What types of plywood are there: types, grades, sizes and main characteristics. FSF plywood

Plywood is divided into grades in accordance with the requirements of GOST No. 3916.1-96. The grade of plywood is determined according to the amount of defects on the surface of the plywood. This refers to traces of knots, which are the most vulnerabilities in any wood.

There are 5 types of plywood in total:

• E (Elite) grade of plywood: no visible defects or blemishes. Minor deviations in the structure of the wood are allowed, of a random nature, except for dark eyes. Not allowed: partially fused, unfused, falling knots, holes from them, wormholes, healthy fused knots, minor brown veins, etc. This plywood can be coated with varnish. Grade E plywood is used to make laminated plywood.
• 1st grade: 1st grade plywood has virtually no defects, partially fused, unfused, falling out knots, holes from them, wormholes with a diameter of no more than 6 mm are allowed. In the amount of 3 pieces. per 1 m², no more than 5 healthy fused knots per 1 m² with a diameter of up to 15 mm are also allowed. and slight brown streaks. This plywood can be varnished. Grade I plywood is used for the production of laminated plywood.
• 2nd grade: in grade 2 plywood, partially fused, unfused, falling out knots, holes from them, wormholes with a diameter of no more than 6 mm are allowed, in the amount of 6 pieces. per 1 m², no more than 10 healthy fused knots per 1 m² with a diameter of up to 25 mm are also allowed, repairing the surface of the sheet is allowed. Knots and open defects are sealed with veneer inserts. This plywood is covered with various finishing materials and paints.
• 3rd grade: in grade 3 plywood, partially fused, unfused, falling out knots, holes from them, wormholes with a diameter of no more than 6 mm are allowed, in the amount of 10 pcs. per 1 m² of sheet surface, healthy fused knots are also allowed without limiting the number. Used for making hidden external review designs, production of containers and packaging.
• 4th grade: in grade 4 plywood, any manufacturing defects are allowed. Partially fused, unfused, falling out knots, holes from them, wormholes are allowed in unlimited quantity with a diameter of no more than 40 mm, only good gluing is guaranteed. Used for the manufacture of durable containers and packaging.

Examples of plywood surface different varieties:

Sample of grade E plywood Sample of grade 1 plywood Sample of grade 2 plywood Sample of grade 3 plywood Sample of grade 4 plywood

Conclusion: The highest grade of plywood is E (elite) - it is extremely rare and is relatively expensive. The market mainly offers plywood grades from 1 to 4. Grade 1 is the highest, grade 4 is the lowest. The higher the grade of plywood, the better quality its surface.

Indication of grade in plywood markings

The grade is written after the plywood size in Roman or Arabic numerals. The sides of the sheet may be of the same type, or they may be different.

Example notation:

• "FC plywood 1525×1525×9 mm, 4/4"- stands for: FK plywood - FK brand plywood, i.e. moisture resistant; 1525×1525×9 mm - sheet size: length 1525mm, width 1525mm, thickness 9mm; 4/4 - grade 4/4, i.e. both sides of the sheet of the same type (in in this case- 4th grade)
• "FK plywood 1525×1525×9 mm, 2/4, w.2"— Difference compared to the first option: 2/4 - grade 2/4, i.e. one side is 2nd grade 2, the other is 4th grade; line 2 - i.e. polished on both sides.

The main “running” varieties: 1/2, 2/2, 2/3, 2/4, 3/4, 4/4.
The 4/4 grade is not sanded, while all other grades are all sanded on both sides.

Both of these types of plywood are widely used, affordable and easy to use. The scope of application of FC and FSF plywood is industrial production, packaging, construction, carriage and machine building. The versatility of the material has been proven over years of use for finishing walls, floors, ceilings, partitions, construction, and design. Let's try to figure out the differences between FK plywood and FSF plywood, and how they can be distinguished visually.

More about concepts

If you decipher the abbreviations:

• - This wood boards, glued together with urea-formaldehyde adhesive.
• – this is plywood + resin glue + plywood. The material consists of several layers of veneer, firmly connected to each other with phenol-formaldehyde glue, which has a resin base.

