What is the thickness of the substrate to choose under the laminate. Laying laminate on an uneven floor - what you need to know

Which will extend the life of the flooring, cushioning and evenly distributing the load on it, provide additional noise and heat insulation, and smooth out minor defects in the base. The choice of substrate is usually carried out according to two parameters: material and thickness.

The durability of the substrate largely depends on the material, it is also the main pricing factor. Thickness is a very important characteristic, which determines how successfully the substrate will cope with the tasks assigned to it. In this case, the thickness should not be maximum, but optimal.

When choosing a substrate of optimal thickness, the following criteria should be taken into account:

• laminate class, its purpose and expected load on it
• laminate thickness
• the degree of unevenness of the base for laying
• floor waterproofing features
• subfloor level in neighboring rooms
• substrate material

The thickness of the substrate from different materials

As a rule, a softer substrate has a thickness limit; a substrate made of denser materials may have a greater thickness.

• substrate from foamed polyethylene(isolon) or polystyrene(iso noise) usually has a thickness of 2-3 mm, the most common thickness is 3 mm
• the most common thickness is 2-4 mm. Some manufacturers, for example, SEDACOR, produce both rolled and sheet cork substrates up to 10 mm thick, but this is too much for a laminate. There is a rolled substrate and a smaller thickness - 1.8-1.85 mm
• combined substrate Tuplex from a layer of polypropylene balls located between layers of polyethylene film - roll material 3 mm thick
• rolled underlay extruded polystyrene, for example, IMS, has a thickness of 2 mm, and sheet - 3-5 mm
• substrate made from wood waste (wood fibres), the so-called coniferous, has a thickness of 4-7 mm. Although the manufacturer positions it as a substrate for various floor coverings, including laminate, its thickness exceeds the optimal value for a laminate. Therefore, if the choice is made in her favor, it is better to limit yourself to a minimum thickness of 4 mm.

Features of the laminate and the thickness of the substrate

The thickness of the substrate should correspond to the thickness of the laminate, for a thin one, 7 mm thick, a two-millimeter substrate will be sufficient; and 4-5 mm.

An indication of the possibility or necessity of using a substrate with a thickness of more than 3 mm should be contained in the manufacturer's instructions. Typically, this underlay is used with a commercial Class 33 laminate, which is particularly stressed and has a high density and strength.

Is it possible to level the unevenness of the base with a thick substrate

A thin substrate 2 mm thick is best used if the subfloor is perfectly flat. If there are acceptable irregularities, a 3 mm thick substrate is suitable, this is the most versatile solution. If the height differences exceed the allowable, the base must be leveled. Often, instead, they try to smooth out defects with a thicker substrate.

If the substrate is dense enough, slightly wrinkled, practically does not cake (cork, coniferous substrates, some types of sheet substrates made of extruded polystyrene foam have such characteristics), you can use a material with a thickness of 4-5 mm. But only if this is due to the characteristics of the laminate and is recommended by its manufacturer, this is not the best way to compensate for uneven subfloors.

It is no coincidence that the thickness of the soft substrate is limited to 3 millimeters, and in no case should it be increased by laying the substrate in several layers. The fact is that it is crushed and caked during operation, and over time, its thickness can be halved. Due to this, a void, a play, is formed under the laminate, and the greater the thickness of the substrate, the greater this play will be. And the voids under the laminate have a very negative effect on the locking joints, leading to their premature failure.

The backlash formed after crushing the substrate of a standard thickness of 2-3 mm will be in the range of 1-1.5 mm, this is quite tolerable. But if on a base with height differences more than the maximum allowable 3 mm per linear meter, lay 2 layers of a three-millimeter substrate, after its caking, a backlash of up to 3 mm is formed. Together with base defects, significant height differences are obtained that exceed the allowable ones. Because of them, the load on the laminate will be uneven, the panels will begin to sag, and the locks may not withstand this.

