Does my piano need a pitch raise?
Unfortunately, it is hard to tell if a piano needs a pitch raise without being there to examine it. If the piano hasn’t been tuned for over a year or two, there is a good chance it will need a pitch rase. Once the pitch of a piano falls below 10%, the strings will require moderate to extreme stretching. This makes the string unstable and requires more work to stabilize and fine tune the piano.
It is not uncommon to add 2,000-3,000 pounds of tension on a piano during a pitch adjustment. This is enough force to lift a small car off the ground. The greater distance from pitch, the greater the stretch of the strings. Depending on how far out the piano may be, it is common to have a few more frequent tunings in the first year to get the piano more stabilized.
Think of the string a a rubber band. If you put the rubber band around 2 fingers and pull them away from each other, you are creating more force. Over time, your fingers will need to spread further to keep the same tension. Strings on the piano produce the same results as the metal relaxes over time.