Fastening the joists to the concrete floor. Types of fastenings for floor joists. Fastening joists with anchors

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, insulating, and 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 everything to be carried out. necessary operations. One of the advantages of this method is the possibility of using relatively inexpensive insulation materials.

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

About the features of fastening lags

When attaching a building material to a concrete base, various tools and fasteners can be used. Fastening wooden logs differs in comparative simplicity. 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). 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 compress inner space premises.

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 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 floors are supposed to high load, 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 the floor covering of the apartment or house..

Conclusion

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

The process of attaching joists to the foundation

Having completed the installation of the foundation of a house of one type or another, you can begin installing the floors of the first floor. They are based on wooden beams or rounded logs laid horizontally directly on the base of the house. It is possible to do such work with your own hands only after carefully studying all the features of the process.

Beams as they are

Floor beams are currently represented by a fairly large list of different products. The simplest option is timber made of regular wood. rectangular section, determined based on specific construction conditions.

More complex look floor lag, which requires a long manufacturing process - I-beams, having a cross-section in the form of the letter H, placed on one of the sides. They are made from high-quality dried and planed wooden blocks and strips of OSB or high-quality moisture-resistant premium plywood.

Principle of operation I-beams in the form of floor lags, it assumes the distribution of the main forces in the form of bending loads along flat stiffeners. Thanks to this, with a small mass, they are able to withstand very heavy loads. In addition, manufacturing technology and strength make it possible to produce I-beams for openings with a width significantly exceeding the standard 6 meters.

Laying logs on the foundation is carried out according to certain rules, which will be discussed later. Immediately before installing lumber, it is necessary to properly prepare it for further use. You should choose high-quality bars made of oak, aspen or wood coniferous species. The main requirements for them are as follows:

The humidity of the lag should be in the range of 14-18%. This is achieved by simple atmospheric or better quality chamber drying. It is strictly prohibited to use damp, freshly sawn wood, since it will not be possible to correctly lay the logs on the foundation due to subsequent warping when they dry.
The logs must have correct geometry in length and cross-section. Before placing the logs on the foundation, they are subjected to additional machining in the form of planing with electric planers. High quality beams can be achieved by using pre-glued parts.
To avoid subsequent destruction of the timber joists under the influence of moisture, they must be carefully protected with protective compounds. This is done by spraying or using paint rollers in two layers with intermediate drying. A cheaper treatment method is to cover the floor joists with waste machine oil. If used, treatment must be carried out a week before installation to remove the characteristic odor.

Attaching joists to the base of the house

Options for attaching joists to the base of the house

The important point is correct fastening joist to the foundation of the house. At the same time, the abundance of base options requires certain installation features for each of them. Let's consider each specific case separately.

Attaching beams to strip foundations

A fairly common type is. It is a base up to half a meter wide, raised above the soil by 0.4 - 1 meter. Not all novice builders know how to attach joists to this type of foundation. There are two main ways:

The first of them involves installing the timber directly onto the base of the house. In this case, the installation of joists is combined with the installation of the side walls of the house. Depending on the frame material used, the logs can be laid by cutting them into a beam or log, covering them with bricks or blocks, making preliminary recesses in them according to the size of the floor parts. This option convenient as it requires minimal additional training.
The second method involves preliminary installation of strapping beams along the entire perimeter of the base of the house. In this case, even before pouring the foundation or directly during the process, anchor foundation bolts are installed in the concrete, protruding 150 mm above the surface. After the mixture has hardened and cured, holes are marked on the strapping bars and holes are drilled at the locations of the heads of the threaded rods. After installation wooden parts they are pulled to the base of the house with nuts and washers, sinking them into the wood. After this, the logs can be laid on the foundation. step-by-step instruction which will be located below.

Regardless of the chosen option for laying floor beams, it must be carried out in compliance with a number of mandatory requirements, which should be discussed in more detail.

Before laying logs on the foundation, it is necessary to correctly calculate the required number of beams. They are installed in increments determined based on the expected thickness of the boards used for flooring. Thus, in the case of designing lumber for finishing covering with a section of 20x100, 20x150, the distance at which the logs are installed on the foundation is only 0.3 meters.