So the thickness of neither polyethylene foam, nor more dense and caking-resistant polystyrene foam substrates under the laminate should not exceed 3 mm.

Additional Factors Determining Substrate Thickness

• The thickness of the substrate should be proportional to the thickness of the waterproofing film
• Due to the impregnation, the bitumen-cork substrate does not absorb moisture; laying it with the impregnation downwards makes it possible to refuse waterproofing, due to which it is possible to increase the thickness of the substrate itself, it is usually 3-4 mm
• Sometimes the laminate is laid in neighboring rooms, and the level of the subfloor in them is different. You can compensate for this difference in height by using a substrate of different thicknesses, but it should be within the recommended range. Therefore, a difference of more than 1 mm in this way is problematic to align

Outcome

The permissible thickness of the substrate under the laminate is in the range of 2-5 mm (for a cork substrate - from 1.8 mm.) The optimal thickness is 3 mm. A thinner underlay can be used with a thin laminate and laid on a subfloor with minimal flaws. A thicker underlay is usually used with a thick, heavy-duty laminate, only on the recommendation of the manufacturer.

The thickness of more than 3 mm has a substrate made of dense, slightly wrinkled and practically non-caking materials during operation, usually these are sheet substrates. The substrate can only smooth out minor irregularities in the base; instead of leveling the subfloor with significant height differences, it is unacceptable to try to solve this problem by increasing the thickness of the substrate.

The choice of underlay for a laminate floor is one step that gets very little attention when it really needs to be taken care of. What do you know about the thickness of the substrate under the laminate? What should she be?

Often such a question leads to a stupor. Some don't know what to say. Others are guided only by basic principles: for lamellas with a thickness of 7 mm, the substrate is 2 mm, for 8-9 mm - 3 mm, 10 and more - 4 - 10 mm. These are very standard indicators and should not be taken seriously. Let's try to understand in more detail the question of what should be the thickness of the substrate for the laminate.

Choice of substrate thickness

Rule 1 The optimum thickness should be between 2 and 5 mm. Here it is also very important to take into account the material, strength, thickness of the lamellas, as well as the curvature of the draft base;

Rule 2 If you choose cork, buy sheets of 2-3 mm. Your choice is polyethylene foam? Take a closer look at 5 mm samples, because over time the material sags a lot, which affects the quality of the entire flooring and its service life.

Rule 3 A thicker layer is used in rooms where additional heat and sound insulation is needed.

! Never lay material in several layers for the purpose. The fact is that such a soft flooring will lead to an increase in the bend in the lamellas. Each time you step on the floor, the load will increase and the comb may break.

What should be the substrate for the best soundproofing properties? Many argue that the thicker the better. In truth, stacking more than standard sizes is not recommended. A more resilient material will compress under any pressure. Let's assume that the permitted height difference is about 2-3 mm per 1 square meter, then the total backlash can reach 3-4 mm. This is the limiting value, taking into account the side joints of the flooring. By increasing the size, you increase the risk of broken joints.

But, it all depends not only on technical indicators, but also on the material:

• Foamed polyethylene and isolon. These are the cheapest options for layers. They are not afraid of moisture, and are also endowed with soundproofing properties. At the same time, mounting them is quite simple and easy. Here the thickness does not affect the properties in any way;
• polystyrene. It is made using aluminum foil. The cost of the layer is very high, but the benefits are many. In addition, the coating fills the entire space between the rough base and the lamellas, is not afraid of moisture or mold;
• cork. This option is not pressed at all. Such a layer has only a positive effect on the sound and heat insulation of the entire room.

So, the substrate for a 2 mm laminate is the so-called necessary minimum, which is able to compensate only the most minor irregularities of the rough base within 2 mm x 2 mm.

As a rule, this is a foamed version, in the structure of which there are airtight air chambers that provide excellent moisture resistance, as well as fairly tolerant sound and heat insulation.

