The lid on the hull

Most decks are surveyed the wrong way round. The teak is looked at first, because it is what the owner sees, and the caulk and fastenings under it last. That order is backwards: what a deck looks like follows from what its seams and fixings have been doing for ten years.

A deck is the lid on the hull, and everything let into it, a stanchion base, a hatch, a windlass, a pane of glass, is a hole that was once sealed and has to stay sealed. A yacht deck refit is the work of taking that lid apart and closing it again as one weathertight envelope, rather than as a teak job, a hardware job and a glazing job booked in sequence.

What the caulk is telling you

Deck caulk is a two-sided joint. It bonds to the plank edges and not to the bottom of the seam, which is why a bond breaker goes in at the base. A seam bonded on all three faces has no free length in which to stretch, and the timber moves anyway.

The failure mode therefore matters more than the fact of failure. Caulk split down its own middle has been asked to take more movement than it was specified for. Caulk released cleanly from one plank edge has an adhesion problem, whether contamination, a missed primer, or a plank moving because what it is fastened to moved first. Black streaks down the topsides say the same thing from outside, because once a seam is open every wash-down carries dirt into it.

Above the screw head

A bunged deck and a bonded laydown fail differently and are measured from different places. On a bunged deck the wear surface ends a few millimetres above the screw head, so the usable timber is what sits above the fastener, not above the substrate. Sand past the bung and the screw becomes a wick straight into the deck.

A bonded deck has no such datum. There is no fastener to hit, the whole plank is wear thickness, and the question moves to the adhesive line and the substrate under it. Two decks laid in the same 12mm teak carry different service lives on that alone, which is why remaining thickness cannot be read across constructions as one number.

A survey therefore reaches the substrate before it reports on the teak. On a composite deck that substrate may be a cored panel, and every fastening penetration is a route into it. On steel it is the coating under the planks. On aluminium it is what stainless fastenings have been doing to the plate around them. None of the three is measured from the same place as the timber above it, and none is answered by a moisture meter run over the surface.

Every fitting lifted is a fresh seal

Deck hardware overhaul is mostly a sealing job. A cleat, a stanchion base, a fairlead, a padeye, each comes off as hardware and goes back as a joint that must stay watertight under load while the structure works beneath it.

Cored decks are unforgiving here. The correct answer is to overdrill the penetration, fill it and redrill through solid material so the fastener never touches core, which takes longer than bedding the fitting back. Backing plates get inspected while they are still visible.

Guardrail stanchions, bases and heights get checked against the code rather than against what was there.

Deck machinery and its penetration

Windlasses, capstans, davits and passerelles come apart with the deck, because the machine and its penetration are one job. A windlass cannot be lifted for the seal detail and dropped back without the overhaul, or overhauled and dropped back onto old bedding compound. Splitting those into two scopes means paying for the same lift twice.

The deck machinery overhaul happens while the deck plate is open. Rams come out for seal kits, and gypsies, brake bands and clutch cones are measured against their wear limits.

Davits, cranes and other launching appliances come back as certificated equipment, which means a witnessed proof load test at the factor stated in the rule, with the certificate and the register entry to match.

The knife edge and the chalk line

Hatches, portlights and windows are where weathertight integrity is demonstrated. Gaskets are replaced as sets, dogs and cams adjusted so compression is even along the whole knife edge, and the chalk test says whether that is true. Chalk the edge, dog down, read the witness line. A broken line in one corner is a leak that has not happened yet.

Bonded glazing is a structural bond, not a bead of sealant. Joint width and depth, primer and cure time are calculated to the adhesive manufacturer's figures, and the aperture flange usually has something to say once the pane is out.

Then it is hosed. A hose test has a nozzle size, a pressure and a stand-off distance written into the class requirement, and a hose waved at a hatch from wherever the surveyor was standing is not that test. It is also booked before the deck is dressed.

Scuppers, gutters and freeing ports

Green water on deck is normal, and the design assumption is that it leaves quickly. Scuppers, deck drains and hatch coaming gutters are the part of the system nobody photographs and everybody blocks, and a hatch gutter with a plugged drain is a bathtub with a seal around it.

Bulwark freeing ports are the same logic at a larger scale, their hinged shutters seize, and they get freed while there is scaffolding to reach them.

Where a yacht deck refit sits in the programme

This work closes before the topsides are painted, and the binding reason is drilling. A penetration finalised before fairing is a hole the paint scheme is built around. One left open is a hole drilled into finished paint afterwards, and no version of that is cheaper than deciding earlier.

So a deck scope has to say, before the vessel is offered to the paint hall, which fittings go back on their original centres, which move and which are deleted.

Teak of the grade and length a full lay needs is bought abroad, and its lead time can set the programme before any labour starts. Ordered after the survey closes, it moves the laying date out by whatever the mill and the freight take. Containment carries a date of its own. A deck lying open in a working basin is open to whatever the next quay is doing, so the weeks her seams are exposed have to fall where the neighbours allow.

At Reviva Refit the man who lifts the fitting and the man who paints around it are on one payroll, and answer to the same programme.

Written at the yard in Tuzla. What is described here is this yard's own practice; the figures that govern any particular deck are the ones in her build specification and her class file.