualities, but it costs less and can well justify itself as the first level of the floor frame connecting the foundation grillage with the finishing layer of lag.

Calculation of material by size

The ability to cope with stress depends on correct calculation design parameters. These indicators, in turn, are determined by the size of the room, layout and configuration of the premises as a whole. For a basic calculation, you can use the span of the room, correlating it with the dimensions of the beam. For example, a 2-meter span must be framed with timber with a cross-section of at least 110 x 60 mm. For 4 m you will need a beam of 180 x 100 mm format, and for 6 m - a standard size of 220 x 180 mm. In turn, the section will determine the distance between the elements. How to attach joists to a concrete floor so that a balance is maintained between structural strength and an acceptable load on the load-bearing foundation under the beams? After all, placement of timber close to solid can cause excessive pressure on the same grillage. With a board thickness of about 20 mm, experts recommend maintaining indentations of up to 300 mm. At 300 mm, the same parameter will already be 500 mm, and 50 mm elements are located at a distance of 1000 mm from each other.

Preparing for work

During preparation, the greatest attention is paid to the condition of the concrete surface. As already noted, the load from the beams can be critical, so the load-bearing base should be brought into proper condition. To ensure that the fastening of the joists to the concrete floor is reliable and durable, the screed is strengthened mortars, putties and primers. In case of significant damage, the cover should be renewed with a sand-cement fill of an acceptable thickness - 4-5 cm. If we are talking about local small defects, then we can limit ourselves to the spot application of priming and puttying agents designed specifically for concrete. As a cosmetic leveling solution, it is worth using a thin leveling fill tile adhesive or self-leveling polymer composition.

Basic methods of attaching joists to a concrete floor

The most common installation methods involve fixing the beams using self-tapping screws and anchor connections. A rigid clamping fit is ensured, which ensures that the structure remains motionless even under dynamic loads. How are joists secured to a concrete floor with anchors? To do this, holes are drilled at the designated points of the beam, after which the hardware is integrated according to the standard scheme. Optimal diameter anchor bolt is 10 mm, and the length is up to 200 mm. 3-4 fasteners will be enough for one segment.

Angle fastening technique

Another common way to fix lags is using corners. Its advantages include a higher degree of reliability, since the lags are secured to each other. At a basic level, parallel joists are screwed to a concrete base. But as an addition, small-format timber is installed perpendicularly. At the joints with the beams they are mounted. As a result, a double fixation system is implemented. It is also possible to attach the joists to the concrete floor with corners without the use of intermediate bars. In this case, instead of direct anchor connections, the technique of lateral fixation of beams through the corner to the screed is used. Direct fastening is carried out with screws suitable size.

Features of fastening without drilling

Refusal to interfere with the structure of beams provides many advantages, increasing the durability of the entire structure. But how to achieve reliable position of the lags without the use of hardware? Fasteners will be used, but in relation to auxiliary elements. These are the same consumables in the form of small bars and plywood sheets that should be fixed to the concrete as load-bearing contours of the substrate. The lags will be attached to their platform without drilling. The support strips are initially installed, after which the beams are laid. Rigid force fixation will be provided using groove connections. They can be provided either in a “lining-logs” combination, or through auxiliary bars running across them, which will be guided along the entire length of the room. This design is complex and requires careful preliminary calculations.

Isolation measures

A layer of waterproofing can be laid before installing the logs, which will facilitate subsequent insulation measures. But experts still recommend starting such work after completing the installation of the beams, since operations with fasteners can damage the laid material. As for the insulation, it is laid in the niches formed between the bars. If the optimized laying of the joists on the concrete floor was carried out only along parallel lines, then there should be gaps between the mineral wool slabs. They are additionally treated with silicone or other sealants, which, in principle, are combined with mineral wool. Pieces of insulation are cut in accordance with the parameters of the empty niches, and then laid on the waterproofing material. As a rule, forceful fixation of mineral wool is not performed - after installation it is enough to cover the material with another layer of hydro- or vapor barrier. In the future, a new layer will be made for the finishing flooring wooden covering from boards.

