How to set logs by level. Leveling the floor with plywood along the joists: a guide to action. Design features of the installation

A variety of methods and materials can be used to construct floors. Floors on logs, which can be installed on any base, including floors on the ground, are considered popular. The main structural element is wooden logs; they are laid in a certain order. A heat insulator is installed between the logs, and communications can be laid. Then the rough sheathing is sewn on top. Usually plywood, chipboard, OSB, and ordinary wooden boards are used, which often act as flooring.

Installation of floor joists can be carried out using various methods, it all depends on the need to level the surface and other installation conditions. When laying, all steps must be followed exactly; the wood will first have to be treated with an antiseptic and fire retardant to ensure protection from insects and fire.

What are the advantages of lag?

Floors on joists have certain advantages over other structures. It turns out not only durable, but also warm. This flooring allows you to level the surface and create a high-quality flooring for soil foundations in private homes. Among the advantages it should be noted:

The logs place the minimum load on the foundation.

1. Thermal insulation characteristics, such a floor allows you to avoid heat loss.
2. Lumber for work has an attractive price; it is much cheaper than concrete screed, which requires some experience in arrangement.
3. There is minimal load on the foundation, this is significant for frame and dilapidated houses. Such floors are also suitable for wooden floors.
4. The floor can be installed at any level required.
5. The consumption of building materials is minimal, which has a positive effect on the budget.
6. Construction time is minimal; there is no need to wait for the mortar to harden, except for floors on the ground, where pouring is done under the supports.
7. An optimal microclimate is created inside the room.
8. You can make joist floors yourself; no special experience is required.

During installation, you need to correctly determine in which direction the logs will stand. There are rules for installing subfloor joists. The finishing flooring is always carried out parallel to natural light, and the logs should go in the opposite direction. This should be foreseen in advance so that you don’t have to correct everything later.

If laying the floor is planned for rooms with high traffic volumes, then the logs must be laid in the direction of travel in order to strengthen the structure and prevent it from loosening. It is important to immediately foresee how the floor boards will go, how the sheathing slabs will go if plywood is used. All fasteners for the finished floor must be on the joists themselves to make the flooring durable.

Methods of fastening and installing joists

To secure the joists to the base, you can use various methods. Previously, nails of the required size were used for this, but this method is not the best and most durable; such fasteners quickly fail. Today, the best method is to use galvanized metal corners and dowels.

Instructions for fastening the joists:

1. All metal corners are attached with self-tapping screws. One plane of the corners is fixed to a wooden beam.
2. Self-tapping screws are screwed in to a depth of 3-5 cm.
3. The lower plane is attached to the beam of the lower trim.
4. For brick supports, it is necessary to apply a layer of waterproofing, and then additionally make fasteners from dowels.

Instead of corners, you can use a special fastening in the form of a U-shaped part. It provides a strong fixation, especially if the bars have to be extended. This method is applicable for large rooms where additional fasteners are required.

The joints for the joists themselves can be arranged in this way:

1. Right next to each other.
2. Using a notch. This method of joining is the most effective, but it is necessary to carry out the cutting very carefully so that the joints are tight.

If it is necessary to strengthen the joint, nails are used to stitch the fastening area.

Additionally, you can use pieces of lumber, which can be approximately 1 m long. If the beams are mounted staggered, then a step of 50 cm or more must be observed between the connection points.

Installing a floor on the ground

Installing floors on joists is not as difficult as it might seem at first glance. They have a simple design; they can be made for an apartment, private house, or country cottage. Unlike concrete pouring, the weight of such a structure is less, but the floor is in no way inferior in strength.

