What is Moisture Resistant Plywood: Everything You Need to Know

Moisture is the number one enemy of wooden structures and projects. Because wood is made up of living cells and structures, water or moisture can easily seep in and attack the wood structure from within.

Without proper protection, wood will eventually decay and lose its strength and form. If you’re using unprotected wood to build your home, you could end up with rotting walls that can place your family’s life in danger! Therefore, it’s best to use suitable materials and to protect the wood you’re using to build different furniture pieces and home projects.

And when it comes to using the suitable building materials, moisture-resistant plywood is the top choice. From the name itself, moisture-resistant plywood is a kind of plywood that prevents moisture and water from seeping in to cause rotting or decay.

Let’s find out more about moisture-resistant wood, its many unique properties, and how you can use this wood for different projects in and out of your home in this guide.

What is Moisture Resistant Wood?

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Moisture-resistant or water-resistant wood was developed to make furniture and cabinets that are constantly exposed to moisture and water. The reason why this wood is waterproof or moisture-proof is its because of the bonding substance used to make the wood.

This plastic resin binds with the wood fibers and makes it unaffected by water even when the wood is near high moisture areas. And because this wood is impervious to water and moisture, you can use this to make outdoor furniture, kitchen cabinets, bathroom cabinets, and other projects.

Regular or untreated plywood is available in standard 4 x 8 inches and 3 x 7 inches, and many other sizes. The thickness of this plywood is from 3 to 25. Plywood that is pre-veneered or laminated can cut down finishing. But not all veneer or laminate hues are available. And to get the best chance of selecting the right color and finish, you must choose the laminate or the veneer before adding this to your plywood.

Why Use Moisture Resistant Plywood?

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Plywood consists of many layers or “plies” of wood, hence the name “plywood.” These plies are sandwiched by hardwood or veneers. The many layers make the plywood strong and ensure that it will keep its shape no matter where you use it. These plies allow you to use wood to make roof decks, cabinets, tables, and many more.

However, like any kind of wood, every ply or layer of plywood can absorb water or moisture. This is through direct contact with water on the surface of the wood or through humidity in the air. And when this happens, the different layers can expand and then shrink as the wood dries. These natural wood behaviors may not be evident and essential in some wood applications.

For wood applications that require accuracy, such as wooden cabinets, wooden furniture, and flooring, expansion and contraction of wood can lead to warping. This can ruin not just the physical appearance of wood but also the structural integrity of timber as well.

Also, regular plywood that’s made from urea-formaldehyde-based adhesives may have many disadvantages. Formaldehyde is easily affected by moisture and degrades after some time. When wood is constantly subjected to water and high moisture levels, the plies will delaminate or pull apart.

Thus, the best alternative is moisture-resistant plywood. This kind of plywood will resist moisture damage as it prevents the natural expansion and contraction of the plywood layers. Builders won’t have to worry about warping and any changes in the appearance and structure of their wooden projects.

People who live in places with high moisture and humidity content must use moisture-resistant plywood. Also, you can use this type of plywood to build cabinets and other wooden storage systems in kitchens and bathrooms with moisture-resistant plywood.

What are the Properties of Moisture Resistant Wood?

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Here are the characteristics of moisture-resistant plywood

Strong Building Material

Moisture-resistant plywood is more substantial and a lot more durable compared to MDF wood. Because of plywood’s exceptional strength, it is used to build high-end furniture as well as cabinets, shelves, and tables. Cutting a moisture-resistant wood in cross-sections will reveal the different layers.

This plywood is composed of wood veneers that are stacked and pressed together. There is a core, front, and back part of the board, and each of these can be made from different materials. You’ll find plywood made from other types of wood; this way, it becomes more affordable for construction use and furniture building.

Stable Building Material

Moisture-resistant plywood is dimensionally stable. This is due to the many layers of wood plies stacked together and glued. Also, plywood has a cross-grain construction which also adds to the stability of this material.

You can tell that many woodworkers and furniture makers acknowledge the stability of plywood, and thus, it’s the choice in doing different projects.