Installation of adjustable joists

The most functional design that allows you to adjust the height of the floor to suit your specific needs. For example, it will be possible to adjust the level of the base specifically to the thickness of the insulating material. But how to fix the joists to the concrete floor so that they are adjustable? The fixation system is quite simple and requires the use of only two elements - a rectangular mounting stand with fastening hardware and a threaded stud. The load-bearing function will be performed by a system of stands securely fixed at the points of fixation of the beams using dowels. A pin is installed in the central part of each stand, onto which the timber is subsequently screwed. This is done using a screw and nut, which will allow you to adjust the height of the floor in the future. That is, you will initially need to make holes in the joists with a thickness corresponding to the diameter of the studs.

Conclusion

The load-bearing base for the floor on logs is widely used in private housing construction due to affordable price and ease of installation. After installation, the user will also have a lot of opportunities to use the free space between the beams - there may be ventilation ducts, the same heat insulator, communication routes, etc. On the contrary, fragility and fragility are usually noted among the design flaws. How to attach joists to a concrete floor with security high degree reliability of the formed frame? Firstly, the strength of the connection between the concrete base and the beam sheathing must be guaranteed - both directly and through auxiliary elements. Secondly, the installation configuration itself must initially be designed for the specific operating conditions of the house. The design must take into account indicators of static and dynamic loads, which will make it possible to more accurately select mounting hardware.

Today, there is a wide variety of possibilities for arranging a concrete foundation in private houses or city apartments. During the work you can use all kinds of flooring, insulation, insulating materials, you can level the concrete surface with a self-leveling solution and use a “warm floor” system.

Laying joists on a concrete floor does not lose its relevance. This method of arrangement is especially in demand when constructing private houses, in which the ceiling height allows all the necessary operations to be carried out. One of the advantages this method is the possibility of using relatively inexpensive insulation materials.

In this article we will talk about how to attach joists to a concrete floor.

About the features of fastening lags

When attaching one or another building material to a concrete base, they can be used various instruments and fasteners. Fastening wooden logs is comparatively simple. The work is carried out in several stages.

Selecting materials and tools

Today, one of the most popular methods of laying joists does not involve attaching them to the floor. With this option, structural rigidity is achieved due to the fact that the joists are fastened together using boards or other material. The method is quite reliable, but there is still a high risk of shifting the floor covering.

Therefore it is best to use traditional version, which involves fastening to the base using anchors or self-tapping screws.

Choosing lags

When choosing a log you need to pay attention to the following criteria:

The type of wood that can play a key role in the strength of the foundation.
The price of the purchased material. It is best to use inexpensive coniferous wood (fir, pine, spruce) when carrying out this work. In this case, grade 3 wood will also work. The main thing is that the humidity level does not exceed 20%.
Dimensions of beams in cross section.

Advice!
The choice of section sizes depends on what type of insulation you will lay between the joists.
In addition, last but not least, you should think about the height of the ceilings.
If the height is small, you should not raise the floors too much, since this way you will compress the interior space of the room.

Choosing tools

To install the logs, you will need tools designed for wood processing and for drilling concrete:

Hammer.
Anchors (such fastenings are selected depending on the cross-section of the beam).
Self-tapping screws 6 mm in diameter, the length of which depends on the size of the beams. They must come complete with polypropylene dowels.
Some carpentry tools: plane, hacksaw, circular saw, etc.

Many home craftsmen are interested in how to attach joists to a concrete floor. The choice between self-tapping screws with anchor fastenings should be based on the planned financial costs.

The first option is more economical, the second is much more reliable. In practice, in most cases, a dowel fastening is sufficient; in addition, cheap self-tapping screws should be screwed in at much smaller increments.

The main advantage of anchor fastenings is that they not only fix the position of the beams, but also press them to the base. This is very important if the finished flooring is quite massive and is subject to frequent mechanical stress.

