Refitting a teak deck — cleaning and recaulking
Cleaning, sanding and recaulking a teak deck — restoring the colour and replacing the seams between planks.
A teak deck is valued for its natural grip and its looks, but it needs thought-out care, because teak is thin and is irreversibly consumed by every sanding. Over time the surface greys under UV and salt, and the seams (the caulking between the planks) crack and lift, letting water below deck. The aim of the restoration is to bring back the colour, clean the grain and rebuild watertight seams. Always start by assessing the thickness of the planks — if the heads of screws or fastenings show, the wood is already dangerously worn.
Cleaning should be as gentle as possible. The best option is a two-part teak set (cleaner and brightener) or a mild detergent, brushing with a soft brush across the grain and rinsing generously. Scrubbing along the grain with a hard brush washes out the softer spring wood and creates grooves, so work across the fibres. Avoid a pressure washer, or use it with great care from a distance, because it easily gouges the surface and damages the seams.
If the surface is badly neglected, it can be lightly sanded, but that is a last resort because of the material it removes. Sand with fine paper (80–120) along the planks, taking off the minimum and levelling the surface. After sanding and drying, teak regains its warm, light brown colour. Put off the decision to sand for as long as you can, and in the meantime keep the deck up by cleaning alone.
Caulking starts with removing the old, damaged seams — they are cut out with a special tool (a reefing hook) or a blade, cleaning the groove down to bare wood over its whole depth. The edges of the planks must be dry, clean and degreased, and often need the primer recommended by the compound's maker. Masking tape is stuck along both sides of the groove to give an even, clean seam edge. Preparing the groove decides the adhesion and durability of the new seam.
Caulking uses flexible polyurethane or silicone compounds intended for teak decks, such as the Sika systems or equivalents from marine sealant makers. The compound is squeezed into the groove slightly proud and then smoothed with a spatula, removing the excess and any bubbles. Once it has partly cured, the tape comes off, and after full curing the excess is pared off with a sharp tool or lightly sanded flush with the wood. Follow the maker's curing times, because fresh compound picks up dirt and smears easily.
After the restoration, the most durable strategy is to let the teak grey naturally and clean it regularly and gently, rather than applying oils that soon darken and need constant renewal. If you want the colour, dedicated teak oils and treatments exist, but treat that as an aesthetic choice, not a necessity. Avoid aggressive scrubbing and frequent sanding — those shorten a deck's life more than anything. A well kept teak deck, cleaned regularly and gently, will last many years.
Wear gloves resistant to cleaning chemicals and protect your eyes, because brighteners contain acids. Protect fittings, windows and varnish from cleaners and sealants. Plan the work for dry weather and moderate temperatures, because damp and heat affect the curing of the seams. A patient, staged approach gives a watertight, clean and good-looking deck without using up more of the precious wood than necessary.
Material prices — products and options
Indicative prices in EUR (incl. VAT), as of July 2026. Products widely available in Europe; prices depend on the shop, the pack size and consumption. The links lead to example shops that ship across the EU. Dollar amounts are converted at 1 EUR = 1.1622 USD (ECB, 7 September 2026) and rounded — treat them as a rough guide, not a price in a US shop. Imperial values in brackets are conversions of the metric figure.
Teak cleaning set (cleaner + brightener)
- Star brite — Premium Teak Cleaner (Step 1)
cleaner for heavily soiled teak, 950 ml (32 fl oz)€25–35 (≈$29–41) - Star brite — Premium Teak Brightener (Step 2)
brightener restoring teak's natural colour after cleaning, 950 ml (32 fl oz)€22–30 (≈$26–35) - Teak Wonder — Cleaner + Brightener (set)
two-stage set for restoring teak, economical€24–30 (≈$28–35) - YACHTICON — Teak Cleaner & Brightener
powder concentrate, cleaner and brightener in one€15–22 (≈$17–26)
Soft brush for scrubbing
- SHURHOLD — hand brush Type 276
soft brush for teak and awkward places, long shape€16–22 (≈$19–26) - Deck brush with a handle
soft-bristled brush on a handle for scrubbing across the grain€15–40 (≈$17–46)
A tool for removing old seams, and knives
- Reefing Hook 2.5 mm (0.1 in)
hook for removing old seams, three sharp edges, for cleaning the grooves€55–65 (≈$64–76) - Caulk Sander with P60 paper
tool for preparing (sanding) the seams for new compound€38–45 (≈$44–52) - GILL — sailing knives
sharp knives for trimming and tidying the seams€15–40 (≈$17–46)
Flexible deck caulking compound
- Sika — Sikaflex 290 DC PRO / 300 ml (10 fl oz)
single-pack polyurethane for caulking a teak deck, black€24–30 (≈$28–35) - Sika — Sikaflex 290 DC PRO / 600 ml (20 fl oz)
economy pack for larger decks, black€30–38 (≈$35–44)
Wood primer recommended by the compound's maker
- Sika — Primer-290 DC (wood)
primer improving the compound's adhesion to teak and mahogany, 250 ml (8 fl oz)€40–50 (≈$46–58) - Sika — MultiPrimer Marine
universal primer under Sikaflex for wood and GRP, smaller repairs, 30 ml (1 fl oz)€14–30 (≈$16–35)
Ancillary materials and safety gear
- Masking tape, spatulas, cloths
edge tape for the seams, spatulas for smoothing the compound, cloths (set)€10–30 (≈$12–35) - Abrasive paper 80–120
sheets for local sanding of the teak (only if it cannot be avoided)€8–20 (≈$9–23) - Chemical-resistant gloves, goggles
protection when working with primer, PU compound and cleaners (safety set)€15–40 (≈$17–46)
Common questions
How often can a teak deck be sanded?
As rarely as possible — every sanding takes away a layer of already thin planks for good. As long as cleaning alone keeps the deck in order, put the decision off; if screw or fastening heads are showing, the wood is dangerously worn and a shipwright should judge the scope of work.
Is a pressure washer safe on teak?
Better avoided. The jet washes out the softer spring wood, grooves the surface and lifts the seams. If you do use one, keep well back and at low pressure — brushing across the grain with a soft brush and rinsing generously is the safer route.
Scrub along the planks or across them?
Across the grain. Scrubbing along the grain washes out the softer layers of wood and creates grooves, which wears the deck away far faster.
Oil the teak or let it go grey?
Letting it weather to grey with regular gentle cleaning lasts longest. Oils darken quickly and need constant renewal, so treat them as an aesthetic choice rather than a condition for the deck's survival.
When do the seams between the planks need replacing?
When the sealant cracks, comes away from the plank edges or lets water under the deck. The old compound is cut out down to clean wood over the full depth of the groove, and the plank edges must be dry, degreased and often primed with the primer the sealant maker specifies.