Acclimatisation of Timber Flooring

By Jeff Harvey

What the acclimatisation process is trying to achieve is allowing the moisture content of the flooring product, to reach equilibrium with the micro-climate or service area where the flooring is to be installed.

This means the boards have acclimatised (in moisture content) to the conditions expected in the long term service of the building. Or Equilibrium Moisture Content (EMC) is where the moisture content of timber will approach under set temperature and humidity conditions.

 I point this out because often I see builders routinely acclimatising in winter months, which could be a recipe for gapping in subsequent summer months. Or conversely acclimatising in summer to grow in winter. This is not to say we should not acclimatise, it is usually the ideal way to go for long term board stability. I suggest achieving the following important factors that can influence proper acclimatisation;

  • SUB-FLOOR CONDITIONS, particularly if there is limited ventilation, often causing an increase in the moisture content of the flooring product. The sub-floor area or substrate must be DRY This could involve using a waterproof membrane.
  • AIR CONDITIONING The influence of air conditioning and certain heating systems on the microclimate
  • STORMWATER, ensure all connections are completed.
  • SUNLIGHT, protection to stop sunlight coming through windows/doors is in place

 However, the above conditions are quite often difficult to produce, particularly for new home builders because when the flooring is installed the air conditioning in particular, has not been installed.

 Keeping in mind the above, I suggest, if the moisture content of the flooring is found to be at a level that is consistent to the long term microclimate of the service area, no acclimatisation in real terms, may be necessary.

 Another, perhaps more practicable way to achieve a result that will cause less problems is to lay the floor immediately (if acclimatising is not possible), then leave it to stabilise till sanding and polishing, and if necessary some filling if gapping occurs.

 The final and important point that all builders and importantly their clients should understand, timber flooring is a natural product that will be influenced by flooring movement in dry periods (shrinkage) or wet periods, (expansion) which will continue during the service life of the floor.

Jeff Harvey

Bowens Flooring Manager