Decks: soft spots, fittings and teak

What to inspect · Power & sail

Most fiberglass decks of this era are cored with balsa or plywood. Water gets in around fittings and rots the core, which shows up as soft or springy spots. Laid teak decks look great but wear thin, and old screwed-down teak can leak into the deck below.

Soft spots and deck fittings

• Walk the whole deck slowly, especially around cleats, stanchions, hatches, the windlass and chainplates. Springy, soft or crunchy spots usually mean wet or rotten core.
• Decks are easier to check than hulls: the skin is thinner, so tapping and moisture readings are more reliable. Still have the surveyor confirm anything suspect.
• Fittings that need rebedding are a common survey finding. Resealing them early keeps water out of the core; leaving them leads to much bigger repairs.
• Look below for stains, rust trails or rot on the underside of the deck and on bulkheads near fittings and window frames.

How teak decks are built

• Modern teak decks are thin planks, often 3/8 to 1/2 inch, laid over a fiberglass or plywood subdeck. Older ones were usually screwed down with a wooden plug (bung) over each screw; in the 1990s builders moved toward gluing them down with few screws.
• A screwed deck shows hundreds of plugs in neat rows. A glued deck avoids most of those leak paths, which is why a boatyard owner writing in PassageMaker calls it far better.

What goes wrong with teak

• Cleaning and foot traffic wear teak away; about 1/8 inch in ten years is not unusual. As it thins the plugs loosen, and water follows the screws down into the subdeck or core.
• The seam compound between planks also ages, cracks and pulls away from the wood. Once the seams fail, water gets under the planks.
• On older trawlers, water can run under the teak to the deck's low point and soak the subdeck there. Feel for softness at that spot and check the underside from the engine room. Water that freezes under planks can lift them and loosen screws.
• Ask how the deck has been cleaned. Pressure washers, and stiff brushes run along the grain, strip wood fast.

Renew or replace: cost examples

• A boatyard owner writing in PassageMaker (April 2020) gave these figures for a typical 42-foot powerboat, assuming no core damage: renew seams, reset screws and sand, about $25,000; remove teak and paint, $30,000; a better synthetic deck, $60,000; new teak, $80,000.
• The same author expects about 25 years from a teak deck. Costs vary widely by region, boat and year, and wet core underneath adds much more. Get your own quotes.

General guidance for recreational boaters, researched from the sources listed and written in our own words. Your equipment manuals, local knowledge, the Navigation Rules and a qualified instructor come first.