How logs are attached to a concrete floor, floor construction and fastening technology. Installing the log on a concrete base Fastening the log with anchors to the concrete floor

Logs are rectangular bars made of wood, used for mounting wooden crate on a cement base. From how well the lag is fastened to concrete floor, will depend on the strength and durability of the finished surface.

Wooden logs.

Materials and tools

The material for laying the base of the floor is softwood and hardwood. The most popular varieties are spruce and pine.

For the manufacture of logs, wood of the 2nd grade is used, having a thickness of 50-60 mm and a residual moisture content of 12-18%. The degree of moisture content of lumber is checked using a special device - a moisture meter. Construction timber should not contain dropping knots, chips, holes and surface damaged by mold.

As an underlying material, fiberboard sheets or cork gaskets are used.

You may also need:

attachment details;
antiseptic;
waterproofing material (polyethylene, hydrobarrier, etc.);
floor primer;
sound and heat insulating products.

Fasteners

To attach the bars to the base, use:

dowel nail;
anchors;
self-tapping screws;
metal corners;
brackets;
stand bolts.

The dowel-nail consists of two elements: a nylon plug and a metal rod with a screw thread. The plastic dowel presses the part, and the bolt, when struck with a hammer, secures the connection.

metal anchor- this is a device designed for attaching a wooden log to. It consists of a spreader mechanism with internal thread and a bolt, during the rotation of which the petals of the device abut against the walls of the hole and secure the beam to the concrete base.

Self-tapping screw - a metal screw with a sharp external thread. It is used only in tandem with kapron or wooden stoppers. When twisting it into a plastic cork, it cuts the passage channel itself. This secures the part to the surface.

Tools for fastening the lag.

Metal corners and brackets made of steel or aluminum perforated profile. With one side they are attached to the floor, the second - to wooden logs.

Stand bolts are studs with threaded couplings, by turning which you can change the level of the future base.

The choice of fasteners depends on the following factors:

Uneven floor in the apartment. Such conditions of performance of work provide for the use of an adjustable fastening. The use of stud bolts ensures that all laid logs will be in the same horizontal plane.
Mechanical load level.
Designed floor height.
Humidity of the concrete base (presence natural ventilation).

When choosing wood for the floor, the following characteristics of the material must be considered:

tree species;
humidity level;
compliance of the quality of products with the specified operating conditions;
profile thickness and height.

For timber, it is necessary to use unplaned boards of the second or third grade from hardwood and coniferous wood, except for poplar and linden.

Lumber defects that preclude their use in the construction of a wooden floor base:

Pores with a diameter of 1-2 mm - indicate the defeat of the bark beetle.
Knots, chips, cracks or bark residue are low grade.
Surface covered with spots different color- a sign of damage by a fungus, mold.
Curvature is a sign of violation of wood drying technology.

Lags on concrete base.

The choice of lag width depends on the area of the room, the type finish coat and the expected load on the base. The larger the volume of the room, the wider the profile needed.

The thickness of the lag, resting with the entire plane on the floor slabs, should be 40 mm, width - 75-100 mm. The width of the beam laid on separate supports is 100-120 mm, the thickness is 40-50 mm.

The height of the log is selected based on the size of the room and the presence in the project of recommendations for the installation of natural floor ventilation. An ill-conceived choice of profile dimensions can reduce the height of the premises by 50-250 mm, taking into account the thickness of the finishing coating.

Enhance bearing capacity elements can be achieved by increasing the number of support posts, which is much cheaper than buying a profile with a larger section. When calculating the amount of lumber, it must also be taken into account that the lag should be installed on a concrete base at a distance of 20-30 cm from the building envelope.

The humidity of the acquired timber and gaskets should not exceed 18%. All logs and substrates must be treated with an antiseptic.

To install a wooden floor on logs, a kit is required specialized equipment and tool:

Roulette construction.
Chalk or marker.
Square.
Hand or electric saw.
Plane.
Chisel.
Hammer.
Mallet.
Electric drill for drilling holes for adjustable fasteners.
Perforator for mounting anchors and dowels.
Water and rack level.
Screwdriver with nozzles of the right size.
Scissors, including for metal.
Knife with a strong blade.
Fly brush or rollers for priming the floor.