To install logs, you need to follow fairly simple instructions:

1. First, the soil base is inspected, after which the soil is thoroughly compacted with a vibrator. If there is no such equipment, then the work can be done with a piece of large diameter log.
2. A layer of crushed stone is then poured onto the ground; it should be approximately 5 cm. This layer will serve as the base.
3. After this, it is necessary to construct the formwork for each support separately. A preliminary diagram of the location of supports is drawn up in accordance with the size of the room and the conditions of construction of the entire structure. If the formwork is ready, then pouring can be done.
4. Next you need to build brick supports. In this case, a layer of waterproofing must be provided between the supports themselves and the base. This will reliably protect the structure from moisture. Another layer of waterproofing should be done over the brick support and a soundproofing gasket should be installed.
5. Next, floor joists are installed. The boards are pre-cut into pieces of the required size, and then their surface is treated with an antiseptic and fire retardant. This will protect them from damage by insects, from mold, and make them more protected from fires.
6. The logs are fixed to the supports with special dowels, which ensure reliability and stability. After this, you can lay a special cranial block, make a primary plank flooring, you can use ordinary boards for it. After rolling, you can lay out another layer of waterproofing material.
7. A heat insulator must be installed between the joists. Various materials can be used in this capacity. Manufacturers offer a wide variety of insulation materials suitable specifically for floors on joists. In this case, you can take expanded clay, other bulk materials, foam boards, mineral wool boards.
8. During insulation, it is necessary to ensure that there are no air gaps or cavities left, as this will negatively affect the condition of the thermal insulation and heat loss will be observed.
9. After this, it is necessary to level the floor joists. The upper horizontal level is determined. All excess is cut off, and the horizontalness of the coating is checked with a building level.
10. The finished floor is mounted from sheets of plywood or chipboard; any floor finishing materials can be laid on them. During installation, you will have to ensure that there is a temperature gap of 2 mm between the slabs, and 10 mm between the slabs and the wall. For strength, plywood can be laid in 2 layers, the total thickness of the sheathing is from 12 mm to 20 mm, it all depends on the requirements for the floor. It is necessary to leave a small ventilation gap between the sheathing and the insulation.
11. After the floor covering is completed, it is necessary to once again check the horizontalness of the floor, and then sand the surface. To avoid damaging the sander, the heads of the screws should be sunk into the wood during fastening. The last step is laying the flooring. The process depends entirely on what material was chosen for the job.

Should I use adjustable joists?

If the floor is not so level, then its height can be easily adjusted with lags. For this purpose, special fastening elements are used that can withstand significant loads, up to approximately 5 tons for every 1 m². Adjusting elements can be made of metal or special plastic. These are threaded elements that can be given the required height. The logs are attached to such elements, and the required height is set. The floor and walls are first marked to determine the level of finishing.

For concrete floors, dowels are used, and for wooden floors, self-tapping screws are used to withstand the necessary loads. After this, all excess is cut off. The logs are attached at the required height; if required, a heat insulator is added to make the floor more comfortable and the microclimate more pleasant. Plywood or chipboard is laid on top, after which you can begin installing the floor covering.

Joist floors are a strong and reliable structure that allows you to level the surface. It’s not difficult to make such a floor with your own hands; there are many options from which you can choose the right one. To work, you only need boards for making logs, a heat insulator and sheets of plywood or chipboard for finishing cladding.

Wooden flooring on joists remains one of the most popular options in private houses and old apartments. Low price, high durability and ease of work distinguishes this method of flooring from other types. If you are building a house and decide to install floor joists yourself, or you need to update old ones, this article will tell you the technology for installing them.

Joist floor technology

If you look at the diagram of the structure of a wooden floor, you can see several basic structural elements:

• The base for installation is a concrete screed, floor slab, wooden beams, or brick columns.
• Then there are layers of waterproofing to protect against moisture from below the floor.
• The floor joists are fastened through the substrate to level the level.
• Insulation is installed between the joists on a backing made of plywood or plasterboard.
• The logs are covered with a vapor barrier membrane on top.
• The top layer is covered with floorboards.

Preparing the base

If the fastening will be on wooden beams, no additional work needs to be done. The joists are simply attached to the ends of the beams level, so there is no need for pads.

