Substrate for plywood on a wooden floor. Laying plywood on the floor. Recommendations for laying plywood flooring

• Date: 20-09-2015
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New technologies for decorating rooms also affect flooring. In most cases, cork, laminate and parquet are used. You should be aware that such materials can only be laid on a flat surface. That is why quite often people are faced with the need to level the floor base made of wood.

For the house, it is better to choose plywood of the FC brand, it is less toxic and well protected from moisture.

There are several methods on how to do this. One of them is the alignment of the floor base with plywood. In order to properly carry out all the work, you will need to know how and with what you can fix plywood to a wooden floor. In addition, you need to know what kind of surface preparation work you need to do.

Advantages

The principle of leveling a wooden floor with plywood on adjustable logs.

It makes sense to use plywood for floor leveling, because it has the following advantages:

1. Low cost.
2. Neighboring layers are perpendicular, so plywood sheets will have good strength in all directions.
3. Plywood sheets are produced in large sizes, which makes it possible to perform accelerated installation in large areas.
4. Plywood sheets can bend well, and they will not break.
5. Plywood sheets are quite easy to transport.
6. Such sheets are unpretentious in use.

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Nuances when laying

Laying plywood on a wooden floor is especially important when the plank floors dry out, loosen and become unusable. Plywood allows you to make repairs in an optimal way - with minimal cash and labor costs.

When sheets on a wooden floor, it is important to know the following nuances:

1. First of all, you will need to check whether the wooden floors sag along the logs. If there are deflections, then it is necessary to completely disassemble the floor covering and repair the base of the wooden floor. If the problem is not in the lags, then it is best to lay plywood on a wooden base.
2. It should be remembered that plywood should not be used where there are large temperature differences and high humidity. for bathroom and unheated premises plywood sheets will not work. To check if there is high humidity near the floor, you need to tightly put a sheet of polyethylene measuring 1x1 m and leave for 3 days. If on inside polyethylene sheet If there is no condensation, then you can put plywood on the floor.
3. The plywood is laid dry with an offset so that at least 3 seams converge at one point. Separate sheets adjusted to the size of the room, while you need to bypass the ledges and fill in the niches. In the process of carrying out such a procedure, it must be remembered that a gap of about 9-10 mm must be left between the scattered plywood. In the future, these gaps will be covered. There should also be gaps between the walls and plywood, which in the future are covered with skirting boards.
4. In order not to confuse the fitted sheets during the final assembly, you need to number them and draw up a plan.
5. Plywood sheets are best cut into 60 cm squares. In this way, a suitable number of damper joints can be obtained. In this case, it will be easier to find delaminations that may not be noticed in solid sheets.
6. Before final laying of plywood, it is recommended to thoroughly clean the base from dust and other contaminants. You can also perform priming, which consists in treating the floor surface with a primer.
7. Plywood must be installed with glue. If glue is not to be used, each sheet must be fixed with self-tapping screws along the edges and diagonals. The fastening pitch should be 18-20 cm. The indentation from the edges should be 2 cm. The screw heads are recessed.
8. Fasteners must exceed the thickness of the sheets along the length of at least 3 times. For example, for sheets of 12 mm are suitable self-tapping screws 40 mm.
9. After laying, the base must be carefully sanded. This can be done with parquet sanders and sandpaper with large grains.

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Preparation work

Installation of plywood on a wooden floor must be done correctly and using necessary tools. The master must have experience with all the tools to be used.

For laying plywood, the following elements are needed:

1. Screwdriver.
2. Electric jigsaw.
3. Building level.
4. Roulette.
5. Self-tapping screws.
6. Dowels.
7. Glue for wood.
8. Plywood sheets.
9. Sealant.

Before leveling a wooden floor with plywood, you need to check the base for suitability for use. In addition, you need to replace old boards and repair creaking elements. It is recommended to check the evenness of the base using the building level.

If the floor surface is not too flat, then it is worth determining the maximum difference in the base. If you need to smooth out small irregularities, you should use a floor underlay. If there are differences of more than 1 cm, you will need to lay the log horizontally. They can be set using the water level.

The choice of plywood sheets will depend on the flooring that is planned to be laid. If you plan to lay carpet or linoleum, it is recommended to purchase sheets of small thickness. If laminate or parquet boards will be laid, plywood 10 mm thick or more must be purchased.

The thickness of plywood sheets that are laid under a laminate or parquet board must be no less than the thickness of the floor covering.

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Plywood brand

Before laying, it is important to choose the right brand of plywood sheets. It can be determined according to the moisture resistance of the material. For industrial construction, the FB and FOF brands are used. For individual works for construction, plywood of the FSF and FK brands is intended.

FC grade plywood can be used in children's rooms or bedrooms because it uses a phenol-free adhesive in the manufacturing process, making the plywood harmless to human health. She has average level moisture resistance and is resistant to mechanical stress.

Plywood brand FSF has elevated level moisture resistance, wear resistance and mechanical strength. These properties will not change with changes in temperature and humidity. This is achieved thanks to special resins, but this makes such plywood toxic. This material is not recommended for use in living rooms.