Don't forget about the waterproofing agent. It must be laid on the concrete floor before the logs are installed.

Advice!
Roofing felt or construction polyethylene can be used as waterproofing.

Features of installation

After all materials and tools are prepared, you can proceed directly to installation.

The instructions provide several steps:

Laying roofing felt on a concrete floor. The joints between the sheets must be glued using construction tape.
Distributing the logs along the base. We lay two of them along opposite walls. The rest should be placed with a certain step, taking into account the rigidity and density of the material laid on top of the logs. Accordingly, the stiffer the material, the smaller the step. The average parameters are 40-80 cm.
If the length of the room exceeds the length of the beams, then they are laid joint to joint. If high joists are used, or a high load is expected on the floors, it is necessary to make end cuts to connect the elements.
Having laid two logs along the walls, we set their height using a level.
We stretch the cord between the outer joists, along which the remaining beams should be laid.
Drill holes in the block and base.
Place an anchor spacer or dowel into the hole in the floor.
Screw in bolts or screws. There are two or three anchors per beam. Self-tapping screws are screwed in in increments of 60 to 80 cm.

If necessary, prepared pieces of timber or boards must be placed under the logs.
We lay insulation between the joists.
We install a vapor barrier membrane on top of the insulation.
The next layer is flooring apartments or houses.

Conclusion

As you can see, installing the floor on joists with your own hands is much easier than it might seem at first glance. Create solid foundation It’s quite possible if you listen to the advice of experts.

Floors on joists are a frequently used design in both wooden houses and apartments. The advantages are undoubted: such a device allows you to use different materials for rough flooring, insulation and sound insulation. They can be used to level any base and carry any kind of material under the floor. engineering Communication. The option is simple to implement, affordable, and the result is a structure that creates minimal load on the foundation or floor slabs.

When installing such a floor on a concrete base, the question inevitably arises about how to connect materials with such different physical properties. One more no less interesting topic, which is discussed on construction forums - is it necessary to attach the joists to the floor at all?

Opponents of fastening argue that such a procedure can destroy the screed; moreover, at the junction of the joists and the base, sound insulation is disrupted and so-called sound transmission bridges arise, and the neighbors below will definitely not like this. But supporters of rigid fixation cite examples from their practice when the deformation of wooden beams negated all efforts to repair the floor.

How is it really going? As for destroying the screed, doing this with a drill by drilling holes in the concrete will not work if the screed is strong enough. A solid foundation– one of the mandatory conditions, without which they will not begin to repair the floor. The old screed, if it has already begun to fall apart, must be removed.

Regarding the violation of sound insulation, the issue is controversial. Yes, indeed, rigid structures are capable of transmitting sound, but is everything so bad? A layer of insulation is placed in the cells between the joists, which has soundproofing properties.

A shock-absorbing pad is placed under the joist supports, which also prevents the propagation of sound waves. The sound transmission bridge formed at the fastening site transmits vibrations into concrete, and this material is quite dense and does not conduct sound as well as, for example, wood. Therefore, the neighbors below are unlikely to notice the difference in noise levels before and after the renovation.

A floor on joists is a structure consisting of many elements: beams, fastening devices, rough flooring. All these parts, moving relative to each other, will emit a constant squeak, which is much worse and the neighbors will no longer like it. One way to avoid unpleasant squeaking is to firmly attach the joists to the floor.

Another argument in favor of fastening is fixing the lag. It is impossible to check the degree of drying of the wood by eye, so you have to trust the seller. Insufficiently dry beams can bend and twist after some time, and this will lead to shifts in the coating, so that the entire complex device will be skewed.

Those who are still wary can opt for a traditional floating floor, that is, a system in which the flooring does not have a rigid connection with load-bearing structures. This guarantees excellent sound insulation, but requires well-dried logs that will definitely not fade over time.

The rigidity of the floating floor is provided by beams securely fastened to each other, forming a lattice. Insulation is placed in its cells, and a rough flooring is attached on top, so that the entire structure is pressed to the floor by its own weight. If everything is done correctly, then such a floor will not deform over time and will last a long time.