Installation of floor joists on a concrete base is done in two ways. The first is to use pads under them to install them in the same plane. The second is to pre-prepare a level base.

This can be done by spot filling uneven areas, pouring screed, or using a layer of sand.

If you are doing installation in a private house on the ground floor, then often in such houses they install it on posts, that is, the floor will go above the ground.

In this case, you will need to first pour a 20-30 cm foundation for each column on a sand base. Then a column of bricks or blocks is laid on this foundation.

They need to be laid at the same level; for this, the height of the columns is adjusted by the layer of mortar in the masonry or the height of the foundation. To increase the durability of the brick, you need to protect it from top and bottom with a layer of roofing felt waterproofing.

Before starting work, remove dirt and install waterproofing.

Calculation of pitch and lag sizes

Before purchasing materials, you need to calculate the costs and dimensions of the logs in advance. You need to buy dry timber, 2-3 grades.

Its cross-section should be rectangular, the height is approximately 2 times greater than the width. Please note that the height should be enough to lay the insulation inside and maintain a ventilation gap of 2 cm.

The longer the width of the room, the wider you need to buy logs. For example, for a 3-meter room it would be optimal to take a beam of 150 * 80 mm, for a 5-meter room - 200 * 150.

The distance between the joists will depend on the floorboard used. For example, for a 24 mm board you need to make a laying step every 40 cm, and for 40 mm you can do it every 70 cm. Most often, a step of 50 centimeters is used, because it is more convenient to lay the insulation inside exactly to size without cutting, and you get good floor rigidity .

Installation of logs

• We set the logs according to the level and place wooden choppers under them if necessary.
• Before installing the main elements, the piping is first installed around the perimeter of the room. To do this, first install logs with an indentation of 0.5-1 centimeter from the wall for a temperature gap. There should be no wedges between the wall and the beam; they will create a squeak when walking.
• Then all intermediate bars are mounted. The location of the floor joists should be perpendicular to the window so that the upper boards are secured along the direction of the light. The finishing floor covering is also laid along the light so that the gaps between the parts are not visible.

• If you need to trim each beam and join a row of several halves, then you need to move this joint each row to increase strength.

Note! The chopsticks do not need to be rigidly attached to the floor; they are simply laid on the base. The main rule when installing is to maintain a reliable and stable fastening so that nothing dangles.

• Many people ask, is it necessary to be tough? There is no need to do this. A rigid mount will conduct vibration noise, reducing sound insulation. When walking, sounds will be transmitted through the ceilings to neighbors.
• However, it is possible to secure the logs together. This will firmly bind the entire structure, and they certainly will not move. Make crossbars from scraps of timber and secure them. Use fasteners for the floor joists - ordinary metal corners 4*4.
• If you don’t make such a harness, then it’s okay. All the same, the structure will then be tied together after sheathing with boards.
• It is important to use only self-tapping screws during fastening. They should be long and thick enough. If you use nails or bad screws, after a short period of time the boards will begin to creak when you walk, as they become loose.

Note! The fewer parts there are in the design, the lower the likelihood of squeaking. But at the same time, it is necessary to ensure reliable fixation of the boards and rigidity of the structure so that it does not shake.

• After the installation of the floor joists is completed, underlays for insulation made of plywood or plasterboard are laid inside them. Then the insulation itself (min. wool, expanded polystyrene, sawdust) is tightly placed between the logs. The vapor barrier is stapled on top of them with a stapler and the floor covering begins.

We dismantled the old floor yesterday.

Level preparation

In this case, we decided to do this: we need to go to the level of the threshold, and put laminate on top. In general, we will install logs on the red brick.

Now we will install a laser level and try to set all the bricks to the desired height. We will install joists more often so that we don’t hit the board on top of the joists, but throw OSB panels directly onto the joists.

