On my property I have a number of wooden bungalows, which have been built 5-6 years ago. There are small holes and cracks in the wood, and in between the planks, that I would like to plug.

I remember, when visiting the Netherlands a number of years ago, seeing a product called liquid wood, sold in tubes, which is made for exactly this. After being applied, it hardens and looks like wood. But when I asked the shop attendant if this product would be suitable for use in a tropical climate, he said "absolutely not".

Does anybody know if any such product, but usable in this climate, is obtainable in Thailand? Or is there any other solution?

Wood putty, Homepro sells many different colours.

If that is the same stuff they use for ceiling trim have not had good experience with it - it hardens and has no elasticity so falls out with wood change from humid to dry season. Perhaps some is better than others?

May be a stupid idea but liquid wood is sawdust in glue. I wonder whether sawdust in silicone would keep its flexibility.

Selley's of Australia makes a product called Plastic Wood, described as a fast setting, wood filling cement, in a tube 50 grams. It's more like glue with wood fibres, very fast setting and hardening. I would think that humid climate would not affect its eventual setting and hardening. I haven't seen any before in Bangkok, either Homepro or Big C. I got my tube in Hong Kong.

If you can't really find exactly what you are looking for, and the gaps/holes are not so big, just fill the gaps and holes with toothpicks, then apply regular glue into the remaining spaces. Let the glue harden, then sand the whole thing down, and paint over it. Works fine this way.