Lay plywood over the old wood floor. Leveling a wooden floor with plywood: everything about laying plywood on a wooden base. By wood type

Repairs in an apartment or in country house necessarily accompanies the lives of most people. And one of the most common problems The problems that have to be addressed in this regard are cold or insufficiently level floors. There are several ways out of this situation, one of them is to make plywood floors along the joists. Whether this will be done with your own hands or with the help of specialists, each property owner decides at his own discretion.

What are lags?

Logs are special wooden or polymer bars or sections metal profile, stacked on concrete base, on top of which the base for the floor is laid. Metal is much easier to work with and is more durable than wood. But there is one significant drawback - metal, unlike wood, is critical to changes in ambient temperature, which can lead to the floor warping. In addition, they will cost less.

It is necessary to take into account that the most suitable species for making logs are coniferous species, especially larch. The parts must be of the correct geometric shape, smooth and without bends along the entire length.

Selection of base material

In order to level the floor with plywood along the joists with your own hands, you need to choose the right material, since not every type of material is suitable for this. There are the following types of floor leveling sheets:

Plywood - multilayer material, the number of layers starts from three.
is an excellent material for leveling wooden floors for subsequent laying of tiles. It is made from shavings and Portland cement with the addition of chemical ingredients.
Oriented strand board (OSB) is a multilayer material in which the chips are glued together with resins with the addition of synthetic wax. Eco-friendly, but bends easier than plywood and is a little more expensive.
(chipboard) has the lowest strength and environmental friendliness.
Fiberboard (Fiberboard) is a material made by hot pressing of wood fiber, very flexible and fragile.

Based on the listed properties of the materials, we can conclude that a do-it-yourself plywood floor on joists in a private house is best made from OSB, DSP or plywood.

About the material

Plywood is the most acceptable option. It consists of veneer sheets glued together in a special way: each new layer has fibers located perpendicular to the fibers of the previous one, which significantly increases rigidity. Plywood varies in characteristics of moisture resistance, durability and environmental friendliness, which depend on what binder material used in production:

The FK brand is made using urea glue, is poorly resistant to moisture, and swells quickly. But it is safe for humans and can be used in rooms with low humidity.
The FSF brand contains phenol-formaldehyde glue, is moisture resistant, but not environmentally friendly due to phenolic emissions.
FB brand is bakelized plywood, resistant to moisture and aggressive environments.
FOF is a laminated (layer-pressed) material called laminate. Used as decorative finishing floor.

To make a plywood floor using joists with your own hands in a country house or apartment, the best way Plywood of the FK and FSF brands made of birch with a thickness of ten to fifteen millimeters is suitable.

Advantages of plywood flooring on joists

The installation of such a floor has a number of undeniable advantages:

strengthening soundproofing characteristics;
increase in thermal insulation qualities;
high-quality quick insulation of the floor by laying heat-insulating material between the joists;
ensuring uniform distribution of pressure on the base;
the presence of empty space between the logs makes it possible to locate various communications in it;
quick leveling of floor surfaces;
good strength characteristics of the coating;
possibility of easy replacement of damaged parts;
Even a beginner without special skills can handle the job;
installing a plywood floor on joists does not require specialized heavy equipment or tools.

Preparation for installation

Mandatory measures before laying floors should be:

inspection of the base;
thorough cleaning of large irregularities;
covering cracks and cracks;
floor waterproofing.

Whatever moisture resistance coefficient plywood or any identical material has, it has a certain hygroscopicity, which leads to the absorption of a certain amount of moisture. Therefore, the main stage of preparation is waterproofing. It is usually carried out with thick plastic film (at the very simple case) or special coating. The concrete floor is completely covered with material, with a slight overlap on the walls. And so that after the film speaks for it. Parts of the waterproofing at the joints are secured with construction tape.

To install floors on plywood joists, galvanized hardware is used for fastening, with a length exceeding three times the thickness of the sheets being fixed.

Which is better: two thin layers or one thick one?

Plywood is composite material. The layers in it are arranged crosswise with fibers to achieve sufficient rigidity and strength. Based on this, it becomes clear that in order to improve such characteristics, it does not matter at all how many layers are laid - two ten-millimeter layers instead of one twenty-millimeter layer or a greater number. And there won’t be a particularly big gain in price.

