RTD vs CDX Plywood – Key Differences, Uses & Best Option

When it comes to construction or home improvement projects, choosing the right plywood can make a significant difference in durability, cost, and long-term performance. Two common types often compared are RTD plywood and CDX plywood. Although they may seem similar at first glance, they serve different purposes and come with distinct manufacturing processes and performance characteristics.

In this guide, we’ll break down RTD vs CDX plywood to help you understand the key differences, pros and cons, and which option is better for your project.

What is RTD Plywood?

RTD stands for Resistance Temperature Detector, a term that refers to the manufacturing process rather than the plywood itself. RTD plywood is made using high-heat and pressure-controlled bonding systems that ensure consistent adhesion between the plies.

Key Characteristics of RTD Plywood:

• Heat-Sensitive Adhesives: RTD sensors are used during production to monitor and control the temperature, ensuring proper glue bonding.

• Moisture Resistance: Offers good resistance to moisture and humidity, making it ideal for outdoor sheathing and roofing underlayment.

• Structural Strength: Designed for strength and dimensional stability under various weather conditions.

• Quality Control: RTD plywood generally meets more stringent quality standards compared to CDX.

What is CDX Plywood?

CDX refers to the grade of the plywood:

• C = face side with noticeable defects but still structurally sound.

• D = back side with more visible imperfections.

• X = exposure rating, suitable for temporary exposure to moisture.

CDX is a type of construction-grade plywood used mainly for structural purposes like subfloors, wall sheathing, and roof decking.

Key Characteristics of CDX Plywood:

• Affordable and Widely Available: Often chosen for budget-conscious construction projects.

• Not Fully Waterproof: Can withstand short-term exposure to moisture but is not meant for continuous wet conditions.

• Less Refined Surface: Rougher texture with more voids and patches.

• General-Purpose Use: Common in framing, sheds, and temporary structures.

RTD vs CDX Plywood: Side-by-Side Comparison

Which is Better: RTD or CDX?

The better choice depends entirely on your project needs:

• Choose RTD if:

  • You need higher moisture resistance.

  • Your project is long-term and exposed to the elements.

  • You prioritize strength and structural integrity.

  • You want better adhesive bonding and fewer warping issues.

• Choose CDX if:

  • You’re working on a tight budget.

  • You need plywood for interior or temporary outdoor use.

  • The plywood will be covered or not exposed directly to weather.

Common Applications

RTD Plywood Uses:

• Roof sheathing

• Exterior wall sheathing

• High-humidity environments

• Long-term construction projects

CDX Plywood Uses:

• Subflooring

• Temporary enclosures

• Wall bracing

• Roof decking under roofing felt

Conclusion

Understanding the difference between RTD and CDX plywood is crucial when selecting the right material for your construction needs. While CDX remains a popular choice for standard subfloors and temporary structures due to its affordability, RTD plywood offers better durability, glue bonding, and moisture resistance—making it the preferred option for long-term and exterior applications.

At AtoZ Wood Company, we offer premium-quality RTD and CDX plywood tailored for a wide range of projects—whether you’re building homes, commercial spaces, or outdoor structures. With a strong commitment to quality, sustainability, and global supply, AtoZ ensures that you get the right plywood at the best price, delivered on time.