The main difference between FC and FSF plywood

FC material is characterized by versatility in terms of application and high strength. Not intended for use in conditions high humidity. The main advantage is low cost compared to FSF materials. The main area of ​​application is the arrangement of floors (used as a substrate for parquet, laminate), furniture manufacturing, interior decoration, production of containers, packaging.

The raw materials for the production of FC are mainly peeled birch, alder, other deciduous trees, and sometimes a combination of several types of wood. Moisture has a negative effect on the inner layers of the material: it deforms, leads to twisting, and delamination. The maximum sheet thickness can reach 40 mm. There are several varieties, depending on the presence and number of knots.

FSF, on the contrary, is moisture resistant, due to which it is widely used in conditions of high humidity. For example, for external and internal roofing works. The material is durable, resistant to mechanical damage and wear.

The raw materials for production are coniferous wood and birch. To impart moisture and fire resistance during the production process, it is treated with appropriate compounds. Used in aircraft and mechanical engineering, industrial production And construction work.

External differences between FC and FSF

Externally, the two materials look almost identical. The only visual difference is the color of the cut. The FC cut is light due to the phenol-free composition of the glue, and is as similar as possible to natural untreated wood. The FSF cut is much darker, with a reddish tint, due to the water-repellent layer.

Effect on the body

Safety of the material in terms of impact on human health - important criterion selection of material. In this regard, FC and FSF sheets have fundamental differences:

The silicate glue used in the production of FC is non-toxic. Due to this, the material is quite suitable for interior work and construction of partitions in dry rooms.

In the production of FSF, phenol-containing glue is used, which has Negative influence on the health of others.

Fundamental differences

To be brief:

FC is environmentally friendly, not moisture resistant, quite fragile, quickly delaminates and breaks under the influence of moisture. Suitable for interior decoration and furniture production.

FSF negatively affects health, is resistant to moisture, has increased strength to pressure fracture. It is used mainly in exterior work: finishing, roofing.

FC and FSF plywood are two options for one of the simplest, most affordable and durable materials, which finds wide application. They are equally in demand in construction work, industry, packaging, mechanical engineering and carriage building. Due to their high convenience, there is practically nothing to compare them with, since they are suitable for floors, walls, ceilings, and partitions. They are also good as a basis for any design ideas.

What is FC and FSF plywood?

First of all, it’s worth understanding the abbreviations:

1. FC is a wood-laminated board glued together using a urea-formaldehyde composition, which is where the abbreviation “plywood + urea-formaldehyde glue” comes from;
2. FSF is a material made by joining veneer with phenol-formaldehyde substances, which is what the combination of “plywood + resin phenol-formaldehyde glue” produces.

What is the fundamental difference?

The first is not at all resistant to a humid environment, but is quite durable and versatile. Designed for dry conditions only. Much cheaper than the second option, therefore it is widely used for the production of furniture, wall cladding, packaging containers, as a substrate for laminate, parquet and other coatings.

Made from peeled wood of birch, alder and some other hardwoods (a combination of these is also possible). After penetration of moisture, it usually delaminates and curls, which is a serious difference between FK and FSF plywood. The thickness of such sheets can reach 40 mm. They are divided into varieties based on the presence of knots.

Pack of FC plywood sheets

The second is characterized by increased resistance to moisture, which it resists very successfully. Thanks to this property, it is in demand in roofing processes and can be used not only inside, but also outside of buildings. It has good wear resistance and mechanical strength.

It is made mainly from birch and coniferous veneer. It can be impregnated with compounds not only against moisture, but also against fire (FSF TV), which is why it has an expanded range of applications: construction, industry, mechanical engineering and aircraft construction.

How to distinguish FC plywood from FSF externally?

No experience in this issue you can get confused because external signs they are hardly distinguishable, which sometimes causes misunderstanding. The only factor that clearly shows the difference between them is the shades of the layers.

FC is lighter, since it is connected with glue without the presence of phenol, which is why the cut sheets are as close as possible to natural color veneer While FSF with increased moisture impregnation has a darker color with the presence of a reddish undertone.