Assuming flooring from a standard tongue-and-groove floor board 30-35 mm thick, the timber installation step can be increased to 0.5-0.6 meters. If you choose 50x150 lumber for the floor, you can safely lay the logs at a distance of 1 meter from each other.

Before laying logs on bricks or wood, it would be a good idea to determine the geometric parameters of the floor beams. For their calculation, the determining value is the width of the overlapped span, that is, the width of the room. So, with a distance from one wall to another of 2 meters, you can use lumber with a section of 110x60, 3 meters - 150x80, 4 meters - 180x100, 5 meters - 150x200, and 6 meters - 180x220 mm.

Installing joists on a slab base

If the base of the house is manufactured in the form that is recommended, the lags can be attached to the foundation in a way different from those described above, but in compliance with the specified installation parameters. It consists of using dowel nails installed through the timber into pre-drilled holes in the concrete.

The process technology is not complicated and is accessible even to novice builders. To install joists with your own hands on such a concrete floor, you can use a hammer drill or a drill with impact mechanism. Pre-drill holes in the timber using a wood drill. Then the parts are laid at the installation site and recesses in the concrete of sufficient depth and diameter are made through them.

Fastening joists to a slab base

Dowel-nails with a diameter of at least 12 mm are installed in place and pressed flush with the surface using a half-sledgehammer or a hammer with a striker weighing at least 1 kg. wooden beams. As a rule, when correct selection parameters of fasteners, installing joists on the foundation in this way ensures high quality their fastenings.

This method is applicable when using logs with a cross-section of at least 150x150 mm. This allows a sufficient amount of backfill or slab insulation from mineral wool, since it is impossible to lay the floor on a foundation without high-quality thermal insulation.

Installation of joists on the floor

When performing work inside a residential building or apartment, the problem of installing joists on a finished concrete floor often arises. This type of work is used if it is necessary to insulate the lower surface of rooms, level it or lay one type or another floor coverings. In this case, two installation methods can be used.

The first method involves rigidly fixing the bars to the base, which can be done in the same way as fixing the logs to the foundation in the form concrete slab. To install the logs in this case, you can use dowel nails or plastic dowels with self-tapping screws of the appropriate length.

Using preliminary markings, or using pre-perforated logs as templates, we drill holes in the floor. Their diameter should allow the fasteners to be tightly installed. Next, we fasten the logs using self-tapping screws or dowel-nails, controlling the horizontalness of the surface of the beams and the overall flatness.

Subsequently, after attaching the logs to the concrete floor with your own hands, you can insulate the base by placing the selected type of insulation in the gap between the bars. Before installation, do not forget to thoroughly treat the wooden parts with antifungal stains and fire retardants, which reduce their flammability.

Not so long ago, in the process of laying logs on a rough base, pieces of plywood or wooden stakes were placed under the beams. In this way it was possible to protect the tree from moisture and level the rough base horizontally. But over time, the substrate dried out and became unusable, which affected the horizontality of the coating. In the article we will look at modern methods fastening the joists to various types grounds.

Features of the use of fasteners

In the process of attaching the log to a wooden base, no special problems arise. To do this, you can use long screws or corners. What about concrete base, into which you can’t easily screw screws? To strengthen the joists on concrete, you need to use special types fasteners. The choice of fasteners required for installing beams to a concrete floor depends on the following factors:

Horizontality of the surface. Depending on whether additional leveling is required or not, height-adjustable or non-height-adjustable fasteners can be used;
Base moisture level. If the logs are mounted on a strip foundation, they will have to be laid almost on the ground. To secure the beams, they mainly use brick pillars, which protect the wood from moisture, acting as an insulating lining;
Degree of load on the base. You can strengthen the joists on the floor using self-tapping screws and brackets. However, if the floor is used intensively, the screws may not withstand the load. That is why the type of fastener is chosen in accordance with the expected load on the floor covering;
Heights of the underground. Wooden floors are prone to condensation accumulation under the covering and rotting. For guard wooden base from rotting and deformation, experts recommend using high supports for logs. They form an underground space under the beams in which air can circulate freely, which prevents the formation of condensation.

