Bakelite lumber is very popular on the market. These panels are made of resin, which in appearance resembles amber or elephant bone. However, the similarities between bakelite and other materials end with external features. Bakelite does not melt or dissolve in any liquid. This is a very strong and durable material. Construction panels made from bakelite are called Finnish or bakelite. They have excellent moisture resistance, due to which this material is used for the construction of formwork in the construction of various objects.
Finnish plywood
How Finnish plywood is made
Finland has a unique climate in which tree growth slows down and wood moisture content decreases. Due to this, the thickness of the annual rings is smaller and the strength is greater. Therefore, building materials made from such wood are better able to resist deformation.
Finnish plywood is made exclusively from birch. First, a thin layer (veneer) is cut off from wooden blocks. After this, they are cut into rectangular sheets of the required size and dried thoroughly. Then they are impregnated with a special solution based on bakelite (a solid resin). Because of this, Finnish plywood is also called bakelite.
When the sheets are thoroughly soaked, they are stacked and placed under a hot press. The resulting slabs are cut to standard sizes and then laminated. A special film is applied to both sides, which protects against moisture and mechanical damage. And the ends are treated with a special acrylic-based paint. It protects against moisture getting inside.
This plywood is distinguished from ordinary plywood by its darker red-brown color. Despite the word “Finnish”, it can be produced anywhere, but only on special equipment and using raw materials and laminated film according to Finnish quality standards. It is this that gives such high strength indicators compared to other laminated materials.
What else should you consider when choosing?
If plywood is created from premium wood, it will have the same elasticity and strength when using both coniferous and hardwood veneer. However, it is worth considering that in most cases the manufacturer indicates in the labeling of moisture-resistant plywood the type of only the top veneer sheets. There may be other wood between them.
However, different designations may be used to describe the type of wood that was used in the manufacture of plywood. If the material says that it is “homogeneous plywood,” it means that all veneer sheets are made from the same type of wood. If the name “combined plywood” is present, we can talk about its use in the production of different types of wood.
Having considered the features, dimensions and other characteristics of moisture-resistant laminated plywood, you can choose the best option in accordance with existing needs.
Characteristics
Special production technology and film give this product incredible properties. Plywood can withstand harsh weather conditions and harsh chemical environments. It can be either with a smooth surface or with a relief mesh. The latter is needed for ease of cutting and to prevent slipping.
The main indicators of the slabs include:
- product dimensions: 2440x1220 and 2500x1250 mm;
- thickness: 6—40 mm;
- density: 650-700 kg per cubic meter;
- temperature indicators: from -40 to +50 Celsius.
Advantages
- Unusually high resistance to moisture;
- Greater wear resistance and strength;
- Ease of use and ease of processing;
- Several variations of the top layer (smooth and embossed);
- Resistance to fungal formation;
- Hard surface;
- Resistant to temperature changes.
How to store it correctly
To preserve all properties as much as possible, the material must be stored indoors or in specialized cases - they will protect the plywood from moisture and UV rays.
To prevent deformation, wood must be protected from overdrying. Sheets may become warped if stored on an uneven surface that is exposed to moisture and dirt.
If long-term storage is planned, the slabs should be removed from the original packaging. Storage must be done carefully. During storage, the sheets should not come into contact with equipment, which could damage the top layer of the material.
Manufacturing technology
Now let's figure out how to make formwork from laminated plywood with your own hands. The algorithm of actions is as follows:
- preparing plywood sheets. We adjust the length of the bars, which on the outer edge should be thirty centimeters longer. One of the sides of each bar is sharpened to make it easier to enter the ground. If the bottom of the base is 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 required sizes corresponding to the future foundation;
- 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. finished panels are installed in parallel;
- the tops of the racks are connected with clamps so that the plywood material does not separate from the pressure of the concrete;
- the corner sections of the formwork structure are reinforced with boards, and spacers are installed to further strengthen the panels;
- The structure is sealed using polyethylene material.
The formwork is ready, concrete solution is poured into it.
Classification by variety
Depending on the quality of the outer surface of the plywood, it is marked with symbols and numbers (E, I, II, III, IV). The letter "E" stands for extra grade. It has impeccable veneer characteristics, while category IV may have defects.
The designation usually appears as a stamp, similar to a fraction, with the numerator indicating the quality of the front side and the denominator indicating the quality of the back side. For the back surface of the material, the same grade or any other lower grade is used, for example E/E or E/I, etc.
If coniferous species were used in production, the letter “X” is added to this marking - Ex/Ex, IIIx/IVx, etc.
Scope of application of Finnish plywood
Having good quality and reliability indicators, plywood has a high price. But, despite this, it has been used in various fields of activity, such as:
- construction - most often for formwork work during monolithic construction of buildings. Due to its good density, plywood can withstand high concrete pressure. And its wear resistance allows it to be used many times;
- Mechanical engineering and carriage building are another area of application for this material. Used for creating bodies of trucks, buses, trolleybuses and their interior decoration (wall and floor cladding). Including for trains, trailers, containers;
- shipbuilding. Due to its high moisture resistance, it is used for finishing the sides and bottom of various ships and yachts. Quite often found when sheathing the entire vessel;
- finishing facilities. Finnish plywood is very well suited for interior decoration. You can often find bars, restaurants, and nightclubs created with its use. As well as racks, partitions, walls and fitting rooms;
- furniture production. It is possible to create any designs: from chairs to cabinets.
This is not the entire list of products used. Literally every day there are new ways to use strong and durable Finnish plywood.
Advantages and disadvantages
The undoubted advantage of plywood flooring is its affordable price.
But it is important to carefully check whether the parquet plywood floor is actually finished (if this is the option chosen). Many samples are delivered unfinished, requiring additional finishing of the floor covering
If the work is completed, the product will be more affordable than the cheapest hardwood boards. It is easy to use instead of traditional laminate.
Installing plywood elements on the floor takes very little time. All work is completed in a matter of hours with minimal effort. The most difficult manipulation is sanding, laying, gluing (optionally nailing), painting (other finishing options) the floor. If the floor is quite large and the configuration is very complex, sometimes you will have to work for 2 or 3 days.
Plywood, which is important, is flexible in use. It can be painted with a variety of colors
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 install a new coating option. Maximum simplification of work is also possible - plywood blanks are simply ordered ready-made and asked to be cut exactly to size.
They sell plywood almost everywhere, in any hardware store - you don’t have to go to a large shopping center or construction goods hypermarket. The variety of its options is determined by the thickness and type of veneer. As a result, choosing a floor covering with ideal characteristics is not so difficult. The multilayer device itself will be an advantage of the material. Thanks to this property, it is quite strong and lasts a long time.
High-quality plywood is quite stable in almost any conditions. It can be used regardless of the climate in a particular area. It is also safe in environmental and sanitary terms (except for certain harmful impregnations). However, one must understand that even the best plywood is relatively weak. Frequent and prolonged walking, falling of various objects, installation and rearrangement of heavy cabinets - this is not her thing.
