If you’re considering building a dock, one of the first questions that may come to mind is whether pressure-treated lumber is a suitable material. The short answer is yes, you can use pressure-treated wood for a dock, but there are important factors to consider before making that decision.
While pressure-treated lumber has long been a common choice for dock construction, modern versions of this material don’t last as long as they used to. Fortunately, there are superior alternatives that can provide greater longevity and durability in a marine environment.
Why Today’s Pressure-Treated Lumber Doesn’t Last as Long
Older pressure-treated wood contained chromated copper arsenate (CCA), a treatment that significantly extended the lifespan of lumber by protecting it from rot, insects, and marine organisms. However, due to environmental and health concerns, CCA-treated wood was phased out for most residential applications in 2004 because this treatment also contained arsenic.
The newer versions of pressure-treated lumber use alternative chemicals, such as alkaline copper quaternary (ACQ) and copper azole (CA). While these treatments still offer some protection against rot and insects, they are far less effective than CCA.
Modern pressure-treated wood is more susceptible to moisture absorption, warping, and premature rot, especially in constantly wet environments like a dock. The high copper content in ACQ and CA treatments also accelerates corrosion of fasteners, which can compromise the structural integrity of your dock over time.
Alternative Framing Materials for Docks

Given the limitations of modern pressure-treated wood, many dock builders are turning to alternative framing materials that last longer and require less maintenance.
- TimberTech® Aluminum Deck Framing – One of the best alternatives for dock framing, this system is made from powder-coated aluminum, which won’t rot, warp, or corrode in a marine environment. It’s incredibly strong and lightweight, making it ideal for dock construction where durability and resistance to moisture are critical.
- Composite Framing – Some high-quality composite framing materials are available, offering superior resistance to moisture, rot and decay.
Best Dock Decking Options
Instead of using pressure-treated deck boards for your dock, consider these superior materials that provide better longevity, durability, and aesthetics:
Composite Decking

- Made from a blend of wood fibers and plastic, composite decking offers excellent resistance to moisture, rot, and insect damage.
- Popular brands like Trex, TimberTech, and Deckorators provide composite decking that requires little maintenance and won’t splinter like wood.
- Many composite options have slip-resistant textures, making them safer for wet conditions.
PVC Decking

- 100% synthetic decking that is waterproof and resistant to mold, mildew, and rot.
- Lighter than composite and won’t absorb moisture, making it a great choice for marine applications.
- Brands like TimberTech AZEK offer high-performance PVC decking that lasts for decades.
HDPE Decking (High-Density Polyethylene)
- Ultra-durable and made from recycled plastics, HDPE decking is resistant to rot, water damage, and marine borers.
- It’s also environmentally friendly and maintenance-free.
Hardwood Decking

For a natural look with exceptional durability, exotic hardwoods are some of the best materials for dock decking. These species are naturally resistant to moisture, rot, and insects:
- Ipe – The gold standard for docks, Ipe is an ultra-dense hardwood that lasts up to 75 years with minimal maintenance.
- Cumaru – Similar to Ipe but slightly more affordable, Cumaru is extremely hard and durable.
- Tigerwood – A striking hardwood with a unique grain pattern and high resistance to water.
- Garapa – A golden-hued hardwood that is durable and long-lasting in marine environments.
- Brazilian Redwood – Offers superior resistance to rot and pests while maintaining a rich, deep color.
- Teak – A premium choice known for its natural oils that resist water absorption and decay.
Conclusion: Choose the Right Materials for a Long-Lasting Dock
While you can use pressure-treated lumber for a dock, it’s not the best choice for long-term durability. Modern pressure-treated wood lacks the longevity of older CCA-treated wood and is more prone to rot and decay in a wet environment. Instead, consider using a longer-lasting framing material like TimberTech Aluminum Deck Framing and upgrade your dock boards to composite, PVC, HDPE, or hardwood decking for a dock that will stand the test of time.
Investing in high-quality materials now will save you money in the long run by reducing maintenance and replacement costs while ensuring your dock remains safe and beautiful for years to come.