Composite vs Marine Grade Lumber: Best Materials for Docks and Bulkheads in Northeast Florida

December 18, 2025

Choosing the right material for a dock, bulkhead or boardwalk is one of the most important decisions a waterfront homeowner can make. In Jacksonville, Ponte Vedra and St. Augustine, many older structures were built with untreated wood, non marine rated lumber or materials that deteriorate quickly near saltwater. These older installations often require frequent repairs or complete replacement.

BOSS Outdoor builds exclusively with composite materials and marine grade pressure treated lumber because both materials are engineered to withstand intense sun, salt exposure and tidal changes in Northeast Florida. This guide explains how the two materials compare and how each should be used for long lasting waterfront construction.

Why Material Selection Is Critical

Waterfront environments expose structures to:

  • Salt spray
  • Moisture
  • UV radiation
  • Marine borers
  • Boat wake impacts
  • Shifting sand and soil

Low grade materials fail quickly in these conditions. Choosing the correct material greatly reduces long term maintenance and improves safety.

composite dock

Composite Materials: Strengths and Best Uses

Composite materials provide exceptional performance for walking surfaces and decking.

Benefits of Composite

Low Maintenance

Composite does not require staining, sealing or painting.

No Rot or Splintering

Ideal for dock surfaces, ramps and boardwalks.

Slip Resistant

Many composite products offer textured finishes that improve traction.

Uniform Appearance

Composite maintains consistent color and shape over time.

Limitations of Composite

Composite is not suitable for:

  • Pilings
  • Structural beams
  • Load bearing framework
  • Bulkhead walls

It is best used as a surface material, not as the structural core of a marine installation.

Best Uses for Composite

  • Dock decking
  • Walkover and boardwalk treads
  • Ramps
  • Stair surfaces
  • Handrails and trim

marine grade pressure treated lumber

Marine Grade Pressure Treated Lumber: Strengths and Best Uses

Marine grade PT lumber is treated to withstand saltwater exposure and marine borer activity.

Benefits of Marine Grade Lumber

High Structural Strength

Perfect for bulkheads, pilings and framing systems.

Excellent Durability

Engineered for long lifespan in harsh conditions.

More Affordable Than Composite

Provides strength without premium cost.

Versatile

Works in virtually all marine construction applications.

Limitations of Marine Grade Lumber

Requires Periodic Inspection

Even marine lumber must be monitored for:

  • Fastener corrosion
  • Minor splitting
  • Surface aging

Natural Weathering

Color and texture change over time due to sun and moisture.

Best Uses for Marine Grade Lumber

  • Bulkhead walls
  • Dock pilings
  • Structural dock framing
  • Boardwalk support posts and beams
  • Dune walkover framing

Composite vs Marine Lumber Comparison

Feature Composite Marine Grade PT Lumber
Structural Strength Low High
Rot Resistance Excellent Excellent when treated
Maintenance Very Low Moderate
Cost Higher Lower
Best Use Surface decking Structural framing and bulkheads

 

Which Material Should You Choose?

For docks

Use composite decking with a marine grade lumber frame.

For bulkheads

Marine grade lumber is the superior choice.

For boardwalks and walkovers

Use composite for the walking surface and marine lumber for the structure.