Laying plywood on concrete under laminate. What kind of plywood is better to put under the laminate. How to level a wooden floor

More and more often prefers to cover the floors with laminate. This material is unpretentious in operation, does not require much effort when laying. In addition, it is aesthetically pleasing and suitable for residential apartments and private houses, as well as for office space. The coating is purchased for a lot of money, but it will be a pity to spend it if the floor creaks underfoot, and even worse, cracks. The reason for these troubles is the uneven laying. Leveling the floor under the laminate can be done with your own hands.

Why do it?

Laminate is made on the basis of fibreboard and consists of layered plates that are assembled into a common floor surface using locking fixed joints. The plates are very rigid, so the substrate or carrier layer under the laminate must be even, otherwise the material is subjected to stress and, accordingly, cracking.

The locks connecting the laminate plates in this case will also wear out quickly, the seams may separate. Therefore, the floor on which the coating will be mounted must be prepared and trimmed. According to the norm the curvature of the carrier layer should be 2 mm per 1 linear meter in all areas of the room.

Alignment of laminate plates is carried out by a floating method, that is, they are not fixed on the base and substrate, therefore, when the coating is folded into a single layer, along the entire perimeter of the room along the walls remains expansion joint. This explains horizontality - one of the important requirements when laying this coating.. On the uneven surface or with a slope, the floor will slowly move to the lowered section of the room, the plates will no longer deform thermally, as they will rest against one edge of the room under a slope, and will begin to collapse.

A very important circumstance is dryness of the surface. Laminate does not like moisture, exfoliates and becomes unusable if water gets in. Therefore, when choosing methods for arranging the base for the subsequent laying of the floor finish, these requirements should be taken into account.

Now there are high-quality boards already covered with various compositions that protect against moisture, and even the locks between the laminate boards have a thin layer of hermetic glue, but under the laid coating it is still necessary to create conditions that exclude any moisture in the structure. At the same time, the floor will delight you for many years.

Types and characteristics of the base

Alignment under the laminate is performed on one of the following bases:

Concrete floors or cement-sand screeds;
Floor slabs in private houses or apartments;
Wooden floors on the logs.

The methods for preparing screeds and floor slabs are usually similar and have the same conditions. Everyone needs to carry out preparatory work. Concrete bases must be cleaned of dirt, dismantled old screed and the old finish coating, if any. Damaged plank floors, damaged tiles, screed are removed. If the floor is made of boards with mold, this rough coating should also be completely dismantled. Plywood sheets or chipboard mounted on wooden joists should be checked for wet spots, delaminated edges.

Required tools:

Sander or sander, respirator and ear protection scraping machine;
Roller or brush. These tools are used to apply a primer to concrete base and antiseptic for wood;
Roulette;
Building level;
Drill with a special nozzle for mixing solutions or construction mixer;
Screwdriver, self-tapping screws, PVA glue, construction gloves;
Beacons - building slats that help level floors.

What is better to equalize?

For leveling concrete foundations, screeds from cement-sand mortars with various components are used. They are suitable for the first layer, as they cover the main large cracks and bumps. But for the floor on which the laminate will be directly laid, another layer of mortar is needed, thinner for evenness and smoothness. Next, you should lay the substrate, which gives thermal insulation. These floors are quite heavy, create a certain load on the floors. This should be taken into account in advance, evaluating the possibility and expediency of arranging this floor in each specific house or apartment.

For alignment concrete floors often use self-leveling mixtures or, in other words, self-leveling floors. When pouring the mixture, the coating becomes perfectly even, all small cracks and the errors of the previous layer are equalized. Only suitable for very level ground.

Expanded clay is also used - the material is often used and lightweight. The weight load on the floors from it is minimal. He has many positive properties: maintain sound insulation, non-flammable, environmentally friendly, does not enter into chemical reactions with the materials used in the construction of floors. Expanded clay coating retains heat for a long time, is very durable, is not afraid of dampness and is relatively inexpensive. Preparation for laying the final floor is carried out very quickly in time, as the material is dry.

There are other ways to dry level the bases. For example, installation wooden beams with a measured step and laying on top of plywood, chipboard or OSB boards, as well as a screed on Knauf technologies dry solutions. In the second case, between the installed metal guides, backfilling is made with fine-grained expanded clay and then leveled with laid gypsum fiber boards (GVL). The surface is reinforced, insulated, soundproofed. The only negative is that GVL boards are moisture resistant, and it is necessary to cover them with a waterproof primer or use special hydrophobized ones.