If you’re using moisture-resistant plywood to build boxes and shutters, cut the plywood’s outer edges and seal these with an edge banding tape. You may also use wooden beading or a membrane to enhance its durability.

Better Bonding Agent

The layers of moisture-resistant wood are bonded together using phenolic resin. This type of resin is a synthetic polymer created from the reaction of phenol with formaldehyde. Phenol resins are from any class of resin used in adhesives and paints and to be used for thermosetting materials like plastics.

High Screw and Nail Holding Capacity

Moisture-resistant plywood can hold screws very well. You don’t need to pre-drill the surface to attach screws, but this is recommended in some projects. Also, nails connect very well whether you’re using a hammer or a power fastener.

Pest Resistant

Insects and pests love wood that readily absorbs moisture. This is because humidity softens wood allowing them to penetrate the deep layers of wood. But moisture-resistant plywood will never hold humidity, and thus, it will resist termites and other boring pests. Also, with low to absent moisture content, this wood will repel mold and fungus growth.

It Has a Lovely Natural Finish or Surface

This type of plywood looks like natural wood with a stunning finish because this has veneer surfaces. A veneer is a strip of natural wood, and thus, you’ll have a texture similar to natural wood as well. Also, you can laminate the surface in moisture-resistant timber, and this preserves the wood longer.

Used in High-Moisture Areas

Moisture-resistant plywood is helpful in environments where there is high moisture, such as kitchens, laundry areas, and bathrooms. You can use this type of wood to make different structures like cabinets, shelves, and tables. If you live in an area with high humidity, then you need this kind of plywood to build various types of furniture in every room in your home.

A type of moisture-resistant plywood is marine plywood. This kind is not just waterproof but is also boiling waterproof. Because of this impressive quality, this wood is preferred for constructing decks and balconies that are directly affected by rain and moisture.

There is also commercial plywood, but this has no resistance to water. And because of this quality, it is commonly used to construct structures that are not exposed to water or moisture, like wardrobe cabinets, bedside tables, etc.

Are There Disadvantages of Using Moisture-Resistant Plywood?

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Plywood is not the ideal material for carving projects. Plywood is much too thin to cut or turn. Also, plywood cores are non-uniform, and thus, this material is not suitable for carving or molding into various shapes.

Also, moisture-resistant plywood is more expensive than MDF wood. However, solid wood is still more expensive than plywood and other types of manufactured wood.

Where Can You Buy Moisture-Resistant Plywood?

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You can purchase moisture-resistant plywood from local hardware stores and distributors. You may also order this kind of plywood from online hardware stores and dealers. Moisture-resistant plywood is abundant and readily available. 

What Are the Brands of Moisture-Resistant Plywood Available?

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Moisture-resistant plywood is available in various brands. The most popular are Archidply, Century, Duro, Greenply, Mayur, Merino, and Uniply. Let’s take a closer look at two plywood brands, Duro and Greenly.

Duro Waterproof Plywood

Duro Plywood is one of the most efficient moisture-proof plywood brands available. Duro is available in varying thicknesses: 4, 6, 9, 12, 16, 19, and 25 mm in 8×4 dimensions. This is not just moisture-resistant but is also boiling waterproof.

Duro uses very strong phenolic resins making this plywood weatherproof. This wood receives unique treatments using preservatives and pesticides to prevent termites and other wood-boring insects. 

Greenply Waterproof Plywood

Greenply Plywood is also available in 4, 6, 9, 12, 16, 19, and 25 mm in 8×4 dimensions. Just like Duro, Greenply is also boiling waterproof, and thus, you can use this plywood to construct decks and outdoor flooring.

Greenply Waterproof Plywood is known as the highest quality plywood for marine and commercial applications. Each plywood has been crafted with precision, correct thickness, and incredible strength.

Other Wood Types with High Moisture-Resistance

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There are many trees with unique characteristics, and one of these is their ability to resist moisture and rotting or decay. Some wood is also more water-resistant than others. So, if you can’t find moisture-resistant plywood in your locale, ask if they have the following wood species.