But when leveling very crooked floors, the number of layers plays a significant role here. When laying one layer, the unevenness will, of course, be smoothed out, but differences will remain at the joints of the plywood sheets. This is where a correctly laid second layer will help - the joints of the slabs of each of them will coincide with the center of the slabs of the other layer.

Conclusion: to insulate a flat base, you can install plywood floors along joists with your own hands in one layer with sheets twenty millimeters thick. When leveling a crooked base, two ten-millimeter layers with plywood slabs laid in a checkerboard pattern are better suited.

Do-it-yourself plywood floors on joists: joists and sheathing

The sequence of steps in this stage is as follows:

To perform the installation, use dried, flat beams with a cross-section of 10 x 5 cm and a length of at least two meters. In addition, they must be kept indoors for two weeks.
Waterproofing is laid on the prepared base, and the beams are treated with an antiseptic.
When installing the logs, an indentation of 25 mm is made from each of the walls.
To neutralize unevenness, use MDF or fiberboard substrates with a side of a square of 20 cm, and linoleum pieces to suppress noise. In places where there are substrates, the logs are attached to the cement base anchor bolts. When laying, a distance of 40 cm is left between the joists.
When all the logs are installed, they move on to installing the sheathing. Its strips are also installed on substrates and secured to the floor and joists with self-tapping screws at a distance of no more than half a meter. It is important that the size of the sheathing matches the parameters of the plywood sheets.
The resulting cavities in the sheathing are filled with insulation and sound insulation.

Sizing, fastening

In order to properly arrange plywood floors along joists with your own hands (photos of the actions are presented in the article), you need to cut the plywood into sheets the right size, optimally 1250 x 2500 mm. For convenience, they can be numbered.

To eliminate the possibility of squeaking during further use, strips of glassine are stapled to the joists before laying the plywood.

The sheets are laid across the joists, secured with screws at a distance of 15 cm. At the joints, the screws are placed in a checkerboard pattern at a distance of 10 mm from the edge of the sheet.

During installation, a gap of about a third of a millimeter is left between the sheets, which is then filled with sealant or elastic mastic and glued with moisture-resistant glue.

Laying begins from the window, the heads of the hardware are completely recessed into the plywood into the drilled holes. If communications are planned, cutouts are made for them.

Do-it-yourself plywood floors on joists: installation of layers

This stage is performed in the following sequence:

Laying the first layer begins from the window with a distance of about half a centimeter from the wall. You can use plywood of the third or fourth grade, since the presence of knots and appearance do not play a noticeable role due to further finishing, and the cost of such material is much cheaper.
Intermediate logs can be an addition to plywood. This is necessary to reduce the size of the cells in order to ensure a good connection between the sheets and the frame. To do this, the logs are connected with crossbars made from scraps, screwing them with steel corners. The size of the cells should be a multiple of the plywood sheets so that their edges always lie on the joists.
The second layer of sheets is mounted offset from the first. The layers are fastened together with self-tapping screws and glued together with PVA or special glue for plywood.
Seal the seams between the sheets.
After laying the last slab, the surface is sanded sandpaper manually or using a grinding machine.

Using the same principle, you can install a plywood floor along joists with your own hands on the 2nd floor of a private house.

To successfully complete the work, you must pay attention to the following:

It is not recommended to lay tiles on plywood: they may fall off due to the expansion of the wood layer.
Uneven surfaces on the screed can be sprinkled with sand, and cracks and holes in the corners can be foamed.
To check the humidity in the room, you need to cover the base with plastic wrap for a day. If perspiration appears underneath, waterproofing is a must.
It is important to follow all installation rules when installing a plywood floor on joists with your own hands. IN wooden house on the ground floor above the ground this is especially true - if the technology is not followed, the entire coating will have to be removed to correct errors.
To ensure good sound insulation, the logs are not fixed rigidly, but are installed on felt or rubber pads to dampen noise.
Before starting the installation of the logs, find the zero level and then level the remaining beams along it.
The insulation must be cut strictly to the size of the cells so that its edges do not bend during installation.
After laying the insulation, a vapor barrier membrane can be attached to the joists with a stapler.
For installation, it is better to use not ordinary hardened black self-tapping screws, but yellow wood screws with a powerful mounting hole.
The sheets must be laid so that not cross-shaped, but T-shaped joints are formed.

