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What Plywood Is Used for Roofing Guide & Tips

What Plywood Is Used for Roofing: Roofing is crucial for protecting structures from the elements, and choosing the right materials is essential for durability. Plywood is a popular choice in roofing due to its versatility. This article explores CDX and OSB plywood, commonly used for roofing. CDX plywood is designed for exterior applications, offering strength and durability.

It has a smooth surface for easy installation of roofing materials. On the other hand, OSB plywood is affordable, moisture-resistant, and can withstand extreme weather. Consider factors such as climate, roof slope, and budget when choosing between the two. Understanding the qualities of plywood for roofing ensures a sturdy and reliable roof structure that withstands the test of time.

What Plywood Is Used for Roofing – Plywood Types

1.1. Exterior Grade Plywood

Exterior grade plywood is commonly used plywood type for roofing. It is basically created to resist the weather and offer the best defense against moisture, humidity, and temperature.

Using strong veneers and waterproof adhesives during manufacturing, exterior-grade plywood is incredibly resistant to water damage. This kind of plywood, frequently referred to as “Exposure 1” or “Exterior,” may be used for domestic and commercial roofing projects.roof plywood

1.2. CDX Plywood

CDX plywood is another popular choice for roofing projects.

This type of plywood is graded using the “CDX” method, where “C” stands for the front face quality and “D” for the interior face quality.

The “X” indicates that the plywood is suitable for exterior applications. CDX plywood features a rough appearance due to its textured surface, which enhances grip and provides added protection against slipping during installation. It is an affordable option that offers decent strength and weather resistance.

1.3. OSB Sheathing

While not technically plywood, OSB (Oriented Strand Board) sheathing is worth mentioning as it is commonly used in roofing applications. OSB is made by compressing layers of wood strands with waterproof adhesives.

It exhibits excellent strength and dimensional stability, making it suitable for roof decking. OSB sheathing is cost-effective, easy to install, and provides a solid substrate for other roofing materials.

2. What Plywood Is Used for Roofing – Plywood Qualities

What Plywood Is Used for Roofing

2.1. Strength and Structural Integrity

Plywood used for roofing must possess sufficient strength and structural integrity to support the weight of the roof, withstand wind loads, and resist sagging or warping over time. It should be able to distribute the load evenly and provide a stable base for roofing materials. Exterior grade plywood and CDX plywood are known for their robustness and ability to handle heavy loads.

2.2. Moisture Resistance

Roofs are constantly exposed to moisture, whether from rain, snow, or condensation. Plywood used for roofing should have excellent moisture resistance to prevent swelling, delamination, and rotting. Exterior grade plywood, with its waterproof adhesives and tightly bonded veneers, offers superior moisture resistance compared to other types of plywood.

2.3. Compatibility with Roofing Materials

Plywood acts as a substrate for various roofing materials, such as shingles, tiles, or metal panels. It is essential to ensure that the chosen plywood is compatible with the specific roofing material you intend to use.

Some plywood types may require additional treatments or coatings to enhance compatibility and protect against chemical reactions or degradation.

2.4. Fire Resistance

Fire safety is a crucial consideration for roofing materials. While plywood itself is not inherently fire-resistant, certain types of plywood, such as fire-rated plywood, are available.

Fire-rated plywood contains additives that provide increased fire resistance, making it suitable for fire-prone areas or where local building codes require enhanced fire safety measures.

3. What Plywood Is Used for Roofing – Tips 

3.1. Proper Installation Techniques

Proper plywood installation is vital for roofing performance and durability. Follow manufacturer recommendations and procedures for success.

Ensure ventilation by attaching plywood securely to rafters or trusses, promoting airflow and preventing moisture buildup. This minimizes damage from rot, mold, or deterioration.

Select corrosion-resistant fasteners designed for roofing to ensure stability. They resist rust and degradation, providing lasting performance and reducing the risk of loose materials.

Adhering to these techniques enhances roof longevity and effectiveness. A well-installed plywood roof with ventilation and secure fastening protects the structure and integrity of the building.

3.2. Regular Maintenance and Inspection

To extend the lifespan of your roof, regular maintenance and inspection are essential. Check for signs of damage, such as loose or deteriorated plywood, and promptly address any issues.

Clear debris, leaves, and moss from the roof surface to prevent water pooling and potential water damage.

Regularly inspect the roof for leaks, damaged shingles, or other indications of roofing problems.

3.3. Climate Considerations

The environment and location are important factors when choosing an appropriate plywood type for your project.

According to Weather, the environmental conditions are different by region such as severe temperatures, unnecessary humidity, or significant rainfall.

Before starting a project or woodworking, Consult with local specialists or contractors who are experienced with the climate in your area to determine the best plywood for your unique environment.

What Plywood Is Used for Roofing – Choosing the Right Plywood

When deciding between CDX and OSB plywood, it’s important to consider your specific project requirements and preferences. Here are a few factors to keep in mind:


Consider the intended use of the plywood. CDX plywood is often preferred for roofing and outdoor applications, while OSB plywood is commonly used for sheathing, subflooring, and other general construction purposes.


Evaluate your budget and cost constraints. CDX plywood is generally more cost-effective, but OSB plywood may offer even greater affordability, especially for larger projects.

Local Regulations

Check with your local authorities and building codes to ensure compliance. Some areas have restrictions on the use of OSB plywood for specific applications, such as roofing.

Moisture Exposure

Assess the level of moisture exposure in your project. If your project involves areas prone to high humidity or frequent water contact, consider using CDX plywood or taking appropriate measures to enhance the moisture resistance of OSB plywood.

Both CDX and OSB plywood have their own advantages and are suitable for different applications. CDX plywood is known for its strength, durability, and moisture resistance, making it a reliable choice for roofing and outdoor projects.

On the other hand, OSB plywood offers strength, stability, and cost-effectiveness, making it a versatile option for general construction purposes.

By considering your specific needs, project requirements, and local regulations, you can make an informed decision and choose the plywood that best meets your needs.


Selecting the right plywood for roofing is crucial for ensuring a durable and reliable roof structure. The types of plywood discussed, such as exterior grade plywood, CDX plywood, and OSB sheathing, offer varying degrees of strength, moisture resistance, and compatibility with different roofing materials.

By considering the qualities of plywood for roofing and following proper installation techniques, regular maintenance, and climate considerations, you can create a robust roof that withstands the test of time.

See This Also: How Plywood Is Manufactured – A Comprehensive Guide

Frequently Asked Questions (FAQs)

Q1: Can I use regular plywood for roofing instead of exterior grade plywood?

A1: While regular plywood may be less expensive, it lacks the necessary waterproofing and durability required for roofing applications. It is recommended to use exterior grade plywood specifically designed for withstanding the elements and providing superior moisture resistance.

Q2: How often should I inspect my roof for maintenance?

A2: Regular roof inspections should be conducted at least twice a year, preferably in spring and fall. Additionally, it is advisable to inspect the roof after severe weather events or storms to promptly address any potential damage.

Q3: Are there any special considerations for flat roofs when using plywood?

A3: Flat roofs require additional precautions due to the absence of natural drainage. When using plywood for flat roofs, ensure proper slope and adequate waterproofing measures to prevent water pooling and potential leaks.