However, most often the joists are still attached to the floor: there are more positive aspects than possible disadvantages.

Work order

The main thing on which the success of the renovation will depend is quality materials. Coniferous wood with a moisture content of no more than 18% is suitable for logs. The purchased beams need to be brought home and allowed to lie in the room for several days so that the material gets used to the microclimate of the room. Those logs that began to bend in the heat should be discarded. By the way, everyone wooden elements The future floors must be treated with an antiseptic so that they do not become moldy and insects do not grow in them. Treatment with special compounds that reduce flammability will also be required.
You need to prepare the floor: remove all debris, smooth out cracks, knock down obvious protrusions. Necessarily applying waterproofing, since the tree needs to be protected from moisture. For this purpose, hydrophobic mastics, penetrating compounds, roll materials and even thick film.
You will need to stock up on tools, fasteners and supports to raise the logs. Substrates must be rigid and not sag over time to prevent play from occurring at the support points. Thin planks, pieces of plywood will do, and construction stores You can buy special plastic backings.
The logs are laid perpendicular to the sunlight falling through the window. Wood is subject to temperature deformation, and with this installation, each lag will be heated evenly. In rooms where there is a certain direction of movement, for example, a hallway, the logs are laid across it. This will make the floor more durable.
Location step beams depends on the thickness rough coating. The thicker and stronger the sheets, the less often logs can be laid. Usually this distance is 40-50 cm. In this case, the outer bars are placed 2-3 cm from the wall, and the rest - depending on the width of the room.
When the entire sheathing is assembled, it is placed in a horizontal plane. The ideal option is to have a flat base; some particularly diligent craftsmen even perform thin cement-sand screed. Of course, if the height difference allows. However, joists are good because they allow you to level even the most imperfect floor, so you can do without a screed. In those places where the beam needs to be raised, substrates are laid under it until the level shows the presence of a plane.
Under all supports it is necessary to put a gasket - a piece of roofing material, linoleum or polyethylene foam. It will act as a shock absorber and also provide additional waterproofing to the wood. Under no circumstances should gaskets be made from soft material! Over time, it will sag under the load, which will lead to the appearance of play, and as a result, to creaking and other friction sounds of structural elements.

Now that the joist system is completely ready, all that remains is to attach them to the floor. The actual fastening is carried out in three ways: dowels + self-tapping screws, anchor fastenings and galvanized corners with self-tapping screws. Which one to choose is a matter of budget and personal preferences of the developer, since each method has its own characteristics.

Video - How to lay joists

Fastening the joists with self-tapping screws

Perhaps the simplest and cheap option, allowing to achieve excellent result. Through holes are drilled in the beams, and symmetrical ones are made through them at the base. They insert it there plastic dowel and screw in the self-tapping screw. Step – 40-80 cm depending on the situation.

The length of the screw depends on the thickness of the timber and should allow it to go 5-6 cm into the base. By the way, some craftsmen recommend self-tapping screws with a neck, that is, those in which the thread does not reach the head. This will allow the joist to be better pulled to the floor.

Fastening joists with anchors

Anchors guarantee reliability and durability of fastening. Their main advantage is in this case is that they not only hold the beam in place, but also attract it to the floor, giving the structure additional rigidity.

Essentially, an anchor is the same dowel, but more powerful. Its advantage is resistance to tearing, so it is used when installing heavy structures that create a high load on the fasteners. A floor laid on joists will most likely not have such situations when its entire complex design will be completely torn off from the concrete surface, so you can limit yourself to self-tapping screws, but the use of anchors is a very common practice.

Fastening is carried out in the same way as in the previous case. Holes are drilled in the joists, which are then duplicated on the concrete base. The joists additionally need to be countersinked to hide the bolt head without damaging the wood.

As a rule, on a room scale, 3-4 anchors are enough to secure one joist. The locking part of the anchor is inserted into the holes in the floor, and the bolt itself is screwed into it through the beam.