Conclusion

At correct installation A plywood floor can last more than twenty years. Just remember that this material is suitable for installation in dry and warm rooms.

It is also worth noting that plywood is suitable not only for arranging wall cladding and subfloors. Craftsmen use it to create unique decorative compositions in the interior. Using old skills - artistic sawing, pictures are laid out from pieces of plywood and parquet is formed.

Cladding of horizontal bases from wood materials carried out different ways. Laying plywood on a wooden floor allows you to complete the work yourself and in a short time. It is important to choose the appropriate type of product, as well as follow all stages of installation on boards.

To do the job correctly and avoid serious problems in the future, you need to take a responsible approach to determining the size of sheet products. In such a situation, it is better not to save too much.

Nuances of choice:

Linoleum and laminate are not afraid of minor deformation movements of the base, so a single-layer flooring can be installed under them; a two-layer scheme is used for laying hard materials such as tiles

On a note! For single-layer installation, it is better to choose a high-class material; defects and warping do not contribute to the creation of a rigid base.

Installation on an old wooden floor

If it is necessary to lay plywood on boards, it is necessary to carry out the work exactly according to the instructions, including several successive steps.

Necessary tool

Devices are prepared in advance. It is taken into account that if the device has replaceable nozzles, then there must be a reserve.

List of tools:

An electric jigsaw with suitable files or a hand saw.
Level at least 1 meter long.
A tape measure and a flat beam (profile), which will serve as a stop when marking.
Screwdriver or drill with power adjustment and bits.
Self-tapping screws of the required size. The rod should pierce the slab and reliably go deep into the wooden surface.
Planer and construction knife.
Stapler.
Brushes and a set of spatulas.
Primer and elastic putty.

Installation of plywood does not require particularly expensive tools; as a rule, it is enough minimum set for working with wood

Products of the required format and substrate are also selected. It is better to purchase small sheets, this will eliminate unnecessary trimming and ensure quick adjustment, especially if there are several layers.

For precise fixation, you will need a suitable type of glue.

Preparing the base

In order for the installation of plywood on the floor to proceed without lengthy adjustments and hitches, as well as to avoid problems in the future, it is necessary to first prepare the surface.

Process technology:
The old decorative coating is completely removed, down to the base. If paint was used as finishing, then sagging and flaking fragments are removed.
The surface condition is assessed. Deformed parts are replaced with new ones, sagging elements are strengthened. The same procedures are carried out with lags.
The presence of mold and mildew is checked. Microorganisms not only destroy wood, but also pose a threat to human health. Infected areas must be removed and adjacent areas treated with a protective compound.
Using a plane, protruding fragments are cut off. This will allow the plywood to fit as tightly as possible.
The gaps between the boards are covered with elastic putty.
The base is coated with a primer with antiseptic additives.

The surface is dried. When installing plywood decking, the most important part is preparation. wooden base

, in this case it is necessary to strengthen not only the floor itself, but also the logs

If work is carried out on the ground floor, then the use of a vapor-permeable film may be required. Such a backing under the plywood is necessary for ventilation.

Cut the material yourself

The slabs are cut into pieces of the required size.

A comfortable and level place for work is prepared. The cut is made on a small elevation, which ensures free passage of the tool.
An installation diagram is drawn up. To do this, the dimensions of the surface are determined and a laying plan is drawn.
According to the parameters, the slab is cut. If the floor is very uneven, it is recommended to cut the sheets into pieces measuring 60 x 60 cm.
Trimming is done exactly along the line. When working with a power tool, you need to set the power correctly to prevent chipping.
If there are defects on the edges, processing is carried out with a file.
All segments are marked according to the drawing.

First, a sketch is created, after which, based on it, the sheet is cut to the required dimensions, while in order to guarantee the avoidance of chips when cutting the material, a hand-held circular saw is used

When cutting plywood with external defects, you should minimize the inclusion of problem areas on the edges.

