What Makes Plywood “Marine Grade?”
Marine plywood is more than just plywood that’s been near water. Two distinct characteristics define how it is built differently: the glue and the veneer. Firstly, marine ply uses a completely waterproof phenolic resin bond between every layer, glueing the veneers together so tightly that moisture can’t get in between them, which causes delamination.
Secondly, the inner veneers are graded to have minimal gaps, unlike cheap ply, where small voids lie hidden between layers – only noticeable when water gets in, and the sheet swells or delaminates from the inside out. Understanding this glue bond type is important to purchasing quality marine ply.
Marine Plywood Thicknesses & Prices
At Online Building, we stock the full range of Marine Plywood Cape Town buyers search for, and we also deliver across the Western and Southern Cape. Our range includes thin sheets for lining and boat interiors and structural thicknesses suited to outdoor builds.
The thinner 4mm Marine Ply (1220×2240) and 6mm Marine Ply (1220×2240) sheets work well for boat lining, light cladding projects, and panel backing. The 8mm Marine Ply (1220×2240) is ideal for cabinetry and boat components, which require a bit more handling. Next up, we recommend the 12mm Marine Ply (1220×2240) for outdoor shelving and furniture, while the 18mm Marine Ply (1220×2240), 22mm Marine Ply (1220×2240), and 25 mm Marine Plywood are for heavier applications, like decking bases.
Marine Plywood vs Shutterply vs Ordinary Plywood
These three building materials often get confused, and using the wrong one in the wrong place can lead to an expensive mistake. Here are some core differences:
Marine Plywood is built to survive long-term moisture exposure thanks to fully waterproof glue and minimal-void veneers. This differs from ordinary structural or utility plywood, which works perfectly for indoor, dry applications but is not built to last in wet conditions. Shutterply has an entirely different job. It forms concrete while it cures and can release cleanly from wet concrete, but it cannot withstand exposure to water afterwards.
The Takeaway
Marine Ply is the right building material selection if your project involves sustained contact with water. That is exactly what it is built for, and we deliver marine plywood Cape Town orders across the Cape. CONTACT US today to place your order and confirm delivery timing.
