Fire-retardant treated CDX plywood is a structural softwood panel that has been pressure-impregnated with fire-retardant chemicals rather than simply surface-coated, so the treatment carries through the thickness of the sheet and is not lost when the panel is cut or drilled. It is the panel specified where a building official or an architect calls for fire-retardant treated wood in sheathing, roof decking or blocking.

The CDX designation describes the veneer grades and the glue: a C-grade face, a D-grade back and an exterior-type adhesive bond. The result is a sheathing-grade panel that tolerates the weather exposure normal to construction, with visible knots, plugs and patches on the face since it is intended to be covered by roofing, siding or finish materials.

Panels are sanded only lightly if at all and cut, nailed and screwed with ordinary carpentry tools. Treated plywood is generally fastened with corrosion-resistant hardware, and cut edges should be handled according to the treater's instructions.

Key Features

• Softwood structural panel pressure-treated with fire-retardant chemicals throughout the sheet, not a surface coating
• CDX construction: C-grade face veneer, D-grade back veneer, exterior-type adhesive bond
• Sheathing-grade appearance with knots, patches and plugs; intended to be covered by finish materials
• Cross-laminated veneer layup gives strength and stiffness in both panel directions
• Standard sheet format cuts, nails and screws with conventional framing tools
• Treatment remains effective at cut edges and drilled holes because it is impregnated into the wood
• Best paired with corrosion-resistant fasteners and connectors, as with other treated wood products

Applications

• Roof decking and wall sheathing where fire-retardant treated wood is specified
• Interior partitions and shaft walls in multi-family and commercial construction
• Backing panels, blocking and plywood backer boards in electrical and telecom rooms
• Stair enclosures, corridors and other assemblies subject to fire-retardant requirements
• Concealed framing and furring work in renovation of existing commercial buildings
• Temporary construction enclosures and barricades where treated material is required

Product Details

• Product Type: Fire-retardant treated plywood
• Panel Grade: CDX (C face, D back, exterior glue)
• Treatment: Pressure-impregnated fire retardant
• Material: Softwood veneer plywood
• Thickness: 3/4 in.
• Panel Size: 4 ft. x 8 ft.
• Surface: Unsanded sheathing face
• Sold By: Each (sheet)

Specifications

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