Underlayment flooring

This process is not always necessary, especially when working with wood flooring, but if necessary, a special underlay is used to provide ventilation and avoid moisture penetration. The procedure is most relevant in a private home.

The film is located around the perimeter of the room without fractures or bubbles. If you need to combine the strips, they must be overlapped and taped. The material is placed close to the walls with a grip of a few millimeters, this will ensure the entire surface is covered. To lay the gasket without displacement, fastening is carried out using a stapler.

Penofol is usually used as a backing for plywood; in addition, you can use a special backing for laying laminate, but, in any case, the material must be vapor-permeable

It is not allowed to carry out work at high surface humidity. To determine the level, a piece of polyethylene film, the product is pressed well around the edges and left overnight. If condensation forms in the morning, forced drying is required.

Fastening plywood boards

Fixation to wooden floor carried out according to the scheme:

If a perfectly flat base is required, scraping is performed.

Laying on the frame

Plywood floors on joists are formed using the following technology:

Supporting parts are set with a fixation step of 40–60 cm. It is taken into account that all products must be placed in the same plane.
The treated slabs must be laid in a checkerboard pattern so that the joints fall on the timber. To fasten the products, wood screws are used. A distance of 15–20 cm is formed between the screws.
Before fixing the flooring, the logs must be treated with antiseptics and fire retardants.

For flooring in domestic premises, logs can be laid in increments of about half a meter, and for highly loaded rooms, logs are installed at a distance of 150 - 200 mm

Attention! With a distance between the support beams of up to 40 cm optimal thickness sheet – 12 mm, 60 cm – from 15 mm.

Plywood finished floor

Parquet flooring is used for finishing.

Scheme of work:

Plywood parquet will be distinctive and create a special atmosphere in the room.

Plywood is more rigid than wood covering, because a sheet of plywood covers an area that cannot be covered by a single floorboard.

Because of this, the strength of the floor and resistance to squeaks and knocks increases.

From the article you will learn how to lay plywood on a wooden floor, as well as the pros and cons of such repairs.

The following types of plywood are most often used in construction:

FC is a moisture-resistant plywood based on urea resin, which is non-volatile and non-toxic. It has strength and elasticity comparable to BS aircraft plywood.
NS – unpolished with casein glue. Before gluing parquet or other hard flooring onto it, it requires sanding.
Ш1 is the main material used for the subfloor. Sanded on one side. The adhesive base is also casein.
Ш2 – polished on both sides, on casein. For lightly loaded parts in dry rooms with comfortable temperature can be used as a substitute for FC.

Main advantages and disadvantages

The inner sheets of plywood are made of cheap material, with a large number of knots and defects that do not reduce the strength of the material. External sheets, depending on the type of plywood, are made of pine or birch. Dimensions plywood sheets reach 2.5 meters in length and 1.5 meters in width. Finished plywood floors are 5-10 times cheaper than laminate floors or solid board. Such floors can be painted in the color you like and varnished. Or use it as a base for applying 3D cast floors.

Plywood floors over wood floors are less attractive than solid wood, parquet or laminate flooring. But their installation costs tens of times less. Not all types of plywood have high moisture resistance and are used for finishing floors Finish plywood cannot be leveled by milling, like parquet or solid boards.

The use of plywood for the subfloor binds the logs into a single structure. Batten connects the logs only along the installation, with each board secured separately. Therefore, plank floors are more susceptible to squeaks and knocks than plywood floors.

Plank floors are not suitable for laying laminate or parquet, unlike plywood floors, which level the surface.

Using plywood in floor construction

Laying plywood on a wood floor places the same requirements on the subfloor as it does on a plank floor. Rigid fixed base – fixed in the walls wooden joists, concrete slab or steel structure ceilings When constructing a floor with wooden load-bearing elements(lagami), them top part becomes the basis for laying plywood. Therefore, lay the logs using building level and a two-meter ruler with which to measure the difference in heights. Attach plywood to such ceilings with wood screws, the length of which exceeds the thickness of the plywood by 3-5 cm.

Flatness concrete slab for laying plywood is 2 mm by two meters. If the height differences are greater, fill the screed along the beacons or use a self-leveling coating. This will avoid areas of loose fit, leading to squeaks and knocks. To secure the plywood, use anchor dowels of length equal to the thickness of the plywood plus 5-7 cm.

