Exterior Plywood Deck Flooring

Exterior Plywood Deck Flooring: Essential Considerations

When designing and constructing an outdoor deck, selecting the right flooring material is crucial. Exterior plywood offers an array of benefits, making it a popular choice for this purpose. Understanding the essential aspects of exterior plywood deck flooring is vital to ensure durability, functionality, and aesthetics.

Choosing the Right Plywood Grade

Exterior plywood is available in different grades, denoted by two numbers separated by a forward slash. The first number represents the face veneer quality, while the second number indicates the back veneer quality. For deck flooring, it's recommended to use a grade such as ACX or ABX. ACX-grade plywood has a smooth face veneer on one side and a more rugged back veneer, while ABX-grade plywood has smooth face veneers on both sides.

Thickness and Plywood Layers

The thickness of the plywood is a critical factor in determining the deck's strength and stability. For residential decks, a thickness of 3/4 inch is generally adequate. However, for larger or heavily used decks, 1 inch or thicker plywood may be necessary. Typically, exterior plywood for decking is composed of 5 or 7 layers, with each layer of veneer perpendicular to the adjacent layers.

Moisture Resistance and Treatment

Exterior plywood is designed to withstand exposure to moisture and weathering. It's treated with a preservative such as chromated copper arsenate (CCA) or alkaline copper quaternary (ACQ) to protect it from rot, decay, and insect damage. Proper treatment ensures the longevity and durability of the deck flooring.

Finishing and Protection

After installation, it's essential to finish the deck flooring to protect it from the elements and enhance its appearance. A penetrating oil-based finish or a clear water-repellent sealant is recommended. Regularly reapplying the finish helps maintain the wood's integrity and prolongs its life span.

Installation Considerations

Proper installation is crucial for the performance and lifespan of the deck flooring. Plywood sheets should be laid perpendicular to the deck joists and secured with galvanized nails or screws. The spacing between the nails or screws should be consistent to ensure proper hold. It's also necessary to leave expansion gaps between the sheets to allow for seasonal movement.

By considering these essential aspects, you can choose and install exterior plywood deck flooring that meets your needs and provides years of enjoyment and functionality.