Comparison
Kiln dried or air dried.
Air dried timber comes to equilibrium with the air around it, and Indonesian air is humid. Move that piece into a heated European or North American interior and it keeps drying, shrinks and opens at the joints. Kiln drying takes the moisture down before the piece is made.
Side by side.
| Criterion | Kiln dried | Air dried |
|---|---|---|
| What it reaches | A specified moisture content, chosen for the destination climate rather than the origin one. | Equilibrium with tropical humidity, which is a long way above a heated interior. |
| What happens at destination | The piece is close to stable, and normal seasonal movement is all that remains. | It continues drying, which means shrinkage, opened joints and checking. This is the complaint file. |
| Time | Days to weeks, and it is schedulable. | Months, and the length depends on thickness, species and season. |
| Cost | Higher. Energy, chamber time and the loss on boards that degrade in the kiln. | Lower in cash and expensive in working capital, since the timber sits for months. |
| Insects | A kiln schedule that reaches temperature deals with what is in the wood. | It does not, which matters for markets that inspect for pests. |
| What it does not cover1 | Neither method satisfies wood packaging rules by itself. Pallets and crates carry their own treatment and mark. | Same. The packaging around your furniture is regulated separately from the furniture. |
| How to specify it | A target moisture content and a method of measurement, checked on arrival with a meter. | Saying air dried says almost nothing, so if you accept it, still specify the moisture content you require. |
Which to choose.
- You sell into a heated climate
- Kiln dried, with a moisture content in the contract and checked on arrival.
- You sell garden and outdoor furniture
- Air dried is defensible, since the piece will live at outdoor humidity anyway.
- The quotation does not say
- Ask. In practice a quotation that is silent on drying is usually air dried.
- You had cracking last time
- This is almost always the cause, and it is fixed in the specification rather than in the finish.
Questions buyers ask.
Does kiln drying weaken the wood?
A badly run schedule damages it, causing case hardening and internal checking that only shows when the piece is machined. A well-run one does not, which is why the mill matters as much as the method.
What moisture content should I ask for?
It depends on the destination climate and the application, so it is a number to agree with your own technical people rather than to copy from a website. What matters is that a number exists and is measured.
Can I check it on arrival?
Yes, with a moisture meter, and it takes minutes. Doing it on the first container tells you whether the specification is being followed and it changes the conversation permanently.
Still deciding?
Tell us the application and the market. We will say which one your specification actually needs, and quote both if it is genuinely close.
Sources
- 1ISPM 15, regulation of wood packaging material in international trade. International Plant Protection Convention (IPPC), FAO. Checked 3 August 2026.