Best Dock Materials for Saltwater: Wood vs Composite vs Aluminum vs Ipe
Tampa Bay is one of the harshest dock environments in the country. Salt spray. Nine months of intense UV. Sudden 3-day rainstorms in June, and hurricanes when we are unlucky. Most dock decking is spec'd by manufacturers in labs. Ours has to survive Tampa reality.
This is the honest ranking of what lasts. We track failure modes on real Tampa docks and update our numbers when we see something new. The manufacturer warranty is not the useful number. The real-world lifespan in Tampa saltwater is.
The four contenders
Almost every dock decking in Tampa Bay comes down to four choices: pressure-treated pine, composite, ipe hardwood, or marine-grade aluminum. Each has a real place. None is universally best.
Pressure-treated pine (PT)
The classic Florida dock deck. Southern yellow pine, treated with copper-based preservatives, milled to 5/4 x 6 boards. Cheap. Familiar. Every crew in Tampa Bay knows how to build with it.
- Cost: $28 per sq ft installed.
- Real Tampa lifespan: 10 to 15 years with annual sealing. 6 to 10 years without.
- Main enemies: UV, standing water, sea salt corrosion of fasteners.
- Maintenance: Annual sealing with a marine-grade product. Pressure wash every 6 months.
- Best for: Rental properties, temporary docks, low-budget builds, or homeowners who genuinely enjoy the annual sealing ritual.
Composite (Trex, Azek, Fiberon, TimberTech)
The Tampa Bay default since about 2018. Recycled wood fiber and plastic pressed into board form, capped with a UV-resistant polymer shell. Modern composites solved the fade and stain problems that plagued the first generation.
- Cost: $55 per sq ft installed.
- Real Tampa lifespan: 25 to 30 years. Most modern brands have 25-year warranties that hold up to warranty claims.
- Main enemies: Very few. Deep gouges are hard to repair. Some cheaper brands fade in full sun over 15 years.
- Maintenance: Hose off. That is it.
- Best for: Almost everyone. If your budget allows, composite is the boring safe answer that ages well.
Ipe hardwood (Brazilian walnut) and Cumaru
The premium option. Ipe is 3.5 times denser than pressure-treated pine. So dense that a board sinks in water. Naturally rot-resistant, insect-resistant, and fire-rated the same as steel. Silvers to a beautiful gray if left untreated.
- Cost: $78 per sq ft installed.
- Real Tampa lifespan: 30 to 50 years without treatment. 40+ with occasional oil.
- Main enemies: Improper fasteners cause the only real problems. Use stainless or the wood outlasts the screws.
- Maintenance: Optional. Untreated it silvers. Oiled once every 2 years it stays reddish brown.
- Best for: Premium waterfront homes, buyers who want a yacht-deck look, and anyone building for the grandkids.
Marine-grade aluminum
The modern industrial answer. Extruded aluminum decking with anti-slip texture, powder-coated or anodized. Popular on modern architectural homes on the Bay. Cool underfoot. Never rots, warps, splinters, or fades.
- Cost: $62 per sq ft installed.
- Real Tampa lifespan: 40+ years. The dock will outlast the pilings supporting it.
- Main enemies: Galvanic corrosion if paired with the wrong hardware. Stainless steel bolted to bare aluminum in salt water fails fast. Always use isolators.
- Maintenance: Rinse occasionally. Zero refinishing.
- Best for: Modern architectural homes, low-maintenance owners, and anyone who really hates splinters.
The hidden cost: fasteners and framing
Decking is the visible part. What kills docks in Tampa saltwater is what is under the decking. Framing lumber and fasteners fail long before the deck boards do.
Fasteners: buy stainless or lose the dock
This is the single biggest hidden mistake in Tampa dock building. Zinc-coated screws and lag bolts rust through in 4 to 8 years in salt spray. Every board is now loose. The dock has to be pulled apart to fix it. Cost to redo: often 40% of the original build.
The right answer is 316 stainless steel throughout. Every screw. Every joist hanger. Every bolt. Adds about $600 to $1,800 to a typical dock. Extends the life 15 to 30 years. There is no argument against this.
Framing lumber
Even under composite decking, the joists below are almost always pressure-treated wood. That is fine, but the treatment level matters. Ask specifically for .60 CCA or .40 ACQ ground-contact-rated lumber. Anything less rated does not last in salt spray, and it is not visible from above so you cannot tell after the fact.
Not sure which material fits your dock?
Take our 6-question Material Recommender. We score every material against your priorities, sun exposure, traffic, and aesthetic.
Piling material: separate decision
Piling material is a whole conversation of its own. Quick version:
- Wood pilings: $320 each. Fine for 10 to 15 years. Cheapest.
- Concrete pilings: $780 each. 40 to 60 year lifespan. Tampa standard now.
- Composite pilings: $640 each. Newer product, 30+ year expected life. Popular on high-end builds.
If you are putting a boat lift on the dock, spec concrete. The lift will outlast wood pilings by decades.
The 20-year total cost picture
The upfront cost is not the whole story. Here is what a 40 x 6 foot Tampa dock actually costs over 20 years, by material.
- Pressure-treated pine: $22k upfront. $6k in annual sealing (20 years x $300). $18k rebuild at year 12. Total: $46k.
- Composite: $32k upfront. $0 in maintenance. No rebuild. Total: $32k.
- Ipe: $42k upfront. Optional oiling. No rebuild. Total: $42k to $46k.
- Aluminum: $34k upfront. No maintenance. No rebuild. Total: $34k.
Composite wins on 20-year total cost. Aluminum is right behind it. Pressure-treated pine is actually the most expensive dock over 20 years, once you count the rebuild. This is the number salespeople hate quoting.
Ready to price your dock in real materials?
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Get my free quotes →The bottom line
Composite is the safe default for most Tampa Bay homeowners in 2026. Ipe is the premium answer if you want a signature look. Aluminum is the modern architectural answer. Pressure-treated pine still has a place for tight budgets and rental properties, but the 20-year math almost always favors composite.
Whatever decking you pick, spec 316 stainless fasteners and concrete pilings if you plan to hold the property longer than 8 years. Those two decisions matter more than the deck material itself.
Lifespans and costs reflect Tampa Bay marine construction data. Freshwater and non-tropical climates yield different results.
