What Are the Various Types of Exterior Plywood for External Use?

Exterior plywood is a type of wood that is made with waterproof glue. This is the most appropriate option for external construction purposes. It is meant to be used for exterior and non-structural applications that need an aesthetic, superior finish. A bonded variety needs to be used for applications that need full, long term exposure. Exterior bonded plywood needs to be treated well against fungus. Its surface must be finished well to reduce surface checking as much as possible. Based on the grades and materials, it can be classified into various types.

Moisture Resistant (MR) grade 

It is also referred to as commercial plywood. This is not a water-resistant plywood variety but can easily withstand some quantity of moisture. This type of exterior plywood is only appropriate for internal use. However, there are many woods that have waterproof variety such as:

• Spruce – Even when cut into thin slices, this material stays strong.
• Pine – This is the most basic underlying external plywood material.
• Mahogany – There are no pockets or gaps in the grains of this material. However, it must be surrounded by a veneer to make it weatherproof.
• Birch – This is the strongest of all materials but is prone to climate changes. Thus, veneers must be used on it to make it capable of withstanding environment extremes.
• Douglas fir – It is stronger than many other types of woods and makes it perfect for any structure that is meant to have high load capacity.
• Oak – It is strong and can resist fungus and insects.
• Maple – This is a decorative material primarily and is included in external plywood to provide a fine texture.

You can use this type of exterior plywood easily for outdoor construction purposes.

Boiling Water Resistant (BWR) grade plywood

This waterproof plywood is suitable for building exterior furniture. According to plywood quality tests with specifications, this kind of plywood can withstand easily water and flood events. Also, it can easily absorb water.

Plywood is constructed by sticking various wood veneer layers one atop the other – known as plies – and then these layers are hot-pressed together. When it comes to exterior plywood, a synthetic plastic resin known as phenol formaldehyde is applied. This makes the plywood water resistant in form.

The wood that is utilized in making this kind of exterior plywood generally comes from guardian, teak and other hardwood trees. These have much more strength compared to mango wood and other softwood trees. Other than being used in manufacturing outdoor furniture, this type of plywood is implemented for preparing furniture pieces such as wooden cabinets that are prone to getting wet.

Marine plywood 

It is the most superior quality plywood that is mainly intended for use in the construction of aircrafts, ships, boats and more. It is used in various industrial for different purposes. This is extremely expensive plywood. Although it can be utilized for manufacturing external furniture, this is not necessary given that the BWR exterior plywood is sufficient for this end.

Other than picking waterproof plywood of BWR grade, you would like to have your exterior furniture become more durable. Adding a sunmica or laminate topping over your plywood surface can be the best way to do so.

You can find decorative laminates in various textures, patterns and colors. These make furniture items look more beautiful and make them capable of withstanding any type of water damage. It prevents the seepage of water into the wood. Hence, it is the best suited for the outdoor construction.