Understanding the construction industry is tricky if you have never dabbled in a building before. Many people find themselves overwhelmed at the number of options they have, even in just the plywood aisle.

One of the newer forms of plywood, RTD plywood, or RTD sheathing, is becoming very popular for exterior applications. However, many people find themselves wondering how different it is from CDX plywood and other popular varieties.

If you need to choose the right sheet of plywood but feel overwhelmed, here are a few of the facts that you need to know.

Before you can decide which type of plywood is right for your project, you need to have a basic understanding of what RTD plywood actually is. In general, plywood is rated according to the number of defects or blemishes that you will find on the surface. It is most common to find plywood labeled with three letters. The first two will range from A to D.

Sheets of plywood that are rated with an A have the fewest blemishes and are often used for finished projects like cabinets or furniture. As you move through the alphabet, you will find that each category has slightly more character than the category before it. For example, a sheet of plywood with a D rating will have many open knots and splits that are not corrected with filler.

The first letter indicates the front side of the plywood. The second letter indicates the backside of the plywood. The last letter indicates the type of adhesive that is used to bind the layers of plywood together.

Most people who are working on construction products are looking for the final letter X. This letter indicates that the plywood is designed for “exposure.” It can tolerate moisture for a short period of time, such as during the construction process. However, you may need something else if it is going to be continuously exposed to inclement weather.

Now that you know all of that, what is RTD plywood, and why is it different? Some people believe that RTD plywood is a new and improved version of the popular CDX variety that has been used extensively in past projects.

Unlike other types of plywood, the initials found here do not indicate the grade of the plywood. They actually stand for the phrase “Resistance Temperature Detector”. This detector is a key piece in the development of RTD plywood. It provides a reading of the temperatures during the bonding process of each layer on this sheet of plywood.

Reading the temperatures is extremely important if you want to create high-quality plywood like RTD. Because manufacturers can see the temperatures, the layers are more likely to bond together better. An improved bond eliminates some of the issues with delamination that is found among other types of plywood.

Many people want to know whether they should use RTD or CDX plywood on their upcoming projects. This can be a little difficult to answer, but most experts generally agree that RTD is the way to go.

CDX plywood is still a great piece of plywood if you are looking to build something that does not require a pristine surface. Many people like to use CDX plywood as subflooring in the construction of new homes. However, more and more contractors are turning to RTD because of its inherent benefit.

Because of the testing available on sheets of RTD plywood, it is less likely for the layers to come apart. This prevents long-term issues for contractors who don’t want callbacks from upset homeowners. However, it is important that you make sure you are getting the right kind of RTD plywood if you really want it to be effective.

So Can RTD Plywood Get Wet?

The wood used to manufacture exterior graded plywood, (such as BCX and RTD plywood), comes from stable types of wood.

You see generally, if wood gets wet, it can shift around and warp. That’s because wood will soak up water like a sponge, causing wood fibers to expand and swell. And then as that water evaporates afterwards, the wood dry’s out, shrinks, and warps.

However, some wood types are naturally stable, meaning they do not warp if they get wet. For example, Douglas Fir wood is an very stable. It is durable, and rot-resistant.

So, BCX and RTD plywood are made from stable timber, such as Douglas Fir. Plywood made from this timber can get soaked again and again, and never suffer severe warping or wood rot.

So, when it comes to exterior graded plywood, wood rot and warping aren’t an issue. It’s simply delamination that needs to be prevented. And preventing delamination comes down to the quality of that plywood’s adhesive.

And What Is BCX Plywood Generally Good For?

It’s used for constructing support structures (specially ones that will not have direct exposure to water).

So, BCX plywood is best suited for high humidity interior areas, (such as wall sheathing, sub-flooring, and roof sheathing). It is not suitable for structures that would have direct exposure to water (such as rainwater).

Can RTD Plywood Be Used Outside?

It can. But like with BCX plywood, it tends to be used on structures that do not have direct contact with rainwater.

It is best suited for those high humidity spaces, like sub-flooring and sheathing. However, it can take on very damp conditions better than BCX can.


Is RTD plywood better than BCX plywood?


RTD Plywood is better because of the way it is created in a manner that helps to prevent delamination. This is most commonly caused by the use of too little or too much glue during the manufacturing process.

What is RTD plywood?

RTD refers to the method used to manufacture the plywood. This is, essentially, next generation CDX plywood which is manufactured with a quality control system using RTDs (Resistance Temperature Detectors) to maintain correct temperature during the bonding process.

What is RTD plywood good for?

Exterior panels sometimes referred to as RTD sheathing, are designed to hold up to constant moisture. They are completely waterproof and are great for installing in places where you expect consistent exposure to moisture. This RTD sheathing is great for roofs and other outdoor applications.

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