Fasteners for floor joists. How to attach joists to a concrete floor. Fastening joists using anchor bolts

Wooden floors are a convenient solution. They are environmentally friendly, wear-resistant, natural and have beautiful view. But what should owners of apartments and houses with concrete floors do? How to install wooden floor joists on a concrete floor? In fact, this technology has been proven, and now we will look at it.

Rigid fastening of the log to concrete floor

Floor construction on joists

A floor on joists is a structure that consists of several functional elements, among them the mandatory ones:

base;
bars;
flooring.

Between the beams and the finished floor, a subfloor can also be installed, but only in private houses where there is room for deepening, because such tiers take away the height of the room.

For correct installation Rigid fastening of the base beams is required to avoid deformations and shifts of the finished floor and creaking. Although there are opponents of this technique who give arguments regarding the violation of thermal insulation and the destruction of the concrete screed.

Forming a floating floor, that is, without fastening it to the screed, can lead to shifting of the coating. And this is fraught with additional installation costs.

The assumption of deterioration in sound insulation is unfounded, since during installation materials for insulation and sound insulation are used. And concrete itself is not considered a conductor of sounds. Therefore, after laying the new flooring its sound is unlikely to change.

Another argument regarding the destruction of concrete also does not have a clear justification. If the screed is of high quality, then drilling will not harm it, much less destroy it. If such defects are found, you will have to re-prepare the subfloor, because a poor-quality one will not withstand even minimal loads.

Leveling the floor with self-leveling mixtures

What do you need to know before starting work?

Before attaching logs to a concrete floor, it is recommended to understand the specifics of such work and select necessary materials and tools. The main thing is the choice of wood, that is, beams. The strength and durability of the structure depends on this, its performance characteristics, the load it will withstand

Material selection criteria

Humidity. The material must be dry, with a moisture content of no more than 18%, and this does not depend on the size or type of wood. This humidity is considered natural, so there should be no difficulties in selecting suitable joists for installing boards. When moistened or dried out in the future, the material will “lead” and the beams will deform the finished floor.
Type of lumber. In this case, the type of wood is not critical, because the joists have many support points, and their number can be increased if necessary. Moreover, their appearance under the floor doesn't matter. That is, bars of 2 and even 3 grades are suitable. If there is a knot in the area of the material that can affect the strength, an additional support is mounted underneath it.
Section. A wooden floor on a concrete base will last a long time, provided correct selection sections of support beams. It should be rectangular, aspect ratio ½ or 2/3. In this case, the logs are mounted on the edge. In this position, the beam is maximally resistant to vertical load. Another condition for choosing a section is the ability to lay the required amount of insulation, because in the case of installation on a concrete base this is important.
Breed. Optimal solution– softwood material. Pine and even spruce are available and have the required specifications. Larch should be used in rooms where high humidity is possible.
Treatment. Before installation, each beam is treated with fire retardants and bioprotection - this will extend their service life.

Waterproofing on concrete floor

Important! After selection, the material is prepared for installation. Each beam is checked for irregularities, bevels, and protrusions. If they are found, they are removed using a plane. It will not be possible to do this when the beams have already been laid.

Tools

Preparation is half the battle, and if you already have the material, now all that’s left is to find the tools to attach the wooden joists to the floor. Since the work involves concrete and wood, the entire set is designed to work with these materials. Minimum list:

perforator;
anchors - fasteners are selected depending on the size of the beam and its cross-section;
self-tapping screws - their diameter is 6 mm, the length also depends on the parameters of the wood, dowels should be included with them;
carpentry tools: hacksaw, plane, circular saw.

The second and third items of the set are interchangeable. Self-tapping screws will cost less, and with their help you can install the joists efficiently. As for anchors, although they are more expensive, their number is less square meter less. At the same time, laying the joists will be faster, since you will have to drill less. What to choose depends on time and financial capabilities.

Beam level control

Preparing the base

During installation wooden flooring For logs you need to take care of a level base. It is recommended to pre-level it if there are differences in level. An uneven concrete floor will be projected by an equally uneven wooden floor. It is difficult to properly lay beams on such a base. For leveling, special filling mixtures are used, which are also called self-leveling. After their use, the concrete in the base without special effort will become smooth.

