In the past, furniture and decorative items for homes were crafted from solid wood, renowned for its durability. However, the introduction of plywood, composed of multiple thin layers of wood or wooden sheets bonded together, revolutionised woodworking. Plywood’s introduction simplified woodworking tasks and expanded its utility across applications, owing to its versatility. Today, diverse types of plywood are available, including marine plywood. This specific type finds application in crafting various items, ranging from kitchen cabinets to bathroom flooring. Read on to discover more about marine plywood, its characteristics, applications, and benefits.
What is marine plywood?
Marine plywood is a specialised type of plywood engineered for water-based applications. Crafted from high-quality hardwood veneers, it is bonded with waterproof glue and undergoes a unique treatment process, rendering it highly resistant to moisture and water damage. One of its notable attributes is its resistance to rotting, warping, and delamination. It can withstand prolonged water exposure without separating. Marine plywood comes in various thicknesses and grades, with each grade denoting the plywood’s quality and appearance. Generally, the higher the grade, the better the quality and appearance of the plywood.
Marine plywood: Grades
Various grades of marine plywood are accessible, each possessing distinct characteristics and applications. When selecting marine plywood, it’s crucial to contemplate the precise demands of your project. Below are the top five grades of marine plywood obtainable in the market, accompanied by their defining features.
A-A grade marine plywood
For those seeking the utmost quality in marine plywood, A-A grade is the ideal choice. It is crafted from premium hardwood veneers characterised by uniform colour and grain patterns, devoid of knots, defects, or voids. This grade exhibits a certain degree of waterproofing, achieved by a waterproof adhesive during the cross-banding process, where each layer is perpendicular to the previous one. A-A grade marine plywood is highly suitable for applications demanding a superior appearance, such as cabinets, boat interiors, and furniture. It offers superior water resistance, high stability, excellent durability, and an elegant appearance. However, it does come with a high price tag.
A-B grade marine plywood
This grade represents high-quality plywood well-suited for marine applications. Crafted from hardwood veneers exhibiting uniform colour and grain patterns, it permits only minor defects, such as voids or knots. Like A-A grade, manufacturers employ a waterproof adhesive during the cross-banding process, ensuring water resistance. Hence, if you’re wondering whether marine plywood can withstand moisture, the answer is yes. In comparison to A-A grade, A-B grade marine plywood may display slight colour variations and minor defects, yet its performance and durability remain consistent. It continues to offer superior water resistance, high stability, and excellent durability. These attributes render it suitable for various outdoor and marine applications.
B-B grade marine plywood
B-B grade marine plywood represents a lower-quality option suitable for applications prioritising strength and durability over appearance. It is crafted from hardwood veneers that may contain patches, knots, and other imperfections while remaining structurally sound. Similar to A-B grade plywood, the veneers are bonded with waterproof adhesive through cross-banding. Although less expensive than A-B and A-A grades, B-B grade marine plywood still offers commendable water resistance, stability, and durability. It is commonly used for decking, subflooring, and other structural applications where appearance is not the primary concern.
Medium-density Overlay (MDO) marine plywood
MDO is a specialised variant of marine plywood featuring a resin-impregnated fibre layer on both sides, serving as a waterproof barrier. Like A-A and A-B grades, the fibre layer is positioned between two layers of hardwood veneers bonded together with waterproof adhesive using cross-banding. MDO marine plywood boasts a uniform surface finish ideal for painting or staining. It provides enhanced water resistance, decent durability and robust stability compared to B-B grade marine plywood. Moreover, it is well-suited for marine and outdoor applications.
High-Density Overlay (HDO) marine plywood
HDO represents a superior grade of marine plywood compared to MDO, characterised by a higher resin percentage, leading to a shinier and harder surface. It provides enhanced water resistance, stability, and durability in comparison to both MDO and B-B grade marine plywood. HDO marine plywood is well-suited for applications demanding a uniform surface finish and superior water resistance, including docks, boat exteriors, and other outdoor structures.
