CDX Plywood

CDX plywood is a type of exterior-grade plywood with a sheathing grade, commonly used in construction and woodworking. A more economical choice this plywood allows for knots and other imperfections on both faces.  The “C” and “D” refer to the grades of the veneer faces, with “C” being a higher grade with fewer defects and “D” being a lower grade with more imperfections. The “X” indicates that the plywood is treated with a weather-resistant, waterproof resin adhesive, making it suitable for outdoor use.

Available in 1/2″, 5/8″ and 3/4″ thicknesses.

This plywood is sold in full 4×8 sheets only.

CDX Plywood
CDX Plywood - Image 2
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Additional Information

Available in stock:

  • 1/2” (15/32) thickness
  • 5/8” (19/32) thickness
  • 3/4” (23/32) thickness

 

Face Grades:

  • C Face: The front face is a C grade. The C grade balances structural integrity with a relatively decent appearance, making it suitable for applications where the surface may be exposed but still visible. This grade allows smaller and sound knots. It also allows for patches to help smooth out the face. This grade also allows minor splits, slight discolorations and small defects.
  • D Face: the back face is a D grade. This grade is used where appearance is not critical, and the primary concern is structural durability for rough or outdoor applications. Typically contains larger knots and can be loose. Patches are common and often visible, used to cover defects or splits. The patches can be irregular and less refined. There can also be other imperfections including splits, cracks, chips, discolorations and other surface defects.

Together, these grades make CDX plywood a durable and cost-effective material, especially for outdoor or rough construction projects.

 

To finish CDX plywood for exterior weather resistance, follow these steps:

  1. Surface Preparation:
    • Sand the plywood surface smoothly to remove splinters and rough edges.
    • Clean off dust and debris to ensure good adhesion of the finish.
  2. Priming:
    • Apply a high-quality exterior primer or sealant designed for plywood or wood surfaces.
    • Ensure full coverage to prevent moisture penetration.
  3. Sealing Joints and Edges:
    • Use exterior-grade wood filler or caulk to seal gaps, joints, and edges.
    • Apply a generous coat of sealant to all cut or exposed edges, as these are most vulnerable to moisture.
  4. Applying an Exterior Finish:
    • Use a durable exterior paint, stain, or waterproof sealant.
    • Oil-based paints or elastomeric coatings provide good weather resistance.
    • Consider multiple coats for added durability, allowing proper drying time between coats.
  5. Regular Maintenance:
    • Periodically inspect for damage or wear.
    • Reapply protective coatings as needed to maintain weatherproofing.
  6. Optional Additional Protection:
    • Use a primer specifically formulated for concrete or masonry if installing on such surfaces.

 

For a more durable and long-lasting exterior finish on CDX plywood, consider these additional treatment options and materials:

  1. Coat with a wood preservative:
    • Treating the ACX plywood with a wood preservative on the unfinished plywood prior to coating with a primer or another coating will enhance resistance to moisture, fungi, and pests, increasing longevity. We recommend using Q8 log oil or a Woodlife product.
  2. Polyurethane or Polyurethane Sealers:
    • High-quality exterior-grade polyurethane offers excellent water resistance and UV protection.
    • Provides a tough, durable finish that withstands weathering.
  3. Marine-Grade Finishes:
    • Marine-grade epoxy coatings or varnishes are specifically formulated for harsh water exposure.
    • These finishes provide superior waterproofing, UV resistance, and durability.
  4. Elastomeric Coatings:
    • Elastomeric coatings are flexible waterproof sealants that can bridge small cracks and movement in the wood.
    • Suitable for areas prone to expansion and contraction.
  5. Combination Approach:
    • For maximum protection, combine epoxy sealing on edges and joints along with using exterior paint or stain.
    • Adding primer suitable for exterior surfaces enhances overall longevity.
  6. Additional Considerations:
    • Ensuring proper ventilation and installation with overhangs reduces direct weather exposure.
    • Applying a waterproof membrane beneath the plywood or on top of the finish can further extend lifespan.