How Much Will a 12 Inch Teak Panel Move
+0.1392" (+3.5 mm)
- Species: Teak (tangential shrinkage 5.8%)
- Starting width: 12"
- Moisture content: 6% -> 12% (a typical dry-to-humid seasonal swing)
MethodΔD = D x ΔMC x (shrinkage% / 30 / 100)
Your actual humidity swing may be smaller or larger than the 6-12% MC example used here — run your own numbers in the movement calculator.
A 12" wide teak panel will grow about +0.1392" (+3.5 mm) across its width from 6% to 12% moisture content — one of the smallest movement figures this site tracks, and one of two real reasons teak became the standard for boat decks and outdoor furniture.
Why this one specifically
Teak's tangential shrinkage (5.8%) is low on its own, but the more famous property is its natural oil content, which slows how fast the wood absorbs moisture from the air or a wet deck in the first place — a low shrinkage coefficient matters less if the wood barely takes on moisture to begin with. Between the two properties, teak resists both the cause and the effect of seasonal movement better than almost any other species commonly available, which is exactly the combination that mattered for a boat deck getting rained on and baked dry in the same week.
What moves the number
Width scales this directly. Because teak's natural oils also slow finish adhesion and glue bonding — a separate issue from movement — the low figure here shouldn't be read as "no prep needed": surface wiping with solvent before glue-up is still standard practice regardless of how little the wood itself is going to move.