What type of plywood is best for outdoor use?
There are many different types of outdoor plywood on the market, each designed to suit specific outdoor conditions. Understanding which one is right for your project will not only help you get the look you want but also ensure that it lasts as long as possible in all weather conditions.
Browsing through an outdoor building supplies store will reveal a huge number of outdoor plywood options – marine grade, exterior grade, rotary cut, finger jointed and more – with prices to match. These terms can be confusing when trying to choose the right plywood for your job. Some basics about construction lumber might help.
Plywood is actually made using three or more thin sheets of wood, known as plies or veneers, which are bonded together with an adhesive. The process of bonding the plies is called laminating .
Wood is a natural product and outdoor conditions can be harsh on any outdoor building material. When it comes to outdoor plywood, these elements can cause problems – cracking, warping and delamination for example – but they affect different types of outdoor plywood in varying degrees. Knowing about these issues will help you choose the right outdoor plywood for your project whether you’re planning some outdoor furniture or new decking.
Exterior-grade plywood doesn’t use the best quality wood that’s available so may contain more knots than other grades. This type of outdoor plywood also contains more resin than other outdoor grades and is less likely to delaminate. This makes it a good choice for outdoor projects, such as outdoor furniture or sheds that aren’t exposed to high winds.
Marine-grade plywood is made up of the best quality wood available and contains fewer knots. It also has more resin than exterior grade plywood which helps to prevent warping and delamination when it’s exposed to moisture. If you’re planning on making outdoor furniture or building a deck, marine-grade plywood will be your best choice because it can withstand external conditions and won’t degrade over time.
Rotary cut plywood comes in veneers rather than full sheets so uses fewer raw materials during production which results in less environmental impact. The downside to this type of outdoor plywood is that it’s more prone to cracking and warping than other types.
Finger jointed plywood is made from smaller pieces of wood which are then glued together. This type of outdoor plywood is the most expensive but also the most durable. It doesn’t contain any knots and is resistant to cracking, warping and delamination. If you’re looking for a long-lasting outdoor project, finger jointed plywood is the best option.
So, what’s the best outdoor plywood? It depends on your needs and budget. Marine-grade plywood is a good choice if you’re looking for an outdoor material that will withstand harsh weather conditions. Rotary cut plywood isn’t the best outdoor plywood but it does have its uses. Exterior-grade plywood can be used outdoors but you would need to coat it with a sealer before using it. Finger jointed outdoor plywood is not widely available so will probably be too expensive for your outdoor project, unless you’re planning on some sort of outdoor decking or furniture that requires a long-lasting outdoor material.