How long does it take a wooden chair to decompose?

Answer 1

It depends if the wood is to be left outside or kept indoors. If kept indoors the wood will last indefinitely.

If left outside it depends on the wood, a softwood will last say 5 years while a hardwood may last 50 years. It is also possible to treat and paint the wood to keep out the wet and kill any rot this should double the life at least.

Answer 2

Depending on the finish and the preservation of the wood a wooden toy train could last a couple hundred years. This is if the toy has not been buried in the dirt.