There are many misconceptions about plywood compared to lumber. Lumber is a piece of wood cutdirectly from a tree and is cut lengthwise or parallel to the trunk of the tree. This is called the grain and the grain is typically in one direction oran arc pattern that is spreading out as a tree is circular in shape.
Plywood is constructed of thin layers, or plies of wood veneer. Veneer is very thin strips of wood cut asa log is rotated past a razor-sharp blade. The plies are then laid down on multiple axis's where the grain runs parallel to the plywood or at a 45-degreeor 90-degree angle. Plywood is made up of 5, 7 or 13 plies and held together with glue between each layer. Because the grain runs in multiple directions,plywood is typically stronger than wood and has an increased resistance to bending.
Marine grade plywood hasmany characteristics that create a more resilient plywood; including strength,resistance to rot, and the ability to hold glue and fasteners well. All of the voids (from the knots of tree branches) are filled to prevent water intrusion,so it’s incredibly durable for outdoor furniture. Plywood was invented and has been widely used since the mid 1800’s. Waterproof glue for plywood was created in 1934 and marine grade plywood became a standard for construction of boat exteriors and interiors. All wood outdoor furniture should have a new coat of wood protectant applied at least every 3-5 years.
Here at HeritageFurniture, we use ¾” marine grade plywood because of its strength and resistance to rotting and moisture. It may be more expensive than normal plywood, but due to our CNC router machine, the curved pieces are cut quicker, with higher tolerances and this saves us time, which saves you money. We will be able to build furniture with pine, cedar or other woods in the future, as the company grows.