Differences in physical and mechanical parameters

Which plywood is less harmful - FC or FSF?

For the manufacture of wood-laminated boards of the FK type, a silicate adhesive is used, which is non-toxic to humans and animals. This equates plywood to safe building materials, suitable for interior decoration and installation of partitions in dry conditions.

FSF is more resistant to moisture because it has a special impregnation based on potentially harmless resins. The glue also contains 8 mg/100 g of phenol, which negatively affects the health of others.

Main differences

To more clearly distinguish between these two types of plywood, we offer a brief comparison of them.

So, FC is absolutely safe for health, is not resistant to moisture, is suitable for interior work and furniture production, is fragile and does not withstand well mechanical impact, easily breaks and delaminates.

While FSF has low environmental friendliness, which is why it can harm humans and animals, it has excellent moisture resistance, is applicable for interior, facade, and any other external work, and has increased fracture strength and pressure.

To understand what kind of plywood there is in terms of structure, properties and dimensions, you should find out on what basis it is produced. These can be various tree species, such as birch, aspen, poplar, coniferous trees, etc.

Options

What sizes does plywood come in depending on the classification. There are 2 main types:

• Standard. This type is characterized by sheets measuring 12.2x15.25 cm. Their length can vary from 25 cm to 15.25 cm. Rectangular - 24.4x12.20 cm and square - 15.25x15.25 cm sheets are most often produced.
• Large format type. The parameters for this category are 18.3x15.25, 24.4x12.2, 25x12.50, 30x15, 30.5x15.25 cm.

Attention! Material with non-standard dimensions is usually produced to individual order.

Its thickness is chosen depending on its purpose in terms of strength. It can be 0.4; 0.6; 0.8; 1; 1.2; 1.5; 1.8; 2.1 cm.

Classification

What types of plywood are there?, if different tree species are used as the basis:

• Combined - made from several types of wood, which are arranged symmetrically with respect to the central layer;
• Birch - has high strength, which is ultimately determined good level physical and chemical indicators of birch veneer, also note the multi-layer structure of the wood;
• Coniferous - the production of sheets is based on pine, which helps ensure strength with a relatively small weight, used in the construction of buildings.

What types of plywood are moisture resistant? It, in turn, is classified according to the level of exposure to moisture on the material. Here main types:

• FSF – with increased water resistance. The gluing of veneer sheets occurs thanks to phenolic resins. It is not recommended to use when interior finishings premises, because it has a negative impact on human health. Perfect option for carrying out external finishing works.

• FC – waterproof. In the process of gluing veneer layers, urea resin is used. This type is intended for use inside the home.
• FBA – non-waterproof;
• FKM is characterized by increased water resistance; it is produced on the basis of melamine resin. This type is considered unique, because it is created using environmentally friendly resin. It is recommended to use it for making furniture and interior finishing work.
• Laminated type - based on FSF sheets, which are covered on both sides with a special film. Used in the manufacture of formwork, multiple use is possible.

• Bakelized type - Bakelite resin is used when gluing veneer. Ideal for aggressive climatic conditions. Unaffected by sea water.

• Marine - similar to the baked version, it is highly durable. It is made on the basis of foreign wood species.
• Flexible - foreign option. It has the property of bending along and across.

Plywood can be sanded in the following ways:

• On both sides (designation Ш2);
• On one side (designation Ш1);
• Without grinding (designation NSh).

Varieties

Depending on the quality, the following varieties are distinguished:

• Grade E – no visible processing defects. There may be minor flaws in the structure of the sheet. It is recommended to varnish or use without coating.
• Grade 1 – has almost no flaws. Minor streaks of brownish color, the presence of small knots or places where they have fallen out are allowed.
• Grade 2 – loose or partially fused falling out knots are allowed; repairs may be possible upper layers. Defects are repaired with veneer inserts. Cover with varnish and paint.
• Grade 3 – possible presence of knots different sizes in any quantity. Designed for products that do not have external visibility.
• Grade 4 – manufacturing defects in the form of fallen knots, wormholes, and edges in unlimited quantities are acceptable. High quality adhesive is recommended.

