How To Make Plywood Waterproof? – Simple Methods


Plywood is used for many purposes, it is easier to use than wood and is easily available in the wood market. Plywood is more widely used in the interior. The use of plywood has been huge in the last few years. It is already available in many size thickness sheets.

Before we learn how to make plywood waterproof, we need to know what material is used to make plywood. In order to understand how to make it waterproof.

To make plywood, thin layers of wood called veneers are glued with each other. Then with the help of hydraulic pressure, all the thin layers of wood are pressed. So that everything sticks together and builds a strong plywood seat.

There are a lot of methods of making plywood waterproof, which different companies and people use. In this blog, I am going to share some special simple and easy methods with you.

1. Varnish Polish Method

The first and cheapest method is to Varnish. Before performing this process, the plywood surface needs to be cleaned with light hands rubbed with sandpaper or sand tools for large areas.

So that the surface of the plywood becomes slightly rough. After this, the surface should be cleaned thoroughly. So that the copal varnish can hold the surface properly with plywood.

Apply two or three coats of copal varnish to the entire surface of the wood. After this, you have to place the plywood in a dry place. where there is no moisture. After the plywood is well dried, you can do one or two more coats to make a good layer of copal varnish. This protects the plywood for a long time

The main use of copal varnish is to maintain the luster of wood for a long time. It also protects plywood or wood from dust, soil, water, and sun rays.

2. Paint

Painting on plywood is another common method that can be easily done around the world. The paint method is widely used to make weatherproof plywood.

But even where Wood talks, nothing is 100% waterproof. Only for a few years can we prevent the plywood from getting spoiled by water, but not at all for safety.

How to paint plywood to make it waterproof?

1. Sanding

You should use sandpaper before painting so that the rough surface of the plywood can be smooth. If the surface of the plywood is too rough then you must do this process. The larger the piece of plywood, the easier it will be to use an electric sander. And sandpaper can be used for small areas.

2. Fill all holes

Monitor the entire surface of the plywood before painting and priming it. If there are any holes, then mix the wood dust and glue and make a paste. All the holes should be well filled. After filling the holes, normalize the entire surface with 100 or 220 grit sandpaper.

3. Primer coat

Now you should do one to two coats of primer. For this, you use a brush for small parts and a roller and sprayer for large parts. After the primer should be allowed to dry well.

After this you should coat a thin paint on the plywood while doing this you will see that the primer will also be visible. But there is nothing to worry about because we will do more coats of paint so that the primer will be completely covered.

4. Paint Coat

After using a thin coat of paint, you should be sanding the entire surface again using 100 grit sandpaper, which makes the surface of the plywood even more smooth.

Now we have completed the entire work, cleaning the dust after sanding on the plywood. 

Now we have completed almost all the work,

After sanding the plywood, the dust should be cleaned properly so that the paint will hold the surface of the plywood properly. In this process, the durability of your plywood goes much later.

Plywood grads

how to make plywood waterproof
Plywood grads

Let us now know about the different types of plywood that are manufactured for water resistance and more. Many plywood companies that are top brands also do not claim lifetime waterproof plywood.

Moisture Resistant Grade Plywood 

It is also called MR-grade plywood. This is perfect for plywood interior use. This plywood is not waterproof. It is treated with resins such as formaldehyde to resist humidity and moisture. We use it mainly for making the home and office cupboards and tables where there is no moisture.

This type of plywood has a low price and is easily available at every wooden store.

BWR  Grade  Plywood 

BMR grade plywood is known as “Boiling Water-Resistant”. These plywoods are more durable than MR grade when we talk about waterproofing.

We can easily use this type of plywood both in the interior and exterior. It is treated with phenolic resins to make it water-resistant.

We mainly use this plywood for the place where moisture cannot be stopped such as for kitchen and bathroom doors. It can be saved from moisture for a long time.

BWP Grade Plywood

The full name of BWP is “Boiling waterproof” which is more durable and expensive than MR and BMR grade plywood.

This plywood is mainly used for marine construction. Where there is an excess of moisture and water. It is also used for house siding. Who always suffers rain and sun

For this reason, this plywood is also called Marine plywood. High-quality wood veneers are used to make BWR grades. Which is made by joining multiple layers together.

Plywood of this grade is put into boiling water for three to four days and then checking for strength and other properties.


The final conclusion of “how to make plywood waterproof”.

Things made of wood can never be completely waterproof, just by using some process we can make the plywood more durable which can be safe from water and weather.

But if you want to use plywood in a place where there is an effect of moisture and weather. So you should use boiling water-resistant (BWR grade plywood) or boiling waterproof (BWP Grade Plywood) along with the use of polish and paint to make it more durable.

Read other articles:

The Advantages And Disadvantages Of Wood Siding

Timber For Decking: Decking Guide

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