Marine plywood: Features
Here are some key attributes of marine plywood:
- Moisture resistance: One of the primary features of marine plywood is its resistance to moisture. It is crafted using a special type of glue that is water-resistant, making it perfect for deployment in humid and wet environments.
- Superior strength: Marine plywood is manufactured from high-quality hardwood veneers bonded together with waterproof glue. This construction imparts superior strength, rendering it suitable for heavy-duty applications.
- Durability: Marine plywood is engineered to endure harsh weather conditions, rendering it ideal for outdoor use. It exhibits resistance to cracking, warping, and splitting, ensuring its longevity.
- High cost: Compared to its moisture-resistant counterpart, commercial plywood, marine plywood is generally twice as expensive. The price of marine plywood varies between brands, with the cost of plywood sheets further influenced by the quality of resin and timber used in their production.
- Versatility: Marine plywood finds application across a broad spectrum of uses, including furniture making, boat building and construction projects. Its robustness makes it a favoured option among professionals.
Marine plywood: Uses
As previously mentioned, marine plywood is highly versatile. Its void-free construction and water-resistant adhesive make it suitable for almost any application that requires plywood, both indoors and outdoors, without concern for moisture or water contact. Here are some key uses of marine plywood.
Boats
The strength and water resistance of marine grade plywood are tailored for use in boat hulls, which are fully sealed to provide years of waterproof performance. Resistant to water damage and collisions, marine plywood is the premier choice for boat construction.
Docks
The durability of marine plywood makes it a preferred material for docks, enduring harsh environmental conditions with minimal maintenance. Marine plywood boards can also be employed in constructing lake platforms.
Kitchens and bathrooms
The high moisture levels in kitchens and bathrooms necessitate materials resistant to humidity and water contact. Marine plywood finds various applications in these areas, from panelling to cabinets to flooring, offering exceptional strength and water resistance.
Exterior furniture
The superior water resistance of marine plywood makes it suitable for exterior furniture, including chairs, tables, and benches. Constructing outdoor furniture with properly sealed marine plywood ensures both strength and long-term performance. Additionally, marine plywood’s smooth hardwood finish enhances the aesthetic appeal of outdoor spaces.
Marine plywood: Benefits
Marine plywood offers numerous advantages over standard plywood, making it a preferred choice for various applications.
- Exceptional water resistance: A primary benefit of marine plywood is its outstanding resistance to water. Crafted with waterproof glue and high-quality veneers treated to withstand moisture and humidity, it excels in boat building, docks, and marine applications.
- Enhanced strength and durability: Constructed with multiple layers of hardwood veneers bonded together using high-quality adhesive, marine plywood exhibits excellent structural integrity. It can withstand heavy loads and extreme weather conditions with ease.
- Cost-effectiveness: Although marine plywood may have a slightly higher initial cost than regular plywood, its prolonged lifespan and moisture resistance make it a cost-effective investment. It requires less maintenance and replacement over time.
- Fungal resistance: Thanks to its water-resistant properties, marine plywood is highly resistant to fungal attacks. This makes it a dependable option for applications where prolonged exposure to moisture is inevitable, such as marine construction or outdoor furniture.
- Prevents delamination: Marine plywood sheets feature a smooth and pore less surface, preventing water from infiltrating the layers of wood, thus reducing the risk of delamination, common in ordinary plywood.
- Versatility: Marine plywood is a versatile material suitable for a wide range of uses. It finds application in boat and yacht construction, as well as in the manufacturing of outdoor furniture, cabinets, and flooring.
Marine plywood: Cost in India
The cost of marine plywood in India varies depending on the brand, quantity, and thickness. Taking all factors into account, here is a table summarising the average prices of marine plywood:
| Thickness | Price per square foot (excluding GST) | Price of sheet (excluding GST) |
| 4 mm | Rs 33.05 | Rs 1,058 |
| 6 mm | Rs 42.50 | Rs 1,360 |
| 9 mm | Rs 56.16 | Rs 1,797 |
| 12 mm | Rs 69.01 | Rs 2,208 |
| 16 mm | Rs 86.62 | Rs 2,772 |
| 19 mm | Rs 103.25 | Rs 3,304 |
| 25 mm | Rs 147.15 | Rs 4,709 |
Is marine plywood same as waterproof plywood?