Set of tools.

Ways to install a lag on a concrete floor

Installation work consists of laying wooden beams on prefabricated or monolithic reinforced concrete bases.

An important condition quality performance works is right choice fasteners and compliance with the technological scheme for arranging the log on the base surface:

The beam should be installed across the line of light from the windows, parallel to the window or doorway. Between the walls and the profile, it is necessary to leave a gap of 25-30 mm wide.
If sound insulation is needed, then the substrate under the logs is laid in a continuous strip along the entire length, without breaks.
Mounting holes and seams between prefabricated elements must be filled cement-sand mortar brand not lower than M150.
Logs should touch the surface of the floor slabs without gaps. The voids between the beam and the base are recommended to be filled with fine sand or filled with mounting foam.
The minimum length of the spliced bars should be ≥ 2 m. Short profiles should be joined end to end to each other anywhere in the room with a seam offset in parallel logs by 0.5 m.
V doorways adjacent rooms, it is necessary to put a broadened beam protruding beyond the partition by 50 mm on both sides. This is done so that the finish coating in different rooms based on the same foundation.
The horizontal level of laying profiles is checked with a two-meter rack tool.
Before the installation of the finishing flooring, the space under the floor is cleaned of wood chips, shavings and debris.

Self-tapping fastening

When mounting on self-tapping screws, it is recommended to use hardware with a nickel-plated surface complete with plastic plugs with a protruding edge for the screw head. The diameter of the self-tapping screw is 3.5 mm, the length is selected taking into account the height of the log - 50-150 mm.

Drilled in lags through holes 0.5-1.5 mm smaller than the screw diameter. Holes for plugs are drilled in the floor slab using a perforator. Then a nylon dowel is inserted into the concrete floor and the profile is laid. Check the alignment of the holes and screw in the self-tapping screw. The horizontal level of the logs is adjusted with fasteners and substrates, loosening or tightening the connection.

Anchoring

Anchors provide a stronger hold than dowel-nails or screws. The principle of installing fixtures is the same as for self-tapping screws, but instead of a nylon dowel, a spacer metal sleeve is inserted into the base. Optimum diameter fasteners - 6-10 mm, length - 50-150 mm. Due to the high density of the connection, one anchor is sufficient per 1 m of timber.

Fastening the lag on a metal corner

Corner fixing.

The profile is fixed on either side to the base of the floor using a dowel or anchor. The lag is placed in the cavity of the corner and screwed with a screw. The distance between the fasteners depends on the length of the room and should be 35-50 mm.

The same procedure can be done using metal perforated brackets. In this case, the beam will be covered on both sides by the fixture shelves.

Adjustable fasteners for the floor base can be of 4 types:

plastic supports (columns);
studs with nut and washer;
polymer bolt-rack;
threaded bushings.

The most convenient are factory-made designs with through threaded couplings, which can be of the following sizes:

0.45 x 0.45 x 2.0 m;
0.45 x 0.70 x 2.0 m;
0.45 x 120 x 2.0 m.

They are supplied with threaded studs for adjusting the height of the profile and dowels for attaching the stud bolts to the base.

Mounting adjustable log.

Assembly order:

Before installing the structure, plastic stand-bolts are screwed into the holes in the profile, on which the logs will rest.
The bars must be placed parallel to each other with a step of 350-375 mm.
Then, holes are drilled in the concrete base for mounting vertical connections. A dowel-nail is baited into this place through the rack.
With the help of a special key, by rotating the mounting stand to the left and right, the horizontal level of the log is adjusted.
The dowel-nail is hammered to the stop, the reliability of the connection is checked and proceed to the next profile.

Fastening the lag to concrete pillars

Under the logs installed on, lay 1-2 layers waterproofing material(roofing material, etc.), the edges of which should extend beyond the boundaries of the base by 30-40 mm. A fiberboard substrate is placed on top of the insulation in one layer. Profiles are fastened with dowels or self-tapping screws.

Docking of the beam must be done only in the center of the monolithic support. Leveling the log level is done by changing the thickness of the linings.