Fastening the beams

Attaching the logs to the concrete floor is carried out according to the following algorithm:

Waterproofing is laid on the concrete floor. It is more convenient to use plastic film, but roofing felt will also work. The canvases are secured to each other and placed on the walls to a height of at least 10-15 cm. The joints are taped with special tape.

Floor elements on joists on concrete

Next, the beams are laid out with a predetermined step, it must be uniform, and the distance from the wall to the first beam is no more than 15 cm. The distance between the logs should not exceed 80 cm. It all depends on the area of the room and the load on the future covering. The distance between the joists also depends on the thickness of the floorboard: the thicker it is, the wider the beams can be attached.
Before putting the logs in spacious room, you will have to think over a system for joining the support elements to each other. For this, metal plates, iron corners and other fasteners can be used.
The first to attach the logs to the walls. They are laid in the place where they will be placed and leveled; if necessary, the height is adjusted using wooden slats.

Note! To ensure that the beams lie evenly together, it is recommended to use laser level.

Insulation between joists with expanded clay

Now holes for installation are drilled in the base of the concrete floor and in the timber. Fastening is carried out using self-tapping screws or anchors. For the first fasteners, a step of at least 40-60 cm is observed; as for anchors, their number can be reduced by 2 times.
After you have managed to attach the first 2 beams, a nylon thread is pulled between them - this is the level of overlap along which the rest need to be mounted. Such a guideline should be stretched at 3-4 points along the length of the beam.

Installation of plywood sheets on wooden joists

The remaining logs are attached using the same mechanism as the first two, while maintaining the level set by the nylon thread.

After installation, insulation is carried out along the joists in the space between them and a vapor barrier is laid. The base is now ready for installation of the floorboards.

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

Before moving on to the description of methods for attaching the lag to the base, consider 2 frequently asked questions:
Is it necessary to install the floor using joists over the concrete floor or make a screed, and is it worth attaching the joists to the floor?
Installing a floor using joists has many advantages over a conventional screed.

Structure 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.
Speed of production due to the absence of the need to wait 28 days of aging concrete mixture.
The ability to insulate and soundproof the floor without additionally increasing the height of the structure. When using mineral wool lag or other insulation, it is laid between them, while when using a concrete screed, it is placed under the screed. Wooden covering itself is warmer than concrete.
Possibility to carry out communications (electrical and heating) in the space between structures. In case of concrete screed This can also be done, but if damaged, repairs will be much more difficult. There is an opinion that when installing a floor using joists, it is impossible to use a water-heated floor. This is not true; there are special ways to make it.
Additional space is created under the floor, improving air circulation
Lags can correct significant foundation defects

In general, if the height of the ceilings and other dimensional characteristics of the room allow you to make a floor with joists, the choice is clear.

Do I need to attach the joists to the floor? Professionals have one answer to this question: definitely. Attaching the joists to the ceiling 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 creaking.

Materials for work

As a flooring for the subfloor, you can use a wide range of materials, for example, plywood with a thickness of 15-22 mm, OSB or chipboard 18-25 mm, tongue-and-groove floor boards with a thickness of 25 mm or more or edged planed boards of the same thickness, DSP if later planned laying tiles.

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

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

The material for the logs is edged lumber coniferous species, it is best to use planed chamber drying. It costs a little more than boards natural humidity, however, will not dry out during use.

The section of the board is selected based on the required characteristics of the floor, usually these are 50*50 mm bars. Logs are usually laid in increments of 400-600 mm. The pitch and cross-section of the lag can be easily calculated using special construction calculators. The logs must be treated with antiseptic impregnations for wood to avoid rotting, the appearance of fungus, mold and damage by wood-boring insects. You can treat them with fire retardants.

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

Tools

To carry out the work you will need the following tools:

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

Methods for attaching joists to a concrete base

There are several ways to secure the joists to the floor slab:

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

Self-tapping screws

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

Through holes are drilled into the logs with a certain pitch, usually 500-600 mm, countersunk to hide the heads of the screws, the logs are laid out around the room, holes in the ceiling are drilled through the holes with a hammer drill to a depth of 60-80 mm, dowels are inserted into the holes and through the logs screws are tightened.

If necessary, spacers are placed under the beams for leveling. It is important to place the pads in the fastening areas.

Fastening to anchors

Fastening with anchors is practically no different from fastening with self-tapping screws. Instead of plastic dowels, metal anchors are used, and instead of self-tapping screws, bolts or studs are used. A hole is drilled in the upper part of the joist with a diameter slightly larger than the washers used, and a hole in depth to hide the head of the bolt or the nut on the stud.

