Determining whether or not you need “marine grade plywood” isn’t always a cut-and-dried decision. You have a lot of factors to consider, including cost, durability, and how much weatherproofing and water resistance is truly necessary for the application you have planned for the product. Additionally, figuring out what the fungible term “marine grade” even means can be tricky.
In our earlier articles in this series (see Parts 1 & 2), we looked at how APA – The Engineered Wood Association standards can give you some guidelines to follow. We also mentioned British Standards, as well as some general factors you can ask individual dealers about to figure out how their products measure up whether they follow either of these formal standards.
In this final article, we’ll take a more practical approach by looking at how the plywood will actually be used and how this crucial factor comes into play when determining whether or not your application requires “marine grade” plywood.
You Should Always Seek Out Quality Marine Grade Plywood for Boat Building
Perhaps you’re looking for marine grade quality plywood because you’re actually planning on building your own boat. If so, seeking out plywood that’s in the highest quality standard for this category makes good sense. There’s practically no other application out there that would subject the plywood to the punishing effects of the elements more than boat building.
Unfortunately, somewhere along the line, someone decided that it would be acceptable to include plywood that isn’t actually conducive to boat building into the “marine grade plywood” label. This broad labeling or, some may even argue, mislabeling can be a cause of great confusion for novice boat builders.
In order to be sure plywood will achieve positive results for your boat building project, you’ll need to pay special attention to the plywood’s ability to bend, its water resistance level, and its overall appearance. It must be a durable surface that can be covered with a fiberglass overlay or decking veneer. As such, it should present a consistent face or show a quality face that will make your boat a source of genuine pride. Another important consideration is weight. When determining water resistance, seeking out at least BS1088 plywood would be your best bet for reliable performance in the long run.
Sometimes You Will Want Marine Grade Plywood for Other Exterior Applications
Exterior applications will vary in the amount of exposure to harsh elements they’ll face. Though they won’t necessarily need quite the amount of water resistance as a boat building application would require, they still need to be far more durable than most interior applications. You also won’t need to worry quite so much about appearance for many exterior applications when compared to the appearance factor for plywood used to build a boat. That’s because in many instances the plywood will serve as a substrate beneath a layer of softwood, composite, or hardwood.
If your commercial building or home is being constructed near the sea or in another area with large amounts of precipitation, it would probably be best to use only marine grade plywood. The quality of marine grade plywood you use for these other exterior applications need not be quite as high as the quality you’d use for boat building. For example, you could choose plywood that allows some voids, whereas you wouldn’t want any voids present in plywood you’d use for building a boat. Loosening up a bit on the standards used in other exterior applications that won’t be submerged in water should lessen the total cost of your project.
Choosing “marine grade plywood” for a project is a complex decision. Be ready to investigate what criteria your lumber dealer uses to determine which plywood will bear the “marine grade” level. Ask questions about the various factors we touched on in this article series. The more you know, the better you’ll be able to make a plywood selection that’s ideal for your specific project.