When it comes to wood there’s a lot more than meets the eye. As keen watchers of Professor Brian Cox’s TV output will know, everything is made up of millions and billions of atoms, however, one thing that you might not know is that even in a solid object – like wood – these atoms are constantly moving and as such are susceptible to environmental influences.
The fact that wood changes depending on the environment can be a particular issue for woodworking professionals as they have to take this into account when embarking upon on a new project. A major influence on atomic movement is changes in temperature which is why the state of the wood is hugely dependent on the season.
Both in the summer and during the day when the temperature is much warmer, wood expands and during the winter and evenings when the temperature is much cooler, it contracts. This is what is known as linear thermal expansion and linear thermal contraction and doesn’t affect wood alone; many metals experience it too.
Humidity affects timber as well as temperature and this is something that you should certainly take into account during the extreme seasons like summer and winter. As wood gains moisture (i.e. when the temperature increases) it expands and when it loses moisture it contracts.
Wood will continue to absorb or release moisture – and therefore expand or contract – until the temperature of the air and humidity levels are balanced. However, wood doesn't swell or contract equally in all directions and it is this dimensional instability which makes wood and unstable material to work with.
Many people are under the impression that a finished wood – i.e. one that is coated in a varnish or stain – is impervious to moisture, however this is not the case and even finished furniture absorbs moisture.
Avoid moisture related furniture problems:
- Climate control within the home is a great way to prevent your furniture warping over time. A dehumidifier will minimise the moisture that’s held in the atmosphere so the chance of your furniture being affected will be signsignificantly reduced]
- The temperature in your home should be kept constant between 15 and 32°C
- Don’t keep wooden furniture near to air vents or radiators
By following this advice and keeping your home at a reasonably constant temperature you can be pretty sure that your wooden furniture will continue to perform as it should and look like new for years to come.