To lay plywood on a steel load-bearing floor structure, two installation options are used - directly on the structure and laying on logs pre-attached to the structure. When installing this way, use for joists wooden blocks, the width and thickness of which are 50 mm. The second installation method is preferable, because it is easier to attach bars without plywood to load-bearing structure using countersunk bolts. And fasten the plywood with wood screws.

When creating a subfloor from plywood, the permissible gaps between the sheets are 5 mm. If the gaps are larger, it is necessary to adjust the sheet to fit required dimensions. When laying laminated plywood for flooring, gaps wider than 0.5 mm are unacceptable. This coating cannot be puttyed or sanded. This will damage the protective and decorative lamination layers. When laying a finished plywood floor for painting, do not allow gaps wider than 1 mm. From the cracks bigger size The putty falls out after two to three months.

Laying plywood on an old wooden floor levels the surface, connects strong and weak areas, thereby increasing the overall strength of the floor. Repair the floor before installing plywood. Replace damaged floorboards, subfloors and joists, repair insulation and waterproofing of the floor. Additionally, attach the subfloor to the joists, and the covering to subfloor. By knowing how to properly install plywood on a wood floor, you will strengthen its structure and be able to avoid repairs in the next two to three years.

Fastening plywood sheets

To fasten plywood, use wood screws; they are sold in hardware stores and construction stores. Drill the plywood with a drill whose diameter is equal to the diameter of the self-tapping screw, and drill a hole half the diameter in the floor boards. Then drill the plywood with a drill with a diameter of 10-12 mm to a depth of 1-1.5 mm. The self-tapping screw will easily screw into the floor boards, and the head will go a fraction of a millimeter below the surface of the plywood. Sheets up to 15 mm thick, used as finished floors in technical rooms, tighten without drilling holes.

When conducting repair work wooden floor apartment owners and country houses Often the old base is covered with sheets of plywood.

Such repairs are quite economical, simple and do not require special skills.

Let's take a closer look at the options for repairing a wooden floor, what type of sheet material to choose for this, and how to lay plywood on a wooden floor.

Material properties

Thick plywood can last for many years

Plywood is a fairly versatile material.

Thanks to the ease of processing, cutting and installation a short time With the help of sheets you can lay a fairly durable floor covering.

With all this, the material is economical, practical and has other advantages:

non-toxic, does not emit unpleasant odors;
has low weight but high strength;
does not break when bent, elastic;
easy to transport;
has a beautiful front surface;
the dimensions of the sheet make the work of laying a new covering less time consuming;
budget;
a huge selection of materials in any hardware store.

When choosing plywood as a future floor covering, it is important to buy the right and suitable material, don't be mistaken about it physical properties. This type of material also has its disadvantages.

Like any wood-based coating, plywood does not like high humidity, requires getting used to the operating conditions before installation, and is capricious in storage.

Plywood does not crack when drying

The sheet is made by gluing together several layers of wood under pressure. Depending on the number of layers, as well as the adhesive and impregnation substances, the properties of the resulting material vary.

What plywood of any grade has in common is increased anisotropy or uniform distribution properties physical activity know the volume of the slab. At the same time, the material does not crack when drying out and is not prone to deformation.

It is these qualities that make plywood an indispensable material for floor repairs. All manufactured materials are divided by grade, surface quality and moisture resistance.

Marking values on sheets

Marking	Designation	Characteristic
Variety	E, I, II, III, IV	Indicates the structure of the sheet gluing, the quality of the front and back layers
Moisture resistance	FSF	Possesses increased level water resistance, strength and wear resistance. Not for use in residential areas, releases toxins.
	FC	Not highly resistant to moisture, but will remain intact when exposed to water for 24 hours.
	FKM	Increased water resistance
	FBA	Suitable for children's rooms, living rooms, bedrooms. One hundred percent environmentally friendly product. Will not withstand prolonged high humidity.
Surface quality	NSh, Sh1, Sh2	not polished; polished on one side; polished on both sides.
Environmental friendliness (formaldehyde level)	E1, E2, E3	E1 - no more than 10 mg, E2 - from 10 to 30 mg

Any other numbers and designations indicate that the product is rejected and does not comply with GOST.

