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 arranging subfloors.
OSB board structure
The named product contains only natural ingredients - wood chips and glue, which is based on natural resins. With the help of a special technology, the chips are laid in certain directions, which gives the boards the necessary flexibility and elasticity. Such high performance makes this material quite versatile.
Materials for making moisture resistant plywood
OSB plywood is an oriented strand board. For its production, wood of coniferous and some deciduous species, often fast-growing trees, is most often used. This choice is primarily related to the environment - manufacturers are trying not to harm nature and not disturb its balance.
OSB production 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, non-business, thin wood is selected. The trunk must be sawn so that the result is blanks of small length, after which they pass through special equipment that turns the blanks into a strip of chips. By the way, for this, chips of different sizes are used. Next, the resulting wood chips are sent to special bunkers, where they are thoroughly dried, after which the chip band 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 in order for OSB plywood to have internal strength, rigidity and the necessary moisture resistance. The mixture enters a special drum, which is also fed with a binder and paraffins.
Next is the 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 roughly chipped. The top layer is laid along the long part of the slab, and across the inner layer.
Then, after the OSB plywood is already formed, it goes under the press. under pressureand high temperatures, the carpet of shavings is significantly compacted. This process is carried out using steel belts pre-lubricated with a special thermal oil. The pressure force is usually 5 N/mm².
Features
This building material has a lot of unique characteristics. Today, none of the existing wood products on the market has such qualities.
Moisture resistant plates are very technologically advanced. They are very easy to work with standard woodworking 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 drive a nail into plywood at a distance of 6 mm or more from the edge - it does not crack.
In addition, this building material is well glued by any joiner's 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 protect the tree from the harmful effects of the atmosphere.
Slabs 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 react 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 strand board has a high fire safety. The described materials were tested in independent laboratories that are accredited by the fire safety services. OSB board (plywood, as it is also called) has passed all tests for fire resistance and the speed at which the flame will spread through it.
Classification by purpose
Today, several types of these plates are offered on the building materials market. They differ in purpose and properties. In total there are four types of such plywood.
OSB-1 is the starting brand. This material has a low density structure. According to reviews, the main drawback 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 anywhere where it will not be exposed to moisture.
OSB-3 plywood is already a real waterproof material and one of the most popular amongconsumers of types of oriented strand boards. This plywood is highly durable and resistant to moisture. It is perfect for cladding prefabricated frame houses.
But one nuance is hidden here, which manufacturers and sellers will not tell about - the plate is reliably protected from moisture only under the condition of a short exposure. If such material is installed as a wall finish 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-proof impregnation. In our country, OSB-3 is very popular as a material for subfloors - in this case, there is simply nothing better.
OSB-4 is, according to consumer reviews, a canvas of very high strength. One of its characteristics is high protection against moisture even during 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, will cost from 500 rubles. The cost depends on the thickness - an 8 mm product 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.
OSB board dimensions and weights
Let's start with thickness. There are several options for these plates, ranging from 8 to 25 mm. According to this indicator, the plates are divided into three groups:
- Thin materials are 8, 9, and 10mm.
- Average thickness is 12mm and 15mm.
- Thickcanvas - 18, 22 and 25 mm.
The weight of the sheet is directly dependent on the thickness. So, with a plate thickness of 8 mm, its weight will be about 16.6 kg. A 9 mm product will weigh already 18.4 kg, 10 mm - 20.6 kg.
One of the factors by which OSB plywood is selected is dimensions. Actually, there are several. The most popular among domestic buyers is 2440x1200 mm, the standard European size is 2500x1250 mm and a very rare size is 2440x950 mm. It is believed that the latest slabs are popular for arranging the floor, although all products can be used with equal success.
Which is better: OSB or plywood
For those who are sure that OSB is something new and ultra-modern, it is worth saying that these boards were manufactured many years ago. Then there was not as much plywood on the market as it is today, and OSB was bought because it was a more affordable analogue of plywood.
In the production of oriented strand board, natural resins are used, as well as waxes and boric acid. Formaldehyde is used in the manufacture of plywood. In terms of safety, OSB is much better - this plate can be used in residential areas. Plywood is not suitable for this, due to the presence of harmful substances.
In addition, for laying floors, for example, OSB of a special design is used - the ends of such products are tongue-and-groove. This is done to achieve high-quality and easy joining of materials between themselves.
When choosing, of course, it is important to navigate depending on the specific situation. BUTif you choose by price, then OSB is also cheaper than plywood.
True, although the price of the material is much lower than what is asked for plywood, this plate should not be used for finishing floors - the appearance will not be aesthetic at all. But, as already 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 experts, due to all the same formaldehydes. From above, both materials can be coated with various protective compounds or varnishes. The slab is better and faster to grind, it also tolerates the primer better.
Thus, it is clear that in different situations you need to use different materials that are more suitable for a particular task.