Here are our 10mm thick OSB panels. We will make two layers with overlap - we will twist it directly to the joists. The logs have a cross section of 100 by 50 mm. In this place it turned out to be 25.5 cm, here it’s a little lower: 25.8–25.7 cm. In general, we will start from this point.

Let's figure out how deep to bury the brick. 25.5 cm minus 2 cm. 2 cm is two layers of OSB. Plus 2 cm - we get 27.5 cm, plus 10 cm - the thickness of the log. Total 37.5 cm. Approximately 5 mm is given for Aquaizol. In total, we need to get 38 cm. There will be 11 lags, the outer ones were measured, the distance was measured, divided into 10 spans - it turned out that the lags will go about 29 cm apart. Now we will place a brick in one place, and then we will start from it.

We placed a brick at 38 cm, we will use it as a beacon. Now we will lower the laser lower, place a car valve on this brick, screw masking tape onto it, and then we will align the rest of the bricks along it.

The laser was placed below.

We install the valve and make a mark.

We begin to install the valve. You can see how much the brick needs to be lowered - about 4 centimeters.

Let's set it to the laser beam.

The beam is exactly on the intended line.

We have completely leveled the bricks, they are all level.

Installation of logs

We clean the joists and coat them with an antiseptic.

This is how we processed them. Preparing the first layer.

First we fasten through one, then we simply fasten the next ones at the ends diagonally.

We level the logs in the same way as bricks, using a laser level. We go through the bulging places with a plane.

The first layer was sewn up and the sheets were completely drawn out. We were thinking about how to sew up the second layer to make a complete dressing. You can make the sheets go in the reverse order, but then the sheet still ends up on the seam.

There was another option - take a sheet by length. But then there will be a solid stripe in the middle.

We settled on this option:

We have two pieces left.

From here we will throw a whole sheet. Cut one sheet in half. This will make an excellent dressing.

We attached the first layer at the intersection. The construction is quite powerful, everything was tied up perfectly in two layers. Everything turned out smoothly, according to the level.

There are small gaps, but this is not a problem for laminate.

We brought the level clearly to the threshold, exactly to this point. We danced from her, we clearly came to her.

All rights to the video belong to: Alexey Stopchik

Laying the floor on joists is the most commonly used type of floor surface leveling. For wooden floors, logs are the main element of the frame. If they are selected and installed correctly, the floor will be reliable and will last a long time. Mistakes made at this stage will be costly: you will have to disassemble the final coating and eliminate defects.

SPECIFICATIONS

Used for waterproofing roofing felt, laying it on a concrete base. The overlap on the walls is 10 cm. The distance between the logs and their height depends on the type of insulation, the finished floor and the load on it. The height is usually from 5 to 10 centimeters(it should be one and a half to two times the width), the distance between adjacent logs 30-50 centimeters.

The best material for making supports is dry coniferous timber of thickness at least 5 centimeters. If, with joists, the floorboard is located parallel to the light rays from the window, then the joists are arranged perpendicular to the boards. You can study the article about it yourself.

Getting a control line

At a convenient distance from the floor (about one and a half meters), using a hydraulic level, place marks in all corners of the room. All marks are connected with a tapping cord, obtaining a straight line. Using a tape measure, using the control line, they check the horizontality of the subfloor near the walls and set the logs at a given distance.

Installation of the first beams

At a distance of 20-30 centimeters from the wall, using several substrates, install the first lag. Having measured the distance from its upper edge to the control line with a tape measure, the outermost joist is mounted at the same height against the opposite wall. These are lighthouse logs: using a long rule or a cord stretched between the outermost logs, it is easy to set the height of all intermediate beams. The deviation from the verified plane should not exceed 1 mm per linear meter. Check the horizontalness of each log and their position relative to each other.

Installation of lags

The lining under the joists must be dense and elastic: euroroofing material, rubber, conveyor belt. To prevent the material from moving, it is fixed to the joists with a stapler. It is convenient if there are several types of lining of different thicknesses. To prevent the logs from moving, they are secured with auxiliary slats of the required length.