Do-it-yourself step-by-step instructions for attaching a log to a concrete base

The simplest solution for installing a wooden covering on logs is to fasten the profile with dowels.

For the production of work, the following materials will be required:

Bar 50 x 70 mm.
Dowel-nail 8 x 120 mm.
Fiberboard sheet.
Polyethylene film.
Insulation mats.

Installation work:

We clear the room of unnecessary items and debris.
We cut out spacers 100 x 100 mm from the fibreboard.
With the help of a water level, we level the floor and mark the places for installing the lag on the walls (it is better to beat off a solid line along the contour).
We prime the surface.
Laying on the base polyethylene film. Each subsequent layer of material should overlap the previous one by 3-5 cm. We seal the joints with adhesive tape.
According to the marks on the wall, parallel to the window opening, we lay out the timber. We splice logs with a corner or perforated plates.
We begin the installation of the structure. To do this, in the lag farthest from the window, we make through holes, the diameter of which should be equal to the size plastic stopper dowel. The drill should pass through the body of the wooden profile and still capture 50-70 mm of the concrete base.
Firmly attach the item to the floor. We check the coincidence of the holes and install the dowel-nail.
Using the marks on the wall, we align the horizontal level with spacers and fix the profile with a hammer blow on the nail head. According to the same scheme, we install the next log at the doorway. Between them we stretch the cord on both sides and continue the installation.
When all the profiles are laid in place, the gap between the base and the joists formed as a result of level adjustment is sealed with mounting foam.
In the gap between the timber we lay the insulation mats and the transverse rails, we first fix the structure.

Step between lags

In accordance with the standards for the construction of wooden floor coverings logs are usually laid parallel to each other.

The distance between them depends on the following factors:

recommended section;

type and thickness of the finish coat.

Table for determining the step between lags.

If thin sheets of material are used for the top layer, then the distance between the lags should be reduced, and if a board 40-50 mm thick is used, the step can be increased.

The gap between the bars is calculated based on the area of \u200b\u200bthe room and the direction of laying the log. It should be borne in mind that with a decrease in the distance between the elements, the volume of purchased materials increases.

The distance between the central axes of the profile laid on the floor beams should be 0.35-0.45 m, in the case of mounting the structure on precast concrete - 0.6-0.7 m.

If a log is laid on posts with a beam thickness of 40-50 mm, the gap should be 0.8-1.1 m. With high operational loads on wooden base(200-500 kg / m²) the step between the installed profiles must be taken from the project documentation.

Fastening the log to the concrete floor using corners, anchors, and self-tapping screws, as well as the tools and materials used.

Before proceeding to the description of the methods for attaching the lag to the base, consider 2 FAQ:
Is it necessary to arrange the floor along the logs on the concrete floor or make a screed, and is it worth attaching the logs to the floor.
The device of the floor on the logs has a lot of advantages over the usual screed.

Construction weight. A wooden floor is much lighter than a concrete floor, which is more important in private construction, because. will make the floor slab thinner, thereby reducing the load on the walls and foundation.
The speed of production of works due to the absence of the need to wait 28 days of aging concrete mix.
The ability to insulate and soundproof the floor without additionally increasing the height of the structure. When using a mineral wool lag or other insulation is placed between them, while when using concrete screed- under the screed. wood flooring is warmer than concrete.
The ability to conduct communications (electricity and heating) in the space between the structures. In the case of a concrete screed, this can also be done, however, in the event of damage, repair will be much more difficult. There is an opinion that when installing a floor along lags, it is impossible to use a water-heated floor. This is not so, there are special ways to make it.
Additional space is formed under the floor, which improves air circulation
Lags can correct significant defects in the base

In general, if the height of the ceilings and others dimensional characteristics the premises allow you to make the floor according to the logs, the choice is unambiguous.

Do you need to fasten the joists to the floor? Professionals have only one answer to this question: definitely. Fastening the lag to the floor will allow you to avoid local deformation of the floor due to changes in the linear dimensions of the wood due to changes in humidity and the appearance of a creak.

Work materials

A wide range of materials can be used as flooring for the subfloor, for example, plywood with a thickness of 15-22 mm, OSB or chipboard 18-25 mm, tongue-and-groove floor board with a thickness of 25 mm or more or edged planed board of the same thickness, CSP if planned in the future laying tiles.

