
As we began to discuss in Part 1, there are many situations in which so-called marine grade plywood may be used. The term in itself describes a fairly wide range of exterior grade plywood that may or may not be able to stand up to the full power of wind and waves. We desire to equip our customers with knowledge that empowers them to purchase the materials their applications require without overbuilding or overpaying unnecessarily.
Exterior Seaside Applications
Exterior plywood used for seaside structures — whether they be used for commercial or residential purposes — certainly needs to be able to hold up to a bit of abuse. At the same time, though, such applications don’t require the same kind of water resistance as boats; neither do they need to project the same pristine appearance, since they’ll typically be used as substrates for exterior solid wood or composite materials. In order to keep costs down (while still providing the kind of weather resistance required), some voids can be allowed in any situation in which the plywood will not be completely submerged in water.

Savvy Plywood Shopping
Because of the wide range of quality under the umbrella of exterior and marine grade plywood, the savvy lumber customer will ask a few of their own questions when shopping for such products. Instead of simply asking for “marine grade plywood,” be prepared to tell your supplier exactly what you need the material to be able to do.
If you are actually building a boat, of course you’ll want to mention that. But if you’re doing just about anything else, you really don’t need the same level of water-resistance, so you certainly don’t want to pay for it. At the same time, you don’t want your plywood to crumble at the first sign of rain.
Boat Building Basics

For applications that need to be able to stand up to full submersion, our Bruynzeel plywood offers 100% weather resistance and BS 1088 certification. As the exclusive North American distributor of Bruynzeel, J. Gibson McIlvain imports this premium product directly from Le Vanneau, France, allowing us to pass along savings to our many boat building customers.
However, it’s still a premium product, and it comes with a price tag to match. If you need this level of marine grade plywood, then it’s completely worth the price. But if you don’t? You really don’t want to buy this stuff. It goes well beyond the requirements of the BS 1088 grade. Using a species sometimes referred to as “Okoume Gaboon,” Bruynzeel uses it in steamed veneers throughout the panel, allowing no defects or joints, whatsoever, creating an added barrier to moisture.
The patented process referred to as Hechthout creates an extremely stable, flat, rigid, and lightweight panel that’s perfectly suited to boat building. Both attractive and usable as either a substrate or a stand-alone product, the tight grain allows for a finish much like glass, with no fear of delamination, rotting, or warping. Bruynzeel offers a 20-year guarantee on all products, further proving this company’s commitment to excellence.