How should I clean and maintain an older teak deck?

Wash your teak deck gently across the grain using salt water and a soft sponge, leaving the wood to weather to a natural silver-grey. Your priority for a 2007 deck is preserving the remaining wood thickness by avoiding stiff brushes, pressure washers and two-part acid cleaners that strip out the soft grain.

Cleaning and Algae Control

Salt water retains moisture in the wood and deters green algae. Use a large sponge or a very soft mop for regular washdowns. Never use a stiff deck brush. If you must use a soft bristle brush for stubborn dirt, scrub across the grain (athwartships). Scrubbing along the grain tears out the softer summer growth and creates deep ridges.

Do not blast green algae or black mould with a pressure washer. Apply a biocide such as Boracol 10RH or Wet & Forget to a dry deck using a soft brush or garden sprayer. Leave the liquid to dry. The weather will wash the dead spores away over the next few weeks. A 5-litre tub costs around £40, requires minimal effort and leaves caulking and adjacent gelcoat unharmed.

Trimming Proud Caulking

Natural wear on a 2007 deck exposes fixings and seams. Teak typically wears down by 1mm every three to four years of active use. As the wood wears, the black caulking stands up above the deck surface. This proud caulking traps standing water, trips feet and eventually gets torn out by deck shoes.

Slice proud caulking flush with the wood. A Mozart trimming knife features a specialised flat blade and a spacer guide, making it the best tool for the job. A sharp, wide chisel used perfectly flat will also work. If the caulking splits or pulls away from the seam edges, water will penetrate the sub-deck. Rake out the failed section and clean the seam edges with acetone. Lay bond-breaker tape in the bottom of the groove and re-caulk using a marine deck sealant like TDS SIS 440 or Sikaflex 290 DC PRO.

Replacing Missing Bungs

A stainless screw head shining in the sun means a wooden plug (bung) has popped out. Water is now tracking down the screw thread into the core of your deck. This represents the biggest threat to older teak.

1. Remove the exposed screw completely.
2. Use a flat-bottomed counterbore tool to drill the hole slightly deeper (standard sizes are 8mm or 10mm). Ensure you cut a clean vertical edge.
3. Re-drive the screw. If the deck is too thin to seat the screw deeply enough to take a new plug, remove the screw entirely. The modern deck adhesive will hold the plank down.
4. Dip a new teak plug in thickened epoxy (such as West System 105/205 mixed with high-density filler). Tap it into the hole, aligning the grain of the plug with the plank.
5. Chisel the plug flush once the epoxy cures.