It is allowed to lay these materials in 2 layers, using sheets of smaller thickness. In this case, the sheets are stacked so that the joints of the sheets do not match. You can use layers different materials, for example, the lower one is chipboard, the upper one is plywood. The strength characteristics of plywood are higher than those of OSB or chipboard, so its thickness may be slightly less, but the cost of plywood is higher.

There is a stereotype that materials based on chips or chips emit harmful gases during operation, however, modern adhesives used for their production of most of their brands are absolutely safe for humans. When choosing a material, one should take into account the type of finished flooring, for example, plywood with crumbled knots is not suitable for laying linoleum, but it is quite suitable for laminate.

The material for the log is edged softwood lumber, it is best to use planed chamber drying. It costs a little more than boards of natural moisture, but it will not dry out during operation.

The cross section of the board is selected based on the required characteristics of the floor, usually these are bars 50 * 50 mm. Logs are usually laid in increments of 400-600 mm. The step and cross section of the lag are easy to calculate using special construction calculators. Logs must be treated with antiseptic wood impregnations to avoid rotting, fungus, mold and woodworm damage. You can treat them with flame retardants.

You will also need: an antiseptic for processing lumber; material for waterproofing (dense polyethylene, special films or waterproofing mastic); primer for dedusting the concrete base (optional, but it will help to avoid dusting the concrete); heat and sound insulating materials, usually mineral wool; self-tapping screws for fastening the rough flooring to the logs; materials for attaching the lag to a concrete base, linings for leveling the floor (plywood scraps, boards or special plastic linings are suitable), vapor barrier film, bars 20-30 mm thick.

Tools

For the production of work you will need the following tools:

roulette,
square,
pencil,
electric saw (circular or reciprocating) or electric jigsaw for sawing and cutting the coating;
perforator for fastening the log to the ceiling,
screwdriver,
grinder when mounted on studs,
chisel,
construction knife,
level,
broom,
brush.

Methods for attaching a log to a concrete base

There are several ways to fix the logs to the floor slab:

for self-tapping screws
anchors,
with special bushings
on galvanized corners or special U-shaped fasteners.

Self-tapping fastening

Self-tapping is the most economical way. Self-tapping screws should be galvanized, with a diameter of at least 4.2 mm, equal in length to the thickness of the logs plus 50-60 mm.

Through holes are drilled in the logs with a certain pitch, usually 500-600 mm, they are countersinked to hide the heads of the screws, the logs are laid out around the room, holes are drilled through the holes in them with a perforator in the ceiling to a depth of 60-80 mm, dowels are inserted into the holes and through the logs screws are screwed on.

If necessary, gaskets are placed under the beams for leveling. It is important to place the linings in the places of fastening.

Anchor fastening

Mounting on anchors is practically no different from mounting on self-tapping screws. Metal anchors are used instead of plastic dowels, bolts or studs are used instead of self-tapping screws. In the upper part of the log, a hole is drilled in diameter slightly larger than the washers used, in depth - to hide the bolt head or nut on the stud.

When mounted on anchors, the installation height of the log can be adjusted using nuts with washers screwed below the log. With this method of adjustment, you can do without pads. The protruding part of the stud is cut off by a grinder. Studs and bolts must be at least 10 mm in diameter

Mounting on special adjustable bushings

The sleeve is a plastic tube with an external thread, on one side of which there is a plug with a hole for a self-tapping screw. Through holes are drilled in the logs with a diameter slightly smaller than the bushing, the bushings are screwed into the holes obtained, the logs are laid out on the floor, leveled by unscrewing the bushings on desired height and are attached to the floor through the holes in the bushings. The part of the sleeve protruding above the lag is cut down with a chisel.

Fixing the lag on the corners

With this method, galvanized corners or special U-shaped fasteners are attached to the floor slab. It is recommended to use so-called reinforced corners or corners with a stiffener to give the structure greater strength. The easiest way to mark the places for attaching the corners is by spreading the floor beams around the room. They are attached to the base with self-tapping screws with plastic dowels.