With irregularities of no more than 4 mm, when minimal alignment is necessary and the laminate cannot simply be laid on the base, and more complex installations of structures are inconvenient and expensive, substrates are used. They come in several types: polyethylene, cork, cork-bitumen, wood chip coatings, polyurethane foam, foam propylene, isolon, foil.

Underlayment is often used on already smoothed floors to better preserve the reverse side of the laminate boards. Most inexpensive option It is, of course, polyethylene foam.

Preparing wooden floors for laminate is a more difficult task and more costly. On the installed new wooden logs, the floor is leveled with plywood sheets, OSB or chipboard. Thickness plywood sheets recommended for laminate - 12 mm. But if the old plank floor is still strong, not wet and suitable for subsequent installation, then partial restoration can be carried out and save a lot.

There are two ways to do this:

Sanding or grinding by machine and manually. Cycling can be done when there are no serious irregularities on the boards. The second way is leveling by laying slabs of the same plywood, chipboard or OSB.
Putty application. Suitable for wooden floors. Irregularities should be shallow, putty is applied in several layers. Each layer requires drying, so it takes a lot of time for such repairs.

Basic ways

When preparing a concrete floor, work is carried out in two stages. First, with the help of a screed (cement-sand mortar), deep irregularities are eliminated, and then a self-leveling mixture is applied, giving a more even finish surface. The work algorithm will be as follows:

In an apartment or in a private house, all remnants of the previous coating, debris and paint stains are primarily removed from the concrete base.
deep cracks filled with a cement-based mixture.
The entire floor area in the room is treated with a primer mixture.
With the help of the building level, rack beacons are installed and strengthened with a solution.
A screed solution is being prepared based on sand 75%, cement 25% brand M400.

A carefully mixed mixture is poured over the floor, spreading to the marks of the beacons. The thickness of the concrete layer at the thinnest point must be more than 7 mm.
After the first layer has hardened, it is desirable to carry out additional priming.
Let the floor dry. When the solution sets, the beacons-slats must be removed, and the voids under them filled with mortar and the surface allowed to dry again.
Cover everything with plastic wrap, which will retain moisture in the layer. Draft application can be considered complete. It is necessary to wait for the complete solidification of the layer before proceeding to the next step.

When preparing a self-leveling mixture, follow the instructions exactly and mix with a special nozzle for a drill or a construction mixer. You should pay attention to the expiration date of the product, as it is limited.
The concrete floor is poured with a mixture.
After three days, the floor will be ready for laying the laminate. For better preservation of the panels, you can lay the substrate.

Expanded clay is often preferred for many positive properties. The sequence of preparation:

The surface of the floor is covered with a film that extends onto the walls by 10-15 mm. The film is a waterproofing layer.
Then, an edge tape is applied around the perimeter of the room, it indicates the height of the backfilled layer.
GVL or plywood sheets are laid on the smoothed expanded clay, fixing with each other with self-tapping screws and special glue. Sheets are laid out in a checkerboard pattern.
After laying the plates, any substrate is laid, and laminate panels are assembled on it.

alignment wooden floor for laminate:

The degree of humidity in the room where the floor is laid should correspond to the humidity of the plywood sheets. It is necessary to wet them before laying and leave to dry in this room. Sheets must be used no more than 50 mm thick.
Logs with a thickness of at least 3 mm are installed and fixed with glue or self-tapping screws.
Plywood must be cut into squares with even edges and laid on logs, joining the edges. Sheets should be stacked in a checkerboard pattern and four sheets should not be joined at once. Between the squares, it is necessary to leave gaps of several millimeters to maintain the temperature balance of the floor.

Cut the required holes.
Fasten with self-tapping screws with invisible heads.
It is necessary to provide a double layer of material near the walls, therefore, layers of GVL or plywood near the walls are laid with a cut fold.

Putty is an inexpensive way to level floors under a laminate. By mixing sawdust and a putty mixture based on PVA glue, you can cover a space with a large footage, spending very little time. This is done as follows:

Carry out preparatory work by cleaning the floor from dirt and dust. Dry sawdust to prepare the mixture must be made wet so that they do not dry out quickly, as they will take moisture from the putty.
Next on the floor you need to fill the beacons from wooden slats or GVL sheets.