Plywood flooring makes the floor stronger, more resistant to deformation. Such a surface is an excellent basis for laminate, parquet, linoleum. Laying plywood on a wooden floor helps to conserve heat by reducing the amount of energy needed for heating. In addition, the top layer of the coating can be changed after some time, if desired, leaving the base in place.

Laminate on plywood

Pressed wood boards successfully used for the construction of rough or finishing flooring. The material is inexpensive, easy to transport, has obvious advantages:

• laying plywood under laminate on a wooden floor takes a little time;
• pressed veneer does not allow rotting bottom side finish coat thanks to good air exchange between material and wood flooring;
• smooth surface extends the service life floor covering;
• plywood sheets weigh a little, while they have sufficient strength, hardness, and are resistant to external influences;
• the canvas is flexible, does not break during installation;
• the material does not have a pronounced smell, is safe for health, suitable for arranging a wooden floor in any room, including children's, medical, etc .;
• rough flooring retains heat well, absorbs noise;
• the canvas is large, forms a minimum number of joints when laying;
• factory grinding makes the surface of the material non-slip, prevents the displacement of materials placed on it;
• the possibility of using for the floor in the kitchen, bathroom, toilet due to its high moisture resistance.

Base for laminate

Leveling a wooden floor with plywood has, however, some disadvantages:

• Instability to fire, rapid spread of flame. Plywood is compressed wood, so the level fire safety the sheet is low;
• The canvas is more expensive than chipboard, fiberboard;
• Laying plywood makes the wood floor a few inches taller. This solution is not suitable for rooms with low ceiling.

Laying plywood on glue

Types of plywood used for work

The material varies depending on the type of wood veneer used in production. Exist the following types canvases:

What kind of plywood to lay on a wooden floor? There are different brands suitable for certain types of work. In industrial construction, plywood of the FB, FOV brands is used. For laying the floor in a residential area, the FSF, FK categories are suitable.

A canvas marked FC can be used to equip a wooden floor under a laminate in a nursery, bedroom. The material is impregnated adhesive composition containing no phenol. The canvas does not pose a danger to human health. Such plywood sheets are quite strong, have an average level of water resistance.

Plywood brand FSF

FSF brand cloth is more resistant to water. The material is strong, durable regardless of temperature, humidity level. The canvas owes such properties to a special impregnation, which at the same time makes the plywood sheet toxic, unsuitable for laying flooring in a residential building.

The canvas is attached to the logs or directly to the floor surface. The first method requires more effort, time due to the need to build a foundation. Leveling a wooden floor with plywood without a lag is done using glue. This method is suitable if the rough surface is flat, durable, and does not have height differences.

Laying on wood floor

Installation on old wood flooring

A flat, solid surface is a good base for laying plywood on a wood floor. The advantage of this installation method is the slight surface elevation after installation. The minimum thickness of the web is 1.2 cm. The cut sheets are attached using special glue and self-tapping screws.

Tools and materials

Required tool

For correct fastening plywood to wooden floor The following tools and building materials are needed:

• electric saw;
• roulette;
• level;
• marker;
• self-tapping screws;
• screwdriver;
• construction vacuum cleaner (a broom will do);
• roller;
• grinder;
• plywood sheets;
• substrate;
• primer;
• glue.

Preliminary preparation

Sheet layout

Before you start laying, you need:

• Check floor condition. It is required to strengthen loosened elements, replace rotten, damp parts, ventilate the room;
• Remove dust, dirt from the surface, prime the floor special composition for a wooden surface. Then you need to dry the base for 16 hours;
• Align minor differences in height, up to 1 cm. To smooth out irregularities, you need adhesive tape and a special substrate for plywood on a wooden floor. The joints between the strips of material are glued with adhesive tape;
• Place the sheets vertically to dry for 2-3 weeks at room temperature or slightly higher;
• Treat the dried cloth with an antiseptic solution;
• Ventilate building materials;
• cover plywood acrylic varnish in several layers. This treatment increases strength;
• Bring plywood into the room two days before laying. The material is placed horizontally. This is necessary in order for the canvas to adapt to the microclimate of the room.

Marking and cutting

Marking by size

Cutting plywood is done in such a way as to minimize the number of joints. The material is sawn taking into account the gaps of 3-4 mm between the sheets and 8-10 mm between the canvas and the wall. The indents allow you to avoid swelling of the coating due to temperature fluctuations, increased humidity. The material tends to increase in size by several millimeters under the influence of the microclimate.

The plywood sheet is sawn with an electric jigsaw. It is required to carefully examine the ends of the blanks for delamination, grind the edges. It is convenient to cut the material in squares with sides of 50 or 60 cm. This helps to smooth out wooden surface to avoid installation defects. Each sawn square is numbered, indicated on the layout of the sheets.