The corners should preferably be different parties beams in a checkerboard pattern. It is important to bear in mind that the lag should rest on the ceiling or lining, and not hang on self-tapping screws.

Sequence of work

The first step is to assess the condition of the screed, if any, and prepare the base. In the normal state of the screed, you can leave it, but if it is cracked or lagged behind the base, it is better to remove it.

The floor slab should be carefully swept or vacuumed industrial vacuum cleaner. Some masters level the base with a self-leveling floor mortar in order to further simplify the leveling of the lag. In this case, you must wait until it dries completely. mortar mix otherwise the lags may start to rot. The drying time is usually indicated on the packaging.

Next, the base is treated with a deep penetration primer, which will avoid the appearance of dust in the future. Waterproofing is carried out to protect against the penetration of moisture into the insulation. For waterproofing, you can use a dense polyethylene film, a special moisture-proof membrane or waterproofing mastic.

Installation lag

The logs are sawn to size, a little less, by 25-30 mm, than the length of the room, treated with an antiseptic for wood, laid out on the floor, extreme 20-30 mm from the walls, the rest - with the desired step, set according to the level, attached to the ceiling with the selected way.

It is necessary to fasten them, observing strict horizontality, preventing even small fragments from sagging or sticking out. Best use for this laser level or a plane builder.

If linings are used, it is best to select them in thickness so that one piece is enough, you do not have to put several. It is recommended to fix the linings with liquid nails, silicone sealant or polyurethane foam.

Warming

vapor barrier

After installing the lag, you can lay electrical wiring or plumbing pipes between them. Next, the insulation is laid, a vapor barrier is attached to prevent the absorption of moisture from the air by the insulation. When installing a vapor barrier, it is important to follow the recommendations of the film manufacturer.

Subfloor installation

fastened rough coating gender. A gap of at least 10 mm should be left between the walls and the coating to avoid deformation due to thermal expansion. Also, a gap is left near the heating pipes and other elements passing through the floor. Sheet flooring (plywood, OSB, chipboard) should be laid apart, in a checkerboard pattern. At the junction of the sheets, additional logs are mounted perpendicular to the main ones in order to fasten the sheets together.

If a board is chosen as a coating, laying should be done perpendicular to the lags, along the length of the board they are joined apart. When using a grooved board, the tongue from the first board is cut off, the board is laid with a groove from the wall.

In general, there is nothing particularly complicated in the arrangement of the floor along the lags. As in the performance of any construction and repair work, first of all, accuracy, accuracy and scrupulousness in the implementation of recommendations are needed. building codes and rules.

One of the most important elements the sexual structure is a lag system. It is from the strength, the choice of the correct step between, the type of wood and the method of installation that the operating conditions of the finish coating will depend.

Choosing a beam for a log

Beams can have different cross-sections and moisture indicators

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

Humidity. When choosing any wood building material, the first thing to consider is its moisture content. If the bars 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 indicator humidity is optimal, because the risks that the wood will pick up 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 lag system is designed to serve as a strong support for the finish coat, so it must be strong. Choice the highest grade optional, because 2 or 3 wood grades will do. The strength of the lag will be compensated large quantity places of support, therefore the main thing is that the lumber does not have areas with mold and fungi. When using a leveling system, pay attention to the number and size of knots. They can become areas of fracture of the support.
Section. It will be possible to determine the shape of the section on the end side. It is necessary to choose the material that will have a clear rectangular shape. The optimal aspect ratio is 1:2 or 2:3, i.e. bars with a section of 50x100 mm and 100x150 mm, for example. In this case, the logs should fit on the edge. This position of the beam will be as resistant to vertical loads as possible. The choice of the beam section should be based on the step with 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 great for supporting a finished floor. For example, pine or spruce are perfect for normal conditions, but where expected high humidity, it is advised to use larch. It is more resistant to moisture and can provide a good service life.
Treatment. It is necessary to ask the sellers if their lumber has antiseptic treatment. If there is none, which often happens, then you will have to do it yourself without fail. In addition to the antiseptic, which will protect against mold and fungus, flame retardants are used to increase the refractory 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. So you can get rid of the likelihood that you will be slipped warped, which will be difficult to level, and you will have to plan a lot with a planer.