The space between them is filled with a solution of PVA, putty and sawdust. Multiple coats may be applied if required to fill and level cavities and cracks. Each layer must be given a drying time. The thickness of each layer should be 20 mm maximum. Filling a new layer must necessarily begin only after the previous one has completely dried.
In the process of work, you should constantly check the horizontalness of the surface to be poured with a building level.

Cycling is easy way leveling the boardwalk. The whole process is carried out using a scraper, and some places that are difficult to access will need to be processed with a manual scraper. With a fairly satisfactory condition of the floor, when the boards are not seriously damaged, they resort to this leveling option. The scraping machine will not be able to eliminate the too obvious relief of the floor, but it will even out small irregularities:

The room where the work will be carried out must be empty.
The floor is checked for defects. Cracks and chips are puttied, as well as various voids between the boards. You can lay them with sawdust. Damaged boards should be replaced if necessary. Check that there are no protruding nails and staples. You can remove the aged peeling varnish with a wire brush. Next, the floor is passed with a peeling machine and thoroughly washed with water or pure alcohol. Give the tree time to dry.

Tapes with sandpaper(paper grain is reduced with each new layer).
Start the process from corner to corner of the room with a snake. The next new strip must overlap with the previous one. Finishing work, you should walk with a scraper, moving parallel to the plank floor.

It is important not to forget to change sandpaper and clean it when working with a sanding machine.
At the end of the work, the floor must be swept or thoroughly vacuumed, and then wiped with white spirit.
To save the reverse side of the laminate, you can lay any substrate.

How to fill in?

Let's take a closer look at leveling the screed with self-leveling mixtures. These compositions are often called bulk self-leveling floors, seamless polymer floors. It must be remembered that dry self-levelling masses are poured into water, but not vice versa. Used for kneading special nozzle on a drill or construction mixer. The consistency is kneaded until all lumps disappear. Next, proceed to installation.

In the case when the area of the room or even the entire apartment is very large, it is necessary to divide it into sections. At the same time, they are poured in one period of time - having started work in the morning, do not transfer to another day. Start pouring from a high level of the base. For faster spreading, spatulas are used and they help to distribute the solution over the surface of the base.

The solidity of the filling of each section must be ensured by a high speed of work, and the sections should not be allowed to dry out. When pouring a new part, the joints must be made with a spatula and smoothly connected to the previous fill. To ensure that no air bubbles remain in the solution, should be walked with a toothed roller or brush.

There is a fill option. tile adhesive under the laminate It is advisable if, for example, after the last layer of the subfloor has dried, cracks have appeared or the areas between the beacons have dried unevenly. This happens if the preparation of the composition was performed with violations, the beacons were installed incorrectly, or the screed was poorly aligned. Also, a layer of tile adhesive can raise the level of the floor. Cement-sand screed or self-levelling mixture has a minimum thickness of 4-5 cm, and pouring them in a small layer, they can crack and peel off. So leveling with glue in this situation is the best option.

To prevent peeling of the tile adhesive, it is necessary to thoroughly clean the surface of the fill from the smallest particles of dust and dirt. Next, you need to prime the base for better adhesion and allow to dry for as long as indicated in the packaging instructions. Then it is necessary to knead the adhesive solution, following the manufacturer's instructions. For leveling with tile adhesive it is necessary to use a wedge up to 3 meters long. The solution must be poured out in parts or completely, distributing it horizontally over the beacons with a wedge.

The primer helps the materials "grab" with each other, that is, it has high adhesion, which allows us to make the structure durable. The absorbency of the mortar from concrete is reduced due to the priming compositions, thereby preventing its cracking.

Warming

It has already been said above about some types of insulation, but let's try to classify them and understand the principle of proper installation in the floor structure under the laminate. When arranging wooden floors according to the installed logs, you can choose the appropriate thickness of insulation and lay it between them. For example, foam, expanded clay or min. cotton wool Insulation in the form of plates must be fixed. Next, on top of the insulation should be laid polyethylene film, which will create a vapor barrier. For a smoother surface, chipboard, OSB or plywood sheets are installed, then laminate panels.

Concrete floors for laminate can also be arranged with insulation along the logs. If alignment is necessary, you should consider how high the insulation layer should be. With a new pouring of the screed, a fraction of expanded clay is added to it or slabs of min. cotton, foam. Self-levelling compounds should be applied in case when there is absolutely no space on the insulation and it can be no more than 1 cm. On concrete pavement flat surface you can put sheets of GVL, foamed polyurethane, polyurethane foam, isolon. The thickness should be no more than 2 cm. You can also lay a membrane with thermal insulation.