Self-tapping screws

The correct laying of plywood on a wooden floor is as follows:

• Spread the substrate on the floor, glue the joints with adhesive tape;
• Lay out the sheets to cut the material as rationally as possible. Plywood is placed taking into account the gaps in case of expansion of the canvas under load, temperature fluctuations. The indents between the sheets are 3-4 mm, from the wall along the edge of the canvas should be 8-10 mm;
• Cut the elements with a jigsaw. For a spacious room, squares with a side of 50-60 cm are convenient. All parts are numbered, the location of the elements is fixed on the diagram;
• Drill holes. Then follows a countersink with a drill bit larger diameter. When laying on glue, additional fastening is required. Holes are made at a distance of 2 cm from the edge. The distance between fasteners is from 15 to 20 cm;
• Apply plywood glue to the wood floor. The layer thickness should be 2-3 mm;
• Lay the canvases, starting with a niche, podium, ledge. Then place the sheets from the center to the edges, sliding the squares like brickwork;
• Press down on the material with a roller to ensure a firm grip;
• Fasten the material with self-tapping screws to ensure greater security, prevent displacement. Hats need to be thoroughly drowned. This will protect the bottom layer of the final coating from damage;
• Check the quality of the laid coating with a level.

Lag installation

Mounting the web on a pre-built structure is more laborious and takes more time. This method is good because it does not require leveling the old coating. The logs themselves should be the same in height. The base is installed on a tree if its surface is strong, strong. The construction of the structure is not recommended in rooms with a low ceiling, because in this case the floor rises by 8-10 cm.

Preparatory stage

Before laying plywood on a wooden floor, you should clean the previous coating, remove dust, large and small debris. It is required to inspect the cracks near the walls and between the floorboards, fill the largest of them silicone sealant. Suitable for this purpose mounting adhesive. The material should be cut into squares, then mark each canvas. A diagram of the stacking of sheets is drawn on paper. The squares are arranged in bricks so that each next row shifts relative to the previous one.

Laying sheets on lags

Logs are slats with a cross section of 40 by 15 mm and a length of 1.5-2 m. The guides are fixed to wooden boards with dowels or self-tapping screws. The logs are mounted so that their top forms a flat plane, and the slats serve as a crate. The space between the guides is filled with material designed for heat and sound insulation. Cords, wires are hidden under the lags.

Written especially for you step by step instructions how to lay, starting from the choice of material and ending with the final polishing of the finished surface.

On the sheets you need to outline, drill, countersink holes. Then comes the laying of the plywood floor itself on the wooden floor. Material attached liquid nails or with self-tapping screws. In the second case, you should thoroughly drown the hats in the canvas so that they cannot damage the bottom of the final coating.

Finishing

Scraping the floor surface

At the end of the laying, the joints are processed with fine-grained sandpaper. Does this job excellently Sander co special nozzle. This smooths out small irregularities, differences in height between adjacent sheets. Next, the floor surface is varnished in several layers.

Is alignment necessary?

The final floor covering can be very demanding on the base. When laying, it is required to create a perfectly flat surface. An old floor almost always requires adjustment in height, especially when it comes to installing the coating directly on the rough surface without using a wooden log structure.

flat base

Laminate and parquet boards are especially capricious. The increased exactingness of the final coating is due to the presence of a system of interlocks, which cannot perform their function when laid on an insufficiently even surface. Differences in height lead to the appearance of cracks, deformation of the floor. Places of loose joints are further clogged with liquid, dirt.

The floor from the boards is durable, environmentally friendly, resistant to abrasion. However, after several decades, the boards begin to creak, dry out or rot from high humidity in room. If you lay linoleum or carpet on an unprepared plank floor, lay a laminate or parquet, then the surface will not be perfectly flat. All defects in the rough base will be visible through the finish finish coating, and in the case of locking systems, installation with unevenness will not be possible.

To make the floor high-quality and durable, under flooring underlay needs to be installed. For this, sheets of plywood are suitable, which will hide all the bumps and imperfections of the wooden floor.

Peculiarities

To choose plywood for leveling the floor, you need to understand the features and classification of the material on the market. Plywood differs in grade, thickness, moisture resistance and material of manufacture.

The main characteristics will help you choose the right sheets.

There are 4 grades of plywood that can be distinguished visually:

• The fourth grade has defects on the surface, rough, there are holes from knots, since the lowest quality raw materials are used for manufacturing.
• The third grade is better than the previous one and there is less marriage on the surface.
• The second grade has minor cracks, smooth.
• The highest quality and most expensive first grade is well polished, all sides are free of defects.

When choosing a variety, they are guided by price and quality. For the construction of the subfloor, plywood of the second and third grades is suitable. According to the processing method, there are:

• Unsanded plywood.
• Sanded (one or both sides).

For installation on the floor, one-sided sanded material is taken, laying the smooth side at the top.

Plywood is made from hardwood and conifers wood (usually from pine and birch). Wood veneer is bonded together with natural and synthetic resins. The top layer can be treated with a lacquered water-repellent compound.

According to resistance to moisture in residential premises, brands are distinguished:

In bedrooms and other living rooms with low humidity, FC and FBA brands are laid, made on the basis of carbamide and albumin-casein glue. They differ in environmental friendliness and average resistance to moisture.