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.

Logs 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. Therefore, beams are used in wooden houses on the floors, and on the ground floor and supporting pillars.

Supporting wooden support beams on poles

Installation of support poles

The support posts are made of brick with a wooden lining, which should not allow moisture coming from the post to rot the wood of the beam.

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

After the concrete is poured and dried, bricks are laid on it one level at a time, which will also have a concrete structure inside. To do this, they leave in the process of pouring the concrete base under the pillars reinforcing wire to a height that will be necessary for the height of one pillar. The extra sections of the reinforcement are subsequently cut by the grinder.

Adjustable support for wooden floor beams

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

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

beams

A layer of roofing material is laid on the prepared pillars. In addition, in the process of manufacturing pillars, they are installed wooden lath as an overlay.

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

Fastening to wooden beams

Attach lags to wooden beams it will be easier than ever. As fasteners, it is advised to use squares. In this case, it is not necessary to fasten the logs on both sides. To save on fasteners for large squares, you can mount the corners in a checkerboard pattern.

Logs on the beams

When using fastenings on beams, it is better to refrain from rigidly fixing the supporting lamellas to the wall. It is worth using a corner mount with the possibility of shrinkage of the supports and movement of the self-tapping screw. At the same time, a technological gap must be left between the wall and the lags.

Fastening the lag to the concrete base

Screw for fastening logs and rails

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

A layer of waterproofing must be laid on the concrete base. Roofing material or ordinary polyethylene film can be used as a moisture-insulating material. In this case, the joints must be airtight, because they are glued with adhesive tape.
The choice of the lag laying step will directly depend on which finishing material will be used. For example, for floorboards with a section of 35–40 mm, a step of 60–70 cm can be used.
Using one log along the entire length of the room is not always possible. Therefore, it is necessary to carry out an even joint of the two parts so that the horizontal level at the junction coincides with the general level. To do this, they can use iron corners or special notches in a tenon-groove. If this is done across the entire width of the room, then it is better to carry out the lag connections in a checkerboard pattern so that subsequently the loads do not cause a break and deformation in this area.
First of all, the extreme lags are fixed. They will serve as beacons for leveling the rest of the bars. To set two bars at large distances from each other, you must use a laser level.
Attach the logs to the concrete base, depending on what their height is. Thin bars are fixed through with dowels and spacers, which are placed in pre-prepared holes. And high supports - special corners.

As a topcoat over the bars, you can use plywood sheets that will serve as a subfloor for laminate or parquet.

Fastening the lag to the strapping of the timber

When performing a lag system, they usually use a strapping of beams, which perform a reinforcing function and allow the lags to be installed at the same level. In order to fix the logs to the strapping, they use a simple method - the corners and brackets are installed on self-tapping screws. At the same time, the latter are advised to put on slightly at an angle so that the logs cannot loosen during operation.

How to attach logs to the harness 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 fasteners connect the bars with a concrete base, squeaks may subsequently occur, and fasteners only for strapping will not cause this.

There are many various ways fasteners, which must be used according to the situation.

On the video you can see how best to mount wooden logs in the loggia in an adjustable way:

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Two weeks ago I put plywood on the logs, the screed was present.