When installing a water floor, metal-plastic pipes are laid directly into the screed with a snake over the entire area of \u200b\u200bthe room. Between the pipe and the laminate panels, the height should be no more than 3 cm so that the heating is felt.

There are three types of electric floor: cable (laid in a sand-cement screed), infrared film, rod mats. It requires less space than water, it is more accurately controlled by temperature.

Successful examples and options

A few examples of leveling surfaces for laying the floor finish coating. An example of cycling a wooden floor by machine. Alignment with plywood sheets on wooden logs, floor insulation. Correct scheme laying plywood on logs in a checkerboard pattern with gaps between sheets.

Alignment of the base with the first layer of screed along the beacons. Gradual pouring of self-leveling mixture. step by step technology dry expanded clay screed devices for leveling the floor for laying laminate. Laying a polyethylene substrate under the laminate.

From the foregoing, we can conclude that it is imperative to carry out work on leveling the floors before laying the laminate. The service life of the floor will depend on the quality of the work done by your own hands and the right materials.

How to level the floor under the laminate, see the following video.

Rigid, clean, dry and always even - these are the requirements that apply to the base for laying laminate flooring. Unfortunately, despite the numerous efforts of manufacturers, many masters still do not know how much it is necessary to level the floor under the laminate.

According to the requirements of all manufacturers of hard floor coverings, including laminate and parquet board, the carrier layer must comply with the instructions and SP 29.13330.2011/SNiP 2.03.13-88. In particular, the basis must be:

Rigid and durable. That is, the floor should not bend or collapse with a force of 15 MPa or more.
Clean - dust-free, free from traces of bitumen, glue, old paintwork and other coatings, soot, etc.
Dry. For cement-sand and concrete screeds, the residual moisture coefficient should not exceed 5%, for anhydride screeds - 1.5%, for wood and wood-containing screeds - 12%. Subject to the above indicators, changes in the geometric dimensions of the draft floors are minimal. Even with sharp drops temperature and humidity.
Smooth and monolithic. Permissible level irregularities - no more than 2 mm for every 2 meters of surface. The base must be virtually smooth, without pits or tubercles, nodules or cracks.

Checking the evenness of the base.

As practice shows, it is the latter condition that is most often violated. Checking the evenness of mineral and wood floors is easy. It is much more difficult to correct the deficiency. But why level the floor in an apartment, house, office or store under a laminate? The answer is simple - for a durable coating service. Any defects under the flooring are a source of constant creaking, crunching and crackling, as well as the rapid destruction of locks and slabs.

Manufacturers of building and finishing materials have developed many optimal schemes for eliminating irregularities, dips, drops, distortions, cracks and other defects in the base. Namely:

The advantage of mineral screeds is high compressive and shear strength, improved density. In addition, they can be used in rooms with normal and high humidity in combination with waterproofing materials. The layer thickness varies from 1 to 100 mm, that is, this series is suitable for eliminating both minor irregularities and significant differences. The disadvantages are a decent mass (with the exception of perlite-based, etc.), a laborious process and a long drying time - from 7 to 28 days.

Prefabricated carrier layers allow you to level the floor under the laminate with your own hands in 1-3 days. This is the most convenient and fastest way to eliminate the shortcomings of the base with a layer of 20 mm or more. The finished dry screed weighs much less than a mineral screed, and you can lay the finishing material immediately, without technological break at 2-5 weeks. The downside is that this type of rough coating is not recommended for wet rooms, moreover, the strength does not exceed 15 MPa.

It would be useful to mention soundproofing. Laminate flooring is laid in a "floating" way, that is, without bonding to the base. For this and some other reasons floor material gives resonance to shock and air (sound) noise. Therefore, it is recommended to lay a noise-dissipating or noise-suppressing layer of vibroacoustic membranes, elastic polymer plates, fibrous mats, under a solid or prefabricated screed, frame systems with GVL and other similar materials. The range of similar products for the floor is wide, it is better to entrust the selection of the best option to a specialist.

Leveling the concrete floor

The concrete base is universal. You can work on it with any existing composition or complex. Therefore, depending on the type of defects, the following alignment methods are used:

grinding

If the surface has slight bumps, sagging, drops, then you can choose the fastest, but dusty way of smoothing - grinding. For this, sandpaper on a manual grater or professional grinders are used, often complete with construction vacuum cleaners.