To properly secure the bars to rough floor, you need to understand not only the fastening methods, but also the types of fasteners. An adequate choice of support will extend the service life of not only the rough, but also the finishing coating.

Types of fasteners

As already noted, attaching beams to the floor involves the use of only two types of fasteners:

Simple - static supports that do not allow you to vary the installation height of wooden elements;
Adjustable - contain screw structures, thanks to which the fasteners can be adjusted in height, which allows you to achieve maximum horizontalness of the base.

What types of fasteners can be used to secure beams to the floor?

support posts;
self-tapping screws;
corners;
brackets;
anchor.

To understand the essence and features of the application of the above parts, let’s consider each of the categories in more detail.

Self-tapping screws

Self-tapping screws are simple fasteners that are used to finish wooden, but not concrete, floors. Enough long rods With external thread capable of attaching beams to wooden floors, but only if the following nuances are taken into account:

Before fastening, both in the beams themselves and at the base, you need to make through holes;
It is necessary to insert a dowel into the through hole and only then screw in the self-tapping screw;
To ensure that the logs do not come off the wooden base, screws are attached in increments of 40-60 mm;
The length of the screw is determined by the thickness of the beams; it is desirable that during the screwing process the “tail” of the screw goes into the base at least 5 cm.

The affordable price of fasteners has made them very popular among home craftsmen. But in order to achieve the desired result, during the installation of the logs it is necessary to take into account the above points.

Anchor

Anchor – combined fastener with self-fastening, which, unlike dowels, not only easily attaches to the base, but also supports the weight of heavy structures. The anchor is one of the most durable and reliable types of fasteners that are used to attach logs to any foundation (strip, pile). If we discard all the “sentiments”, the anchor is still the same dowel, but with a more powerful base.

During the process of fastening the lag, the anchor is mounted in approximately the same way as a self-tapping screw:

Through holes are made in the beams, after which symmetrical, but not through, holes are made in the base;
To disguise the bolt head, the beams must first be countersinked;
Since the anchor is very strong and is capable of supporting heavy structures, no more than 4 fasteners will be required to attach one beam;
The locking parts of the anchors are inserted into the resulting holes, through which the bolts are screwed;
When stitching the joists through, you need to ensure that the bolts go deep into the base by about 6 cm.

To strengthen beams on a rough base, experts recommend using anchors with a diameter of 8 to 10 mm. Metal rods of this thickness can easily withstand very heavy loads.

Brackets

Brackets are cantilever supports that serve as a static base for fastening parts in vertical plane. As a rule, they are used in the process of attaching joists to support pillars. Cross-shaped (x-shaped) curved parts have fixed flaps into which timber is placed. The price of such products is much higher than in the case of self-tapping screws, however, the range of possibilities for such fasteners is much greater.

Very often in the process of laying a subfloor on strip foundation install brick pillars. They act as supports and protect the tree from moisture. Since the lag becomes dented over time, it can become deformed without additional fasteners. The only convenient and reliable way securing beams to supports - using brackets.

Support posts

Posts for logs – support structures, which are assembled from bricks with a cross-section of 1-2 bricks. In fact, these elements perform the task of an “invisible” lining, preventing the impact of dampness on the wood. The columns are mounted when laying the rough foundation on a strip foundation or concrete. Since the level groundwater can be constantly changed to protect the logs from water, specially forming an underground.

In order to properly strengthen the logs and erect columns, the following points should be taken into account:

It is undesirable to build supports from hygroscopic materials - artificial stone or sand-lime brick;
Do not install posts on loose soils that can be washed away by water;
Supports that will be installed on non-flowing soil must be made above the soil level in the underground by at least 2-3 rows of masonry;
It is advisable to lay the pillars with a single-row dressing, maintaining the same height level for all supports;
You can attach the beams to the supports using brackets, anchors, or special corners with self-tapping screws for concrete.

Corners

Corners – galvanized metal parts with two planes located orthogonal to each other. The price of such fasteners is largely determined by the size of the elements themselves, as well as their thickness. The degree of strength of the corners directly depends on the mentioned parameters. In the process of fixing the lag, it is advisable to pay attention to such nuances.

