What is Marine Plywood Made From?

Author Chigwell Building & Joinery

Date 08/10/19


Most people have heard of plywood and will most likely own something made from plywood, such as a piece furniture.

But whilst it's a very commonly used material in the construction and furniture industries, many people are unaware that there are actually different types of plywood available for different uses.

These varying kinds are intended for different uses and purposes, and as a result they have slightly differing properties and construction.

Marine-grade plywood is one such example.

The term marine might give off the wrong impression that it is suitable to withstanding extreme moisture or contact with water.

However, do not be fooled as marine ply not strictly 100% waterproof.

Marine plywood is however, a reasonably high quality type of plywood.

It is constructed from hardwoods rather than softwoods, with each layer affixed using waterproof grade glue to prevent de-lamination.

Consequently, it is often used in exterior construction and outdoor furniture projects, certain types of boat, and it is also considered to be a good choice for use in coastal areas where natural air moisture levels are considerably higher.

So what is marine plywood made from that makes it a much stronger material than regular ply?

Read on to find out more, or use a jump link below to skip to a desired chapter:


Chapters

  1. What is Marine Grade Plywood?
  2. What is it Made From?
  3. How is Marine Plywood Made?
  4. What is it Used For?
  5. Is It Better Than Regular Plywood?
  6. Conclusion

What is Marine Grade Plywood?

Marine plywood is highly recommended for outdoor projects as it is more resistant to moisture than other types of plywood.

However, it is still made in the same manner as any other plywood sheets you'll find on the market, as it is still constructed from thin veneers of wood sealed together under high pressure.

In the case of marine plywood, that bonding agent is made for water submersion.

Like other types of plywood, marine plywood is also given different standardisations by manufacturers.


What is it Made From?

Marine plywood is constructed from water resistant tropical hardwood, and as these are naturally water resistant, they make marine plywood better than other types of plywood in situations where moisture levels are higher.

There are certain wood species, such as cedar, cypress and redwood, Western Larch or Douglas Fir, that have a natural resistance to decay.

Whilst marine plywood is not pressure treated to enable it to withstand decay, high quality grade veneers are used to increase its resistance.

As a result of this, it is made to withstand moisture far better than standard plywood as it will be well protected with water resistant materials.

How is Marine Plywood Made?

Marine plywood is available in different grades namely:

  • A-A
  • A-B
  • B-B
  • MDO
  • HDO

As with other types of plywood, marine grade plywood is composed of thin sheets of wood veneers, which are arranged in perpendicular layers so as to make it stronger.

Cross lamination is used so as to have the plies perpendicular to each other, so that the panel will be given additional strength in both directions.

Finally, the panel is bonded under high heat and extreme pressure.

When it comes to marine plywood, waterproof glue is used to bond the layers, making it ideal for use in areas where humidity levels or moisture is higher than normal.

Due to the waterproof glue, you do not need to worry about the layers de-laminating over time.


What is it Used For?

Marine grade plywood is good for exterior use, and as a result it is recommended for various projects such as external structures and outdoor furniture.

Some of the most popular uses of marine plywood include:

  • Patio furniture: such as benches, tables and chairs.
  • Pergolas: could very well be constructed from marine plywood, as it is a feasible but inexpensive option compared to other types of wood.
  • Planters: ideal as marine plywood can withstand the moisture and humidity from the soil.
  • Porches and Decks: a good staining and sealing, and you can have a great deck or porch made out of marine plywood.
  • Boats and Sailing Equipment: there are basic boats for sale made from marine plywood, which will serve well for those who have fishing or sailing as a hobby. Marine plywood is ideal to form simple boat structures, and as long as it is properly sealed inside and outside, it will be waterproof.
  • Boat Docks: marine plywood is taking over the traditional sanded lumber to construct boat docks as it can do well for quite a long time. After some years, its longevity can be increased further with some weatherproofing treatment.
  • Lake Platforms: building a lake platform where you can fish and suntan is a great idea, and using marine plywood to construct it is ideal. All it takes is gluing several marine plywood sheets together, protect them using a waterproof sealant, and bolt it to a weight at the bottom of the lake.
  • Bathroom and Kitchen Walls: kitchens and bathrooms are the rooms whose walls are most susceptible to splashes. Marine plywood is ideal as it can withstand such moisture quite well.
  • Bathrooms and Kitchen Subfloors: spills on bathroom and kitchen floors, and overflows from showers and toilets are common, but with marine plywood sub-flooring you can be safeguarded from deforming and rotting floors.

Is It Better Than Regular Plywood?

In short, marine plywood almost always performs better than regular plywood.

The main reason is that it can better withstand humidity and moisture, unlike the most basic type of plywood which would end up warping should it be exposed to high levels of humidity or moisture.

The main difference is that marine plywood, and exterior types of plywood, will be better sealed and treated.

On the other hand, plywood used for interior projects will be thinner.

To give you a basic idea, regular plywood sheets would typically have between three and five layered veneers, whereas marine plywood would typically have twice as many layers.

Despite this, never forget that at the end of the day this is still plywood, and though it is of a better quality, you should still make sure that it is well maintained from time to time.


Conclusion

If you are considering purchasing plywood for an outdoor project, or constructing something that will be used outdoors or placed in areas of high humidity, then it is highly recommended that you opt for marine ply.

This is because it is more suitable to withstand high humidity and moisture since it is bonded together with waterproof glue or phenolic resin.

The combination of water resistant hardwood that this plywood is made from, and this type of glue, will basically make this plywood waterproof and last longer.

Marine ply is also extremely strong and can withstand high levels of pressure.

So it makes for an ideal building material in a wide range of projects and applications.