What are some basic differences in PVC decking?

The biggest difference is that PVC decking is made entirely from plastic, while composite decking is typically made from a blend of wood fibers and plastic. Both are popular low-maintenance alternatives to traditional wood, but they perform a little differently—especially in Western Washington's wet climate.

PVC decking: Plastic throughout

• No wood fibers
• Very good moisture resistance
• Often costs more
• Can expand and contract with temperature

Composite decking: Wood fibers + plastic

• Often more affordable
• Wood-like look and feel
• Moisture performance varies by product
• Can contain more recycled or reclaimed material

What we would choose for your deck

• Choose PVC if you want maximum moisture resistance, especially for an elevated deck or an area exposed to frequent wetting, and you're comfortable with the potential price premium.
• Choose capped composite if you want a good balance of appearance, durability, and initial cost.
• Compare four-sided-capped composite with PVC, too. A well-protected composite board may be a better value than moving straight to a premium PVC product.

For TimberTech specifically, the comparison is between its Advanced PVC line and its Composite line. TimberTech describes Advanced PVC as having no wood or organic fillers, while its composite boards contain wood fibers and polymers; some composite collections have a protective cap on all four sides.

One final caution: PVC decking itself does not waterproof the area underneath your deck. If your goal is a dry covered patio below, you'll still need a separate drainage system such as TimberTech DrySpace, designed and installed for that purpose.