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 it is laid finishing coat in the form of tiles, laminate, parquet, linoleum, etc. The material for the base is usually a concrete screed. It is used less frequently in wooden houses, but, for example, city apartments and private brick cottages 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 necessary parameters. If this was not possible, then pre-treatment of the logs will require the use of a jigsaw, a 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 install both thin vapor and waterproofing insulators and thick insulation in the form of mineral wool slabs.

Types of floor joists

Most common format floor joists- beam with rectangular or square 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 acceptable load on load-bearing base 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 sand-cement filling of an acceptable thickness - 4-5 cm. If we're talking about about local small defects, then you can limit yourself 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 The 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. On basic level parallel running logs are screwed to the 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 of a 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 sheet, which must 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 of wooden planks will be made for the finishing flooring.

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 logs to a concrete floor while ensuring a high degree of 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.

IN modern construction or a private renovation, the question may arise of how to attach logs to a concrete floor - after all, such a base can be called the most suitable for a plank covering. The advantage here is that the screed itself is a waterproofing barrier, and when pouring, a film or roofing felt is used, and it is usually insulated with expanded clay or even extruded polystyrene foam.

If you do everything correctly, then the entire installation process will turn out to be simple and even interesting, which we will tell you about now, and also demonstrate a video in this article on our topic.

Installation stages

Concrete

Note. You can pour a cement-sand screed without adding crushed stone or screenings, but its strength will be much lower, especially if the base is soil. Therefore such simplified version Suitable only for those cases where the base is reinforced concrete floors.

Let's start with what we need level base and if this is done on the ground, then it must be leveled and compacted, and then a sand-crushed stone cushion must be poured, as they began to do in the top photo. It is better to lay the waterproofing under the pillow, with a fold over the wall along the height of the entire screed, and although many do this on top of the pillow, experience shows that cut-off insulation is more effective at the very bottom.

Beacons are installed on the cushion, as required by the instructions for leveling any screed - they are best mounted on a cement-sand mortar, to which a little tile adhesive is sometimes added for elasticity. The distance between the profiles should be approximately 10-15 cm less than the length of your rule that you will use at the moment.
For ease of leveling, you can first mark out an approximate line along the perimeter of the room along the height of the screed and install the ends of the beacons along it. But the length of such profiles needs to be leveled with your own hands, because they are flexible; moreover, after installation is completed, check them by tensioning the thread in several places so that their height completely coincides with each other. Start pouring concrete no earlier than the next day, otherwise you will knock down the beacons with mortar and rule.

For pouring, it is best for you to use the M300 brand of concrete, the component ratio for which you see in the table above, although this is not prerequisite, but with advice. However, you can also order any brand at the nearest reinforced concrete unit, but its price, naturally, will be higher.

Recommendation due to the fact that cutting reinforced concrete with diamond wheels and diamond drilling of holes in concrete is best done in frozen solution, then operation of the filling can begin only after 28 days. Otherwise, the mounting dowels will not hold, and, moreover, laying the wooden floor earlier will lead to dampness.

Lags

Now, after the filling has dried, you need to decide on the distance, since you will fasten the logs to the concrete floor taking into account the thickness of the coating. For example, if it is a plank floor made of oak boards 40-50 mm thick, then the distance between the slats can be about 50 cm, but if it is an inch board or the same OSB (OSB), let it be 12 mm - this will be too much, and the floorboards will sag. In such cases, the distance should be reduced to 40 cm, and sometimes even to 30 cm ().

Considering that the logs will be laid on concrete screed, that is, you won’t need to fit tightly to the base thick timber— a slats with a cross section of 50×50 mm will be sufficient. But if the installation is carried out on concrete floors that do not have flat plane(usually this happens in multi-storey buildings), then use 100×50 mm timber.

So, if your ceilings are installed unevenly, then installation can be done using anchor bolts with adjusting nuts. The alignment principle is clearly visible in the photograph - you simply tighten or unscrew the nut, thereby determining the height of the beam. Considering that it will be 100×50 mm or 100×100 mm, then you will need an anchor of at least 200 mm (