The FSF brand is placed in the corridor and in the kitchen, where greater moisture resistance is needed.

The thickness of the canvas determines the number of layers of veneer. Their odd number is laid perpendicular to the previous one, creating a strong construction material. For subfloor flooring, plywood with a thickness of 10 mm or more is taken.

Plywood lends itself well to fastening with self-tapping screws, does not crumble or crack.

The analogue of plywood in the construction market is OSB - oriented strand board. Such materials have similar properties, but differ only in production. For plywood, wood veneer is the raw material, and for OSB, wood chips are processed with natural resins.

OSB is divided into different categories:

• The first is suitable for minimal stress and dryness.
• The second - is made for impenetrable residential premises.
• The third one is characterized by high moisture resistance and durability.
• Fourth - used in the construction of walls.
• Lacquered or laminated - coated protective layer varnish or laminate.
• Grooved - at the joints has a connecting groove.

The best solution for the subfloor will be OSB 3, grooved and easy to install. Such sheets are produced with a thickness of 0.5 cm to 4 cm.

Pros and cons

When it is difficult to decide which substrate is better: plywood or chipboard, you need to consider the advantages and disadvantages of each material. plywood cover has the following advantages:

• Withstands heavy loads.
• Light weight.
• It is flexible, has high bending strength and deformation.
• There is no foreign chemical smell.
• High leveling ability.
• Easy to handle, saw.
• Easy to operate.
• Smooth beautiful outer surface.
• Keeps the heat in the room.

Advantages of using oriented strand boards:

• Affordable.
• They don't flake off.
• Surface without defects.
• Various sizes.
• The panels are lightweight.
• Resistant to harmful insects.

But all wood materials have general disadvantage – big influence they have moisture on them. Humidity will quickly destroy wood raw materials, so it is better to lay moisture-resistant brands of coatings. Reverse negative side moisture resistant panels- environmental friendliness. They emit formaldehyde, which is harmful to health, but it is he who helps fight moisture.

Both leveling materials have a high degree of ignition from open fire, therefore, before laying the material, care must be taken to increase the fire retardant properties.

If you lay the flooring on the logs, then up to 10 cm in the height of the room disappears. This is not always acceptable in certain situations. To lay the sheets, it is necessary to make a clear calculation so that there is no waste and unnecessary work on alteration. It is recommended to fasten these materials with self-tapping screws with an average pitch of 20 cm.

Such sheets tolerate fasteners well and are tightly attracted.

The differences in price between plywood and OSB of the same brand are not the most significant, but OSB is cheaper. In suitable and unpretentious conditions, OSB boards can be laid, but plywood is suitable for a durable wear-resistant coating.

Materials and tools

Plywood and OSB are similar in laying technology. To cover the floor with wood sheets, use the same installation tools. Mounting materials are the same. In order to quickly and efficiently lay plywood sheets on a rough plank floor, you need to stock up on basic construction tools. The work will require:

• Level for measuring the evenness of the floor.
• Screwdriver or screwdriver for screwing screws.
• Drill for drilling holes for dowels.
• Roulette for measuring the required length.
• Jigsaw or hacksaw for sawing plywood sheets to the desired dimensions.
• Sanding attachment for drill or Grinder for grinding joints between sheets.
• roller or paint brush for applying primer.
• Broom or vacuum cleaner for garbage collection.
• Spatula for applying glue.
• Hammer for nailing.

To improve the moisture-resistant and fire-retardant properties of the material, it is advisable to use special flame retardant compounds and primers.

It is better to lay plywood or OSB on water-dispersion glue bustilat, PVA. These grades are suitable for gluing wood surfaces. They are safe for health, have no smell and dry within a day. The adhesive is easily applied with a spatula or brush (depending on the consistency).

You can fasten plywood sheets on self-tapping screws and nails. If the laying of materials is carried out in an apartment, it is preferable to use self-tapping screws with dowels, since working with a drill and a screwdriver is easier and quieter than a hammer with nails.

Preparatory work

Before starting the installation of plywood on a wooden floor, the main preparatory work. First, an assessment is made of the original rough wooden base. Visually assess the condition of the floorboards, the presence of ill-fitting and creaky floorboards.

Check the construction level for differences and uneven surfaces.

Then the skirting boards are removed. All loose boards must be additionally fixed with nails or self-tapping screws to the lower beam. Floorboards affected by the fungus are replaced or cleaned, impregnated with an antifungal compound. Warped and damaged boards must be replaced. The protrusions on the surface are cut off with a planer and polished. Slots and cracks are filled with sealant or glue.

After the repair, garbage, sawdust and dust are cleaned with a broom or a vacuum cleaner. Raw plank floor being processed antiseptic. Roll material can be laid under the plywood floor as noise insulation and insulation.

Penoplex or isolon of small thickness is suitable for the substrate. Connect the strips of the substrate to each other with construction tape.

