There’s no getting away from how good teak looks on the outside of a yacht – hence it’s almost a pre-requisite that even in standard trim many new boats have teak cockpit seats, any plenty of owners are tempted into paying to upgrade to a full teak deck. Given that teak provides unbeatable grip, even when wet and with the boat well heeled, there are ways in which this is also a practical move.
However, although it’s a potentially very durable material for marine use, if teak decks are not treated carefully they can quickly deteriorate, leaving the owner with a significant five-figure bill for repair or replacement. Don’t underestimate this – for a 40ft boat a new deck will cost upwards of £20,000 – and it’s a bill that all too frequently comes as an unpleasant surprise to the owner.
The biggest problem is that the gorgeous scrubbed look that we all see on photos of superyachts and classic vessels literally wears the deck away – at up to 1mm of thickness a year. The trouble here is that, while the grain of the wood is very hard, the fibres between the grains are soft and are easily scrubbed away. With some decks only 12mm thick, and even the best only 15-18mm, it doesn’t take long to inflict potentially terminal damage.
The improvements in adhesives over the past 15 years or so means that modern teak decks are not mechanically fastened to the boat with screws, which fortunately means there’s less risk of water finding its way into the deck’s foam or balsa core and causing significant structural damage. However these decks may also be thinner than those of older boats – in some cases as little as 7mm thick.
Treat them gently
So what can be done to maximise the lifespan of a teak deck? The obvious answer is to avoid scrubbing the decks – for a boat kept in a sunny environment all that’s needed is a regular (ideally twice daily) wash with salt water. This also has the advantage that it does not strip the natural oil out of the timber and after a few weeks the decks will acquire a natural silver-grey patina. Although in the eyes of some observers this may not look as sexy as freshly scrubbed teak, it’s exactly what anyone searching for a second-hand yacht should be hoping to find.
Unfortunately, in more temperate climates, teak decks may need more attention than this – but it still pays to be as careful and gentle as possible. If you have to wash the decks use light pressure on a very soft-bristled brush and always brush across the grain. This will minimise removal of the soft timber between the grain and significantly reduce the rate of wear.
On the other hand, using a stiff bristled brush, or worse still, a pressure washer, will maximise damage to the timber. It may feel as though these are quick routes to a clean deck, but this is also a quick route to a big boatyard bill that in many cases will amount to a significant proportion of the total value of the yacht.
If you really want a scrubbed teak look for special occasions make sure you let the teak cleaner – which contains oxalic acid to bleach the timber – do as much of the work as possible. Again, patience is the key here – the less actual scrubbing you do the better. A generous application of teak oil will then help to maintain the appearance afterwards.
Surveying teak decks
Signs of a deck that’s in need of attention include loose caulking, movement of wooden plugs over screw heads and splits or cracks in the timber. The more extensive these problems, the closer the decks are to the end of their life. Small problems are generally easy and quick to fix and are perhaps best done in fine weather during the summer, rather than waiting for a winter refit.
It’s always a mistake to ignore these problems – they can escalate surprisingly quickly until the stage is reached at which the only option is to replace the entire deck. Cracks in the timber can be opened out with a small chisel or Dremel type tool, allowed to dry thoroughly and then filled with an epoxy based filler. Loose caulking should be picked out, the affected area cleaned back to bare wood, ideally with a router, and the affected caulking replaced.
With older decks that are screwed down, once the teak plugs above the screw heads start to become thin they tend to fall out. This looks unsightly but, even worse, provides a route for water to get into the structure of the deck. However, in many cases the screw can be removed and its hole drilled out to a level two or three millimetres lower. A new, thicker, teak plug can then be glued in place above the screw head.
Providing it’s not waterlogged underneath, in many cases a deck that’s significantly worn and has damaged caulking can also be given a new lease of life. Start by sanding it smooth, then remove all the caulking, using a router to make the groove between the planks 2-3mm deeper than the original. This will give sufficient depth for new caulking to adhere successfully. Once the caulking has been applied the deck will need to be sanded again to get rid of the excess caulking compound.
If any other problems are sorted at this same time, this procedure can help a carefully looked after deck to last for a further 5-10 years, yet should cost a small fraction of a new teak deck.