The units can be rented, but the components (abrasive wheels, nozzle cups for stone and concrete, a respirator, goggles) will have to be bought. Or hire specialists with their own equipment.

Partial leveling with repair mortars

To seal cracks, potholes, local depressions, as well as to create slopes on balconies or terraces, it is not necessary to re-form a thin or medium layer screed. Use special compounds called repair. These are dry mixes based on cement / gypsum binder, ready-made pastes or polymer filling compounds, the main difference of which is in the following properties:

fast set of strength;
small processing area or layer thickness;
short drying time - from 1 hour to 3 days.

When choosing products, please note that the compositions are universal (for indoor and outdoor use) and intended exclusively for indoor use. According to the manufacturers, they are suitable for any finish coating in residential and commercial buildings.

Concrete screed

Under the tie layer is meant top part subfloor construction, on which absolutely any finishing coating is mounted, from ceramics to laminate. The tie is designed for:

creating a flat, as smooth as possible surface;
ensuring the static and dynamic strength of the structure;
uniform distribution of deformation loads on the underlying layers or supports;
formation of the required slopes.

Mineral screeds are characterized by the same density of the entire formation and compressive strength of 150 kg / cm² or more. The surface should not have cracks, sags, chips and other defects. The thickness varies from 3 to 10 cm depending on specific conditions (type of base base, availability of communications or floor heating systems, type of reinforcement, etc.).

Screed layers are made from:

industrial dry mixes. Easy to use ready-made DSP, packaged in bags of 25-50 kg. They are closed with water or polymer dispersions.
cement-sand mortar, manufactured independently. This will require cement grade not lower than M400, fine-grained quartz sand in an approximate ratio of 1: 3 (by weight). Pure water is added to the composition, approximately 0.45 or 0.55 liters per 1 kg of binder. The finished mass must be homogeneous, gray color, stamps not less than 150-200.
concrete. Foam concrete of category not lower than B3.5 (ρ=600-1000 kg/m³), light masses like expanded clay concrete, perlite concrete of class not lower than 5.0 (ρ≥1300 kg/m³), as well as standard concrete of class B15 (corresponds to M200) are used . Screeds made of cellular and lightweight concrete masses are distinguished by porosity and high heat-insulating properties. In contrast, classic concrete gives less shrinkage and a stronger layer.

Mineral floor screed is formed in 5 stages:

The optimal drying time for the screed is at least 28 days, regardless of the layer thickness.

Self-leveling floors

They are dry industrial mixtures consisting of a binder, fillers, modifying additives. Issued in a wide range and include:

Thin-layer levelers working with a layer from 0 to 30 mm. They are characterized by a high degree of spreadability and a minimum drying time - up to 5 days;
Finishing thin- and medium-layer compositions designed to form a smooth and even floor up to 60 mm thick for laying laminate, parquet, linoleum. Drying period - up to 14 days;
Basic or universal mixtures for primary leveling with a layer up to 100 mm. Used both indoors and outdoors. After 14-21 days, the surface is ready for installation of the laminate.

For weak bearing structures, lightweight mixtures are produced in which the quartz filler is replaced with crushed perlite, expanded clay, etc.

It is not difficult to form a floor from self-levelling compounds: the mixture must be mixed with water, applied as quickly as possible manually or mechanized way onto the prepared substrate, level it slightly and roll it with a spiked roller to deaerate.

Draft self-leveling mixtures are often confused with bulk decorative floors. The former are dry compositions based on cement or gypsum, the latter are polymeric (polyurethane, epoxy, methyl methacrylate) liquid or semi-liquid compositions designed to form so-called 3D coatings.

In fact, this is a prefabricated flooring made of sheet durable materials, fixed on a concrete floor with self-tapping screws or on a frame support. Such structures are indispensable if:

Wet processes must be avoided;
It is necessary to speed up the production of works;
It is required to significantly raise the level of the carrier layer (adjustable floors) or smooth out the differences.

There are many design options. We list the main ones:

Bulk

This is a structure, the lower layer of which is a backfill of expanded clay, expanded perlite mass, quartz or silica sand, fine-grained slag and other inorganic bulk materials with a maximum fineness modulus of 2-5 mm, moisture content of not more than 1%. Instead of non-metallic filler, XPS boards tightly laid to each other can be used, mineral wool or polystyrene (PSB-35 or 50).

Dry screed on a bulk basis.

The top layer is formed from durable sheets of GVL, chipboard, OSB or plywood. It is best to use Knauf-Superpol with a 50 mm mounting seam, tongue-and-groove chipboard from QuickDeck, etc.