The plywood is fastened after drying to avoid deformation. To do this, the material is brought into the room and left for 2-4 days. The optimal solution to protect against moisture and fire, both sides of the panel will be treated with a primer or acrylic varnish. The technology of laying wood sheets requires an indent from the wall in the amount of 1-1.5 cm between sheets up to 0.5 cm.

This must be taken into account when cutting and laying plywood blanks on the floor.

To relieve stress from the material during operation and ease of installation, the sheet is cut into 4 parts using a jigsaw. All parts are preliminarily placed and adjusted, the layout is drawn and the workpieces are numbered. Lay the sheets with an offset to reduce the number of joints and avoid crossing.

If you follow all the rules when laying plywood, it will serve as a high-quality, durable base for any floor covering. Finishing decorative material can be overridden and plywood base will remain the same.

Alignment methods

The leveling method depends on the evenness of the subfloor. Differences in height of more than 1.5 cm suggest plywood flooring along the logs. Minor irregularities are covered with plywood directly on the wooden floor.

Boards with a difference of less than 1 cm are aligned with supports in the right places. As a support, thin squares, bars of wood or plywood are used.

Laying plywood on the floor can be done with or without underlayment. The lining roll is rolled out over the entire surface and fastened with adhesive tape. Plywood material is spread on top in accordance with the scheme, the evenness is checked and fixed with self-tapping screws. In this case, sheets with a thickness of 1 cm are needed.

Without the use of gasket material, an adhesive fastening method is used. small area the premises are covered with glue by 2-3 mm, starting from the corner. A sheet of plywood blank is superimposed on top and pressed tightly. Additionally, you can screw a few screws for better fixation. This method is used to install the rest of the room.

Laying birch plywood does not require special skills and can be done by hand.

When a plywood sheet does not lie flat, bends, there are slight differences in height with other blanks, supports are used. Anchor points are placed in ill-fitting places and fixed through with self-tapping screws.

If fiberboard lies on a wooden base, then dismantling is carried out if the material is old, warped from moisture, crumbles and exfoliates at the edges. Fiberboard is not recommended to be laid on the floor, since the sheets deteriorate from moisture and have poor leveling properties due to their small thickness.

To level significant differences in height, logs are used. As a log, boards of the required length with a section of 3-5 cm by 7-10 cm or coniferous plywood slats of the same size are used. The location of the lag depends on the thickness of the plywood and the load during operation. Small thickness requires a smaller distance between the lags, starting from 40 cm. You should not use sheets less than 1.5 cm in height. The installation of the log is designed in accordance with the layout of the plywood in the room, so that the joints are laid in the middle of the timber.

The horizontal installation of the lag is measured by a water or laser level. The evenness of the entire floor depends on the accuracy of installation. The lags are attached to the glue and screwed with screws. Bars are placed perpendicularly between them, obtaining a reliable crate, on which plywood blanks are laid.

If you put plywood on concrete screed, then during operation, plywood sheets will take the brunt of the blow. Microcracks form on the wood, but they do not affect the quality of the floor.

The wood building material from which the subfloor is made is in good contact with any exterior trim. This has a positive effect on the condition of the floor over the years. The surface remains smooth, without cracks, bends.

Another advantage of using plywood is the ease of installation. This material is easy to cut into pieces and quickly laid. One person will be able to carry out all the work with minimal experience behind him, and at hand the most common construction tools.

Plywood has low thermal conductivity, which reduces heat loss in the room. And if you take sheets of the highest grade and fine grinding, then you can use them for the final finish.

Where not to apply

Despite all the advantages, plywood sheets are not recommended for use in rooms with high humidity. This is their minus. Plywood is not laid in baths, pools, showers, bathrooms. Of course, there are moisture-resistant laminated varieties, but their price is high, so not everyone wants to use them on a large area.

It is not advised to cover the floor with plywood in rooms with a strong temperature difference, for example, on unheated dachas. Strong heat after freezing can cause the sheets to warp.

What kind of plywood to lay

Before laying plywood on the floor, you need to familiarize yourself with its characteristics:

• the brand for the dwelling must be FC. This is the safest option, although its moisture resistance is not very high. Laminated products are also used, but they are higher in cost;
• class for security purposes choose E1 or E0.5;
• inexpensive 3rd and 4th grades are suitable for the subfloor; for a finishing one, you need to take a higher grade. Often there is a designation of varieties 2/2, 2/3, 1/2 and the like. So indicate the grade of veneer from different sides;
• the moisture content of the sheets should be no more than 15%, the lower it is, the better;
• plywood used for the subfloor must have a thickness of at least 12 mm, for finishing, a value of 10 mm is allowed. Can be applied in two layers. In workshops, workshops, public areas with high traffic, the thickness can reach 2.5 cm;
• for subfloors, unpolished plywood, designated NSh, is suitable. It can also be polished on one side - Ш1.

Laminated plywood with a mesh texture is used mainly for flooring in transport. She is suitable for finishing on the terraces country houses, outbuildings.