While both marine plywood and waterproof plywood offer resistance to moisture, they are not the same. The primary difference lies in their construction and intended use.
- Marine plywood is specifically engineered for water-based applications, such as boat building and docks. It is crafted from high-quality hardwood veneers bonded with waterproof glue, typically phenolic formaldehyde resin. This construction ensures superior strength, durability, and resistance to delamination, even when exposed to prolonged water contact. Marine plywood undergoes stringent quality control measures to meet industry standards for marine-grade materials.
- On the other hand, waterproof plywood, also known as BWP (Boiling Water-Proof) plywood, is designed to withstand occasional exposure to moisture but may not be suitable for constant immersion in water. It is constructed like marine plywood but may use different types of adhesives and may not undergo the same rigorous quality checks as marine plywood. Waterproof plywood is commonly used in applications, such as outdoor furniture, kitchen cabinets and bathroom fittings where occasional moisture resistance is required.
Marine plywood vs other plywoods
Marine plywood is crafted from high-quality wood, with the number of plies typically double that of other plywood variants, ranging between 10-12 layers. Only hardwood piles are utilised in its manufacturing process. Great care is taken during the construction of marine plywood to ensure the planks or sheets of timber are arranged and joined seamlessly, leaving no crevices. This meticulous arrangement is believed to be the reason behind the plywood’s ability to resist delamination even when exposed to water. Moreover, marine plywood employs a synthetic plastic resin, specifically phenolic formaldehyde resin, as its adhesive, rendering it waterproof. Therefore, the type of wood used in manufacturing and the adhesive employed distinguishes marine plywood from other plywoods.
In a nutshell
All in all, marine plywood stands as a cornerstone in modern construction, revered for its exceptional durability and resistance to moisture. From boat building to outdoor furniture, its versatility and robustness make it a preferred choice for various applications. Its high initial cost is offset by its longevity and minimal maintenance requirements, rendering it a cost-effective investment in the long run. As a testament to its quality, marine plywood continues to be a staple in the arsenal of builders, ensuring reliability and longevity in their projects.
FAQs
What is marine plywood?
Marine plywood is a specialised type of plywood designed for water-based applications. It is crafted from high-quality hardwood veneers bonded with waterproof glue, making it highly resistant to moisture and water damage.
Where is marine plywood used?
Marine plywood finds application in boat building, docks, kitchens, bathrooms, and exterior furniture due to its exceptional strength and durability.
How is marine plywood different from other plywoods?
Marine plywood stands out due to its construction using high-quality wood and a unique adhesive, typically phenolic formaldehyde resin. It features a higher number of plies, usually double that of other plywood variants, ensuring superior strength and resistance to delamination, even during water exposure.
What are the different types of marine plywood available?
Marine plywood comes in various grades, each with specific characteristics and applications. The top grades include A-A grade, A-B grade, and B-B grade, offering various levels of appearance and performance suitable for different projects.
What are the benefits of marine plywood?
Marine plywood offers exceptional water resistance, enhanced strength and durability, fungal resistance and prevents delamination. Despite its higher initial cost compared to regular plywood, marine plywood proves cost-effective in the long run due to its longevity and minimal maintenance requirements.
How much does marine plywood cost in India?
The cost varies based on factors, such as brand, thickness, and quantity. In India, the average prices range from Rs 33.05 per square foot for 4 mm thickness to Rs 147.15 per square foot for 25 mm thickness.
| Got any questions or point of view on our article? We would love to hear from you. Write to our Editor-in-Chief Jhumur Ghosh at jhumur.ghosh1@housing.com |