Sweep and prime with penetrating primer
- With a water level we transfer the floor mark from under front door, taking into account the clean floor (which now, in general, is unknown what it will be, so I took the maximum margin - 2 cm). We transfer to the wall, raising it by 1 m.
- We make several level marks +100 mm on the walls with a water level.
- Starting down from the +100 marks, we draw a height contour (-18 mm) on the walls along the perimeter
- Calculate and draw on a sheet of paper the scheme of laying plywood sheets and the log - taking into account that the joints (longitudinal or transverse) of the sheets should lie on the log, etc.
- We form linings for logs from 1 layer of glassine (to the screed) and pieces of fiberboard 3.5 (as well as layered fiberboard) 8 by 12 cm in size.
- Approximately lay the extreme log on the lining, then with a level and a tape measure we achieve three parameters - height (the outline on the wall helps), horizontality and the desired distance from the walls
- having stepped on the log, we drill the log, lining and screed through the win 6.0x300, insert the plastic dowel at 6, and using the "thick" long (4x90) self-tapping screw as a doboy, drive the dowel all the way with a hammer. We unscrew the self-tapping screw, screw in a 3.5-thick self-tapping screw of suitable length, tighten it, the head sinks 1-1.5 cm in the log.
- With even planed lags, you can step over one self-tapping screw and screw in the next one, the rest later.
- We fix the log at the opposite wall
- We fasten the intermediate logs, checking the thread stretched between the extreme ones. You can lay logs through one, and then without a thread - at a level of 1 m or a short rule.
- Install all lags
- We lay glassine between the lags
- We put noise insulation on glassine (something like a thick padding polyester, although after a long search we found something natural, which we were glad about)
- We attach 2 mm soundproofing (something like thin dense foam rubber) on top of each lag over the entire surface with double-sided tape
- We put a sheet of plywood according to the scheme
- We impose a pattern of fiberboard on the plywood area above the lag - a 152cm x4cm strip with holes at an equal distance, mark the drilling points with a pencil.
- We insert a 3 mm drill into the drill until it stops - so that only 25 millimeters sticks out, we drill a hole until it stops, while the lower edge of the cartridge countersinks a hole for the screw.
- We screw 41-45 mm self-tapping screws until the head is completely buried.
- Before laying an adjacent sheet in those places where the second joint fundamentally falls into the space between the lags, we fasten (in advance!) A small bar of 10 cm exactly in the middle, the protruding part of which will be a support for the adjacent sheet, which is also screwed to it.
- Look like that's it...

Important:
- We put plywood apart
- When splicing the lag, we do not allow the repetition of the splicing place on neighboring ones in order to avoid the effect of "folding"
- At the stages of laying the lag, it is very useful to sometimes impose a sheet of plywood and see how it all turns out in reality
- When splicing the lag, we do not allow line violations - we splice by applying additional. bar on the side - so as not to guess later where to screw
- In case of an uneven screed, when choosing the level of the subfloor, we take into account the level of the highest point - so that even when the log is trimmed, it does not become thinner than 30 mm.
- In the case of laying on slabs, cleaning and foaming of joints are added to the work
- About the bundle was recently posted
- Sometimes (always?) already after fixing the lag, in some places you find differences in height (the level "mumbles"). To straighten the "holes" we use additional. gaskets made of fiberboard with a cut to the middle (so as not to completely unscrew the screw), to straighten the bumps, either we pull out the excess, or we clean off these miserable 0.5 mm with large sandpaper. We even built a "two-handed" nazhd for this purpose. on the bar - very effective. Maybe because there was no planer in this apartment :)))

After leveling the log, the level of 1m, after a small push, slid freely across the log without stumbling - it’s very nice to watch :))) The black floor itself almost does not sound (and they were very afraid of it), and after laying the finishing (any) I think it will completely calm down.

Logs pine (dry ???) 50x50 and 50x40, distances between logs 35-45 cm, plywood FK 18, non-sanded, lag fixing pitch - 50 cm, pitch of self-tapping screws on plywood - 16 cm.

A lot of me taken from a respected forum.

I won’t write about my wife’s exclusives like “pouring a bottle of lavender oil evenly on the soundproofing under the floor”, implemented by us - this is an amateur :))))

I will be glad if it helps, as well as if there are additional. questions.
Photo here:
http://mfoto.ru/ru/470797778

And, of course, the inevitable criticism...

Sincerely,

There are two main ways to prepare a suitable horizontal base for the laying of floor coverings currently in use: screed and subfloor laid on load-bearing beams. In order for the flooring to be durable, not change its geometry under load and at the same time serve for a long time, it is necessary to properly fix the lag to the concrete floor or other supporting structures that are provided for in specific situation. The article will discuss the devices with which you can attach wooden rails, as well as how to use them, some of which can be viewed in the attached thematic video materials.

How to choose a beam for a lag?

Correct selection lumber, which will be used for the construction of the flooring for laying the finish coating, will guarantee the durability of the structure, and its ability to withstand the proposed loads without deformation of the surface. What should you pay attention to first of all?