The length of anchor bolts can be very different, from 45 to 200 mm. You need to buy those that will be buried in the base, stitching through the lag, by 6 cm. The recommended diameter is 10 mm.

Galvanized metal angles are another option for attaching wood beams to a concrete floor. To do this, one side of the corner is connected to the beam by screwing a self-tapping screw into the wood. The depth is 3-4 cm, and it is recommended to do it at an angle to increase strength.

The remaining side of the corner should rest on the floor. It is fixed on this base using the methods already described above: with dowels or anchors. As an option, you can use not corners, but a U-shaped profile.

An adjustable system costs more, but is easier to use and will make it easier to achieve horizontality. Here, instead of anchors, plastic posts are used, screwed into wood and attached to the base with dowels. The height can be adjusted by rotating special bolts, the protruding part of which is cut off after the adjustment is completed.

So, you will have to decide for yourself whether to attach the logs to the floor or not. This definitely should not be done in wooden houses, but as for rooms with a concrete base, fastening will not hurt. The technology is simple and accessible to everyone; the main thing in such work is to choose high-quality materials and strictly follow all the rules. Then none of the structural elements will become loose over time, and the floor on the joists will be reliable and durable.

Video - Attaching joists to a concrete floor

One of the most important elements The floor structure is a log system. It is from strength, choice the right step Between the types of wood and the installation method, the operating conditions of the finishing coating will depend.

Choosing timber for logs

Timbers can have different sections and humidity levels

As already mentioned, it is the joists to the floor that perform one of the most important functions. Therefore, in order for floor coverings to last for a long time, it is necessary to choose the right one. construction material. It will be necessary to pay attention to many factors, otherwise the bars may deform under load and cause damage to the finish coating.

Humidity. When choosing any wood building material, the first thing you should pay attention to is its moisture content. If the beams are not dry, they will not undergo strong linear changes during the drying process. Therefore, at the time of purchase, the timber should have a moisture content of no more than 16–18%. This humidity indicator is optimal, because the risks that the wood will gain moisture or dry out are minimal. It is worth noting that both of these processes can cause deformations, only their directions will be different.
Type of wood. The joist system is designed to serve as a strong support for the finishing coating, so it must be strong. Choosing the highest grade is not necessary, because grade 2 or 3 wood will do just fine. The strength of the logs will be compensated by a large number of support points, so the main thing is that the lumber does not have areas with mold and fungi. When using a leveling system, you should pay attention to the number and size of knots. They can become areas where the support breaks.
Section. The shape of the section can be determined by the end side. It is necessary to choose a material that will have a clear rectangular shape. The optimal aspect ratio is 1:2 or 2:3, i.e. beams with a cross section of 50x100 mm and 100x150 mm, for example. In this case, the logs should be laid on edge. This position of the beam will be maximally resistant to vertical loads. The choice of beam cross-section should be based on the step at which they will be laid and what layer of insulation is planned to be used.
Breed. The most common option is conifers, which have affordable prices and are perfect for supporting a finished floor. For example, pine or spruce are perfect for normal conditions, but where high humidity is expected, it is recommended to use larch. It is more resistant to moisture and can provide a good service life.
Treatment. You need to ask the sellers if they have lumber antiseptic treatment. If there is no such thing, which often happens, then you will have to do it yourself. In addition to the antiseptic, which will protect against mold and mildew, fire retardants are used to increase the fire-resistant properties of the material.

Advice! You need to select lumber very carefully. It is best to select the samples you like from the warehouse yourself. This way you can get rid of the possibility that they will give you warped ones, which will be difficult to level, and you will have to do a lot of planing with a plane.

Choosing the right building material is only half the battle. It is worth dwelling on how logs are attached to wooden beams in a wooden house, on concrete floors and a strapping system.

Joists on supports in a wooden house

For logs, bars with a cross section of 50x100 mm are usually used. From this it is clear that they are not the only strengthening system. That’s why they use beams in wooden houses on the floors, and on the ground floor they use support pillars.

