In the construction market, plywood is very popular. It is used in many areas. This material consists of several glued sheets of wood veneer, processed in a certain way. Synthetic resins are used to connect the layers . Due to this, all types of plywood are to some extent protected from moisture. But there are some species that are better than others to prevent moisture. This is waterproof plywood.
Production Features
Wood-laminated boards capable of withstanding prolonged exposure to moisture are referred to as FSF according to GOST.
Sheets of waterproof plywood are produced using specially selected substances. These substances also protect the material from moisture. Apply drying oil for wood impregnation, paintwork. In some types, the coating is puttyed with compositions using PVA, fiberglass is used.
Already at the stage of forming the plates, the degree of moisture resistance is set. This is done by adjusting the composition of the synthetic resins used to adhere the layers. Therefore, knowing the substance that was used as glue, you can determine the degree of moisture of the material:
- Plates made using urea substances have a moisture resistance limit in the region of 5-10%. Such materials are able to withstand only short-term exposure to moisture.
- 10-15% resistance to moisture provides the use of phenol-formaldehyde compounds. Plates of this type can be used for outdoor applications.
- Water-resistant laminated plywood is not subject to destruction under the influence of moisture. It is protected by a film deposited on the surface of the plate.
Advantages of the material and its disadvantages
The production method makes the plywood strong and resistant to deformation. This is achieved due to the presence of several layers and special adhesive compositions. Therefore, the following advantages of such plates can be distinguished:
- Moisture resistant. Waterproof plywood is not destroyed by moisture. It does not stick to layers and is not deformed.
- Easy to use. High material strength does not interfere with the processing process. Plywood is easily processed using various tools. It is easy to mount.
- Compatibility with other building materials. Most often, waterproof plywood is used as an additional material. It easily connects to natural and polymeric building materials.
- Wear resistance. Plywood withstands mechanical stress without compromising integrity.
- Resistance to temperature extremes.
- Wide scope of use.
- Aesthetics. Externally, the plywood has an original wood pattern and color.
- Affordable price. Plywood boards are cheaper than solid wood. And you can always save by choosing a lower grade material.
The only drawback of the material is the presence of harmful substances that make up the glue. It is about formaldehydes. Therefore, it is not recommended to use plywood in residential premises and where there are children or people suffering from allergies.
Application area
Waterproof plywood is used in many industries. Most often it is used in construction. It is used in the following processes:
- Sheathing of walls, floors, roofs.
- Interior decoration of buildings.
- For the manufacture of decorative elements.
- As a reusable formwork.
- For billboards.
- For the production of containers.
Due to its strength, reliability and low weight, waterproof plywood is used in the construction of ships, railway transport, garden furniture. A separate view of it from peeled birch is used even in aviation.
Types of plates
Given the degree of moisture resistance, plywood is made of several types:
- FC. This is a material that is made using carbamide-formaldehyde compounds. It has an average moisture resistance. But differs in good environmental friendliness. It is used for interior work, furniture and decor.
- FSF has enhanced moisture protection. Phenol-formaldehyde resins are used as an adhesive . A rough floor, a roof lathing are made of such material, containers are made, billboards.
- FBS has the greatest protection against moisture and swelling. This is bakelizirovanny moisture resistant plywood. Use it in shipbuilding and aircraft industry.
In appearance, waterproof plywood is divided into five grades (from 1 to 5). If the boards are made from hardwood, the letter E is added to the numbers in front when marking. In the case of coniferous raw materials, the letter X is used.
The quality of surface treatment of the material is characterized by unpolished (NS), with one-sided grinding (-1) and with two-sided grinding (-2).
There is also a classification based on the amount of formaldehyde in the material. With a content of up to ten milligrams per hundred grams of the mass of material, they say about the emission class E-1. If the resin contains from ten to thirty milligrams, then indicate the class E-2.
Plate sizes
The average dimensions of the material are 1.22 x 2.44, 1.25 x 2.50, 1.52 x 3.05, 1.52 x 1.52 m. This is not all, but only the main dimensions by which waterproof plywood is made. The thickness of the plates can be from 9 to 40 mm. It depends on the number of layers of wood. There can be from three to twenty one.
- FC plywood is produced with a length of 1.525 m. Its width can be 1.22, 1.27 or 1.525 m.
- FSF has a width of 1.22 and 1.25 m. Its length is 2.44, 2.5 m.
- The dimensions of the FBS plywood vary in length from 1.5 to 7.7 m, in width from 1.2 to 1.55 m.
User reviews
According to consumers, waterproof plywood is a quality material that is not afraid of moisture and atmospheric effects. They also note the high strength of the material.
In addition, ease of installation and handling are noted. It is possible to hammer nails into slabs, twist self-tapping screws, make holes in them, and so on. And all this does not cause any difficulties.
Of the minuses, consumers note the difficulty in transporting plywood. This is due to the large dimensions. The dimensions of waterproof plywood are always more than one meter. Due to this plate, not all types of equipment are placed. Therefore, for the transportation of material, it is necessary to look for suitable transport.