Suitable material

Which plywood to lay on the floor depends on many factors:

lay sheets on top of the old coating;
laid on joists;
used as finishing or as a leveling base under decorative material.

For the floor, choose birch sheets, which are stronger than other species

It is important to understand which plywood is best to use for various types works For floors on joists, as well as for the base under roll material, it is better to choose birch sheets, they are harder.

To save money, it is appropriate to use grade 3 or 4 unsanded material as a leveling base.

Under hard decorative covering: laminate, parquet, plywood can be used coniferous species. For grouting joints, putty is selected to match the color of the selected material: birch or pine needles.

To level the base, use sheets with a thickness of 1 to 1.5 cm.

Before purchasing, draw a plan for laying and cutting plywood to optimally select sheet sizes and reduce the amount of waste.

Preparation and laying on old boards

Before laying plywood on the floor, the material should be allowed to rest in the room at room temperature and humidity no more than 55% for several days.

The sheets are always laid in a run-up pattern: that is, with the seams offset by at least 1/3 of the side.

There should be a gap of 10 mm between the wall and the plywood layer: plywood is a living material, therefore, in order not to spoil the decorative coating, you need to give it the opportunity to breathe.

The material can be glued to old floor boards

If you decide to lay the slabs on the boards of the old covering, they should be carefully secured. It is necessary to screw the boards to the joists so as to get rid of creaks and deflections.

The slab should be screwed to the floor with self-tapping screws, securing it around the perimeter and diagonally in increments of 15 - 20 cm.

Installation begins from the wall opposite to front door. During the entire process, be careful to ensure that the sheets do not form waves. The seams should be sealed with acrylic-based putty.

If the plywood will be processed as decorative covering, then it is better to lay high-grade sanded material, rubbing the seams with wood-colored putty, which must be sanded after drying.

Laying plywood on joists

When laid on joists, you can at the same time insulate and waterproof the floor

If it is possible to remove the old wooden covering, then it is better to do this and lay the sheets over the joists. At the same time, you can check the strength of the coating structure and, if necessary, strengthen it.

It is also possible to carry out additional measures to improve hydro- and thermal insulation, which is important for the floors of the 1st floor. When laying sheets on beams, you should calculate the distance between the logs so that one sheet falls on at least 3 guides. For all the details of the process, watch this useful video:

To add additional rigidity, you can mount the sheathing by making jumpers made of beams between the joists. Carefully secure the sheets with self-tapping screws to the joists.

When laying, the sheet should not bend under the weight of a person, otherwise during operation the putty from the seams will begin to collapse, which will cause deformation of the top decorative coating.

Advantages of plywood covering

Plywood flooring is considered by most experts to be a good alternative concrete covering for the floor.

This option eliminates the hard work of installing a leveling screed; installation will not take much time and the plywood will serve as additional insulation.

In addition, it is a warm and pleasant material to use.

Unlike plank flooring, installation of plywood is economical in terms of money, time and does not require special skills.

The disadvantages include the need additional processing sheets or stacking decorative material. Be careful when purchasing, remember that not all plywood is suitable for flooring in residential premises due to its environmental friendliness.

Modern room finishing technologies have also affected floor coverings. Residents give their preference to such ones as cork, parquet board, laminate When using these materials do not last place are occupied by the requirements for the evenness of the base. In view of this, quite often one has to face the need to level a wooden floor. There are several ways to do this process. One of them is leveling the floor with plywood. To carry out this work correctly, you need to know how and with what help plywood is attached to a wooden floor and what preparatory work should do.

Why plywood?

Plywood has the characteristics necessary for its use during construction and repair work. She has:

relatively light weight;
sufficient hardness of the material surface;
high quality grinding;
resistance to water (for moisture-resistant varieties);
absence of unpleasant odors;
availability of installation technology.

Plywood is indispensable for leveling wooden floors.

Besides affordable price it has the advantages that are necessary for such work. Namely:

due to the perpendicular arrangement of adjacent layers, plywood sheets have high strength in all directions;
production large sheets plywood allows for accelerated installation over large areas;
plywood sheets bend well without breaking;
plywood sheets are convenient for transportation and unpretentious in operation.