Attention! The grade of plywood is determined by the number of knots per 1 sq. m.

Plywood is a popular material used in construction, furniture production, technical and decorative items. There are several types of it, which it is advisable to understand in order to purchase what you need. In particular, it is useful to find the main difference between FC and FSF plywood as the most popular materials.

Any plywood consists of layers natural veneer, firmly glued together. The only difference is the wood that is used to produce the veneer, the method of arranging thin layers and the composition for gluing or impregnation. The dimensions of the sheets do not depend on these parameters and can be the same for different types.

In FK type plywood, the veneer layers are glued together using urea-formaldehyde glue. IN FSF materials gluing is carried out using phenol-formaldehyde glue resins. This is the fundamental difference between the types of FC and FSF, from which corresponding consequences follow.

The external difference between FC and FSF is manifested in the color of the layer. The ends of FC plywood are lighter, while FSF has a noticeable reddish dark shade. This is explained by the fact that urea-based glue becomes transparent when hardened, while formaldehyde resins are colored.

The difference between FSF and FC is as follows:

• adhesive composition;
• moisture resistance;
• strength;
• end color;
• price;
• content of hazardous substances.

And all this depends mostly on the glue. The urea composition is soluble in water, so FC plywood products are afraid of getting wet. FSF, unlike FC, is a moisture-resistant material.

Note! The difference in cost is noticeable. With the same size and grade (quality), the price of FSF is usually higher than FC.

Of course, the cost will be affected by the location of production, additional processing and some other factors. But The general trend can still be traced.

It should be noted that there is also another type of plywood - FOF. She belongs to the group special purpose. The difference between FOF and FSF plywood is that the former is covered with durable laminated film. So her moisture resistant properties increase even more.

Application of FC

FC plywood sheets are made from hardwood, mainly birch, poplar, and alder. This is wonderful material premium grades which are distinguished by a light, smooth surface.

The peculiarity of FC is that, due to the adhesive, it does not withstand prolonged exposure to moisture and, when wet, swells and delaminates. At the same time, if such plywood is used in a dry room, it exhibits high strength characteristics.

FC plywood is used to make beds, sofas, and boxes for transporting goods; they cover walls with it, and place it on the floor under parquet or laminate. Like other species, its thickness varies, reaching a maximum of 40 mm. The varieties depend on the presence of knots, sprouts, cracks, darkening and other defects.

The question may arise: should FSF or FC plywood be used for flooring, for example, under parquet? These two types are suitable, although moisture-resistant FSF plywood products (low grade, sanded and unsanded) are preferable. The difference between them will also be in price. If the room is not damp, it is not ground floor, not a basement, then in order to save money you can use FC. Most often, when laying floors, sheets with a thickness of 10-12 mm are used.

Application of FSF

FSF sheets are used as roofing material, for the construction of stages, sports grounds, temporary structures, billboards. This plywood is widely used for formwork, and the best option here is the laminated material because it can be used several times (up to 100).

Although furniture for residential premises is not made from FSF, it is excellent for garden benches, gazebos and other structures. Another common application is truck flooring and van lining. It is allowed to make boxes for transporting non-food products from FSF sheets.

Security difference

There is another important difference between the materials under consideration. It concerns the safety of their production, use and disposal.

FSF contains phenol formaldehyde, which makes you think about the safety of the material. Phenol and formaldehyde, from which glue is made, are poisonous and negatively affect the skin, mucous membranes, Airways. Disposal of products with their contents is problematic.

As phenol-formaldehyde resin hardens, it becomes less hazardous, but vaporization of both phenol and formaldehyde is possible. Sanitary standards require monitoring of these parameters.

When purchasing, you should pay attention to the emission class harmful substances. If the certificate of conformity states E1, then such plywood can even be used in the bedroom. Class E2 cannot be used indoors.

FC plywood is safe for indoor use, since urea-formaldehyde adhesive is an order of magnitude less toxic than phenol-formaldehyde. The emission of phenol in it is minimal.