Maintenance
Dock and Deck Maintenance in a Coastal Climate
The highest-value maintenance on any waterfront structure is an annual inspection from underneath at low tide, checking pilings, framing and hardware. Surface maintenance matters for appearance; what happens below the deck decides how long the structure lasts.
6 min readUpdated November 2025By Jacksonville Dock Builder
Maintenance that actually matters
Most waterfront maintenance advice is about appearance — cleaning, sealing, keeping the boards looking good. That is worth doing, but it is not what determines whether your structure is sound in fifteen years.
What determines that is below the deck: the pilings, the framing and the hardware. And almost nobody looks at them.
The annual inspection
Once a year, at low tide, with a screwdriver. Half an hour, and it is the single highest-value thing you can do for a dock.
Pilings. Probe each one at the waterline and just below it. Sound treated timber resists firmly; compromised timber gives, often with a thin shell over a hollow core — exactly what marine borers produce. Then look at the bottom around each pile. If sediment has been excavated away, scour has reduced the embedment even though nothing above water has changed.
Framing. Press firmly on joists from underneath. Check the ends where they meet stringers, and anywhere water can sit in a joint. Rot works from the connections outward and from the inside out.
Hardware. Look for rust streaks running down from bolt heads, brackets and joist hangers. In this climate, corroding fasteners are structural, not cosmetic, and they generally mean the whole structure was fastened with the wrong specification.
Movement. Push hard laterally at the top of the structure. Any sway, anywhere, is worth investigating.
Decking. Last. Soft boards are usually the symptom of something underneath.
On a deck, add one check and put it first: probe the rim joist of the house behind the ledger. If it gives, stop and get it looked at properly.
Surface care by material
Pressure-treated timber
New treated lumber carries a lot of moisture from the treatment process. Let it dry before sealing — coating it too early traps that moisture in.
After that, the cycle is clean then seal. Cleaning means a proper wash with an appropriate cleaner, not just a hose. Sealing needs a dry window of a couple of days, which Florida summers rarely provide, so plan it for the drier months.
Be careful with pressure washing. Low pressure and a wide fan tip is fine. High pressure erodes the soft wood between the grain, leaving a permanently rough surface that then weathers faster than it would have.
Composite
Wash it. That is the maintenance programme.
The one thing worth watching in this climate is organic growth in shaded, damp areas — it is what makes composite slippery, and routine washing deals with it. Use a cleaner suited to the product; some household cleaners can affect the cap.
Hardware, either way
Rinse anything metal that is within reach of salt spray. Replace corroding fasteners rather than leaving them — one failing connection tends to indicate many.
Boat lifts
Three habits make most of the difference:
Rinse after use. Fresh water on the drives, cables and hardware. Salt air is relentless and this costs nothing.
Inspect the cables. They are the wearing item that fails most consequentially. Look for broken strands, corrosion and flat spots. Replace on condition.
Check the bunk carpet. Worn carpet marks hulls, and permanently damp carpet against gelcoat causes its own problems.
Before and after a storm
Before. Follow official guidance first. Generally: remove everything loose from the structure — furniture, ladders, coolers, anything that becomes a projectile. Take the boat off the lift and move it rather than raising it higher and strapping it down; surge lifts boats off cradles and takes lifts with them. Secure or remove accessories.
After. Check four things specifically, because surge does specific things:
- Is the decking still fastened everywhere? Surge pushes up before it pushes sideways and lifts boards off the frame from underneath.
- Is the structure still square? Racking is common and not always obvious.
- Has the bottom around the pilings changed? Scour during a surge event can remove a lot of material quickly.
- Does anything move that did not move before?
A dock can look entirely normal after a storm and have lost meaningful capacity. If in doubt, get underneath before loading it.
A simple schedule
| When | What |
|---|---|
| Monthly, in season | Rinse lift hardware; clear debris from the deck and from under the structure |
| Every 6 months | Walk the structure looking for loose boards, wobbly railings and rust streaks |
| Annually, at low tide | Full inspection from underneath — pilings, framing, hardware, movement |
| Every few years | Clean and reseal treated timber; sooner on surfaces in full afternoon sun |
| Before each storm | Clear loose items; move the boat; follow official guidance |
| After each storm | Check fastening, squareness, scour and movement |
If an inspection turns up something you are unsure about, dock repair covers what the fixes involve, and repair versus replacement covers how to tell which you are facing.
Want this applied to your property?
General guidance only goes so far. Send photographs and rough dimensions and we will tell you what applies to your shoreline specifically.