Installation of beams, reinforcement of floors near doorways

There is high traffic in doorways, which increases the load on the floor. Therefore, in these places, reinforced double logs are laid, the edges of which protrude on both sides of the opening. The coverings of adjacent rooms will rest on these reinforced beams.

Installation of beams

If the length of the beams is not enough, they will have to be joined along the length. The joints must be staggered with a spread of at least 50 cm, and technological gaps of 1.5-2 cm must be maintained between them. Irregularities found on individual beams are planed locally with a planer. These are the general rules for installing a frame made of beams. The technology may differ depending on the base on which it is mounted.

Joists on the floor beams of the lower floor or basement

Such floors are made in houses made of wood and mineral materials. There are load-bearing beams between floors and on the ground floor, where they insulate the floor from contact with the ground and serve for ventilation and thermal insulation. If the finished floor is installed directly on the beams, sound vibrations are transmitted to the walls, making the structure too noisy.

Joists on floor beams

Logs on the ground

Significantly reduces the level of vibration and sound vibrations installed on independent supports not connected to the wall structure. The supports for the logs are made of red brick. The foundation for the support bricks is a layer of compacted crushed stone or a separate concrete foundation for each brick. Instead of bricks, screw piles are sometimes used. A layer of crumpled clay is laid on the ground as an incompressible base.

Joists on the ground need waterproofing

The distance between adjacent supports is 50-100 cm, 30-50 cm between rows. If the logs will be joined along the length, the joint should be on a support. The height of the supports is calculated so that the distance from the underside of the floorboard to the layer of crushed stone or soil is no more than 25 cm. Waterproofing is provided by a layer of roofing material placed under the logs. The spacer between the joists and the brick support is wooden blocks treated with an antiseptic, the thickness of which is at least 2.5 cm.

Joists on reinforced concrete

For reinforced concrete bases, you need an elastic lining, the thickness of which should be at least 1 cm. To fix the lags, it is convenient to use direct hangers, such as those used when working with drywall. They are secured to the concrete base with strong dowels through rubber gaskets. Movable and elastic gaskets of various thicknesses subsequently take on the entire load, help set the joists and absorb vibration; you cannot do without them.

Option for attaching joists to a concrete base

If a reinforced concrete slab has significant unevenness, you should not compensate for this with a large number of spacers; it must be leveled with a screed.

Adjustable joists

Special polymer posts equipped with threads help accurately and quickly

One of the main methods that can be used to make a flat floor surface is to lay boards or sheet materials on a pre-created sheathing, where logs serve as load-bearing elements. One of the primary tasks, the implementation of which directly affects the final quality of the floor surface, is the alignment of the joists in the horizontal plane, their reliable fixation, as well as treatment with protective compounds and waterproofing. You can learn how to adjust the position of wooden beams, as well as some of the nuances of the process of installing a frame under a horizontal floor surface by reading this article. Thematic video lessons offered for viewing will help you consolidate the information received.

Features of the floor by joists

There was a period when developers began to move away from the technology of laying the subfloor on wooden blocks. This was due to the fact that in this way it was difficult to achieve a perfectly flat surface, which was necessary for laying modern floor coverings. Preference was given to screeds made with cement-based mortars.

Now modern technologies for the production of lumber make it possible to produce wood products that are distinguished by regular geometric shapes, and special impregnations make wooden beams durable and prevent their deformation. More advanced materials have also appeared at a reasonable price for decking, such as plywood and OSB boards. This made it possible to return to the technology of installing floors using joists, bringing it to a higher quality level.

