25mm Marine Plywood BS1088 2440mm x 1220mm (8' x 4')

Colour and finish are representative only and may vary slightly as this is a natural product. Marine Plywood is made from solid veneer wood, meaning the finished surface gives a wooden appearance. Therefore, images may vary slightly from delivered products due to the natural variation in colour and grain. 

What is 25mm Marine Grade Plywood?

25mm marine ply is a premium structural hardwood plywood panel, specifically manufactured and certified to meet the rigorous BS 1088 standard for use in marine craft construction and demanding exterior or high-moisture environments. 

Constructed exclusively from durable hardwood veneers bonded with a fully waterproof (BS EN 314-2 Class 3) adhesive, and featuring a high-quality core with minimal or no voids, it provides exceptional strength, stability, impact resistance, and long-term durability against decay and delamination when sealed and maintained. 

It is the superior choice for applications demanding the highest level of performance in wet conditions.

Applications

Marine plywood 25mm delivers excellent results in a wide range of interior applications and exterior applications. Fit for structural use, it can be relied upon in flooring, roofing, wall and external joinery. 

• Marine Craft Construction: Boat hulls, bulkheads, decks, stringers, interior cabinetry, transoms, and structural components.   
• Exterior Construction (High Exposure): Signage, external joinery (when fully protected), structural components in exposed locations, vehicle bodywork (trailers, horseboxes), docks and pontoons (framework).
• Demanding Wet/Humid Interior Areas: High-spec bathroom fit-outs (e.g., structural base for tanking systems), swimming pool area linings, changing rooms, laboratories.
• High-Load Structural Applications: Where a combination of exceptional strength, stability, and moisture resistance is required.
• Premium General Joinery: When a highly durable, stable hardwood panel with a quality face is desired for demanding projects.

Benefits

• Maximum Water & Weather Resistance: Combines a fully waterproof glue line with durable hardwood veneers for reliable long-term performance even with prolonged exposure to moisture, humidity, and demanding weather conditions (when adequately sealed).   
• Superior Strength & Rigidity: The 25mm thickness combined with multi-layer, cross-laminated hardwood construction provides outstanding strength, stiffness, impact resistance, and load-bearing capacity.   
• Void-Free Core for Integrity: The solid core construction mandated by BS 1088 prevents internal water pockets, ensuring panel integrity and reducing the risk of hidden decay or delamination.
• Enhanced Durability & Rot Resistance: Utilises naturally durable hardwood species offering better inherent resistance to fungal decay compared to softwood plywoods.   
• High-Quality Surface Finish: High quality face veneers provide a smooth, solid base suitable for high-quality paint, varnish, or epoxy finishes.   
• Reliable Structural Performance: Manufactured under strict quality controls to meet the demands of structural applications in wet or external environments.

What Defines BS 1088 25mm Marine Grade Plywood?

BS 1088 is the British Standard specification that defines the stringent requirements for plywood intended for marine craft construction and other applications requiring high performance in wet or exterior conditions. Unlike standard exterior grade plywood, genuine BS 1088 Marine Plywood guarantees:   

• Durable Hardwood Veneers: Manufactured only from timber species classified as durable or moderately durable regarding resistance to fungal decay (common species groups include Meranti, Okoumé, or similar tropical hardwoods). Softwoods are not permitted.   
• Waterproof Glue Bond (EN 314-2 Class 3): Bonded using an adhesive (typically a phenolic resin) that meets the highest requirements for water resistance, capable of withstanding continuous weather exposure and even boiling water without delamination.   
• High-Quality Veneer Grading: Both face and back veneers must meet minimum quality standards (often Grade B or better), limiting knots, splits, and repairs to ensure a sound surface.
• Void-Free Core Construction: BS 1088 mandates a solid core with minimal or zero core gaps (voids) between veneers. This is critical to prevent internal water trapping, which can lead to blistering, delamination, and internal decay over time - a key differentiator from standard structural plywoods.   
• Thickness Tolerances: Manufactured to precise thickness tolerances.

BS 1088 certification provides assurance of these qualities, making it superior to standard "WBP" (an outdated term) or general exterior plywood (e.g., EN 636-2 or EN 636-3) for demanding wet or external applications.   

Finishing, Sealing & Working Advice

• Waterproof Glue vs Wood: Remember, BS 1088 guarantees a waterproof glue bond and durable veneers. However, the wood veneers themselves still require protection from moisture to prevent cosmetic changes or surface degradation over long periods.   
• Mandatory Sealing for Exposure: For any application involving exterior exposure or significant wetting, it is absolutely essential to thoroughly seal ALL faces, edges, and any cut-outs or drill holes. Use a high-quality marine-grade varnish, paint system, or epoxy sealant according to manufacturer instructions. Pay particular attention to edge sealing, applying multiple coats.
• Preparation: The high-quality face veneers usually require only light sanding before finishing. Ensure surfaces are clean and dry.
• Cutting: Use sharp blades suitable for hardwood plywood (e.g., fine-toothed circular saw or jigsaw blades) for the cleanest cut. The 25mm thickness requires appropriate tools and provides significant rigidity.
• Fixings: Use corrosion-resistant fixings (stainless steel is recommended for marine/exterior use). Pre-drilling pilot holes, especially near edges, is advised for screws due to the density of the hardwood.