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

Mounting on special adjustable bushings

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

Attaching joists to 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 to lay out the floor beams around the room. They are attached to the base with self-tapping screws and plastic dowels.

It is advisable to place the corners on different sides of the beam in a checkerboard pattern. It is important to take into account that the joists should rest on the ceiling or linings, and not hang on self-tapping screws.

Sequence of work

The first step is to assess the condition of the screed, if there is one, and prepare the base. If the screed is in normal condition, you can leave it, but if it is cracked or detached from the base, it is better to remove it.

The floor slab should be thoroughly swept or vacuumed with an industrial vacuum cleaner. Some craftsmen level the base with a self-leveling floor mortar to make it easier to level the joists in the future. In this case, you must wait until it dries completely. mortar mixture, otherwise the logs may begin to rot. The drying time is usually indicated on the packaging.

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

Installation of logs

The logs are cut to size, slightly smaller, 25-30 mm, than the length of the room, treated with a wood antiseptic, laid out on the floor, the outermost ones 20-30 mm from the walls, the rest - with the required pitch, set according to the level, attached to the ceiling of the selected way.

It is necessary to fasten them while maintaining strict horizontality, preventing even small fragments from sagging or protruding. It is best to use a laser level or plane builder for this.

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

Insulation

Vapor barrier

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

Installation of subfloor

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

If a board is chosen as a covering, the installation should be done perpendicular to the joists, and the boards should be joined staggered along the length. When using a tongue-and-groove board, the tongue from the first board is cut off, and the board is laid with a groove away from the wall.

In general, there is nothing particularly complicated about installing a floor using joists. As with any construction and repair work, first of all, accuracy, accuracy and scrupulousness in following recommendations are required building codes and rules.

New technologies for laying floors have not been able to displace logs from construction, which are used as a base for wooden floors. The only drawback of logs is that after their installation the height of the room is significantly reduced, so it is more advisable to install logs in houses and apartments with high ceilings.

How the lags are attached to a concrete floor will be described below, but for now it’s worth talking about the advantages of such a flooring device over others. In the space underneath you can place electrical and other cables, as well as pipelines, for the installation of which you do not have to cut walls. In addition, floors on joists turn out to be much warmer not only because they are made of wood, but also because of the ability to lay insulation between the base beams. In addition, additional sound insulation of the room is provided. It is worth adding that the concrete base will be the most reliable support for lathing wooden floors.

Preparing the base before laying the logs

Most residential buildings have concrete floors. To lay the logs, they only need to be properly prepared. Of course, such work is quite labor-intensive, but for the long life of the wooden floor it is certainly worth the effort.

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Pouring the foundation for joists in a country house

For those who build houses on suburban areas, we can advise not to lay the logs on the ground, but to arrange them on concrete, because even compacted soil does not have the same strength as a concrete floor. The easiest way to pour a concrete base is around the perimeter of the strip foundation.

Concrete is poured onto a compacted and horizontally leveled bedding made of sand, crushed stone or AGS, the surface of which must be carefully smoothed to prevent breakthroughs of the waterproofing film laid on it. The ceiling must be reinforced. To do this, reinforcement or rods are placed on top of the waterproofing. There must be a gap between the reinforcing lattice and the bedding so that after pouring the concrete, the reinforcement will be thicker. After the concrete has completely hardened, which lasts about a month, a leveling screed is poured.

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Apartment floor repair

Those who are going to lay joists in apartments where concrete floors were installed during the construction of houses should not “relax” either. More often than not, it turns out that foundation repairs are inevitable. True, in some cases it is possible to lay joists on a concrete floor without precisely leveling it (one of the sections will be devoted to this method), but it is imperative to bring the ceiling into proper shape.

The first priority in preparatory activities- remove old flooring. After this, the old screed is removed. Often it ends up in a dilapidated state. To remove it you will need:

perforator;
construction hammer;
shovel.

Using a hammer drill or crowbar, the old screed is removed down to the solid base. Noticeable protrusions also chip off it. After cleaning construction waste Cracks and depressions in the ceiling are sealed with mortar. After this, the base should be thoroughly dried. In the future, all operations both in apartments and in houses under construction are performed in the same way.