The dimensions of the sheets are chosen in accordance with their own needs, they are not of fundamental importance for laying. It should be borne in mind that the larger the sheet, the greater its mass. The process of transportation and manipulation during installation becomes more complicated. To avoid stress in the material under load, large sheets are sometimes cut. When sticking to a screed, it is convenient to work with squares of 75 x 75 or 60 x 60 cm. Elongated strips are suitable for logs. AT large rooms they may or may not be cut.

Domestic manufacturers offer plywood good quality, which is quite suitable for the floor. The same applies to Western European brands. Concerning Chinese goods, then here you need to be careful when choosing, because there are products that do not meet the standards. For example, the declared thickness may be greater than the actual one.

Subfloor laying options

Plywood is easy to lay on a flat concrete screed in the apartment. Sheets 12 mm thick are glued to the surface, after checking its horizontalness. Height differences should be no more than 2 mm, otherwise it is necessary to fill for leveling and wait for it to dry completely.

Note! For any installation at the joints of the sheets, it is necessary to leave gaps of 2.5-3 mm, retreat from the walls by 1-1.5 cm. This will avoid deformation during temperature and humidity changes, there will be no squeaking, deflections.

Plywood sheets are laid with a slight offset so that there is no clear joining of the four corners. This installation increases the strength of the flooring.

The most common mounting method is wooden lags. He is able to replace the screed. The surface is perfectly smooth, it can be used for any finish. Legs can be adjustable. How to perform such an installation will be discussed below.

With a height difference on a wooden floor, fasteners in the form of studs or screws are used, which allows you to level the surface without using a log. This is an interesting installation method, in which fasteners (screws, self-tapping screws, studs) are drilled over the entire area at the same distance from each other. The height of their heads should be at the same level. You can check this with a laser or a regular level. It is necessary to screw the hardware evenly. Foam is squeezed out between the fasteners and a thick plywood sheet is laid on top.

Lag installation

If it is necessary to insulate the floor, level or raise it, then logs are used. Do-it-yourself installation of a plywood floor along the logs is more laborious.

It is recommended to take plywood with a thickness of 12 mm or more. Can use two layers of 9mm sheets or take sheets different thickness, but that in one layer they are all the same. The top layer can be laid out from thinner sheets. Total thickness plywood cover can reach 25 mm. The second layer is laid so that the joints do not coincide with the first.

Bars with a section of 70 x 50 are used as a log. Bars and plywood sheets must be aged at room temperature for several days before they are mounted. Moreover, the plywood must be in a horizontal position so that there are no bends.

The lags are screwed with anchor bolts to concrete base or strong wood screws (if, for example, laying goes on an old wooden floor). The first log goes at a distance of 30 cm from the wall, then the subsequent logs are laid in increments of 50 cm, strictly parallel to each other.

Note! For screwing plywood sheets to the logs, only high-quality self-tapping screws for yellow wood are used.

Self-tapping screws must be fully tightened and not break. Their length must be at least three times the thickness of the plywood sheet.

Of the tools used are a circular saw, a laser level, a meter and a screwdriver. It will be nice to impregnate all wood materials with fire protection.

The walls do not always go smoothly, so the first sheet must be leveled with a level and a square. Next, sheets are measured, cut with a circular saw and laid out on the surface. The layout should be with a run-up so that more than two corners meet at one point. And do not forget about the deformation gaps.

Self-tapping screws can be quickly screwed if countersunk holes are drilled in advance. It is convenient to use a screwdriver with a countersink. The distance between the screws is 20–30 cm. At the same time, there must be at least 8 fasteners on one sheet.

After the floor is laid, everything is fixed, the left joints are sealed with special mastic.

Leveling plywood sheets

In old houses, there are floors with worn wooden boards. If the wood is not rotten, then it should not be removed. It is enough to remove the old paint, remove debris, level the floor with plywood sheets from above. Such a multilayer flooring will be an excellent heat insulator. As a finish, you can use laminate, linoleum, parquet board.

Laying plywood on a wooden floor is carried out in the same way as on a screed, leaving expansion joints(gaps). Fix the sheets with self-tapping screws, twisting them so that the hat is recessed. Then they level everything with a grinder, cracks, putty grooves. If it is necessary to install a parquet board, then cover the substrate.

Plywood is not laid under a wooden floor from a board. Natural wood is quite massive, materials from it are laid directly on the logs.

Finished floor

There is controversy over whether plywood can be used for fine finish gender. Many people say that such floors look unpresentable, but there are good examples of fine plywood flooring.

Note! If you want to lay out a finishing floor with plywood, then choose high grades with a polished front surface.

For decoration use square or rectangular panels. If you plan to lay out some special pattern, then first make a sketch. The most common layout option is staggered or herringbone. It is very similar to wooden parquet.

The base on which the plywood slabs will be laid must be perfectly flat, regardless of whether it is a concrete screed or wood material. The surface is primed, which ensures good adhesion. Next, markup on plywood sheets and cut the slabs to the required size. Each plate is numbered, as in a sketch or diagram, in order to know exactly where to lay it. This is especially important for a complex pattern, but if all the plates the same size and form, there is no need for numbering.

