Why Wood Species Matters for Outdoor Use

Choosing the right wood species for outdoor projects is crucial for longevity, appearance, and value. Unlike indoor applications where appearance might be the primary concern, outdoor projects must withstand moisture, temperature changes, UV exposure, and potential insect attack. The right species can mean the difference between a project that lasts decades and one that requires replacement in just a few years.

Understanding Natural Durability

Wood species vary dramatically in their natural resistance to decay and insects. This resistance comes from:

• Natural extractives: Chemicals in the wood that repel insects and fungi
• Wood density: Denser woods are harder for insects to penetrate
• Moisture content: How quickly wood absorbs and releases moisture
• Cell structure: Tight grain resists water penetration

Premium Outdoor Species

Alaska Yellow Cedar (Chamaecyparis nootkatensis)

Considered the gold standard for outdoor applications, Alaska Yellow Cedar offers unmatched durability and beauty:

Advantages:

• Exceptional durability: Can last 50+ years outdoors untreated
• Natural decay resistance: Class 1 durability rating
• Insect resistance: Natural oils repel most wood-boring insects
• Dimensional stability: Minimal warping and movement
• Beautiful appearance: Distinctive yellow color that weathers to silver-gray
• Fine grain: Takes finishes beautifully
• Pleasant aroma: Natural cedar scent

Best Applications:

• High-end decking and outdoor furniture
• Siding and exterior trim
• Marine applications and boat building
• Garden structures and pergolas
• Outdoor sculptures and art projects

Considerations:

• Higher cost than other species
• Limited availability in some regions
• Color changes over time (some consider this a feature)

Western Red Cedar (Thuja plicata)

A popular and accessible choice for many outdoor projects:

Advantages:

• Good natural durability: 15-25 year lifespan outdoors
• Lightweight: Easy to work with and transport
• Stable: Low shrinkage and movement
• Aromatic: Pleasant cedar smell
• Readily available: Sustainable harvest from Pacific Northwest
• Cost-effective: Good value for natural durability

Best Applications:

• Deck boards and railings
• Fence boards and pickets
• Siding and shingles
• Outdoor furniture
• Raised garden beds

Considerations:

• Softer wood prone to denting
• Can develop surface checking
• Natural tannins can cause staining

Other Durable Options

Douglas Fir (Pseudotsuga menziesii)

Strong and versatile, though requiring treatment for ground contact:

Advantages:

• High strength: Excellent for structural applications
• Good appearance: Attractive grain pattern
• Readily available: Pacific Northwest staple
• Cost-effective: Good value for strength

Best Applications:

• Deck framing and structural components
• Pergola beams and posts (above ground)
• Outdoor furniture frames
• Fencing (with treatment)

Considerations:

• Requires treatment for ground contact
• Can develop pitch pockets
• Moderate natural decay resistance

Redwood (Sequoia sempervirens)

California's premium outdoor species:

Advantages:

• Excellent durability: Natural decay resistance
• Beautiful appearance: Rich red color
• Stable: Minimal movement
• Insect resistant: Natural tannins repel insects

Considerations:

• Higher cost
• Limited availability
• Environmental concerns about harvest

Treated Lumber Options

Pressure-Treated Southern Pine

The most economical choice for many outdoor applications:

Advantages:

• Affordable: Lowest cost for treated lumber
• Widely available: Found at most lumber yards
• Strong: Good structural properties
• Long warranty: Many products come with 25+ year warranties

Best Applications:

• Deck framing and joists
• Fence posts and rails
• Landscape timbers
• Foundation sill plates

Considerations:

• Can warp and twist as it dries
• Chemical odor initially
• Requires special fasteners
• Limited staining options initially

Pressure-Treated Lumber Grades

• Above Ground: For applications not touching soil
• Ground Contact: For posts, sill plates, within 6" of ground
• Foundation: For permanent foundation contact
• Marine Grade: For saltwater and freshwater applications

Matching Wood to Application

Decking Applications

Species	Durability	Appearance	Cost	Maintenance
Alaska Yellow Cedar	Excellent	Premium	High	Low
Western Red Cedar	Good	Good	Medium	Medium
Pressure-Treated	Good	Basic	Low	Medium

Structural Applications

For framing, beams, and posts:

• Above ground: Douglas Fir, Southern Pine
• Ground contact: Pressure-treated lumber
• Marine/wet conditions: Alaska Yellow Cedar, pressure-treated
• Heavy loads: Douglas Fir, engineered lumber

Siding and Trim

For exterior finish work:

• Premium appearance: Alaska Yellow Cedar, Western Red Cedar
• Paint grade: Properly primed Pine or Fir
• Budget option: Pressure-treated with quality primer

Finishing and Maintenance

Natural Finishes

For preserving wood's natural appearance:

• Clear sealers: Protect while showing grain
• Semi-transparent stains: Add color while showing texture
• Natural weathering: Allow graceful aging to gray

Maintenance Requirements

High-Durability Species (Alaska Yellow Cedar):

• Can be left natural with minimal maintenance
• Annual cleaning and inspection
• Optional re-staining every 3-5 years

Moderate-Durability Species (Western Red Cedar):

• Benefits from protective finish
• Annual cleaning
• Re-staining every 2-3 years

Treated Lumber:

• Allow to dry before staining (3-6 months)
• Annual inspection for loose fasteners
• Re-stain every 2-4 years depending on exposure

Cost-Benefit Analysis

Initial vs. Lifetime Costs

Consider the total cost of ownership:

Alaska Yellow Cedar:

• High initial cost
• Minimal maintenance costs
• 50+ year lifespan
• Excellent long-term value

Western Red Cedar:

• Moderate initial cost
• Moderate maintenance costs
• 20-30 year lifespan
• Good balance of cost and performance

Pressure-Treated Lumber:

• Low initial cost
• Moderate to high maintenance costs
• 15-25 year lifespan
• Best for budget-conscious projects

Environmental Considerations

Sustainability Factors

• Harvest practices: Look for sustainably managed forests
• Local sourcing: Reduces transportation environmental impact
• Durability: Longer-lasting wood reduces replacement frequency
• Treatment chemicals: Modern treatments are much safer than older formulations

Making the Right Choice

Questions to Ask:

1. What's your budget? Include initial cost and maintenance
2. How long do you want it to last? Match durability to expectations
3. What's the exposure level? Full sun, protected, ground contact?
4. How important is appearance? Natural beauty vs. painted finish
5. How much maintenance are you willing to do? Some species require more care

Our Recommendations by Project Type

High-End Deck:

Best Choice: Alaska Yellow Cedar
Alternative: Western Red Cedar
Budget Option: Pressure-treated Southern Pine

Garden Fence:

Best Choice: Western Red Cedar
Alternative: Pressure-treated Pine
Posts: Pressure-treated (ground contact rated)

Outdoor Furniture:

Best Choice: Alaska Yellow Cedar
Alternative: Western Red Cedar
Budget Option: Douglas Fir with protective finish

Structural Framework:

Above Ground: Douglas Fir
Ground Contact: Pressure-treated Southern Pine
Marine: Alaska Yellow Cedar