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Preparing the base for leveling

Apply to dry base antiseptic composition and primer. After this, the overlap is processed bitumen mastic in 2 layers. The mastic is also applied to the walls to a height equal to the thickness of the future screed. Please note that the smoother you make the screed, the easier it will be for you to install the logs, which all you have to do is lay them on an ideal horizontal surface. Therefore, create a plane before filling it. This operation is simple, but requires patience and precision in marking. To do this you need:

painting cord;
hydraulic level;
dowel-nails;
roulette;
synthetic threads;
gypsum;
beacon profiles.

Make a chalk mark on one of the walls (near the corner). Apply it at any height. Using a level, place a point at the opposite end of the wall. Stretch a cord rubbed with chalk between the marks and, pulling it back, beat off a horizontal line on the wall. Make lines on the other walls in the same way. Using a tape measure, determine the point on the floor furthest from the chalk line. Place a mark opposite this point on the wall, move up 2-3 cm from it and place another mark. This will be the level of the future screed.

Measure the distance between it and the chalk line and place marks along it near the corners of the walls. Pulling the cord between them, beat off horizontal lines. Along them, drive 3-4 dowel nails into each wall. Pull the thread between the opposite surfaces.

The screed plane is ready. Now you can place beacons under it. They head from the far wall towards the entrance. The extreme profiles are located 15 cm from the walls. The distance between the beacons should be 20 cm less than the length of the rule. The profiles are attached to the base with gypsum cones, the pitch of which is 30 cm. After the gypsum has hardened, the solution is poured and leveled with the rule.

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How to prepare the bars?

While the screed is drying, start preparing the lag. It is best to use coniferous wood for them. When purchasing, choose the straightest beams. When calculating their number, you need to take into account:

the distance between the walls of the room (it is better to avoid laying composite logs);
the thickness of the floor covering, on which the distance between the beams depends.

The table shows the dependence of the floor joist pitch on its thickness.

The following table provides data on the relationship between the distance between the joists and the thickness of the plywood or OSB floor.

It should be noted that plywood and OSB are superior in strength to solid wood materials.

After purchasing floor joists, they must be thoroughly dried.

Drying of the beams is carried out in a closed area sun rays indoors.

Figure 1. Diagram of an adjustable stand with sound insulation.

Drying time takes 10-12 days. The logs are laid at a certain distance from each other, and transverse bars are laid between their rows (every 0.7-1 m). Gradual drying of wood does not guarantee that all logs will retain their original shape, so they should be purchased with some reserve.

The screed froze and the joists dried out. You can start installing them. In front of it, waterproofing made of polyethylene or bitumen is laid on the floor. The beams are treated with antiseptics and fire retardants. After this, their installation begins.

When building houses made of wood, builders often wonder about fixing the timber to the concrete floor, because these are two different materials, which means the fastening technique will be different. Wooden beams are secured using two methods: overhead installation and rigid fixation. Attaching the joists to the concrete floor will not only increase the thermal insulation of the premises, but will also hide possible unevenness of the concrete surface.

Appointments

Before installing a decorative coating on the floors of buildings and structures, use the beams on the surface made of concrete mortar. Using logs, a high-quality frame is obtained, suitable for further laying of coverings. In addition to the fact that the bars are an intermediate structural element, they also have the following purposes:

provide the room with additional air flow;
create sound absorption in the room;
increase thermal insulation, thereby reducing heating costs;
allow you to hide engineering Communication;
create uniform loads on the foundation;
provide the surface with an even structure, which is necessary for the finishing coating.

To attach logs to a concrete surface, you first need to maintain a certain gap between them. Use a board with a thickness from which the step size will be based when laying the beams on concrete. So, a board, two centimeters thick, is fixed to the beams in increments of 200 mm.

How to choose the right material?

In order not to make a mistake with the choice of material, take into account the following points:

price;
cross section in joists;
variety;
the wood from which the logs are made;
length.

If your budget is limited, you don't have to buy expensive wood. Fir and spruce have no less service life if the material is processed correctly. It is not necessary to choose a flat surface and solid color, these indicators have no meaning. However, it is important to pay attention to humidity, which should not exceed 20%. Before use, the material is kept at home for a year, this will allow the lag to accept the humidity of the room and dry out.

Tools

To attach the joists to concrete surface, you need to use tools for both wood and concrete. The following tools are used:

jigsaw;
perforator;
chisel;
anchors, screws.