Advice! To make the joints look better, chamfer is removed from the ends of the plywood. You can also use T-shaped plastic inserts at the joints.

First, the plates are laid out on the floor, then finally glued. To give a shade, plywood is treated with stain and opened with several layers of matte varnish. You can use opaque paint to hide bumps and stains if they have formed after applying the stain. One of the design options is to seal the joints with putty, paint with enamel paint, which will protect against moisture and hide imperfections.

Both in new buildings and in houses commissioned several decades ago, residents are faced with the task of leveling the floor to change the floor covering, whether it be linoleum, parquet or parquet board, laminate or something else. But modern market offers so much a wide range of that it is sometimes difficult to give preference to one or another building material.

The purpose of this article is to dispel all doubts and help you make a balanced, reasonable choice before starting repairs in own house or apartment.

Features: pros and cons

Of the variety of materials suitable for these purposes, the choice comes down to four of them:

1. plywood;

When choosing flooring for leveling the floor, you need to take into account the features of each.

• fiberboard- material from compressed wood fibers, pre-treated with steam. Synthetic resins or paraffin are used as a binder. The production technology does not allow making fiberboard of great thickness, and the raw materials used (most often it is wood processing waste) cannot achieve satisfactory strength. Of the entire list, plates of this kind are the most fragile. Moreover, if the draft surface has significant, and even more so local solid protrusions, for example, an influx of concrete or a piece of reinforcement sticking out of the screed, this species material can be damaged even at the marking stage.

• DSP- slabs of chips of small and medium fractions, bound by cement. In addition, a number of chemical additives are added to the composition to reduce negative impact chips for cement. At the same time, DSPs have a high density, and hence more weight with the same area. They are quite fragile to fracture, although somewhat stronger than fiberboard, while being more resistant to moisture, heat, and much less susceptible to mold fungus.

• OSB- a board made of large chips, bonded with phenolic-based resins. It is important to remember that at enterprises with incomplete quality control, the production technology may be violated, then the release of phenols may exceed the permissible limits.
• Plywood- the most environmentally friendly of this list. Technically, it consists of several layers of birch (rarely coniferous) veneer glued together. It has a relatively low specific gravity, and surpasses all other materials from this list in strength.

For a number of reasons, it is plywood that is much more convenient to use for repairs:

• Saving time. In addition to the usual formats of 1.5x1.5 meters, sizes of 2.5x1.25 meters and 3x1.5 meters are also made - a large area can be covered in one time.
• Saving effort. Even a leaf big size can be carried by one person.
• Elasticity. Adjacent veneer layers are oriented perpendicularly, providing strength in all directions. This quality will provide higher wear resistance both during installation and during floor operation.

• Elasticity. If there are some local irregularities of the subfloor in this place, the sheet will be washed without much loss, and this area will remain flush with the rest. Due to the elasticity, the material will not crumble or crack either during installation or during operation.
• Environmental friendliness. In most cases, natural resins or natural-based adhesives are used, which increases environmental and consumer safety.
• Porosity. Due to its natural origin, this provides ventilation, which will prevent decay of the lower surface of the finished floor.

The given brief characteristics are quite enough to make an unambiguous conclusion: a plywood floor in terms of a number of properties better than sex from OSB-plate, DSP or fiberboard.

Which one to choose?

For rough work, there is no need to select top grades. Moreover, the third grade is also suitable for repairs (according to current standards, there is also a fourth grade, but it is almost never found on the market) - for the set goals given choice optimal. Small irregularities, roughness needs to be cleaned sandpaper or cut with a knife.

Of course, if there are obvious geometric violations, “curled up with a screw” or, as builders also say, “behaved”, as well as sheets with obviously not right angles, such options are not applicable.

When buying, it is also important to check if there was any damage during storage - for the absence of chips, kinks, damp areas, traces of the vital activity of rodents, insects or mold.

Many repairmen determine the quality of the sheet literally by smell - undamaged material has a noble woody smell with barely noticeable notes of glue.

You can often hear from sellers the classification designation according to international standard ISO (and sometimes, according to their own system quality, up to “grade F-1 class TBS”), so you need to clarify the grade according to Russian GOST, or, looking at the packaging, the grade of the product must be noted.

Perhaps part of the material will go to waste, so it is better to purchase with a small margin, about 5-10%.

As for thickness, builders are guided simple rule- the thicker the better. Indeed, a thicker substrate can hide larger defects. In this case, you should not overdo it, the minimum is 8 mm, the recommended one is from 14 to 22 mm. In any case, the underlay must not be thinner than the final floor covering.

It is preferable to use sheets of large dimensions, but if their transportation or installation is difficult, smaller dimensions can also be used.

Some stores may offer cutting to more convenient for transportation.

What to process?

In order not to reduce the quality in the future, it is enough to carry out a simple preliminary processing.

This step consists of a few simple steps.

