Deck board spacing seems like a small design choice. It isn’t.
The right layout depends on the decking material, where the structure sits, and how it will handle Charleston’s sun, tides, wake, and changing moisture levels.
Why We Prefer Six-Inch Lumber Decking
Charleston Dock Doctors LLC generally prefers 2” x 6” Critical Structure decking boards over wider eight-inch lumber.
When six-inch lumber decking is installed wet, we typically place the boards tightly together without an initial gap. As the lumber dries, it naturally shrinks. Over the following weeks, small spaces often begin appearing between the deck boards.
Starting with a large gap can leave a much wider opening after the lumber dries. That’s enough room for fishing lures, pins, keys, and small tools to slip through.
Gone forever.
Small detail. Big difference.
Eight-inch decking can work, but wider boards may be more prone to curling or pulling around fasteners as they repeatedly get wet and dry. Depending on the application, they may also require additional fastening.
At Charleston Dock Doctors LLC, we typically use stainless steel deck screws when installing lumber decking in these marine environments.
What About Composite Decking?
Composite decking is different because its movement characteristics aren’t the same as wet pressure-treated lumber.
Spacing requirements vary by manufacturer, product, temperature, framing layout, and application. That means the correct gap for a composite deck should follow the product requirements and the conditions of the structure rather than a one-size-fits-all rule.
A floating dock on Lake Moultrie won’t face exactly the same conditions as an elevated pier along the Stono River or a tidal creek near James Island.
That’s why site-specific review matters.
Charleston Dock Doctors LLC handles dock repair, pier re-decking, floating docks, and other marine construction projects throughout Charleston, Mount Pleasant, James Island, and the surrounding Lowcountry.
Planning a dock repair or re-decking project? Charleston Dock Doctors LLC can review the existing structure, explain your decking options, and help determine an appropriate layout for your waterfront.
Visit CharlestonDockDoctors.com to request a quick estimate.
