Plywood is widely used as a building material for structures, walls, roofs, flooring, furniture and so much more. There are different types of plywood by ply, core, uses, etc. Each type has its own characteristics including material, ply, size, veneer, grade and more to match with specific project. Understanding different types of plywood will help you narrow your choices to find the suitable kind for your needs.
Plywood by ply
“Ply”, as it refers to plywood, means the layer used to form the boards at various thicknesses. Each layer is a wood veneer that can glue together to create a number of plies. Ply achieves the right depth and makes the boards stronger. Some parts of the home require specific standards for the number of plies, especially with the walls and roofing.
3-ply is one of the most common types of plywood. This type has 3 layers of veneers and is strong enough for simple home projects. Moreover, it can look more decorative than plywood with more plies. The 3-ply is usually used for indoor woodworking projects.
5-ply means that the plywood board has 5 layers of veneers. This type is often used in tasks that require less strength and durability than those in exterior use.
Multi-ply plywood comprises several veneers, usually 7 plies or more. It is strong and durable enough to make an unyielding frame that can stand wind, rain and damage. Therefore, multi-ply plywood is commonly used in exterior construction and roofing.
Plywood by material
A veneer which is glued together to make plywood is a thin sheet of wood. The veneer can be made from various types of wood and creates different types of plywood
Manufacturers will use softwood to make plywood. Below are some common types of softwood plywood:
– Pine plywood
– Cedar plywood
– Redwood plywood
Although made from softwood, plywood is still strong and durable enough typical exterior construction such as sheathing, roof and sub-flooring. Softwood plywood is also used to make shelving, doghouses, sheds and more.
Manufacturers will glue hardwood veneers at right angles to make incredibly strong boards. Some examples of common hardwood plywood are:
– Maple plywood
– Oak plywood
– Walnut plywood
Hardwoods are the best choices for strong frames such as furniture, packing products, musical instruments and other intricate projects.
Plywood by structure
Manufactures will use different structures to make various types of plywood for certain uses.
Overlaid plywood is a type of plywood that utilizes the same structure of regular sheets to make stronger and more durable boards than traditional plywood. Overlaid plywood has an overlaid face that is smooth enough to keep water and other particles from damaging or sticking to it. The coating also helps it resist scratches and abrasions that can happen during transportation and construction.
There are 2 types of overlaid plywood:
– HDO: High Density Overlaid
– MDO: Medium Density Overlaid
HDO uses more resin than MDO, making them a bit more expensive.
Structural plywood, also known as sheathing plywood, is famous not for looks, but rather, strength. Manufacturer uses a very strong adhesive to ensure that the plywood can be used for framing and building structures. It usually has C and D grade. CDX plywood can be considered as the most common type of structural plywood.
Plywood by use
Plywood can be used for different purposes. Each purpose requires certain standards for dimension, veneers, glue, etc.
Aircraft plywood is known as the highest-grade, most durable kind of plywood. It uses hardwood like mahogany or birch. The veneers are light, flexible and strong. Aircraft plywood is not only strong but also resistant to heat and moisture. It is usually used in the heftiest projects such as airplanes, boats and furniture.
As its name, exterior plywood is used for outdoor works. It has weather and water-resistant glue. Manufacturers use hardwood like oak to create strong and sturdy plywood boards. The boards can handle wind, rain and resist mildew and mold from damp conditions. In some locations, it is required to stand up unusually harsh seasons.
With marine plywood, also known as marine grade plywood, manufactures use water-resistant exterior glue for the same layered construction as other woods. The plywood is not resistant to mold, rot or mildew. It uses a top-performing water-resistant glue between layers. This ensures that the glue will still work even if the wood becomes damp.
According to APA – Engineered Wood Association, marine grade plywood consists of Western Larch or Douglas Fir woods and must have a B-grade or better. It has no knotholes on the surface and is one of the best constructed plywood on the market. A common type in the marine grade kind okoume plywood. It is used mostly in outdoor and decorative furniture like planter boxes, benches and gazebos.
Along with mentioned above kinds, there are still many different types of plywood, according to your location. You may come across commercial plywood, flexible plywood, decorative plywood, composite plywood and so on.