The minimum thickness of the backfill screed is 40 mm and the maximum is 100 mm. This type of subfloor is suitable for both slab and beam floors (monolithic, prefabricated, etc.).

frame

In fact, this is a well-known floor on logs. On a concrete base, wooden slats are installed according to the level or metal profiles with an interval of no more than 40-50 cm, insulation is placed in the "windows" at will. Sheets of plywood, chipboard and other similar materials are fixed on top of the frame.

Adjustable

The floor is laborious in execution, but useful in new construction or reconstruction. Wooden logs or sheets of plywood are supported by threaded fastening and supporting elements screwed into them: rods-racks, bolts-racks, anchors, etc. The position of the supports in height varies due to the rotation of the bolt around its axis. They fix the level of the rack with a dowel-nail or a special stop that does not allow the structure to go astray.

The principle of adjustable floor.

Hard

This is the simplest carrier layer in execution, which allows you to level the concrete base and increase its heat-insulating properties. On the cleaned and primed floor with the help of hardware, " liquid nails» or polymer glue sheets of plywood, GVL, chipboard and other similar materials are fixed in 1-2 layers. Optimal Thickness flooring - 12-24 mm.

The choice of method depends on the financial capabilities and the condition of the base concrete base. It is best to invite a specialist who will determine the necessary parameters and offer options for eliminating deficiencies with detailed costing.

How to level a wood floor

If you plan to install laminated parquet on boardwalk, then you need to check each plank. Floor elements must sit firmly, evenly and tightly to each other. A base that meets these criteria does not need additional preparation.

But if there are noticeable differences, irregularities and other shortcomings, then the following technologies are used for alignment:

Any of the above leveling methods allows you to create an even, strong and reliable base for laminate flooring. Of course, some skills and knowledge will be required for the job, so if you are not confident in your abilities, contact the professionals.

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Currently, one of the most popular and common flooring is laminate, which has a number of advantages over other materials:

firstly, it is quite an affordable price;
secondly, excellent operational properties;
thirdly, it is ease of care;
fourthly, a large assortment of laminate;
Fifth, it's a great aesthetic look.

In addition to the above, a relatively quick and easy laying process can be added. Despite this, in order to properly lay the laminate, you need to know a few basic points. One of them is the correct preparation of the base, and for this, among other things, you need to immediately determine what it will be made of. One of the most popular materials for this is plywood. What kind of plywood to put under the laminate in different rooms and conditions?

Features of plywood as a building material

Laying laminate flooring, as well as other floor coverings (tiles, parquet, parquet board, linoleum and so on), requires careful preparation and alignment of the base. Today, plywood is most often used for these purposes, since this building material is very affordable and has optimal qualities, among which it is worth noting:

The strength of the material, which allows it to be used both in residential areas and in office and industrial premises.
Lack of smell.
Durability.
Can be used for underfloor heating.
Resistance to synthetic agents (cleaners, detergents, etc.).
High wear resistance.
Sufficient rigidity.
Good thermal insulation properties.
Large sheet sizes, which is very convenient and practical.
Good pressure resistance.
Versatility and practicality.
Easy installation of plywood sheets.

Plywood classification

In order to correctly answer the question of what kind of plywood to put on a laminate, you need to know the main types and types of plywood, as well as the basics of classifying this building material.

Plywood is classified according to the following criteria:

plywood brand - determined by the degree of water resistance of its connection;
material grade;
surface type - can be polished or not polished;
construction thickness and sheet format;
scope of use of the material;
environmental safety class (emissions), depends on the content of formaldehyde in plywood.

What plywood to choose for laminate

Considering all of the above properties and average price on plywood, the best option is considered to be laying birch plywood under a second-grade laminate, grade FN (medium moisture resistance) - recommended for individual construction. Grade Sh1 is polished on one side only, and the emission class is E1 (formaldehyde content per 100 g of material is less than 10 g). The thickness of the sheet should be from 12 mm.

Also, when choosing plywood for laminate, it is necessary to take into account the type of alignment. There are three main ways here:

On the lag.
On the wooden floor.
On a concrete pavement or on a cement-sand screed.

The first method is considered more capital and thorough, although more time-consuming. At the same time, it is possible to almost perfectly level the base of the floor under a laminate or any other laminate flooring. With this method, plywood with a thickness of 12 - 16 mm is usually used.

