Solid wood is reasonably mould resistant if it is kept reasonably dry. Wood does well in rooms with moderate humidity. Mould will usually only appear if there is a moisture problem from leaking plumbing or a particularly humid environment.
If wooden floors develop any mould it should be dealt with immediately.
Mould will produce spores that pollute the air inside a home. Some of these spores are very bad for health. Block moulds spores can cause low grade flu symptoms and constant lethargy.
Mould can form on the surface of wood, and it can also penetrate the surface and start to break down the wooden structure. It takes some time for mould to spread under the surface, but once the mould has progressed this far the infected wooden board must be replaced.
Use a screwdriver or blunt knife to test the wooden board that show signs of mould. If the implement can be easily pushed into the wood then there is heavy mould, and the timber plank will need replacing.
Surface mould can be removed with diluted bleach; mix 1 part bleach to 8 parts water. Let the solution sit on the mould for twenty minutes, and then clean with a scrubbing brush.
When cleaning mould it is best to wear old clothes (including shoes) that can be disposed of; mould will easily spread to clothing and contaminate other areas.
If you suspect a problems then it might be advisable to have the home professionally inspected for mould.
Where some flooring materials like carpet must be disposed of after a mould infestation a wooden floor can often be retained with some re-sanding and perhaps some repair work. Measures should be taken to ensure the mould problem does not return.
Floor sanding will restore decent condition timber floors to virtually new condition.