How Does Humidity Affect My Piano?
Topic Series Notes: Piano Environment
A good understanding of how humidity relates to the health of your piano has the potential of adding years of life to your piano. I believe every piano owner would benefit from reading these short articles.
Humidity Swings And Piano Parts
Everything in a piano is either made of wood or depends on wooden parts to function. Wet humid conditions swell and warps wooden parts and dry parched conditions shrinks and cracks wooden piano parts.
While high humidity badly affects a piano and low humidity badly affects a piano, even worse is swinging back and forth, which is what we have in Kansas City ~ hot humid summers and cold dry winters.
Dryness causes wood to crack, which is the most serious damage, and many times those cracks would never develop, without first going through a period of damp humid conditions.
Soundboard Pressure Ridges
Let’s take the soundboard for example:
The soundboard already has a great deal of pressure exerted on it and wet humid conditions cause it to swell, pushing the wood grain with great force the soundboard sometimes develops a “pressure ridge”. On grand pianos, you can see these pressure ridges if you lower your eye-sight to just above level with the soundboard ~ to the point where the light glares off the soundboard. Once you spot a “pressure ridge” you can run your finger across the ridge and feel it under your finger.
At this point the pressure ridge is not considered a crack and no piano manufacturer will warranty a “pressure ridge”, yet if the piano goes through a period of dryness, this is where the crack will most likely develop. “Pressure ridges” can be seen on many pianos still sitting on the dealer’s showroom floor. This is one more, of the many reasons why you should never, never, never buy a piano without having a professional piano tuner examine the piano before you buy.
Soundboard cracks usually do not cause much of a problem to the tone and overall sound of your piano unless the soundboard ribs loosen and begin to buzz and rattle. Unless there is a rattle or buzz the soundboard will still perform. (For more information on why soundboard cracks do little to harm piano tone – see this Steinway technical.)
Humidity Swings And The Piano Pinblock
Piano Pinblock
A more serious problem that may develop as a result of “humidity swings” is pin-block damage. The pinblock is what holds the tuning pins. The quality and condition of the pinblock determines the tightness of tuning pins and is one of the most important factors in tuning stability. For many manufacturers, including Steinway, the minimum specification allowed for tuning pin tightness, to pass inspection and exit the factory is only 50 inch pounds. While technicians, like myself, would like all new pianos to measure 75 to 85 inch pounds many leaves the factory with much less.
What This Means For The Piano Owner?
A piano is still tunable at 50 to 60 inch pounds, but once the pinblock loosens to the point the tightness of the tuning pins only measures 25 to 30 inch pounds, we generally consider that piano no longer a tunable piano. After a piano has gone through a few seasonal changes, it is not uncommon for the pinblock to loosen five to ten inch pounds in the first five years of service. To avoid getting stuck with one of those 50 inch pound pianos, never, never, never buy a piano without a professional piano tuner appraising the quality of the piano before you buy.
-
- Piano Pinblock
-
- Dry Piano Pinblock Conditions
-
- Moist Piano Pinblock Conditions
-
- Rusted Piano Tuning Pins and Piano Strings
-
- Piano Pinblock Damage (Tuning Pins Removed)
-
- Rusted Piano String Damage
-
- Piano Bridge ~ Dry Conditions
-
- Piano Bridge ~ Moist Conditions
-
- Cracked Piano Soundboard
-
- Sluggish Piano Action Resulting From High Humidity
-
- Sticking Piano Keys Caused From Too Much Moisture ~ Humidity
Note: About the above “Piano Bridge” pictures ~ The piano soundboard is designed to have a crown. The image for “Dry Conditions” shows a flat soundboard which is not accurate. In dry conditions I am sure the soundboard flattens more than it should but not completely flat. The image that shows “Moist Conditions” is demonstrating too much crown ~ which is what happens in moist conditions.
Piano Repair
Skillful Repair Creates Happy Customers
One advantage of this business is being able to pick between in-home piano services / maintenance and or shop rebuilding. Since being shut away in a piano repair shop all day is not my desire, I have focused on creating happy customers in their homes.
Whatever in-home service or repair your piano requires, I will direct my many years of experience towards creating the most pleasing musical experience possible.
Sticking Keys
If you are having a problem with sticking keys it is a good idea to write down exactly which key is problematic.
The simplest way to record which key is sticking is to start numbering the “C’s” starting from the lowest: C1, C2, C3… etc…
The highlighted keys above would be recorded as D#1, G2, A#3, B5, and F#7
Avoiding Piano Repair Pitfalls
I hope, your piano does not require extensive rebuilding repair. However, if you do need such repair services, I can consult with you about the best approach and help avoid pitfalls.