In older pianos, the primary cause of strings slackening is the tuning pins which are embedded in the wrest plank (or pinblock) become loose either due to general wear and tear over the years, or (more commonly) because the wrest plank has developed splits across or around the pin holes due to the wood drying out. Another primary cause is the movement in the soundboard. This board is made of spruce and is responsible for the resonance of the piano. Spruce is used because of its elastic nature ; the more elastic the soundboard the more pleasant the tone. The steel strings bear down on this soundboard through 'bridges' which in turn allows their vibrations to be amplified.
Atmospheric changes - Due to the very nature of the whole construction, pianos are very sensitive to atmospheric changes in temperature and barometric pressure. During the warmer months the atmosphere is quite humid and 'water laden' and the wood absorbs this and swells. The strings therefore tighten which causes the pitch to raise and the piano is then out of tune.During the winter if heating is used, the moisture evapourates from the wood which therefore shrinks and the strings slacken and the pitch drops, again resulting in the piano being out of tune. If these variations become too severe it can ultimately lead to the soundboard cracking which becomes a very expensive repair option. Controlling temperature and humidity therefore plays an important part in preserving your piano
Moving a piano - contrary to popular belief does not usually make a piano go out of tune. Again it comes down to environment and atmospheric conditions. If a piano is moved from one room to another within a uniformly heated house, then it is unlikely to go out of tune (even if it is being moved up or down stairs). If the piano however is being moved to a different location which has dissimilar conditions then it will almost certainly need tuning a couple of weeks after it has been moved.
Continuous and heavy playing - will also make a piano go out of tune quickly since the strings are being continually vibrated and will therefore slacken off over a period of time. If a pianist is playing that continually however, it is likely that they will be having their piano tuned 4 - 6 times per year. In commercial environments pianos can often need tuning on a weekly or monthly basis depending on useage and (again) environmental fluctuations.
Age of your Piano - has great influence on the tuning stability. We have mentioned that very old pianos may well go out of tune quite quickly due to the condition of the tuning pins and the pinblock. Young pianos (less than 5 years old) can also suffer from tuning instability due to the strings stretching and needing to 'bed' in. Once it has however stabilised, and provided the general principles of environment are adhered to, the piano should hold it's pitch extremely well.
Small upright pianos - which do not have particularly good supporting (i.e. bracings) at the back of the piano will often not hold their pitch particularly well. This is a limitation of 'budget' made instruments where cost of manufacture plays an important part
How much does piano tuning cost ?
The following table shows our pricing structure for piano tuning and servicing. These prices relate to normal hours of business, being Monday - Friday 9:30am - 4:00pm. Tunings are available out of hours, and at weekends, but do bear additional costs.