The widespread use of this method of constructing a floor surface is also explained by the popularization of wooden construction, when houses are built from logs or timber. In such a building, any floors other than wood would look inorganic. However, logs as a frame for flooring are used not only in wooden houses. This floor leveling technology is used everywhere. In private houses, including on the second floor, in city apartments and even in office premises. Its advantages, such as, for example, will help explain the popularity of this technology:

• the relatively low cost of the material/labor complex, especially when it comes to installing floors on the second floor of the house;
• the ability to qualitatively insulate the floor surface by laying a thick layer of insulation;
• the created surface is immediately ready for installation of finishing materials (does not need drying and maturing, like concrete);
• it is convenient to lay communications under the flooring;
• the frame made of bars, as well as the flooring, have a relatively low weight, due to which the load on the floors and supporting structures is noticeably reduced;
• The workflow is quite simple, making it accessible to many home craftsmen.

This floor also has some disadvantages:

• despite the use of fire retardants, wood remains a combustible material;
• the use of logs, for example, in an apartment, involves a reduction in useful volume;
• impossibility of making heated floors.

Base surfaces for installing joists

A horizontal frame made of wooden beams can be made in any room. But the base surface that serves as support for the joists is different. If the floor structure is assembled on the ground floor of a private house with a ventilated underground, the supporting elements are columns poured with concrete or lined with brick. In apartments and some houses on the second floor, where a reinforced concrete slab is poured as an interfloor partition, the latter is the base for installing load-bearing beams. When a ground floor is made on the first floor of the house, a rough screed is prepared for installing the bars. Let's look at the installation rules and methods for aligning the load-bearing beams in each option.

Important! If the interfloor ceiling in a house is made of timber, its surface is the basis for plywood, OSB or board flooring on the second floor. The alignment of the beams occurs during the construction phase of the building.

How to align load-bearing beams on a reinforced concrete slab?

You can install logs on the slab using several devices, such as:

• screw adjustable supports;
• support brackets;
• anchor fastenings.

Screw supports and metal brackets are used when it is necessary to raise the floor surface relative to the base surface in order to lay insulation between the joists. With the help of these devices it is convenient to fasten the bars and adjust their position relative to the horizontal. Another advantage of such devices is the absence of contact of wooden beams with the concrete surface, which eliminates the need to waterproof the logs.

Anchors are used when the beam is laid directly on a concrete surface, and its position is regulated by all kinds of pads. This is done when the thickness of the thermal insulation layer is not of great importance, but at the same time there is a desire to minimize the usable space.

To level the logs and install them in the same plane, you need to use a hydraulic level and a long (1.5-2 m) spirit level. Using a water level, marks are made on two opposite walls that correspond to the horizontal line in which the load-bearing beams should be located.

The outermost logs are installed and leveled first, which are located approximately 10 cm from the wall. First, one edge of the beam is set according to the mark that determines the desired horizontal level. Then the position of the other edge is adjusted so that the floor support is horizontal. The same should be done with the block against the other wall.

When the outer joists are set and secured in a given position, strong twines are stretched between them so that their sagging is minimal. Tensioned threads located in the same horizontal plane will serve as a guide for adjusting the position of the intermediate lags. To mark the horizontal line, if possible, you can use a laser level. This will speed up the process and perhaps improve accuracy somewhat. You can see how the logs are installed on metal brackets, as well as their alignment, in the video below, which shows the entire process of installing a plywood floor base along the load-bearing beams on the loggia.

Joists on columnar supports

In this case, in order to avoid problems with the alignment of the logs, the supports for them themselves should be made so that their upper platforms are in the same plane. The principle is the same - the horizontal line is marked, in which the top points of the columns will be located and the threads are pulled. If the supports are made of reinforced concrete, the formwork elements are placed along the threads. When the columns are laid out of brick, the masonry is adjusted according to the guidelines.

The beams are installed on the made supports after laying 2-3 layers of rolled waterproofing on them and are fixed with metal angles or anchors through the joist body to the surface of the column. Load-bearing wooden crossbars are leveled by placing wooden or plastic wedges.

Important! It is necessary to lay waterproofing material not only between the surface of the column and the joist, but also between the support and the ground, so that moisture does not destroy the supporting structure.