Such layers are very popular due to their low cost. The pluses include the fact that they are not infected with either fungi or bacteria, and also do not provide much interest to insects or rodents. But, it is worth noting the negative side: the sheets do not retain their shape well, sag over time and are afraid of ultraviolet radiation.

! In some cases, such material is also equipped with a layer of aluminum foil or a protective metallized film.

If you're looking for a really reliable 2mm layer, check out the Silent System underlay from the Norwegian company ALLOC. It is characterized by increased soundproofing properties, a dense surface and a porous structure. Recently, the Norwegian company ALLOC has begun to produce laminate with an already glued substrate (Original, Original Trend and Domestic).

The best option is a 3 mm laminate underlay. It immediately solves several main problems:

1. Finally smooths out the unevenness of the base;
2. becomes a shock absorber between the coating and the screed;
3. dampens the impact noise that occurs when walking.

Under such a layer, it is necessary to additionally lay a plastic film (0.2 mm).

A good example of such a layer is Isoplaat. The material has high mechanical strength, thanks to which it can withstand pressures up to 20 t/sq.m. at the joints. At the same time, due to its porosity, it is light and rather soft, which means that it quickly smoothes out any defects.

If the board is sufficiently dense and thick (8-10 mm), then underlay for laminate 10 mm used as an option for leveling surface irregularities, because the impact of the load in the place of the gap can lead to breakage of the locks.

In truth, the latter option is practically not used, since it does not justify itself. BUT, in the case of installation in a room with low traffic, its use is very helpful.

And lastly, do not think that the thickness can save the entire flooring or hide all the flaws. For a while, yes, but not forever.

The thickness of the substrate under the laminate: 2, 3, 4, 5, 7, 10 mm. What should be the thickness of the substrate?

Laminate is a rather demanding coating that needs a flat and solid base. Level differences, pits, tubercles, cracks on the subfloor significantly reduce its service life. They become the cause of unplanned additional loads on the interlocks of the slats. Even one hole in the base will create a "failure", stepping on which you will bend the lamellas, testing the lock joints for strength. Sooner or later, this will lead to the appearance of visible cracks, loosening, and possibly breakage of the locks. Thus, the life of the flooring will be reduced, and the appearance from the very first day will leave much to be desired.

So what to do? There are two options: either use traditional methods of leveling the base, or use alternative methods that neutralize the negative effects of unevenness. Let's consider all these methods.

Applying a leveling underlay

Let's make a reservation right away: a surface is considered a suitable basis for a laminate, the height differences on which do not exceed 2 mm / r.m. These are permissible curvature rates at which the internal stresses of the coating are insignificant and do not lead to breakage of the locks. Exceeding these figures needs to be corrected.

The easiest way to eliminate the unevenness of the base is to use from:

• polyethylene foam;
• expanded polystyrene;
• extruded polystyrene foam;
• polyurethane;
• natural cork (option - from a mixture of cork and bitumen or rubber);
• wood fiber boards.

Any underlay available on the market can compensate for some of the unevenness of the base. The quality of the result depends on their density and thickness. For example, a conventional 2 mm thick polyethylene foam underlay levels the surface of the base up to 1 mm/m.p. Wood fiber underlays "ISOPLAAT" or "Quiet running" are more efficient. Plates "ISOPLAAT" with a thickness of 4 mm are able to compensate for differences of up to 3 mm/r.m., and with a thickness of 12 mm - as much as 5 mm/r.m.! Approximately the same abilities and wood-fiber substrates "Quiet move".

Base Leveling

In the event that the drops exceed the capabilities of the substrates, then more efficient methods must be used. The most common substrates for laminate flooring are concrete slabs or wooden floors. Each of these options requires its own approach.

concrete surface

In most urban apartments, the “rough” floor is formed by concrete slabs. To align such a base, follow the step-by-step instructions:

1. Prepare the base. Remove the old coating, clean the concrete slab from debris and dust. If there are deep cracks, pits, chips, pre-seal them with cement mortar.
2. Prime the surface. Priming improves the adhesion of the finishing screed and the concrete base. In some cases, it is desirable to use not an ordinary primer, but a waterproofing one. This is true for repairs in kitchens or on the first floors, located above damp basements.
3. Perform alignment. If the base is problematic, with large elevation changes, then it is more practical to use the usual one. Prepare it yourself (the ratio of sand and cement is approximately 3: 1) or buy ready-made dry mix. There should be enough water so that the consistency of the screed resembles very thick sour cream.
4. Install (preferably special metal profiles that do not need to be removed after work is completed) in increments of 0.5-1 m. This step can be more if there is a long rule, and a physically strong man performs the screed. Spread the cement mortar between the guide rails, leveling the screed with the rule.
5. After the solution hardens a little (2-3 hours is enough), the cement screed is additionally leveled with a foam or wooden float. The cement screed dries and gains strength for a long time. Laying a laminate on its surface is recommended no earlier than after 2 weeks.

If you don’t want to mess around with a cement screed, there is a much more modern, albeit more expensive solution - use it.

Leveling mixes - the easiest way to level a concrete floor

Dilute the dry mixture in water, according to the instructions, and then simply pour it onto the base, leveling the solution with a spatula. In order to remove air from the mixture, roll its surface with a roller with rubber spikes. This will make the surface smoother, without holes from small air bubbles on the surface. Mixtures harden much faster than a cement screed, so you can start finishing the floor covering in a few hours.

wooden floors

Work according to the following plan:

1. Tidy up existing wood flooring. Inspect the wood floorboards for cracks, crevices, and other imperfections. All this must be eliminated with putty. , then inspect the lags, if necessary, replace them. Fix the boards again on the logs, preferably with self-tapping screws, not nails - it’s more reliable. It is possible that during this operation some parts will have to be replaced with new ones.
2. If there are significant bumps and irregularities on the wooden floor, you can correct the situation (grinding). You can easily rent a cycler machine, it is not necessary to buy new equipment for one-time work.
3. Level the wood floor.
4. After puttying and sanding, it is quite possible that your wooden floors are already completely ready for. Check the base with a level, if everything is in order, then the alignment is complete. If the irregularities are significant and it was not possible to correct them, it is necessary to lay sheets of plywood or OSB boards on top of the floorboards. Use material with a thickness of 15-20 mm.

Sheets of OSB or plywood are screwed to the wooden floor with self-tapping screws, while making sure that the edges of adjacent boards are at the same level

There is another option - pour over a self-leveling mixture. This should be done in exactly the same way as when leveling concrete bases. In this case, you will get a flat and smooth screed, ideal for mounting the coating.

Replacing chipboard or fiberboard laminate with vinyl

If you do not want to carry out complex work, you can use the existing alternative to capricious material. This is a new type of flooring, called "". It, unlike the usual dies made of chipboard or fiberboard, can be laid on an existing, not sufficiently even base.

The flexible version is available in the form of strips, each of which consists of two layers: the upper part is made of a mixture of polyurethane with aluminum oxide, the lower part is made of vinyl. The lower part is shifted in relation to the upper one by a couple of centimeters, forming a free thin layer of vinyl around the perimeter. An adhesive smart tape is applied to it, thanks to which the planks are glued to each other at the ends. A "floating" floor structure is formed, without direct attachment to the base. Therefore, pits, bumps and cracks will not be “imprinted” on such a coating, unlike glue-based vinyl tiles.

Video: leveling the floor under the laminate

The connection using a smart tape is called a glue lock, by analogy with Click and Lock mechanical locks. However, the adhesive joint is more elastic, so it will not break on uneven floors. For example, Allure Floor vinyl laminate can withstand base drops of up to 5 mm. At the same time, the resulting coating in appearance is no different from a standard floor covering or wooden parquet. And in terms of performance - even wins. Vinyl, unlike wooden counterparts, is absolutely moisture resistant and much stronger, which is confirmed by strength class 42-43.

The performance of laminate flooring depends on many factors, including the thickness of the substrate and the grade of the laminate. The manufacturer of the floor material in the instructions for the coating determines with his recommendations what thickness of the substrate for the laminate will be the most optimal, indicates the method and criteria for selecting the base. Most amateur and professional installers of parquet-laminate coatings try to adhere to the recommendations, since excessive thickness of the laminate with the substrate can cause inconsistencies in the coatings of different rooms and prevent the doors from opening normally.

How does laminate flooring work?

Durability, attractive appearance of the coating and high quality of the overall web of single lamellas can only be ensured using a material with a complex multilayer structure:

1. The outer surface is a laminated layer based on a thick and durable acrylic or melamine acid polymer film;
2. The core of the laminate panel is made from pressed cellulose fibers with the addition of viscose and a binder, waterproof grades are made on the basis of impregnations and PVC materials;
3. The underside of the lamella is usually covered with an acrylic-latex compound to improve adhesion to the substrate.

Laminate coating is conditionally divided into two strength groups, conventional and reinforced. The first include home coatings, classes 21 - 23 with a lamella thickness of 9 mm. The second group includes commercial laminate 31, 32, 33 class, designed for high abrasion and contact load, with a standard substrate thickness of 4 mm.

Class 31 material is used for public institutions and offices with a small load, class 32 laminate flooring is the golden mean, used for bank offices, shopping centers and commercial institutions with an average load. The thickness of class 33 laminate is the maximum among laminated coatings and reaches 12 mm. And for each class there is its own optimal combination of lining thickness and material from which it is made.

Why is it so important to guess with the thickness of the substrate

With all its advantages, the laminate coating is very sensitive to the quality of the prepared substrate. According to the requirements of SNiP, for laying a home laminate flooring, it is necessary to provide:

• The difference in height over a two-meter length of the coating is not more than 2 mm;
• Local defects of a point type or a small “hillock - depression” with a height difference do not exceed 3 mm;
• The slope on the base of the floor is no more than 4 mm on a two-meter section of the coating.

The requirements for the laminate are quite stringent, so many manufacturers, due to the optimal selection of the quality and thickness of the substrate, consider it possible to reduce the height of the defect on the base to 3 mm. The material and correctly selected thickness of the substrate under the laminate allows in some cases to solve the problem of uneven bases. In some types and brands of laminate, a very soft porous layer of foam is applied on the inside of the coating, which compensates for the formation of air cavities under the laminate when the material does not fit snugly against the lining.

In addition, the thickness and resistance to contact pressure of the substrate determines whether the laminate will pop and creak underfoot. The appearance of such a creak indicates friction between the individual parts of the lock, for example, the end surface of the spike can rub along the edge of the groove of the second lamella.

It is impossible to choose the thickness of the substrate so that two joined laminate panels are exactly in the same plane. This is affected by the curved floor, furniture and interior items that load the laminate flooring. Therefore, the situation with a creaking lock is quite well known to the manufacturer, who is trying to eliminate creaking with special types of substrate of various thicknesses and anti-creaking paraffin coatings for lock joints.

The main problem of the substrate-laminate pair is not the presence of pops or squeaks, although they also introduce some discomfort. The problem is that if the substrate is not thick enough, the laminate sheet is suspended in the air above the defective floor area. If you strongly press down with a pointed heavy object, for example, put a stepladder on the lock and climb it, then the ladder support can simply break off the section of the lock connecting a pair of lamellas.

If the destruction process were local, concentrated on a small area, then the destruction of a joint two to three cm long would not affect the strength of the joint in any way. In practice, the lock is deformed, and a long break line is formed. Each time you have to step on a deformed area, the spike of the lock is destroyed more and more, and there comes a moment when the laminate no longer pops and creaks, because the joint is destroyed.

It remains to remove the lamella and replace it with a new one; the damaged area cannot be repaired.

Optimum substrate thickness for laminate flooring

To correctly choose the thickness of the substrate for the laminate, you will need to take into account three main indicators:

• Rigidity of the laminate board. The stronger and thicker the lamella, the less its reaction to pressure from furniture, legs, stepladders. A rare but very popular class 34, 15 mm thick, can be laid on a self-leveling floor with a substrate of 1 mm or without it at all;
• The quality of the concrete screed for laying the laminate flooring, the presence of defects and slope on the surface. The more bumps and sharp chips, the greater the chance that the thickness of the substrate is not enough to compensate for the defect;
• The contact stiffness of the substrate material, the ability of the web to contact crushing, without the occurrence of an elastic reaction.

Note! The soft substrate is designed to be crushed without destruction and elastic deformation, to take the load from the laminate, redistribute it over the entire surface and compensate for sharp protrusions on a poured or concreted base.

In theory, the thinner the laminate, the thinner and stronger the substrate can be used. But in practice, the minimum thickness of the base is limited to the optimal 3 mm, the maximum thickness of the substrate does not exceed 4 mm. In some cases, for class 33, a 5 mm sublayer can be used. But that's not all, for a particularly durable class 34, you can use a maximum lining up to 7-8 mm thick.

The process of determining what suitable thickness of underlayment should be always comes down to the quality of the prepared subfloor.

What gives the use of cork

Cork canvas or sheets are ideal for use as a laminate underlay. Cork wood is very light and soft. At the same time, the softness of the cork substrate is combined with a small degree of elasticity, which is enough to resist crushing and at the same time absorb protruding pointed defects on the concrete floor well.

If you imitate a floor defect and strongly press a cork surface with a sharp object, the material is simply pressed through to a shallow depth, without an elastic reaction. This means that the cork base will simply "absorb" the defect in its structure, without transferring force to the laid laminate.

Cork lining material is produced in two types - in sheets and in the form of a rolled web. Cork sheet boards are used for heavier 23 and 33 laminate classes. Cork slab perfectly suppresses and dampens noise, has excellent thermal insulation and sound insulation. A rolled cork lining is laid on self-leveling floors, without treating the base with waterproofing mastics and primers. On concrete screeds, a sheet cork lining is used, but before laying, the concrete is treated with primers of the type of concrete contact and laid with film insulation.

The only significant drawback of the cork substrate is its low resistance to soaking and damage by pathogenic microflora. There are many branded underlays for laminate flooring made from different varieties of cork, but not all of them work equally well as a lining. The best options for underlays are cork materials from Spain.

The thickness of the cork substrate is from 2 to 4 mm. Cork is one of the few completely sustainable materials used as a lining under laminate flooring. Cork fabric burns well, but in combination with laminate it smolders faster, without releasing toxic decomposition products of polystyrene and propylene.

Substrate alternatives

In addition to the rather expensive cork wood, foam materials are widely used as lining materials, such as expanded polystyrene or composite Tuplex. French development is the smallest closed balls of expanded polystyrene, sealed in a "sandwich" of polyethylene film. The thickness of the canvas is 2-3 mm.

According to its characteristics, Tuplex is closest to cork substrates. Most of the polymers used have mediocre vapor permeability, with the exception of bubble polyethylene. The additive in the form of polystyrene balls made it possible to obtain a very flexible and at the same time soft material, which has exceptionally high capabilities in redistributing the load on the laminate over the surface of the base.

Typical errors in the selection of the substrate of the required thickness

The most common variant of incorrect laying of the substrate is associated with an attempt to save on material. Instead of a full-fledged base under the laminate flooring, many mountain craftsmen try to lay out pieces of the substrate only in the places of depressions on the concrete base.

Often, a concrete screed is performed indoors in several stages of concreting, from different materials. In such cases, one edge of the concrete floor is “littered” or has a slope to the side or in the center of the room. In such cases, would-be craftsmen lay out the defective area with glue and a cheap polystyrene foam substrate 2 mm thick. As a result, after laying the laminate, the place with the reinforced substrate sticks out with a “hump”, and after a couple of months, due to the collapse of the lining, the laminate begins to clap and creak.

The second way to save is based on the fact that an expensive cork underlay or Tuplex is laid like a warm floor on a roll basis. The canvas is laid only in the central part of the room and pedestrian areas. The rest of the backing is replaced by cheaper polystyrene and fiberboard. As a result, it turns out that a part of the laminate, lying simultaneously on two types of lining material, quickly loses the strength of the joint and moves around.

Conclusion

Following the recommendations of the laminate manufacturer when selecting the substrate material and its thickness is the only right decision to ensure the durability and reliability of the flooring. For a home version of class 23 laminate, you can use a 3-4 mm thick substrate with guaranteed laying quality; for heavier lamellas, the thickness can be increased to 5 mm, but only if there are no height differences exceeding 4 mm per two meters length.

Laminated panels are considered one of the most convenient and practical types of decorative coating. Manufacturers produce them in different versions, among which there are models with protective layers. By the way, this is one of the few types of flooring, the installation of which is possible in rooms with high humidity. However, in terms of mechanical stability, this coating is very demanding, and the question of how to lay a laminate on an uneven floor is particularly acute. Of course, there are no ideally even foundations, but significant errors can adversely affect the further operation of the panels.

Can laminate flooring be laid on uneven substrates?

Regular modernization of laminated coatings in order to increase wear resistance and physical strength expands their areas of application. This is facilitated by the presence of protective layers, and reliable locks. Nevertheless, long-term use on a wooden or concrete base with high altitude differences is not recommended. Even if the laminate is laid on an uneven wooden floor with minimal variations in levels in different areas, there is a risk of deformation of the flooring at the points of attachment of the panels. In extreme cases, high-strength commercial models of 32 and 33 categories of wear resistance can be used, but even under this condition, the service life will be noticeably reduced.

Does the above mean that if there is an uneven floor, you should completely abandon the laminate or replace it with a more suitable material? Of course no. Firstly, any coating will not last long on a base with high-altitude differences. Secondly, laying a laminate on an uneven floor is quite feasible without negative consequences, but subject to appropriate preparation, including measures to level the subfloor.

Floor leveling technologies

Not every leveling method will fix defective concrete or wood floors. A lot depends on how big the difference in height differences is. For example, if it is no more than 0.5 cm per 1 m, then you can get by with laying the substrate, the main function of which is precisely to eliminate defects on the surface of the coating. This is the easiest and most affordable way not only for leveling, but also for providing cushioning, sound absorption and floor insulation. More serious damage in the form of pits, cracks, chips and tubercles will have to be repaired either by replacing the coating elements, or by completely updating the surface. The second option is appropriate to use if you need to lay the laminate on an uneven concrete floor with significant differences in height. If the errors on an uneven floor are insignificant or are represented by point flaws, then you can limit yourself to grouts or primers. They will make the base even and smooth.

What underlay to use?

You can fix an uneven floor with different floorings, among which there are both natural and synthetic. If the laminate is laid in a residential area, then, accordingly, it is better to use natural material. These include cork substrates, linen and coniferous linen. But it should be borne in mind that the leveling function of these materials is not their main quality. First of all, natural fibers and a cork base create optimal conditions for ventilation, noise reduction and thermal insulation. If you have to lay the laminate on an uneven floor with deep damage, then it is better to prefer artificial substrates. This category is represented by rubber, bitumen and polyethylene foam flooring. The environmental friendliness of these materials is far from perfect, but compensation for irregularities and comfort in the operation of the laminate will be guaranteed.

Leveling underlay

The substrate for laminated panels is installed directly on the base. But before that, you should make sure that the rough surface is free of debris, sand and grease stains. If possible, existing defects should be primed and sanded. At least, such processing will eliminate small defects. Before laying laminate flooring over an old wood floor using an underlay, you should also evaluate the durability of the boards. Rotten floorboards are replaced, as in the future this can only be done after the laminate is dismantled.

The substrate is spread in rolled strips in the direction of further installation of the lamellas. The material is overlapped, while the strips are fixed to each other with adhesive tape. It is important to note that the substrate should not be attached to either the laminate itself or the rough base. The leveling board in the form of slabs is laid so that the elements converge end to end with each other. Panels are fixed to each other with adhesive tape.

Methods for leveling a concrete screed

In this case, in addition to the substrate, self-levelling compounds or a traditional cement screed device can be used. Both methods are appropriate to use only with significant deviations in the levels of the base in different areas, since the laying of new coatings will inevitably lead to a reduction in the height of the room. Laying a laminate on an uneven floor using self-leveling compounds is considered the most effective, but this option is also considered the most costly and also difficult to implement. The usual pouring of a new screed will be cheaper, will hide the deepest depressions, but is the most time-consuming way to level the concrete floor.

Use of self-levelling compounds

These are the so-called self-leveling floors, which, after drying, form an almost perfect surface, allowing you to lay the laminate with maximum reliability and durability for it. But it is advisable to use such compounds only on the condition that the height differences do not exceed 3 cm. In more severe cases, only a cement screed will correct the situation. The preparation of the composition will not take much time - as a rule, bulk mixtures include two components that are thoroughly mixed. Next, the resulting composition is poured onto the problematic coating and leveled with a spatula. Also, a needle roller may be required in the work, with which air bubbles are removed. Further laying of the laminate on an uneven floor filled with self-leveling mortar can be carried out after about 10-12 hours, that is, after the coating has hardened.

Creating a new screed

The work uses a classic composition for cement mortar, for which formwork is preliminarily created. Wooden slats are installed on a thick mixture a meter apart. After that, the solution should solidify. It is necessary to pour the mixture from the far corner, in parallel aligning it with the rule. During the movement of the mixture, it shifts to the right and to the left, which makes it possible to exclude voids with air from the mass. A day after pouring, the resulting screed must be moistened with a roller, moistened again and checked for strength. If the coating has acquired sufficient hardness, then the screed must be covered with plastic wrap and left in this state for several weeks until completely dry. Then do-it-yourself laminate flooring is laid on an uneven floor using a new screed. Presumably, the height of the ceilings with this method of compensating for height differences will be reduced by 3 cm.

Leveling a wooden floor

Usually, problems with rough plank decking arise from improper installation. The reason may be either the expansion of wood under the influence of temperature and humidity changes, or the initial violation in the laying pattern. In both cases, the situation can be corrected. This is done by replacing individual boards with lags, or by completely renovating the flooring if the existing flooring cannot be restored. The main thing in this part of the work is to avoid mistakes in installation, use high-quality material and correctly ensure the fixation of the logs and boards. Provided that these rules are followed, laying laminate on an uneven wooden floor will not cause problems and will allow you to form a durable decorative floor. But it is important to remember that over time, boardwalk can become unusable due to biological processes, and high-quality laminate can last up to 25 years. Therefore, it is necessary to compare the operational resources of coatings in advance so that one of them does not have to be renewed ahead of time.

Conclusion

Flaws and defects in the subfloor are quite common, especially in the case of dilapidated floors that have not been repaired for decades. Leveling procedures allow not only laying the laminate with ensuring the strength and durability of the coating, but also create a reliable foundation for the room as a whole. The same wooden floors with deep damage pose a danger both to the operation of the decorative coating and to the entire structure of the house. The same applies to the concrete floor, the correction of the errors of which is a necessary condition for laying any finishing flooring.