The moisture level of a timber floor must be kept at a moderate balanced level if the floor is to last. Optimum moisture levels of about 7-8% gives the floor optimum strength and durability. Some humid regions do better with floors that have a 10-11% moisture content.
Wood will absorb or loose moisture to the surrounding environment. If the atmosphere is humid the wood will tend to soak up some moisture. If the atmosphere is dry the wood will lose moisture. Both of these situations can cause the timber floorboards to change shape and move in relation to each other.
The environment inside a home can change due to summer and winter seasons, long term dry and wet weather, or because of heating and air conditioning. Adding a humidifier to increase humidity levels can compensate for low humidity bought about by these conditions.
Some warning signs to look for:
Cupping – This is where the edges of the timber board rise above the middle of the board, a situation caused by the underside of the board having more moisture than the top. Occasionally this is caused by poo installation.
Crowning – This is when the centre of a timber board bulges upward. It is caused by moisture (perhaps water from a large spill) on the surface of the floor. The floor can at least partially be restored to a flat surface when the moisture levels stabilize.
Buckling – this is an extreme moisture problem where the wet timber floor boards pull up subfloor. It is the result of extreme wet conditions such as a floor or pluming accident. Fortunately it is quite rare.
Laminate flooring combines several layers of timber to optimising strength while giving an attractive surface layer. This makes laminate flooring one of the most stable flooring options. It will experience very little expansion and contraction with changing humidity and moisture. However it will suffer damage in a flood.
Good timber flooring lasts for generations, but moisture can cause the floor surface to become uneven. A moisture meter, some measures to stabilize the room’s humidity, and re-sanding of the floors surface can all contribute to a stable, level long lasting floor surface