European Larch (Larix decidua)

Larch wood is known to have a high resistance to moisture and decay. There are many species of larch: European, Japanese, Western, and Tamarack larches. Let’s take a look at the most popular, the European Larch.

The European larch is a deciduous tree despite being a conifer tree. It is a common ornamental tree in Europe and is known for its ammonia fumes. It is widely used as a decorative veneer wood.

  • Distribution: This larch species is found in Central Europe
  • Tree Size: 85 to 150 feet tall and 2 to 3 feet wide
  • Average Dried Weight: 36 pounds per cubic feet
  • Specific Gravity: .45, .58
  • Janka Hardness: 740 pounds-feet
  • Appearance: the European Larch heartwood has a yellow to reddish-brown hue. The sapwood is narrow and white. This is easily differentiated from the heartwood. You’ll find a lot of patterns, rings, and knots on the surface, but these are more visible when the wood is flatsawn.
  • Grain and Texture: this wood may have spiraled or straight grain with a medium to fine texture. There is a noticeable greasy feel over its surface.
  • Resistance to Rotting: this wood is durable to rot and decay.
  • Workability: This wood has natural resins that can gum up blades and saws. It isn’t easy to sand.
  • Presence of Odor: this larch species have a distinct odor when it is worked.
  • Availability: the European Larch is used as construction wood, and thus the price can be moderate.
  • Uses: this wood is helpful as construction wood, flooring, veneers, fence posts, boatbuilding, and utility poles.

Peroba Rosa (Aspidosperma polyneuron)

The Peroba Rosa is another type of wood with fantastic moisture deterring properties. It is commonly used to create musical instruments because of its natural acoustic properties.

  • Distribution: the Peroba Rosa is common in Brazil and Argentina
  • Tree Size: 100 to 125 feet high and 4 to 5 feet wide
  • Average Dried Weight: 47 pounds per cubic feet
  • Specific Gravity: .65, .75
  • Janka Hardness: 1,670 pounds-feet
  • Appearance: the Peroba Rosa has a pinkish-red to yellow heartwood. You’ll also find streaks of brown or purple on the surface. The sapwood is gray to yellow. This wood tends to become darker as it ages.
  • Grain and Texture: This wood has straight to semi–interlocked or irregular grains. It has a fine and even texture. The end grain is porous and diffused with no particular arrangement.
  • Resistance to Rotting: this wood is very durable and resistant to rotting and decay. It may be susceptible to termites and other boring insects.
  • Workability: this wood is very easy to work with. However, it can cause blunting on blades, cutters, and saws. It works great with glues and finishes.
  • Presence of Odor: the Peroba Rosa has no specific odor or smell.
  • Availability: this wood is starting to become scarce, and thus, the price could be from moderate to high. It is classified as an imported tropical hardwood species. 
  • Uses: this wood is helpful for general construction, carvings, turning, veneer, furniture, and cabinets.

Cumaru (Dipteryx odorata)

The Cumaru is also known as Brazilian Teak and is famous for wood flooring. This wood has strong resistance to moisture and thus will make durable and long-lasting floors.

  • Distribution: this wood is found in Northern South America
  • Tree Size: 130 to 160 feet tall and 3 to 5 feet wide
  • Average Dried Weight: 68 pounds per cubic feet
  • Specific Gravity: .86, 1.09
  • Janka Hardness: 3,350 pounds-feet
  • Appearance: the Cumaru has a medium to dark-colored heartwood with a red or purple hue. There are also some cumaru species with yellow or green streaks on the surface.
  • Grain and Texture: this wood has interlocked grains with a medium texture. You’ll also notice a waxy or greasy feel on the surface. The end grain is diffuse-porous. There are gum and mineral deposits seen on the grain.
  • Resistance to Rotting: Cumaru has excellent moisture-repelling characteristics. It is very durable and will never decay and be affected by borers and termites.
  • Workability: This is a dense wood and thus can be hard to work with. It can be surface-planed to create a smooth finish. It contains silica and, therefore, will blunt your cutters and blades. Cumaru also has high oil content and thus will not work with glues. You need to pre-screw your nails and screws before attaching them.
  • Presence of Odor: you will notice an odor similar to vanilla or cinnamon when you’re working with Cumaru wood.
  • Availability: This is an inexpensive hardwood and, thus, preferred by budget-conscious homeowners.  
  • Uses: this wood is commonly used in heavy construction, furniture, cabinets, railroad ties, turning, handles, bearings, and more.