Preparatory stage of work

Naturally, laying plywood on a wooden floor must be done correctly and using necessary tools. It is good that the master has experience working with this equipment. To lay plywood you will need: a screwdriver; jigsaw; level; roulette; self-tapping screws with dowels.

Tools required for work

Before you begin leveling a wooden floor with plywood, it is recommended to check the substrate to ensure its suitability for use. Replace old rotten boards and repair creaking ones. It would be a good idea to check the evenness of the base. If the floor is uneven, then you need to determine the maximum surface difference. Small deviations can be smoothed out by laying a special substrate. Differences of more than one centimeter require laying the logs exactly horizontally. They are set using a water level. The choice of plywood depends on the flooring that will be installed subsequently. If it is carpet or linoleum, you can use thin sheets. For parquet or laminate flooring, you must choose plywood thicker than 10 mm.

Note. The thickness of plywood laid under laminate or parquet must be no less than the thickness of the floor covering.

Deciding on the brand of plywood

Before starting work, you need to decide on the brand of the product. It is determined in accordance with the moisture resistance of the material. FB and FOF grades are used for industrial construction. For individual construction work FK and FSF grade plywood is intended.

In the production of FC plywood, glue without the use of phenols is used. Therefore, it is completely harmless and can be used in bedrooms and children's rooms. It is resistant to mechanical stress and has average water resistance. It is produced both in polished form (Sh1 – polished on one side, Sh2 – on 2 sides) and in unpolished form (NSh).

Before starting work, you need to decide on the brand of the product.

FSF grade plywood is characterized by increased water resistance, wear resistance and mechanical strength. These properties do not change even with changes in temperature and humidity. This is achieved through the use of phenol-formaldehyde adhesive resins. At the same time, these resins are quite toxic. Therefore, it is not advisable to use such plywood in residential premises.

“Cutting” and fitting plywood

First of all, we “cut” the plywood in accordance with the size of the room. In this case, it is necessary to take into account the size of the damper joints: 3-4 mm between the workpieces and a centimeter at the walls. If this is not done, changes in temperature and moisture will lead to “swelling” of the finished base. Upon completion of cutting, we check the ends of the workpieces for delamination and defects. It is not advisable to use damaged sheets; they must be replaced.

After this, we lay the plywood on the wooden floor in the order in which they will be attached. It is not recommended to make a junction of four corners. We lay plywood sheets in the manner brickwork, with a shift. Then you need to number all the sheets. Focusing on the joints between the sheets, mark the locations of the joists and remove the workpieces. The joints of the plywood sheets should be in the middle of the joists.

Installing joists on a wooden floor

The logs for leveling the floor are made of plywood 3-4 cm wide. We lay them according to the marks made. We attach the joists to the floor using special glue for wooden products or self-tapping screws. During the installation process, gaps may appear between the floor and the joists. We put pieces of plywood of suitable thickness in them. Before laying, coat both sides with glue.

Logs that serve as the basis

The same must be done if the base has differences in height. Horizontal arrangement The lag is determined using the level. The evenness of the future floor depends on the thoroughness of this process. After laying the logs, a sheathing is made; its size must correspond to the size of the plywood. The space between the joists can be filled with a sealant.

Attaching plywood to wood floor

After the logs are installed, we attach the plywood to the wooden floor according to the diagram. Before this, the workpieces must be treated with an antiseptic. We fasten using self-tapping screws with plastic dowels. To prevent the plywood from being damaged by hammer blows, drill a hole equal to the diameter of the dowel in the places where the screw is screwed in. And then we countersink a hole with a larger diameter. The screw head will be hidden in it.

The final treatment of plywood depends on the chosen floor covering. The surface under the carpet is covered with several layers of varnish. For laminate, the plywood base is carefully sanded and then coated with protective varnishes. Under the laminate or parquet, a special noise-absorbing substrate is placed on the base.

Using this plywood flooring technology, you can level almost any base. If the work is carried out carefully, the result is a durable and Smooth surface. After that, you can lay either linoleum or parquet on it. Laid on such a foundation flooring will last more than one year. In addition, the plywood layer serves as additional thermal insulation.