In the second option, if the wooden floor is sufficiently even and reliable, then the plywood under the laminate can be placed directly on it and screwed with self-tapping screws or screws. For this, plywood with a thickness of 10 mm or more is used.

Requirements for the base of the floor under the laminate

Before you start laying plywood under the laminate, you need to know what requirements are placed on the base, and be sure to take them into account.

Here are the main ones: maximum evenness, strength and reliability, environmental Safety and moisture resistance, which must be selected taking into account the level of humidity in each particular room. Particular attention should be paid to this factor when plywood under the laminate will be laid on concrete or a cement-sand screed.

It is recommended to check the humidity of the room before work, if this cannot be done using special devices (psychrometer, hygrometer, barometer, etc.), then you can use the following method. Put a plastic film on the concrete base of the floor for three days, pressing the edges tightly.

If after this period no condensation has appeared on the inner surface of the film, then the humidity in the room is normal. Before laying, plywood sheets are recommended to be treated with an antiseptic - this will protect them from fungus and mold.

Step-by-step instructions for laying plywood under laminate

Check that you have the required tool. You must have:

level;
a hammer;
screwdriver;
roulette;
electric jigsaw;
impact drill or professional hammer drill;
self-tapping screws and screws.

Prepare outer base. To do this, mark the border of a completely new floor covering around the entire perimeter of the interior. At this stage, the preparation or replacement of wooden floors and wooden gaskets under them is carried out. The lag is laid in increments of 40 to 55 cm.

It is recommended to fill the space between the installed lags with a special basalt external insulation or other soundproof building material. Thanks to this, the floor will be silent and quite warm.

You need to set the logs in height using wooden wedges and soundproof gaskets. Between the previously laid logs, bed gaskets, as well as wedges, it is imperative to put a layer of linoleum or foamed polyethylene. Near the walls, the logs must be laid with a gap of 2 - 5 cm.

Laying cross bars. At this stage, the arrangement of the floor lathing is completed and you can proceed to the next stage.

Lay plywood. It should be remembered that it must be well dried, especially if the material has been outside for a long time. Before laying, plywood sheets must be cut into squares - the standard size is 750 by 750 mm.

They are screwed to the lags with a small interval - 3 - 4 mm of the gap between the sheets. This will further prevent the floor from squeaking. In addition, the tree has the ability to change volume (shrink or expand - depends on the air temperature in the room). Therefore, so that the floor does not start to “walk”, and leave such gaps. Plywood is fastened using self-tapping wood screws - a pitch of 50 to 75 mm is considered optimal. It is important when arranging the floor in the corridor or hallway to put plywood sheets across the movement. With this option, the floor becomes much more reliable and durable.

With height differences of up to 10 mm, it can not be leveled, and plywood can be laid under the laminate without the use of wooden slats. The thickness of the sheets must be at least 17 mm.

If the irregularities of the base are insignificant, then sheets of plywood are laid on it on an adhesive mastic or fixed on special dowels.

The use of plywood under the laminate with the implementation of all the above stages of work allows you to make a reliable, durable, environmentally friendly and beautiful floor.

When it comes to renovating an apartment, all people try to find any way to save not only time, but also money. Walls and ceilings are elements of premises that are not as demanding in finishing as the floor, because it is flooring sets the style.

Even if you decorate the walls with gold, the ceiling with silk, and leave the floor bare, the “chip” of the room will be lost. That is why we will talk about how to hide the flaws of the concrete floor.

Plywood is an excellent material

You ask why plywood, and not some other material, because you can fill the floor with a cement screed, in extreme cases, put fiberboard?

The answer consists of several points:

The price of the material. It is one of the most affordable among those offered on the construction market (a harmonious combination of cost and quality).
It can be called practical and convenient for do-it-yourself work when there is no special equipment.. Even fill cement screed takes longer than laying plywood on an uneven concrete floor.
wood material considered environmentally friendly, although adhesive mixtures are used in production, but they are harmless and non-toxic. At least until they are exposed to fire.

Note!
Disputes about what better foundation under the laminate - concrete or plywood, so far they have not led to anything.
Some argue that cement is for centuries, others argue for the availability of wood material.

But before you decide to purchase this material, you need to know that plywood is of high quality and reliability, there are 4 different varieties:

I grade is considered the highest quality, can even be used for cladding various surfaces, as there are practically no flaws on it. Only small brownish streaks are allowed.
II grade is more affordable, but also appearance its not so clean, there are veneer inserts and small knots. The optimal plywood for a concrete floor without a log is durable and not so “biting” at a price.

