Teak — Density, Movement, Workability & Cost

Teak (Tectona grandis) has a reputation as the most dimensionally stable outdoor wood there is, and the reputation is only half right. Its total volumetric shrinkage of 7% is genuinely among the lowest of any commercial timber — but its tangential:radial ratio of 2.3 is one of the higher figures on this site's entire species list, worse than red oak's 2.1. Teak moves very little in absolute terms and unevenly between the two grain directions; both statements are true at once, and a boatbuilder choosing between flatsawn and quartersawn teak decking needs the second fact as much as the first.

Silica, not hardness, is what dulls a blade

At 40.9 lb/ft³ and 1,070 lbf, teak isn't especially hard by exotic-hardwood standards — softer than African padauk (1,710 lbf) and purpleheart (2,520 lbf) by a wide margin. What wears out a cutting edge is silica deposited in the wood's own cell structure, unrelated to density: expect to sharpen two or three times as often as an equally hard, silica-free species would demand, and use carbide tooling wherever the budget allows. Everything else about machining teak is easy — it saws cleanly and holds a screw well.

The tangential:radial split, worked out for an actual deck-scale panel

A 30"-wide flatsawn panel — a realistic width for an outdoor tabletop or a wide deck section — moving from a humid 16% moisture content down to a drier 10% MC (the kind of swing an uncovered outdoor piece sees between a wet season and a dry one, larger than the indoor 12%-to-6% swing used elsewhere on this site) contracts about 0.348" (8.8mm) across its width, computed from teak's own 5.8% tangential shrinkage figure. That's a substantial number for an outdoor build to plan gaps around, and it's exactly the movement that a lower-total-shrinkage species like western redcedar would not produce at the same width and swing, despite teak's reputation as the more "stable" outdoor wood. Run your own dimensions on the wood movement calculator. That 1.5"-thick, 30"-wide, 6-foot outdoor tabletop weighs about 76.7 lb — check other sizes on the wood weight calculator.

Gluing and finishing fight the same natural oils

Teak's own oils migrate to a freshly cut surface within roughly an hour and will defeat a glue bond that isn't made promptly — wipe the joint with acetone and glue immediately, and favour epoxy over PVA, since epoxy tolerates the residual oil considerably better. Film finishes have the identical problem outdoors: they struggle to cure fully against the oil and eventually peel in weather regardless of brand or preparation. The traditional, and still the most honest, answer is to leave teak bare and let it weather to its familiar silver-grey, or apply a penetrating oil and accept reapplying it on a schedule rather than expecting a single coat of anything to last.

Cost, durability, and where the reputation for cost comes from

At around $45 per board foot, teak is one of the most expensive woods on this entire site, priced in the "exotic" tier alongside gaboon ebony and cocobolo — a price that reflects genuine two-century-plus demand from the shipbuilding trade as much as scarcity. It earns that price with durability: very durable, resistant to both termites and marine borers, which is the specific combination that made it the standard for ship decking long before synthetic alternatives existed. Burmese teak (historically the highest-regarded source) carries EU and US trade restrictions tied to sanctions and documented legality of origin rather than a CITES listing — teak itself is not CITES-listed — and plantation-grown material from Central America and Indonesia is the mainstream legal supply for most buyers today.

Where it's used, and a safety note that surprises people

Boat decks and trim, outdoor furniture, shower and spa fittings, veneer and general joinery are the five uses teak shows up in most, all of them leaning on water resistance rather than looks alone. The dust is a recorded sensitiser — dermatitis and conjunctivitis are commonly reported, with asthma less common but documented — and old-growth material tends to be more reactive than plantation-grown stock, which is one more practical argument for plantation teak beyond the sourcing-legality question.

Questions specific to teak

Should I oil my outdoor teak furniture, or let it go silver? Both are legitimate, and it's a maintenance-commitment decision rather than a right-or-wrong one: oiling keeps the honey-brown colour but needs reapplication every few months outdoors, while letting it silver naturally requires no maintenance at all and doesn't harm the wood's durability either way.

Is plantation teak actually as durable as old-growth teak? It's genuinely somewhat less durable — plantation trees are harvested younger, with less heartwood oil content built up, so plantation teak weathers a bit faster and is marginally less naturally rot-resistant than old-growth material, though it still outperforms almost every other species on this list outdoors.

Why is teak decking on my boat cupping even though everyone says teak doesn't move much? That reputation refers to total shrinkage being low, not to the tangential-versus-radial imbalance being small — teak's 2.3 ratio means flatsawn boards genuinely can cup, and quartersawn or edge-grain decking strips are the standard marine answer for exactly that reason.