Plywood is a relatively cheap wood material that is used for a wide range of diy woodworking projects. If you plan on using plywood for a weight baring structure, it is important that you get the right width of plywood. In today’s article, I will discuss whether 1/2 plywood is strong enough for shelves.
Is 1/2 plywood strong enough for shelves?
Yes, ½ inch plywood is strong enough to be used in shelves. On average, ½ inch plywood can hold around 30-35 ponds per square foot.
If you plan on putting 30 plus pounds of weight on the shelves, I suggest that you upgrade to ¾ inch plywood, which can hold up to 50 pounds per square foot. Additionally, it does not warp as easily as ½ inch plywood.
Aside from thickness, there are other factors that affect the weight plywood can hold including the number of plies (layers), type of wood, and number of supports on the shelf. I will breakdown each factor below.
Number of plies
Plywood is made up of thin layers of wood called plies. The plies are glued together, and each layer is rotated 90 degrees when it is added. This creates a cross grain composition which helps the overall plywood board stronger. It also helps prevent bending in the wood, especially when it is exposed to water.
As expected, the number of plies (or layers of wood sheets) that a plywood has directly affects how much weight it can hold. Plywood that is 1 inch thick or less typically either has 3,5, or 7 plies. Just about all ½ inch plywood have 3 plies, but there are a few that have 5. The ones with 5 will support more weight and be less susceptible to bending and warping.
On the other side, it is very common for ¾ and 1 inch plywood to have 5 or 7 plies, which adds extra strength. While 3-ply should only be used indoor, some types of 5 and 7-ply can be used outdoors. If your shelves will be outside, I suggest that you use WBP plywood since it is weather resistant.
Type of wood
The type of wood that your plywood is made of will also affect how much weight you can put on your ½ plywood shelves. There are two types of wood that is used in plywood: Hardwood and Softwood.
Hardwood is much stronger than softwood and can hold more weight. It also lasts longer. Some of the most common types of hardwood include Red and White Oak, Birch, Walnut, and Maple. While these forms of plywood will hold more weight for your shelf, they do tend to cost more money.
Softwood is less durable than hardwood and cannot hold as much weight. Some of the most common types of softwood plywood include Pine, Spruce, Redwood, and Cedar. While not as strong, they are generally cheaper than hardwood plywood.
Ways to strengthen your plywood shelves
Now that you know all of the factors that go into the strength of plywood, I also want to share some easy ways to strengthen your plywood to hold more weight.
Adding a layer of sealer over your plywood will help keep it compact and hold more weight. It will also prevent it from warping over time.
If you want to add more strength to your plywood shelf, you can attach two pieces of plywood together.
You can also add more support joints to your shelf to help take some of the weight off the plywood itself. This also helps prevent the plywood from warping.
It is also important that you firmly attach your shelves at a 90 degree angle. If there is any deviation, it can weaken the wood and cause your objects to fall.
As mentioned above, ½ plywood is strong enough for shelves. That being said, there are other factors that affect the strength of plywood, including the number of plies and the type of wood. It is important that you don’t put more than 30 pounds per square foot on the shelf.
If you plan on putting heavy, expensive items on your shelf, I suggest you upgrade to a ¾ or 1 inch plywood.