To install an anchor frame for floors with joists, the following tools are used:

hacksaw;
building level;
hammer drill

You can secure the adjustable frame in a concrete field using the following tools:

chisel;
finisher;
laser level;
drill and bit;
hammer.

To fix the concrete floor to the joists, fasteners are chosen based on the budget. Self-tapping screws are cheaper than anchors, but the latter are more reliable. Anchoring fasteners allow you to attach wooden beam to the floor surface, pressing it, this is important when constructing a massive concrete surface.

Mounting methods

To attach the logs to the concrete floor, two types of timber laying are used. One of them is the lack of fastening of the joists to the floor. This method provides structural rigidity by fastening the lags to each other using a board. The disadvantage of this method is the possibility of shifting the floor covering. To avoid such a problem, fasten the log to the surface with anchors, corners or self-tapping screws.

Another fastening method is to attach joists to the concrete surface. Installation includes application thermal insulation materials and floor surface leveling solutions. This option for installing logs will save on expensive insulation materials.

Self-tapping screws

Fastening the beams into the concrete surface using self-tapping screws significantly reduces the cost of the structure and simplifies the installation work. To do this, holes are made through the board using a drill, and points at the base of the floor are marked through them. This is necessary to make recesses in the coating and screw in the screws. The installation step should be within 4-8 centimeters. The distance between the holes is affected by the structure being manufactured. Self-tapping screws are used in a length depending on the thickness of the timber, but it should not be less than 0.5 cm. Experienced builders It is advised to choose self-tapping screws that have a so-called neck, this means that there is no thread in front of the head, which makes it possible to better attract the board to the floor surface.

Anchors

By using anchors in construction, greater resistance to tearing out is ensured. Which justifies the high price of the material. Their use is relevant in the construction of heavy structures with a large load on fasteners. Installation of anchor fasteners on a concrete surface is carried out according to the following instructions:

Holes are made in the board and marks are made on the concrete through them. I make the same holes in the joists so that later I can hide the bolt heads in them.
Using anchors, reliable fastening of the beams is ensured.
Next, the locking elements of the anchor are placed into the resulting holes in the base of the floor, after which a bolt is screwed into them.
The length of the fastener is different and can vary from 45 mm to 200 mm. The length and diameter of the anchor fasteners are affected by the thickness of the beams.

Corners

Fixing wooden blocks using corners occurs as follows:

One of the sides of the corner is attached to the wooden base with screws. The insertion depth should be at least 0.3 cm.
When fastening, you need to rest the free side of the corner on the floor. It must be fixed using the same method as fastening anchors and self-tapping screws, i.e., make through marks and insert dowels into them and screw in self-tapping screws.

Installation of a floor base using adjustable joists is relevant today due to its significant number of advantages. These include:

elimination of surface irregularities;
defects in the base of the floor in the form of cracks are hidden;
Sound insulation and thermal insulation are provided;
protection against fungus and rot is obtained.

Highly reliable fastening is obtained due to the presence of plastic bolts, which are a fastening and adjustable element. This design allows you to make a wooden floor on a concrete base of decent quality in a short time.

A significant advantage of this mount is the possibility of adjustable lags. This happens due to ventilation features fastenings Applying adjustable joists, it becomes possible to hide utility lines. And possible thermal insulation will reduce heating costs.

One of the most important elements The floor structure is a log system. The operating conditions of the finishing coating will depend on the strength, choice of the correct pitch, type of wood and installation method.

Choosing timber for logs

Timbers can have different sections and humidity levels

As already mentioned, it is the floor joists that perform one of the most important functions. Therefore, so that the floor coverings serve properly long term, you need 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 endure 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. Choice of the highest quality optional, 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 cross-sectional shape can be determined by end side. It is necessary to choose a material that will have a clear rectangular shape. Optimal ratio sides - 1:2 or 2:3, i.e. beams with a 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 sellers whether their lumber has 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, to concrete floors and to the 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 beams are used wooden houses on the floors, and on the ground floor and 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 a sand cushion is made. 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! Plank flooring is usually oriented in the direction of the sunlight 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 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 material or ordinary polyethylene 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 general level. To do this, they can use iron corners or special cuts in 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 concrete base subsequently, squeaks may occur, but fastening only to the harness 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 logs in a loggia in an adjustable manner:

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