Not sure what plywood to buy for your project? Read this article to learn the types of plywood and how to divide it.
If it is the first time you want to buy a multilayer sheet, it is not surprising that you will wander on the website of Khavaran or various manufacturing or importing companies and be overwhelmed by the wide range of products in this market. Because different types of multilayers are as diverse as their applications.
Plywood is a very strong product that is usually made from pressed wood layers. Usually, this product is sandwiched together with glue, compressed and then heated. The layers are placed at different angles, so the streaks on one layer are in one direction and on the next layer in another direction and this process continues.
As you know, wood shrinks and expands due to moisture in the vein. In multilayers, this movement is suppressed due to the alternating direction of the layers. Therefore, the dimensional stability of the multilayer is more than the average of 2×4. The composite state and the materials in the plywood make it resistant to warping, twisting, cracking, breaking and shrinking. The minimum number of layers is three layers, and in general, the higher the number of layers, the better.
Different types of multilayers come from its wide application. Did you know that a special type of multilayer is even used for airplanes? Kind of like that for a boat? Another type for furniture? And its types in the construction of roofs and gables and sub-flooring? These wide applications are the reason for the existence of multilayer types in the market.
Depending on the type of project, the type of tree, the degree and size of the multilayer are determined.
• Multilayer with a central layer of wooden layer is the main type of multilayer. It is laminated, with layers of wood glued together and very strong.
• Multi-layer with central MDF layer is made of several wooden layers that sandwich the central layer of MDF. This product is very stable and has a more uniform thickness compared to the multilayer with the central layer of wooden layer. This type of plywood is often used to make doors.
• Multi-layer with a central layer of timber that is made of sandwiched timber between wooden layers. This type of multilayer is often used to make classification and long shelves.
• Special facade laminate is often used for beauty on the exterior of the building and has a CDX rating. C is the grade of coating on the work, D is the grade of coating on the back of the work, and X indicates the glue used for the facade. In general, CDX multilayer is durable against low humidity and should be covered with other materials such as bricks.
• Underlayment that is waterproof and usually thicker (18mm or more). This plywood has a tongue and groove construction (marked T&G on the sheets) to prevent squeaking.
The grade indicates the physical appearance of the multilayer. In general, there are 4 multilayer grades available:
• Grade: A In grade A multilayer, the front and back of the sheet is almost free of defects, the surface is smooth and sanded and practically without knots. It is suitable for cabinet doors and furniture and exposed surfaces (not covered with other materials) and can be painted.
• Grade B: Grade B plywood is smooth and sanded, but the front and back of the work has defects, some of which can be repaired with patches or wood fillers. This grade is cheaper than grade A.
• Grade C: Grade C plywood is not sanded and knots up to 4 cm wide can be seen. It may include a large section that is patched and filled. This plywood is suitable for substructure and applications that are not visible.
• Grade D: Grade C multilayer is not sanded and knots up to a width of about 7 cm can be seen. Grade D plywood, full of patches, fillers and some unrepaired defects. This plywood, like grade C plywood, is suitable for concealed structural applications.
When the sheet contains two letters, such as A/B, A refers to the work and B refers to the back.
In general, there are three main sizes of multilayer panels in the world:
244×122 cm
270×122 cm
122×122 cm
Of course, in Iran, for example, the Khavaran site is the only available multilayer size of 244×122.
Different laminates are available with different thicknesses and in a variety of sizes. In general, there are multiple layers from 3 mils to more than 4 cm thick. The thickness of the multilayer you choose depends on the type of project. Thin multilayer is suitable for the layer between the sub-floor and the main tile. However, a thicker laminate is needed as the sub-layer itself or to cover the structure that connects to the skeleton.
When you go to Khavaran or wood sellers’ website to buy plywood, it is better to know in advance what you need. For multi-layers that are painted, choose grade A or B according to your budget and carefully check the visible side. There can be a lot of variation between sheets, so don’t hesitate to pull out and check several sheets before you buy. If the edges are exposed, make sure there are no holes or cracks in them. Morflor Wood Parquet Industries uses grade A plywood produced by itself to produce its engineering parquet. Unfortunately, due to the high volume of parquet production, it has not been possible to supply this multilayer to the market so far.
