Pine Plywood

Pine is the most common type of wood used to manufacture plywood products of all types. Construction-grade softwood plywood is almost all made of pine. Of all the woodlands in the United States, there is more land covered by pine trees than any other type of tree. This is mainly because pine is an inexpensive wood due to its commonality and high growth rate.

The way pine grows makes for a high percentage of using wood from the tree. Trunks of pine trees are almost always straight, without splitting into branches. Instead, branches grow out from the trunk at a right angle. This causes those branches to sag with time, giving the pine tree its distinctive triangular shape. It also means that the trunk runs pretty much the tree’s entire height, although it gets narrower as it gets higher.

The number and type of branches a pine tree has means the wood has many knotholes. Pine wood without knotholes is more expensive, mostly due to its rarity. This is used for finish work, either turned into dimensional lumber or architectural moldings. Pine with many knotholes usually is used only for structural work, where other materials will cover it. But some people like the knotholes because they give a more rustic look to furniture and home construction.

This long, straight trunk is ideal for manufacturing low-cost plywood, which starts by putting logs on a huge lathe so that large sheets of veneer can be peeled off the log. Quarter-sawn wood veneer, used in hardwood plywood manufacture, doesn’t yield as much per log. Added to the fact that hardwood trees don’t have the long straight trunk of pine means that much less plywood veneer can be cut from a hardwood log for the manufacture of plywood.

The resulting plywood is lightweight in comparison to plywood made from other woods. That makes it easier to work with. Finished projects are also easy to move around. Pine itself is less expensive than other varieties of wood, such as the many types of hardwoods. Therefore, pine plywood is also less costly, often considerably less expensive.

Nevertheless, the lightweight and soft texture of pine does have disadvantages. While fairly stiff and sturdy, it does tend to wear down over time. Pine will scratch more accessible than some dense hardwoods, especially when compared to oak, maple, or walnut. This means that when used in projects with rough use, pine will show wear faster and may wear out sooner.

Pine grain is smooth, with small pores that don’t absorb much. The color can vary considerably, ranging from a yellowish brown to a deep reddish brown, even though pine is often known as a “white wood” and is often called by that name. It accepts paints well, which bond very well to the wood. However, it does not do as well with staining, as the wood does not absorb stain evenly, especially when comparing heartwood to sapwood. So stained finishes applied to pine may not come out evenly.

Types of Pine

While we think of pine as one single type of wood, generally sold that way, pine plywood does not come from any specific type of tree. Rather from a family of trees that all share the common name of “pine.” There are 126 species of pine within this family, although they don’t all exist in the same place, and not all are used for manufacturing pine plywood. A few types of pine plywood are commonly enough known to have their names:

• Knotty Pine has many visible knots that give off a rustic look. However, the knots are small and tight, so they don’t weaken the wood.
• Heart Pine – has fewer knots, so it is not as great for a rustic look. However, it is dense, strong, soft, and easy to work with. Heart pine comes from the heartwood, the oldest wood in the tree, and is cut from the oldest pines harvested. 
• Douglas Fir – This type of wood is tightly packed (knots and grains). Unlike other types of pine, it paints well and stains well, giving an even appearance.

Uses for Pine Plywood

Softwood plywood is most commonly used for construction but is also used for industrial purposes. In construction, it is most often used for wall and roof sheathing on homes and sub-flooring, although OSB is also allowable by building code for these applications and is often used in place of softwood plywood due to its lower costs.

This is not to say that pine plywood can only be used for construction. Higher grades of pine plywood are used to manufacture various projects, especially by do-it-yourselfers and woodworking hobbyists. AC grade pine plywood provides the hobbyist with a plywood product that has a good surface finish and is not expensive. People make a considerable amount of furniture out of pine plywood, especially when they want an antique or rustic look. Bookcases, wardrobes, bed frames, chairs, and tables are all made out of this plywood product.

Pine plywood, specifically marine-grade pine plywood, is used to make boats. This is an excellent choice because of its lightweight and high strength-to-weight ratio. Marine-grade pine plywood is manufactured without any voids, as those can cause more rapid delaminating when exposed to a high-moisture environment.

Lower grades of pine plywood, such as BC grade plywood, are often used for making rough-use furniture, such as shelving and workbenches for the workshop. This provides high strength at a lower cost. Since the finish isn’t so important in these applications, using the BC-grade plywood rather than the more expensive AB or AC grade makes sense.

Cautions with Pine Plywood

Like any other plywood product, pine plywood is susceptible to water damage, especially when water is soaked up through the end grain. This can be limited by sealing the edges of cut pieces, an excellent idea if the project is regularly exposed to water. If your project doesn’t cover or seal the edges, you can fill the plywood edges with the painter’s caulking. Run a bead down the edges of the board. This can easily be painted over. Then wipe it into the grain with your finger, adding more caulking when needed.

Remember that furniture and other projects made with pine are not as durable as those made with more complicated, denser wood. While convenient, easy to work with, and lower cost. Projects may not last as long, especially if exposed to a lot of wear.

You can increase the durability of these projects by edging the pine plywood with hardwood pieces. While those will still wear, they won’t wear as heavily as the pine plywood will. It is also essential to periodically refinish plywood that receives a lot of wear, as the finish protects the wood, especially against moisture. Should the finish wear off and not be replaced, the underlying wood will likely become water damaged.