We feel it; every day. We all talk about it. The weather. But where we live and the changing seasons - how does it affect a floor indoors?

 
 
The impact of changing humidity and temperatures on wooden floors can be very significant.
 
The humidity and the temperature are, however, very easy to control by:
 
    • completing all wet jobs before commencing the installation of a wooden floor;
    • ensuring sub-floor sufficiently dry before the installation commences;
    • avoiding moisture from underneath by using damp proof membranes, possibly together with primers or
       vapour barriers;
    • allowing sufficient acclimatisation of the floor before installation;
    • providing necessary expansion gaps for the floor;
    • taking precautions preventing extreme humidity by using (de)humidifiers;
    • staying within comfortable room temperatures;
    • only gradually increasing or decreasing the temperature between the floor and the sub-floor, if above
      under-floor heating.
 
It is very important to state that problems are usually due to outside factors. Failure to comply with moisture content recommendations and site condition requirements can result in excessive shrinkage or expansion of the boards, cupping or concave floor boards or even walls being dislocated! Therefore always use a professional, authorised installer.
 
Remember: Your wooden floor simply tries to stay in balance with its surroundings. Give it space and make yourself comfortable!

Equilibrium Moisture Contect (EMC)
 
A wooden floor is a completely natural product. Natural timber is hygroscopic and thus continually takes up and gives off moisture to keep in balance with its surroundings. The point where the wood is in balance is called the equilibrium moisture content or EMC. However, continuously changing temperatures and humidity results in a continuous, natural shrinkage and expansion, mainly seen on the width of a board.
 
This shrinkage and expansion can be reduced by choosing wood species which do not show high movements when installed and by choosing products which are more stable, such as engineered flooring. And it can be made less visible by only choosing solid planks up to 130 mm wide as well as to perform a correct installation and especially by controlling the temperature and humidity levels.
 
Moisture Content (MC)
 
Humidity in the wood is very similar except that here it is called moisture and is expressed as a percentage of water compared to the weight of wood with zero MC, i.e. without any water in its cells. If the cells of the wood can contain or absorb a lot of water then the MC can actually be above 100% (= the weight of the water is higher than the weight of the wood itself).
 
Relative Humidity (RH)
 
In the air, relative humidity (RH) is expressed by the percentage of the amount of water vapour the air can hold before it is totally saturated, reaching a maximum of 100%. The higher the temperature of the air, the more water vapour it is able to hold before it condenses out as water droplets.
 
As the temperature rises, for example outdoors during the day or when we raise, by heating, the indoor temperature, the RH will go down as the warmer air is able to hold, and absorb, much more water from the surroundings. This water is generally not readily – or immediately – available and is the reason that the RH often falls to 50% in the afternoon when the temperature is at its highest.
 
When the air cools during the night, or air reaches cooler areas, the air cannot hold the same amount of water and condensation may start. This is the reason that, outdoors, we often have moist surfaces in the ...