Interior Vs Exterior Plywood: Understanding The Difference Between Them
Flexibility and versatility are major factors that make plywood a popular material on construction sites. However, plywood is suitable for a wide variety of applications only when you know which type to use when and where.
Different types of plywood are designed for different types of environments, and one of the biggest mistakes you can make is using interior plywood for a project that is better suited for exterior plywood. The result, not to be dramatic, can be catastrophic.
That is why you need expert guidance. Fonthill Lumber Inc., one of the most reliable suppliers of premium plywood in Ontario, can help you understand the differences between the two so you can use the right material for your project.
This simple, contractor-friendly guide will help you learn where each type of plywood performs best.
What Is Interior Plywood Used For? Understanding Its Purpose
Interior plywood, as the name suggests, is best used indoors. Meant for dry, climate-controlled spaces, interior plywood retains its durability only in environments with minimal moisture exposure.
The most common applications of interior plywood include:
- Subfloors – but in dry climates only
- Interior walls
- Cabinets and construction of other furniture
- Shelves and built-in units
- Millwork
Most contractors harbor a soft for interior plywood, and the common reasons for that include:
- Price-to-value ratio
- Smooth, consistent surface
- Pliability, as plywood is easy to cut, fasten, and finish
- Availability of the material in multiple thicknesses and dimensions
If moisture is out of the question, you can expect interior plywood to perform well for a long time to come. Inherently durable, it can enhance the aesthetics of your project. However, we must emphasize limiting moisture exposure, as prolonged contact with water can cause this material to either swell, delaminate, or lose its structural integrity.
What Is Exterior Plywood Used For? Exploring Its Merits
Exterior plywood, unlike its interior counterpart, is actually capable of handling moisture exposure and varying climatic conditions. It is manufactured with the help of water-resistant adhesives that allow it to maintain its stability when exposed to rain, humidity, or changes in temperature.
Exterior plywood’s resistance to moisture makes it suitable for applications such as:
- Roof sheathing
- Wall sheathing
- Sheds and outbuildings
- Exterior subfloors
- Covered outdoor structures
Exterior plywood is the right for your project if it requires lumber material that:
- Resists the effects of moisture, especially delamination
- Maintains its structural integrity even in varying weather conditions
- Holds fasteners in a reliable manner
- Is approved for exterior applications
Please bear in mind that exterior plywood is not waterproof. However, it is designed to tolerate moisture exposure in a much more effective manner than interior plywood.
Why Using The Right Plywood Is Critical
When working in a province like Ontario, you cannot risk using the wrong plywood. Its fluctuating temperatures, humidity, and seasonal moisture make it critical to choose the right material. Especially if your project demands the building of structures such as basements, garages, entryways, and roof systems.
While using exterior-grade plywood is acceptable indoors, the converse can lead to several issues, including:
- Swelling and buckling
- Fastener failure
- Premature plywood replacement
- Inspection issues
- Costly callbacks
However, we must warn you that using exterior plywood indoors can increase your project’s budget by quite a bit. So be mindful of your final choice and ensure it fits within your project’s constraints.
Conclusion
Using the right plywood is the fastest way to ensure your project delivers the kind of results expected from it. When you know the difference between interior and exterior plywood grades, you are better informed to make the right choice. However, when it comes to lumber, choosing your supplier is just as important as picking the perfect material.
Fonthill Lumber Inc. supplies professional-grade exterior and interior plywood in custom configurations to builders and contractors across Ontario. Contact us to get high-quality materials of a consistent finish and thickness.
FAQs
Can interior plywood be used outdoors for temporary builds?
No. Because even short-term exposure to moisture can cause the structure to swell and delaminate.
Is exterior plywood more expensive than interior plywood?
Yes, it is slightly more expensive due to its added durability and water-resistant properties.
Should garages use exterior plywood only?
Yes. Even if the plywood is being used in the indoor part of a garage, it still should be exterior plywood so it can handle the humidity and temperature swings garages are subject to.
