Is kiln dried cedar used for Vancouver decks?

Kiln dried cedar is used for deck boards in Metro Vancouver, but it's the exception rather than the rule — most cedar decking installed here is green (unseasoned) or air-dried lumber.

Here's why that distinction matters for your project.

What You'll Typically Find at Lumber Yards

The vast majority of Western Red Cedar decking sold in Metro Vancouver comes from BC mills and arrives at the lumber yard with relatively high moisture content — often 19% or above. This is considered "green" or partially air-dried lumber. It's what most deck contractors use, and it performs well when installed correctly. The trade-off is that green cedar will shrink and check (develop small surface cracks) as it dries in place after installation. This is normal and expected, not a defect.

Kiln dried cedar (KD or KDAT — kiln dried after treatment) has been dried in a controlled oven environment down to roughly 15-19% moisture content or lower. It's more dimensionally stable, less prone to warping and twisting after installation, and checks less aggressively as it acclimates. It also accepts stain more evenly right away because the surface isn't still releasing moisture. The downside is cost — kiln dried cedar typically runs 15-30% more than green cedar of the same grade.

Does It Matter in Metro Vancouver's Climate?

Honestly, less than you might think — and here's the nuance. Vancouver's ambient humidity (60-80% year-round outdoors) means that even kiln dried cedar will re-absorb moisture from the environment fairly quickly after installation. The wood reaches an equilibrium with the surrounding air regardless of its starting moisture content. So the dimensional stability advantage of kiln dried cedar is most pronounced in the first season after installation, before the wood has had time to acclimate.

That said, kiln dried cedar is worth considering for tight-fitting applications — picture frame borders, fascia boards, and decorative trim where gaps from shrinkage would be visually obvious. For field decking (the main deck boards running the length of the deck), most experienced Vancouver contractors install green cedar with slightly tighter spacing, knowing the boards will shrink to the correct gap as they dry. A contractor who installs green cedar with wide gaps is leaving you with a deck that looks sloppy from day one.

The grade of cedar matters more than kiln drying for most homeowners. Clear or tight-knot cedar (CTK) with minimal knots and straight grain will outperform standard or knotty grades regardless of drying method. Knots are the first place cedar checks and splits, and they bleed tannins that stain the deck surface and anything below it.

Practical Tips

In Metro Vancouver's wet climate, the most important cedar decisions are grade selection, proper board spacing for drainage, and a consistent maintenance schedule — not whether the lumber was kiln dried. Whatever cedar you install, plan to clean and re-apply a penetrating semi-transparent stain or oil every 1-2 years. Avoid solid film-forming stains, which peel and trap moisture in Vancouver's persistent dampness. Penetrating products like Sansin, Armstrong Clark, or Cabot Australian Timber Oil allow the wood to breathe and hold up far better through our wet winters.

If you're sourcing cedar yourself or want to specify kiln dried to your contractor, ask for KDAT (kiln dried after treatment) if the lumber is also pressure-treated, or simply "KD" Western Red Cedar for untreated decking. Not all suppliers stock it consistently, so call ahead.

Need help finding a deck contractor who can advise on the right cedar grade and specification for your specific project? Vancouver Deck Contractors can match you with experienced local builders for free — or browse the Vancouver Construction Network directory at vancouverconstructionnetwork.com.