Grade III is used for internal works when the surface is finished with something, but not for the floor, which is constantly under load. Suitable for leveling walls, garage and utility room.
IV, it is used only in cases where the budget for repairs is too cut.

Note!
It should not be strictly within the framework of all rules and standards - from 18 mm to 28 mm.
Thinner sheets are more suitable for horizontal surfaces.

Floor leveling plywood

This section contains detailed instructions for all the manual work that needs to be done so that the plywood flooring on the concrete base is correct and effective. Remember, the result will be positive only if you strictly follow all the requirements and sequence of work.

Material preparation

Before the material, they must be sawn and cleaned.
Sawing is done either with a hacksaw for wood (no power tools are required), or using an electric jigsaw. In the first case, there are two minuses: the end will be too torn and slightly uneven, it will also take more time and effort. With the help of a jigsaw, sawing plywood can be done in 5-10 minutes.
To eliminate cutting defects, it is necessary to process the ends with sandpaper: remove burrs and roughness. This at least provides increased safety, even if you work with gloves.

Surface cleaning

Before you start attaching plywood to concrete floor, the surface should be treated:

First of all, the floor is cleaned of all kinds of irregularities, old materials and dust.
All cracks and deep chips are sealed with cement mortar.
When working surface clean, you can prime it in one layer, no matter what you use, roller or brush - the main thing is that the tool is of high quality.

plywood fasteners

Now the laying of plywood on the concrete floor under the laminate can begin, for this you need:

Prepare glue for plywood and concrete to interact with both surfaces.

Note!
Trying to save on a fixing base, you can get a low-quality coating (base), which in a few years will be in free movement.
This will lead to numerous creaks and expensive repairs, depending on the materials that were chosen as finishing.
Therefore, glue for laying plywood on a concrete floor is better to buy foreign and with an average price tag.

Degrease the surface of the plywood on the side that will be laid on the floor.
Lay on the floor if necessary. waterproofing material, which is fixed at the joints with a special adhesive tape (although an ordinary masking tape is also suitable).
Installation of plywood begins with the placement of beacons of a horizontal level. You can use small cemented pins, or draw a line on the walls.
After - glue for concrete and plywood is applied on small plot(slightly larger than the stacked sheet of material) and rubbed with a notched trowel.

The plywood itself is laid after 1-2 minutes, so that the glue grabs a little. Before laying it on the glue, inspect the surface of the material, the side that is worse is placed on the floor.
Tap the material well with a mallet.
Drill 6-8 holes around the perimeter with a drill.

Using a screwdriver, fix the plywood on the dowel-screws.

Important!
Before attaching it tightly, expose the sheet relative to walls and other surfaces.

Leave the plywood floor alone for 1-2 days, then sand the surface.

Now you can lay any floor covering, observing the installation rules.

Features of laying plywood

Before gluing plywood to concrete, make sure that the room is adequately insulated (relevant for country houses). For example, if you chose a laminate for the floor, then you should use additional insulation which will make the flooring warmer. Plus, in this way, you protect the material from moisture.

Another feature - the thickness of plywood should not be less than natural wood(parquet), it is better - even if there is more.
Do not forget that between the sheets of material there should be temperature gaps from 2 to 5 mm, which will allow the material to expand and contract without any consequences.
We have already talked about how to glue plywood to concrete - the glue must be of high quality, but we did not mention what types there are. One-component - without hardener, two-component - with hardener (hardens within a few hours).
To apply the adhesive solution, it is better to use a notched trowel. As for those cases when the plywood will be finished with ceramic tiles, we advise you to use a rubber spatula, it will not damage the edges of the material.
Using plywood of various thicknesses, various linings can be used to eliminate irregularities, for example, fiberboard sheets, although they are not moisture resistant.

Do not forget about safety, especially when working with glue and plywood ends. It is enough to use gloves and protective plastic glasses to avoid adverse effects.

Well, now you know how to fix plywood to a concrete floor without outside help and expensive construction crews. Although, on the other hand, the demand for the quality of work will be on you, and not on outsiders who must guarantee positive result or free revision.

Conclusion

We tried to tell in the most detail in our article about how to lay plywood on a concrete floor, and if everything worked out for you, then we didn’t try in vain. However, do not be upset if something suddenly does not work out, for example, problems with leveling the surface (the most common problem).

You can solve it in three ways: