Features and varieties of moisture resistant plywood

Description and characteristics

High quality plywood is obtained by pressing several (from 3 to 10) thin sheets of wood (veneer). The transverse arrangement of the fibers in the sheets makes it possible to make plywood a very durable material. For construction and repair needs, plywood is suitable, the basis of which is the waste of birch wood pulp processing. For the manufacture of furniture, plywood is practiced on the basis of coniferous veneer. The process of creating film faced plywood differs from the usual one already at the stage of preparing the raw materials. Adhesives include components that make it possible to reinforce and film each individual panel. This allows each component of the laminate to be liquid-tight throughout its entire thickness.

The outer coating has a density of 120 g / m2. In addition, the natural color of such a laminate gives the floor a dark color that accurately reproduces natural wood. By adding a dye, you can change the color of the plywood from extremely light to extremely dark. According to the manufacturers, domestic plywood in accordance with GOST does not contain poplar inclusions. But made in China in its structure can have almost 100% poplar sawdust. Such material will be of the lowest quality, its use in any industry can become a kind of risk.

Material characteristics:

• the water content in the material is not more than 8%;
• density indicator - 520-730 kg / m3;
• size discrepancies - no more than 4 millimeters;
• the amount of phenol-formaldehyde resins is approximately 10 mg for every 100 g of material.

These characteristics are generally accepted for all types of high-quality film faced plywood. It is interesting to note that fewer veneers are used to make thick sheets than thin sheets. At the same time, the 20mm thick slab is being used intensively for the production of modular furniture. And slabs with a thickness of 30 millimeters, in turn, are used in works related to exterior and interior decoration.

Manufacturing process

Plywood of this type is a plate that is very rigid in bending. The main properties of the building material, which ensure its high popularity, are strength, lightness and water resistance. Birch veneer is used as a raw material. In the lower grades, the core of the plywood sheets may consist of softwood. Finnish moisture resistant plywood is made only from birch. After drying, the veneer is cut and impregnated with alcohol-based or water-based bakelite resin solutions. Such processing protects wood from fungal attack, rotting, exposure to aggressive environmental factors, including moisture, high and low temperatures. Impregnation is carried out by dipping the veneer or smearing it on both sides. The adhesive composition must be at least E1 safety class. Then the sheets are stacked and treated with hot steam under a press. In this case, the veneer layers are glued together, forming a strong conglomerate. The presence of exfoliated fragments, bulges and air pockets in it is not allowed. The finished product is cut in accordance with the established standards and a protective film is applied to the surface - laminated. The transverse edges are painted over with an acrylic moisture-resistant compound.

Technical properties

Material thickness varies from 6 to 40 mm, standard sheet sizes are 2500 × 1250 and 2440 × 1220 mm.Density per 1 m³ - 650 kg. Along the wood fibers, the modulus of elasticity of the material is at least 6000 MPa. The outer surface of plywood can be smooth or embossed. The latter is more convenient for cutting, it is used in cases where sliding of the material is undesirable, for example, when installing the floor. A characteristic feature is a light brown or reddish brown shade of the surface due to the covering film.

Film faced plywood is not inferior to low-alloy steel or plastic in terms of wear resistance. Its advantages:

• the ability to withstand temperatures in the range from -40 to + 50 ° С, resistance to melting and combustion;
• moisture resistance;
• environmental friendliness;
• dielectric properties;
• high hardness and strength;
• ease of processing.

Varieties of plywood

The types of plywood depend on the glue used in the production:

FC - waterproof plywood. In its manufacture, cabamide glue is used;

FSF - plywood with increased moisture resistance. Here veneer sheets are glued together using phenol-formaldehyde glue;

FBA - non-waterproof plywood. In this case, albuminocasein glue was used to glue the veneer. FBA plywood has insignificant moisture resistance, but is very appreciated by those who put the environmental friendliness of the material to the fore;

FB - plywood, which, thanks to the use of bakelite varnish, can be used in especially humid conditions and in water.

And these are just the main types of plywood. There are many more stages of classification, depending on the thickness of the sheet, the number of layers, type of wood, grade, degree of finishing and type of additional processing.

Manufacturers

In Russia, several enterprises are engaged in the manufacture of Finnish plywood. The technological process is based on the use of domestic raw materials. Its processing is carried out using Finnish equipment.

1. Holding "Ivestlesprom", which owns the Vyatka plywood plant. This enterprise produces high-class Finnish film faced plywood only from excellent quality birch veneer using Finnish equipment.
2. OOO Zavetluzhie. The Nizhny Novgorod woodworking company has been operating since 2005. The product range includes types of plywood of 1–4 grades, as well as finished products made of it.
3. Production group "Sveza". It is the largest domestic manufacturer, whose plants are located in various regions: St. Petersburg, Kostroma, Vologda Oblast, Perm Krai. Sveza's products have international certification.
4. Syktyvkar Plywood Plant LLC is also one of the largest domestic manufacturers of large-format plywood and wood-shaving materials. The goods of this enterprise are manufactured in accordance with high international standards.

Finnish plywood requires the use of sophisticated expensive equipment and belongs to a high class of wood building materials. For this reason, its price per sheet is slightly higher than that of other species.

The table shows distributor prices for laminated Finnish plywood, depending on the thickness and format of the sheets.

When choosing Finnish plywood, it is recommended to focus on the domestic version, as a better, safer and more environmentally friendly one, made strictly in accordance with GOST. Similar materials made in China from poplar or bamboo veneer, despite the lower cost, emit more formaldehyde, since they are processed with cheap adhesive solutions and are less resistant to external influences.

Pros and cons of using plywood for flooring

Plywood covering has a whole list of technical advantages in comparison with other types of building materials:

• the material has the minimum moisture content - up to 15%;
• when excessive mechanical stress occurs, plywood extinguishes most of it, preventing damage to the concrete floor;
• in the manufacture, natural veneer is used without the addition of harmful impurities that are present in chipboard and OSB. It is worth noting that more and more people are laying OSB on the floor, since this material has proven itself well;
• the material plays the role of thermal insulation from rough floors;
• unlike pouring a cement screed, laying wood slabs on logs is a less time-consuming process;
• plywood has high resistance to bending, so it can withstand very heavy loads;
• There are several grades and grades of plywood that make it suitable for use as a rough and finish floor covering.

Among the disadvantages of laying material on logs, the following points can be distinguished:

• poor resistance to large temperature changes;
• the material is afraid of moisture, so it is advisable to use it in dry rooms.

What else should you consider when choosing?

If plywood is created from wood of the highest grades, it will have the same elasticity, strength when using both softwood and hardwood veneers. However, it should be borne in mind that in most cases the manufacturer indicates the type of only the top veneer sheets in the marking of moisture-resistant plywood. There may be other wood between them.

In this case, different designations can be used to describe the type of wood that was used in the manufacture of plywood. If the material says that this is "homogeneous plywood", then all veneer sheets are made of the same type of wood. Given the name "combined plywood", we can talk about the use in the production of different types of wood.

Having considered the features, dimensions and other characteristics of moisture-resistant film faced plywood, you can choose the best option in accordance with existing needs.

Varieties of plywood

Manufacturers existing at the moment can offer a huge number of building materials, which differ somewhat in technical characteristics.

Plywood boards can be divided into several of these types:

• production;
• furniture;
• construction;
• design;
• packing.

Structural and building boards are best suited for covering timber frame structures because of their increased strength and durability. Do not ignore the level of moisture resistance.

You can consider the following types of plywood:

• FAB - does not include formaldehyde, so it is ideal for residential applications. It has the ability to strongly absorb moisture, so it is not used for a bathroom, but it is just right for a kitchen.
• FC - repels moisture well, but is not designed for constant contact with water.
• FSF - the outer part of the sheets is covered with a moisture-repellent mixture, which allows it to be used in rooms with high humidity.
• FB - such plywood is impregnated with bakelite varnish, due to which it is practically not afraid of prolonged exposure to moisture.
• BS - used in shipbuilding due to its great flexibility and water-repellent properties.
• BV - has increased flexibility and strength, but quickly degrades on contact with water.

When laying plywood on a concrete floor, according to the advice of experts, moisture-repellent types should be laid between the rough base and the front coating. An intermediate layer of quality material will prevent future deformations caused by temporary or permanent high humidity.

Benefits of using plywood for formwork

Plywood formwork is quickly assembled and can be reused many times

Plywood formwork has several advantages over wooden panels:

it has a high deformation threshold, therefore, concrete elements do not deform

It is important to use vertical supports every 60-100 cm
installation of plywood formwork is less time-consuming, the boards are knocked down faster than in the case of boards
the ability to get a flat surface without joints
this formwork can be used repeatedly. At the same time, it is easy to adjust it directly on the construction site.

Recycling plywood

After the formwork has been removed, the plywood must be cleaned and dried. Then it can be reused.

Recycling options:

1. It can be used on another object
2. Use it as a sub-floor or slab
3. Plywood formwork can be sold

Manufacturing technology

Now let's figure out how to make a formwork from laminated plywood with our own hands. The algorithm of actions is as follows:

• preparing plywood sheets. We adjust in length the bars, which from the outer edge should be thirty centimeters longer. One side of each bar is sharpened to make it easier to enter the ground. If the bottom of the base turns out to be wider, and the plywood sheets rest against the support boards, then it is not necessary to sharpen the racks;
• plywood is cut into pieces of the desired size, corresponding to the future foundation base;
• the support bars are set in increments of sixty to one hundred centimeters, the tops are placed horizontally. Plywood sheets are fixed to them using self-tapping screws or nails. ready-made shields are installed in parallel;

• the tops of the racks are connected with clamps so that the plywood material does not disperse from the pressure of concrete;
• the corner sections of the formwork are reinforced with boards, spacers are installed to further strengthen the boards;
• with the help of polyethylene material, the structure is sealed.

The formwork is ready, concrete mortar is poured into it.

Laying plywood on the floor

4.1 Plywood for sub-floor

Laying a sub-floor made of plywood is the fastest, most affordable and simplest way, and it also has several varieties.

Laying plywood on a concrete screed Laying plywood on a concrete screed. Sheet with a thickness of 10-12 mm. glued to the base. It is used when there is a level concrete screed of normal quality. The main thing is not to forget about expansion joints when laying. The gap is 3-4 mm. between the sheets, as well as between the sheet and the wall, will allow the plywood to play and adapt to the environment.

Adjustable plywood floors This installation method can be used with a difference in height. It is enough to use special fasteners.

Adjustable plywood floors do not require the installation of a log, and the height difference is leveled by fasteners located under the plywood.

Installation of plywood on logs or floor beams Laying plywood on logs or floor beams.

Plywood, over 12 mm thick. mounted on a prepared base. The method is laborious, usually used when you need to insulate the floor or raise it to a certain height.

Adjustable beams Adjustable beams allow you to position the plywood sheet so that it can compensate for the difference in floor height.

4.2 Leveling the floor with plywood

Leveling the floor with plywood Quite a common situation is when the floorboards have partially lost their appearance, but nevertheless do not cause any complaints. Then the floor covering is laid on top of them.

But so that the finishing coating does not become unusable, an intermediate floor (in this case, plywood) should be laid on the boards, which will level the surface.

Styling plywood on wooden the floor is made using hardware and is characterized by simplicity and high speed of work.

In order for plywood laid under a laminate, under linoleum or under a parquet board to perform its functions for a long period, you need to adhere to the following installation rules:

securely fasten all sheets, taking into account the deformation gaps;

"drown" the hats of the hardware into the sheet;

remove irregularities with a grinder;

fill in depressions and cracks;

lay the underlay.

But laying plywood under a wooden floor is absolutely not required. Due to the massiveness of the floorboard, it can be laid on logs or on a flat concrete screed.

4.3 Plywood finish floor

Craftsmen can create a real palace parquet from plywood. In this case, special requirements are put forward for the quality of plywood. Only the first grade is allowed, the surface of the front side of the sheet must be sanded. To create a beautiful pattern, the plywood is treated with wood stain, and the laid plywood parquet is sanded and opened with several layers of parquet varnish.

Plywood floor pattern Plywood parquet Plywood floor stained

What plywood is used for formwork?

Plywood is divided into types depending on what kind of glue is used in its production. For the construction of the formwork, the following types of this material are used: plywood FBA, FSF, bakelized.

FBA

This is a type of plywood in which layers of veneer are glued together with albuminocasein glue. This makes it environmentally friendly and ranks among natural materials. It can be laid in living quarters. However, for repeated use as a formwork material, it is not the best option, since it is not resistant to moisture.

Environmentally friendly FBA plywood is used indoors, but not practical as a reusable formwork material

FSF

This type of plywood is moisture resistant. The layers in it are glued together with phenol-formaldehyde resin, which determines its moisture-protective qualities. It is recommended to use it for outdoor work, including the creation of formwork. It will withstand many cycles of use. Phenol-formaldehyde resin is toxic, therefore it is not environmentally friendly to use such plywood indoors.

Formwork made of this type of plywood can be reused

Laminated plywood

A lamination layer on the plywood surface improves its moisture resistance. Usually, FSF plywood is laminated from hardwood, more often from birch. Such plywood can have a smooth or corrugated surface, which gives it anti-slip properties. It is film faced plywood that is often used for formwork.

Lamination increases the moisture resistance of plywood

Not film faced plywood can be not sanded and sanded on one or both sides. The main purpose of grinding is to improve the aesthetic qualities of the material. It also removes minor surface defects and, as a result, makes the material more resistant to mechanical damage - chips and warpage.

Bakelized plywood

In it, the layers are glued together with bakelite resin. It gives the material special strength and resistance to aggressive environments. Thanks to this, it can be used in different climatic conditions. Bakelized plywood can withstand temperature changes, even significant ones - from -50 ° C to + 50 ° C. It is used in humid tropical climates and conditions of the far north. If construction takes place in one of these regions, this type of plywood will do just fine.

Bakelized (bakelite) plywood is used in extreme climatic conditions

Russian or Chinese plywood?

Plywood of Russian, Finnish and Chinese production is presented on the domestic market. The first two practically do not differ from each other in quality; plywood of some Finnish brands is even produced at factories in Russia. At the same time, the cost of the Russian one is significantly lower. Chinese plywood can be used in low-rise construction as an economy option. Its quality is low. It is unsuitable for repeated use in multi-storey construction.

Types of plywood

FC

For the manufacture of such a material, a urea-based glue is used, containing a large amount of formaldehyde resins.For this reason, plywood sheets of the FC type are recommended to be used for removable formwork structures. The boards are resistant to moisture, albeit to a lesser extent than laminated plywood 18 mm thick, but if you use it carefully, the turnover rate will be from twenty to twenty-five cycles of use.

FBA

Sheets of this plywood material consist of veneer layers connected by an albuminocasein adhesive. The material is environmentally friendly, quite comparable to natural raw materials. Approved for use in living rooms. It should be noted that such plywood is of little use as a formwork, because it does not withstand the effects of a humid environment poorly.

3> FSF

In the manufacture of waterproof sheets of this type of plywood, phenol-formaldehyde-based glue is used, which gives the veneer layers strength and the ability to withstand moisture. In addition, FSF plywood sheets are distinguished by an increased level of wear resistance, their turnover reaches thirty-five to forty-three working cycles. There is one drawback - plywood is advised to be used for outdoor types of work. The problem is that from humidification and changes in temperature, the glue begins to release phenol.

FBK

In such a material, the layers are connected with bakelite varnish. It is not afraid of humidity and temperature changes, it perfectly resists atmospheric loads and changes in climatic conditions. In short, sheets of such plywood can be used for formwork at any performance characteristics. The Finnish material FB has an analogue in terms of resistance to wear and an indicator of mechanical stability.

FBS

This type of plywood is used most often. In its manufacture, veneer layers are subjected to a special treatment using bakelite glue containing alcohol. This technology gives plywood an additional level of strength and resistance to microorganisms. The high density of plywood helps it withstand significant vertical and horizontal loads. And if formwork for the foundation is made from such plywood, then sheets with a thickness of 8 - 15 mm will be enough. The adhesive composition increases the flexibility of plywood sheets.

Peculiarities

There are many options for such a material, they all differ in their width, coating and manufacturing features.

In order to choose the optimal product, you need to pay close attention to the study of the characteristics. Plywood is an ordinary sheet that is created using wood

In turn, it goes through several stages of processing, which gives the product its unique properties.

The process of gluing the layers is due to the use of special compounds, which are usually obtained on the basis of resins. The result is a lightweight material that can also boast of its resistance to temperature extremes.

Among the main advantages of such a product are the following.

• Resistant to moisture, so the material can even be used to decorate a bathroom. This can be achieved due to the fact that upon contact with water, the plywood sheets do not delaminate and do not lose their shape.
• Ease of processing and installation. This material is famous for its strength, so you can use any tools for processing without fear. Plywood can be easily cut, sawn or drilled, which favorably distinguishes it from the background of other materials.
• The ability to combine with other materials. It should be noted that film faced plywood is very often used as an additional material, therefore it is perfect for finishing the ceiling, floor or roof. Most experts use this plywood in combination with natural wood.
• Huge scope of application.Film faced plywood can boast of its unique performance characteristics, which makes it possible to use it in the process of finishing works, in the production of furniture and decorations.

A distinctive feature of moisture-resistant film faced plywood is that it takes much longer to process during the manufacturing process, and is also covered with thicker paper. This paper is impregnated with a special composition, which makes the finished product durable and allows it not to lose its properties for a long time. In addition, it provides water resistance.

Film faced plywood differs from other materials in that it is almost not susceptible to temperature changes, therefore it can be used even in a bath. The special layer also protects against the effects of cleaning agents, including aggressive abrasives. Another feature of such plywood is that it contains a minimum amount of phenol. As a result, a more elastic and durable material is obtained, which also has a varnished protective polymer layer.

Advantages and disadvantages

The undoubted advantage of the plywood floor is its affordable price.

But it is important to carefully check whether the parquet plywood floor is really finished (if this is the option chosen). Many samples are delivered unfinished, additional finishing of the flooring has to be done

If the work is completed, the product will be more affordable than the cheapest hardwood boards. It is easy to use in place of traditional laminate flooring.

Installation of plywood elements on the floor takes very little time. All work is done in a matter of hours with minimal effort. The most difficult manipulation is grinding, laying, gluing (option - nailing), painting (other finishing options) of the floor. If the floor is quite large and the configuration is very complex, it will sometimes be necessary to work for 2 or 3 days.

Plywood, which is important, is flexible in use. It can be painted with a wide variety of paints.

Or you can - abandon the usual boards and use squares or even a more intricate shape. And even if you don't like the result, you can always put on a new coating option. The maximum simplification of work is also possible - plywood blanks are simply ordered ready-made and asked to cut them exactly to size.

Plywood is sold almost everywhere, in any hardware store - it is not necessary to go to a large shopping center or a hypermarket of construction goods. The variety of its options is due to the thickness and grade of veneer. As a result, it is not so difficult to find a floor covering with ideal characteristics. A multi-layer device would itself be an advantage of the material. Thanks to this property, it is quite strong and serves for a long time.

Quality plywood is quite stable in almost any environment. It can be used regardless of the climate in a particular area. It is also safe in environmental and sanitary terms (except for some harmful impregnations). However, one must understand that even the best plywood is relatively weak. Frequent and prolonged walking, falling of various objects, installing and rearranging heavy cabinets are not about her.

Views

It is of two types: FBS and FBV. In the manufacture of the FBS brand, an impregnation dissolving in alcohol is used. PBV production is based on water-soluble resins.

Technical characteristics of plywood.

FBS is the most expensive and high-quality brand that is made by completely immersing veneer in bakelite resin. This method allows for good saturation of the inner and outer layers. The resulting material is renowned for its strength, moisture and fire resistance.

FBS 1 is a plywood with reduced strength. In its manufacture, the outer layer, like the inner one, is not impregnated with resin, but only lubricated.But even this method allows this brand of plywood not to lose its properties even in sea water.

In the production of FBS A, birch veneer is also coated, but a material with low environmental characteristics is used, which makes this grade plywood suitable only for internal structures in the mechanical engineering industry.

FBS 1-A is the cheapest type. Such material is also not very resistant to weather conditions. During its manufacture, the transverse layers are not coated with resin.

FBV is a type of plywood with a water-soluble resin. Her outer layers are impregnated with Bakelite, and the entire middle is only smeared. This material is used to create indoor structures.

In the manufacture of FBV 1, the entire veneer is only coated with resins that dissolve in water.

Plywood selection criteria for formwork

What is the best plywood to use for formwork? The building materials market offers a huge selection of different types of plywood, differing in composition and processing options. In addition, the product line is presented from numerous manufacturers.

And if you still doubt which formwork material is best, pay attention to certain criteria:

plywood thickness for foundation formwork. The final price of plywood depends on this indicator, and it is quite understandable that the desire to save money immediately appears. But one should act wisely. If the plywood turns out to be too thin, you will not achieve a good result - the formwork panels will bend from the pressure created by the concrete solution, and their destruction may occur. The optimal solution is considered to be a plywood thickness of 1 - 1.2 cm, and if concrete is to be poured with a thick layer, experts recommend using a more reliable 18 - 20 mm film faced plywood;
grade. Plywood material is of different classes, the most expensive of which is considered "extra". Samples of I - IV classes are considered cheaper. The material should be selected taking into account its intended use, and most often it is plywood of I and II classes, which has a good margin of safety;
feedstock

When purchasing plywood, you need to pay attention not only to the glue used in the production, but also to the veneer material. Preference is most often given to coniferous woods or birch

Each of these varieties is affordable. More expensive materials include fir, larch and teak plywood sheets. If difficult operating conditions are expected, it is recommended to buy a reliable and expensive material that can withstand a large number of work cycles.

GOST defines several options:

• the standard is square sheets, the length of the sides is 122 and 152.5 cm. There are rectangular sheets, the length and width of which is 152.5 and 122 cm, respectively. The main advantage of such material is its acceptable cost;
• large format. On sale you will find film faced plywood, the parameters of which are 3000 x 1500 x 18 mm. It is more convenient to use such sheets of material in the construction of plywood formwork for walls. Their cost is slightly higher than the standard ones, but the shields are made without joining seams. In addition, for pouring 2 meter walls, the formwork panels will turn out to be solid;
• non-standard. It is possible to manufacture plywood material according to individual customer requests. This creates certain advantages, but the cost of such an order increases significantly.

An important criterion that you should pay attention to when choosing plywood is the quality with which the surface of the material is processed. The ideal solution would be flat and smooth sheets.

Their application will allow:

• speed up the dismantling work, because plywood sheets separate from the hardened concrete much easier;
• the monolithic surface is smooth, plywood lends itself better to subsequent processing.

> An important feature of the choice of film faced plywood for formwork is the country in which the product was produced. Today, material from domestic and Chinese manufacturers is in demand, while plywood from China is less expensive.

It is used as an economy option when a low-rise facility or structure with small architectural forms is being built. As a rule, such black plywood used for formwork can withstand a limited number of cycles, but is well worth the cost.

With large working volumes, it is recommended to purchase domestic material and, for the reliability of its use, install plywood formwork on metal racks. To increase the rate turnover of film faced plywood for formwork, experienced specialists advise using special lubricants - barrier or chemically active. In the first case, you create additional protection, and in the second, you increase the plywood's resistance to moisture.