• Drying. Before starting repairs, plywood must be brought into a dry warm room and withstand at least a week (ideally - from two to three weeks). This will save her from excess moisture, which she could absorb during transportation and storage. Such a long drying time is due to its structure - moisture that has penetrated into the deeper layers evaporates much more slowly than from the surface layers.

• Biosecurity. To avoid the multiplication of destructive microflora, you can soak at least the outer layers with antiseptic solutions. This will save residents from the musty smell of dampness if water seeps from above or condensation accumulates from concrete.
• Airing. After antiseptic treatment, withstand at least a day. Of course, while maintaining minimal gaps.
• Add moisture resistance can be applied in one or two layers of acrylic-based varnish.

Preparatory stage

At least two days before the start of work, plywood must be brought into the room where the repair will be carried out. The workpieces must be laid horizontally, allowed to “rest”, relieve excess stress in the structure caused by storage in a vertical position.

The floor must be prepared: remove the old plinth, remove all debris, dust, knock down the irregularities of the concrete and cut off the protruding parts of the reinforcement, soak with an antiseptic solution.

If flooring is performed without a log, the concrete surface must be leveled, if possible, with a cement-sand mortar, then apply a primer and allow to dry. Cement-sand mortar seizes for several days, allocating all this time in environment excess moisture so it's best to start preparing early.

If the height differences during the level check turned out to be large, it is necessary to perform a screed or lay logs to compensate for irregularities.

If laying is carried out on top of old boards, inspect their condition. Rotten or crumbling areas must be replaced, creaking or staggering - fixing. On a wooden base, you also need to apply a primer, an antiseptic and dry it.

At the next stage, you need to lay out the sheets as they will subsequently be fixed. Compensation gaps should be provided: between the elements 3-4 mm, from the wall 8-10 mm, this will avoid swelling if the temperature or humidity conditions change.

In the process of cutting, it is necessary to coat the ends of the sheets with glue in order to avoid their cracking in the future.

Mark the workpieces, while indicating the orientation of the workpieces in one direction, either with the inscription itself or with an arrow. For example, indicate the row with a letter, the number with a number, that is, A1 is the first element in the first row. This will help avoid confusion in the future. For convenience, you can sketch a laying scheme on paper.

It is worth avoiding cases when the corners of four neighboring fragments converge at one point. In other words, lay out the workpieces "in a row", as in brickwork.

Materials and tools

For installation, you will need the following tool:

• Electric jigsaw. It is unlikely that it will be possible to cover the floor with solid sheets, and, perhaps, when the angle formed by the floor and the wall is not perfectly even, it may be necessary curly cutting. In addition, it will be necessary to bypass the riser pipes at their exit points. For these purposes a circular saw much less suitable, as it allows only a straight cut.
• Building level. A level at least 2 meters long is preferred, as a shorter tool will not allow you to notice unevenness at long distances.
• Roulette and pencil. After preliminary unfolding, carry out the necessary marking and marking before cutting.

• Construction knife.
• Screwdriver with a bit suitable for the fasteners used.
• Vacuum cleaner or broom.
• Funds personal protection: durable gloves, glasses, knee pads, if necessary - headphones (ear plugs).

From additional materials:

1. Self-tapping screws (self-tapping screws) - if laying on logs or an old wooden floor. Fasteners are selected according to a simple formula - the thickness of the fixed element is multiplied by three. For example, if the sheet is 20 mm, then the length of the self-tapping screw is at least 60 mm. In this case, the screw should not be longer than the total thickness of the flooring and the wooden base.
2. Dowels corresponding to self-tapping screws - if mounting on concrete or screed.
3. Wood glue (usual PVA is most often used) or "liquid nails".
4. Sealant (polyizol).

Mounting methods

Depending on the condition of the repaired premises, apply different methods installation of the rough base:

• over a concrete floor (or screed);
• over an old wooden floor;
• on the lags.

Based on this, one or another mounting technology is used.

On the old floor

The technology of laying plywood on old floor boards is quite simple. In your own house or apartment, it is quite feasible to do these works with your own hands. After all preparatory activities you need to spread and cut the substrate. It is important to avoid laying "overlap", preferring "butt" so as not to add bumps. Fasten the joints of the seal with a wide adhesive tape, cut off the excess.

Then proceed to the layout according to a pre-drawn plan, observing the markings. Start from the corner, gradually expanding the "spot" in both directions.

The elements are screwed with self-tapping screws, retreating from the edge of at least 2 cm, and with a step between the attachment points of not more than 20 cm, sinking the hat.

How to lay on logs?

For the log, a beam of coniferous wood is selected, with a section of at least 50x50 mm. Preference should be given to a dried timber without visible violations of geometry (not twisted “into a screw” and without bends along the longitudinal axis), without chips and other mechanical damage.

To isolate wooden elements from dampness from below, before laying them, it is advisable to lay a preliminary insulation (polyizol), fastening the seams with adhesive tape.

It will be correct to start laying logs from the highest point selected using the level. It is important to keep the beam laying step uniform, 50 - 60 cm, no more.