Iroko (Milicia excelsa)

Iroko is mainly used as an alternative to teak wood. This stable, durable, and lovely hardwood are helpful in making furniture and other specialty items.

  • Distribution: Iroko grows in tropical areas in Africa
  • Tree Size: 100 to 130 feet tall and 3 to 5 feet wide
  • Average Dried Weight: 51 pounds per cubic feet
  • Specific Gravity: .68, .82
  • Janka Hardness: 1,840 pounds-feet
  • Appearance: The Merbau has an orange-brown color when it is newly cut but can become darker when the wood grows older. You will notice color differences between boards. Expect tiny yellow mineral spots throughout the wood. These spots help people identify authentic Merbau wood from fake ones.
  • Grain and Texture: this wood has a straight grain, but some may possess interlocked grains. It comes with a coarse texture and a natural luster. The end grain has large pores and mineral deposits.
  • Resistance to Rotting: Merbau wood is resistant to rotting and insects.
  • Workability: this wood is difficult to cut because it can gum up and dull saw teeth and blades. It works well with finishes and glues.
  • Presence of Odor: This wood has a unique odor when it is worked. The smell can cause sneezing and respiratory irritation.
  • Availability: this is imported hardwood so expect high prices. 
  • Uses: this wood is helpful in making musical instruments, turning, flooring, furniture making, and decorative items.

Teak (Tectona grandis)

Teak is grown in massive plantations in Myanmar. It is a stable wood with incredible strength and impressive resistance to rotting and decay.

  • Distribution: this wood is from southern Asia and also from plantations in Latin America and Africa.
  • Tree Size: 100 to 130 feet tall and 3 to 5 feet wide
  • Average Dried Weight: 41 pounds per cubic feet
  • Specific Gravity: .55, .66
  • Janka Hardness: 1,070 pounds-feet
  • Appearance: this wood has a lovely gold to brown heartwood. It can darken with age.
  • Grain and Texture: the grain is interlocked or wavy. It has a coarse texture and slight luster. Unfinished teak has a greasy feel because of the wood’s natural oils.
  • Resistance to Rotting: teak naturally repels insects, termites, and borers. It has high decay resistance and is very durable.
  • Workability: This wood contains high silica levels and can cause blunting of knives, blades, and saws. It is easy to work with, and despite having natural oils, it works well with glues and finishes. Some wood workers wipe the surface of teak with solvent before applying any finish or paint to remove some of the natural oils.
  • Presence of Odor: teak has a leather-like odor when it is newly cut.
  • Availability: teak is widespread all over the world, but it remains expensive. Large and non-figured teak wood is the most expensive compared to small pieces of teak. 
  • Uses: This wood is mainly used to build boats and ships. Teak is also popular in furniture making as you’ll find teak furniture, cabinets, and armoirs. This wood is also helpful in carving, veneer, exterior construction projects, and for turning small objects.

Final Words

Moisture-resistant plywood has a lot of unique benefits. It is resistant to rotting and decay because moisture can’t penetrate within the plywood layers. It won’t warp or change its shape, too, because it won’t accept water. This plywood is also resistant to insects, boring pests, and termites, especially when appropriately treated.

Moisture-resistant plywood is perfect for high humidity areas in your home like kitchens, bathrooms, and laundry or service areas. If you live in a room with high humidity, this type of plywood will work well for you. There are also some disadvantages of using plywood. It’s not good for carving and turning and is not as durable as solid wood.

And if you can’t find moisture-resistant plywood or would like to use solid wood for your projects, then you must use the above-mentioned water-resistant wood species. Remember to buy only good quality and authentic solid hardwood from reputable suppliers. Always consider and compare the prices of wood before you make a purchase. Finally, add a finish on wood even if it is rated as moisture-resistant. This will further preserve the beauty and the structure of wood for your projects.

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