Supporting wooden support beams on poles

Installation of support pillars

The support pillars are made of brick with a wooden overlay, which should not allow moisture coming from the pillar to rot the wood of the beam.

The installation site for the pillars is dug to a depth of 50–60 cm, and sand cushion. A layer of waterproofing from roofing felt sheets is applied, and formwork is performed with a height above the ground level of 30–40 cm.

After the concrete has been poured and dried, bricks are laid on it one level at a time, which will also have a concrete structure inside. To do this, during the process of pouring the concrete base, reinforcing wire is left under the pillars to the height that will be necessary for the height of one pillar. Excess sections of reinforcement are subsequently trimmed with a grinder.

Adjustable support for wooden floor beams

The step between the pillars for one beam is within the range of 60–100 cm, and between adjacent beams – 150–200 cm.

Attention! Floor coverings made from boards are usually oriented in the direction of incidents through the window. sun rays. Therefore, it will be necessary to take this fact into account and orient the beams in the same direction as the finishing floor.

Beams

A layer of roofing felt is laid on the prepared pillars. In addition, during the manufacturing process of the pillars, it is installed on them wooden slats as an overlay.

The beams will rest mainly on strip foundation, and the pillars should serve only as reinforcing elements and in no case take the main burden. Therefore, their level should not exceed the level of the foundation tape.

Attaching to wooden beams

Attach the joists to wooden beams it will be as easy as shelling pears. It is recommended to use angles as fasteners. It is not necessary to attach the logs on both sides. To save on fasteners for large squares, you can attach the corners in a checkerboard pattern.

Joists on beams

When using mounts on beams, it is better to refrain from rigidly fastening the support slats to the wall. It is worth using an angle fastening with the possibility of shrinkage of the supports and movement of the screw. In this case, it is necessary to leave a technological gap between the wall and the logs.

Attaching joists to a concrete base

Screw for fastening joists and slats

The use of beams and pillars on a concrete surface is eliminated, because the logs will be laid and attached directly to the concrete surface. You can cope with this task alone. The order of actions will be as follows:

A layer of waterproofing must be laid on the concrete base. As a moisture-insulating material, you can use roofing felt or ordinary plastic film. In this case, the joints must be airtight, so they are sealed with tape.
The choice of lag laying step will directly depend on what finishing material will be used. For example, for floorboards with a cross-section of 35–40 mm, you can use a step of 60–70 cm.
Using one log along the entire length of the room is not always possible. Therefore, it is necessary to make an even joint between the two parts so that the horizontal level at the junction coincides with the general level. For this they can use iron corners or special cuts into the tongue and groove. If this is done across the entire width of the room, then it is better to connect the joists in a checkerboard pattern so that subsequent loads do not cause fracture and deformation in this area.
The first step is to secure the outermost joists. They will serve as beacons for leveling the remaining bars. To align two bars at large distances from each other, you must use a laser level.
The logs are attached to the concrete base depending on their height. Thin bars are fixed through and through with dowels and spacers, which are placed in pre-prepared holes. And high supports - with special corners.

As a finishing coating on top of the bars, you can use sheets of plywood, which will serve as a subfloor under laminate or parquet.

Attaching the joist to the timber frame

When making a log system, they usually use a frame made of timber, which performs a strengthening function and allows the logs to be installed at the same level. In order to secure the logs to the frame, a simple method is used - the corners and brackets are installed on self-tapping screws. At the same time, the latter are advised to be installed slightly at an angle so that the logs cannot become loose during operation.

How to attach joists to a frame without using nails

The use of a strapping system is typical for frame houses and other types that do not have a rigid base, where an accurate and even connection is possible. When connecting bars with fasteners to a concrete base, squeaks may subsequently occur, but fastening only to the strapping will not cause this.

There are many in various ways fastenings that need to be used depending on the situation.

In the video you can see how best to attach wooden joists in the loggia in an adjustable manner:

average rating more than 0 ratings