Moisture-resistant OSB plywood is one of the new inventions in the woodworking industry. This material is unique in its versatility - it is widely used in construction. This plywood is used in the construction of wooden and frame houses, buildings from SIP panels, for the arrangement of rough floors.
OSB board structure
The named product in its composition has only natural components - wood chips and glue, which are based on natural resins. Using special technology, wood chips are laid in certain directions, which gives the boards the necessary flexibility and elasticity. Such high rates make this material quite versatile.
Materials for the manufacture of moisture resistant plywood
OSB plywood is an approximate particle board. Coniferous and some hardwood, often fast-growing trees, are most often used for its production. This choice is primarily associated with the environment - manufacturers try not to harm nature and not upset its balance.
OSB manufacturing technology
The production of this material is carried out in several stages. These include:
- Selection of suitable wood.
- Mixing.
- Formation.
- Pressing and finishing the plate.
Let's consider each of them in more detail. So, at the sorting stage, not business, fine wood is selected. The trunk must be cut so that the result is a workpiece of small length, after which they pass through special equipment that turns the workpiece into a tape of shavings. By the way, chips of different sizes are used for this. Next, the resulting chips are sent to special bins, where they are carefully dried, after which the chip tape is sorted by size.
At the second production stage, the so-called mixing takes place - special phenolic or isocyanate resins are added to the material. This is necessary so that the OSB plywood has internal strength, rigidity and the necessary moisture resistance. The mixture enters a special drum, which also contains a binder and paraffins.
Further molding stage. This procedure is carried out using a special station with pressure rollers, as well as a magnet and scales. The magnet helps to exclude various foreign bodies and objects from the future plate. At this stage, the product becomes approximately chip. The top layer is laid along the long part of the plate, in the inside - across.
Then, after the OSB plywood has already been formed, it goes under the press. Under the influence of pressure and high temperatures, the chip carpet is significantly compacted. This process is carried out using steel strips, pre-lubricated with a special thermal oil. The pressure force is usually 5 N / mm².
Specifications
This building material has a lot of unique characteristics. Today, none of the wood products on the market has such qualities.
Moisture-resistant boards are very technological. They are very easy to process using a standard set of carpentry tools.
The product also has a high holding capacity. As part of this type of plywood , large chips are used. Such canvases perfectly hold nails and other fasteners. Many craftsmen hammer a nail into plywood at a distance of 6 mm or more from the edge - it does not crack at the same time.
In addition, this building material is well bonded with any carpentry adhesives, subject to preliminary grinding of the surface. Also, the plate can be painted with any paints. By the way, if plywood will be used outdoors, then experts recommend treating its surface with protective compounds that will reliably save the tree from the harmful effects of the atmosphere.
Plates have good physical properties. So, their density fluctuates in small values, depending on the specific manufacturer (the average value of the density indicators is 640 kg / m³).
OSB performance
As for the level of moisture resistance, OSB plywood is a wood product that does not give a reaction to changes in humidity and temperature changes. The plate also complies with the North American standard - according to it, the product should not change its geometric characteristics if it is operated at temperatures of + 20 ° C and a humidity level of 65%.
Oriented particle board is characterized by high fire safety. The described materials were tested in independent laboratories, which are accredited by the fire safety services. The OSB board (plywood, as it is also called) passed all the tests for fire resistance and the speed with which the flame will spread through it.
Intended classification
Today, the market for building materials offers several types of these plates. They vary in purpose and properties. There are four types of such plywood.
OSB-1 is an initial brand. This material has a low density structure. According to reviews, the main disadvantage of this product is the complete absence of at least some moisture resistance. Plywood of this brand is most often used in the manufacture of furniture.
OSB-2 already has higher strength and density characteristics. However, according to experts, this is still not a moisture resistant material. This plate can be used almost everywhere where it will not be exposed to moisture.
OSB-3 plywood is already a real waterproof material and one of the most popular types of oriented particle boards among consumers. This plywood has high strength and resistance to moisture. It is perfect as a cladding for prefabricated frame houses.
But here there is one nuance that manufacturers and sellers will not say about - the stove is reliably protected from moisture only under the condition of a short exposure. If such material is installed as a wall decoration in the bathroom, then a layer of additional protection must be applied to the surface. Damage can be avoided by painting the surface and applying moisture-proofing. In our country, OSB-3 is very popular as a material for rough floors - in this case, nothing is simply better.
OSB-4 is, according to consumer reviews, a canvas of very high strength. One of its characteristics is high protection against moisture, even with prolonged exposure. There is a drawback, and it is the only one - this is how much the named OSB plywood costs. Its price is quite high - a sheet measuring 1250x2500 mm, and this is a standard size, it will cost from 500 rubles. The cost depends on the thickness - a product of 8 mm costs from 500 rubles., 12 mm - from 680 rubles., 15 mm - from 880 rubles., 18 mm - from 980 rubles. But the price also depends on the manufacturer.
Dimensions and Weight of OSB Boards
Let's start with the thickness. There are several options for these plates, in the range from 8 to 25 mm. According to this indicator, the plates are divided into three groups:
- Thin materials are 8, 9, and 10 mm.
- The average thickness is 12 and 15 mm.
- Thick canvas - 18, 22 and 25 mm.
From the thickness in direct proportion is the weight of the sheet. So, with a plate thickness of 8 mm, its weight will be about 16.6 kg. A 9 mm product will weigh 18.4 kg, 10 mm - 20.6 kg.
One of the factors by which OSB plywood is chosen is size. In general, there are several of them. The most popular among domestic buyers is 2440x1200 mm, the standard European size is 2500x1250 mm and the very rare size is 2440x950 mm. It is believed that the latest slabs are popular for flooring, although with the same success all products can be used for this.
Which is better: OSB or plywood
For those who are sure that OSB is something new and ultramodern, it is worth saying that these plates were manufactured many years ago. Then the market did not have as much plywood as it is today, but bought OSB because it was a more affordable analogue of plywood.
In the production of oriented particle boards, natural resins are used, as well as waxes and boric acid. In the manufacture of plywood, formaldehydes are used. From a safety point of view, OSB is much better - this plate can be used in residential premises. Plywood for this, due to the presence of harmful substances, is not suitable.
In addition, for laying floors, for example, OSB of a special design is used - the ends of such products are grooved. This is done to achieve high-quality and easy joining of materials among themselves.
When choosing, of course, it is important to navigate depending on the specific situation. And if you choose for the price, then OSB is also cheaper than plywood.
True, although the price of the material is much lower than that which is requested for plywood, this plate should not be used for fine floors - the appearance will not be aesthetically pleasing. But, as has already been noted, in the dispute - which is better, plywood or OSB on the floor - the latter wins significantly in environmental terms.
OSB or plywood for walls?
Plywood as a material for walls is not recommended by specialists, due to all the same formaldehydes. From above, both materials can be coated with various protective compounds or varnishes. The plate is better and faster to grind, it, in addition, better tolerates the primer.
Thus, it can be seen that in different situations it is necessary to use different materials that are more suitable for a particular task.