Humidity. The beam, which is usually used as a log, must be dry. Moisture content of wood, regardless of the species used, at the moment installation work should not exceed 18%. This is a natural moisture indicator for lumber. That is, the likelihood that moisture will occur or, on the contrary, further drying of the wood (both processes lead to deformation) with this moisture index is minimal.
Type of wood. Logs, unlike beams, have more support points, the number of which can always be increased. So the type of wood does not play a special role. Grade 2 or 3 lumber is quite suitable. If a large knot or other defect affecting strength is found in the beam, it is enough to install an additional support in this place.
Section. The main requirement is the shape of the butt. It is necessary that the cross section of the timber be rectangular, with an aspect ratio of ½ to 2/3. In this case, it will be correct to put the lag on the edge. In this position, the bar is maximally resistant to vertical load. The size of the section is selected so that its larger size allows you to lay a sufficient layer of insulation, and the smaller one allows you to lay and attach (taking into account the possible joining of fragments) a board, plywood or OSB without any problems. The strength of the lag can always be increased by installing additional supports.
Type of wood. For a lag, they usually choose an inexpensive scaffolding conifers - suitable pine or even spruce. It is advisable to put larch bars where high humidity is expected.
Treatment. The bars dried to the desired moisture content should be treated with protective impregnations. This will make the wood resistant to moisture, microorganisms and insects. If desired, it can be treated with flame retardants, which significantly reduce the combustibility of wood.

Important! Attention should be paid to the relief of the surface of the beam to which the board or board material. If there are irregularities on it, they should be removed with a planer. This must be done before installing the lag.

Properly selected and processed lumber is half the battle. Now let's look at how to properly attach the logs to the base, including concrete, in various situations.

Laying lag with slight floor insulation

This situation usually happens in apartments where the ceilings are low, so it makes sense to save space as much as possible. Moreover, there is a heated room below, so a small layer of insulation is enough, which is more needed as a sound insulator.

In this case, a small section of the lag is selected, which are laid directly on reinforced concrete slab or small regulators wooden coasters. There is no special need for waterproofing in such a situation. An exception is when the apartment is located on the ground floor above a damp basement. Then it makes sense to cover concrete surface polymer film or treated with bituminous mastic.

In this case, metal corners or anchors can be used as fasteners. There is no need to firmly attach the bars. Such a fixation of the lag is enough so that they do not move during the laying of plywood or boards. Professionals sometimes do not fix the guide bars at all if they are in a stable position, since the lag frame does not experience other loads, except for vertical ones, during operation. An example of such a situation can be seen in the video below. floor board or sheet material(plywood, OSB), when rigidly connected to the underlying supports, form a monolithic shield that does not have the possibility of lateral displacement.

How to fix the logs at a distance from the concrete floor?

This option for installing load-bearing beams is used if you want to lay a thick layer of insulation or simply raise the level of the floors. A similar situation arises when installing a wooden floor on a rough concrete base made on the ground, on loggias and balconies. This also happens in living rooms apartments, when, with large differences in the position of floor slabs, there is a desire to make the floor surface on the same level.

If it is necessary to significantly raise the log above the plane of the slab or concrete screed, two devices are most often used to help adjust the position of the bars and securely attach them. These include:

screw adjustable supports;
metal brackets.

Screw fasteners have an extended support platform that is connected to a vertical threaded pin. The lag is attached on top with nuts. By screwing in / out of the screw, it is possible to accurately and conveniently adjust the position of the bars, exposing them in the same horizontal line.

Important! Screw supports are the most expensive fixtures for installing load-bearing bars. They are usually used when installing floor structures over large areas.

The brackets are U-shaped and are different heights. First, they are attached to a concrete base along a line with a calculated step. Then a beam is inserted into them and fixed with self-tapping screws on both sides or a through bolt.

Atypical situations

Sometimes at home old building when trying to replace a wooden floor with a new one modern design, you have to deal with atypical floor slabs. In these cases, one has to think non-standard ways laying and fastening lag. One such situation is described in detail in the following video. As you can see, in addition to the standard methods of fixing the bearing bars, you can come up with many more methods. In fact, it does not matter how the lags are attached, the main thing is that they are correctly located in the horizontal plane and withstand vertical loads.