The Importance of Humidity in the Music Classroom

Throughout the year, I often meet with parents and students to discuss the importance of humidity for those who own string or woodwind instruments. Today, I would like to extend that conversation to our teachers and educators.

Wood is a porous material that is constantly changing, and both insufficient and excessive humidity can lead to various issues with your instruments. Because most school music programs own quite a few wooden instruments, teachers need to understand and maintain a properly humidified environment. The cost of the instruments or the type of wood used in their construction does not relieve the teacher or the school of the responsibility for proper care and maintenance.

A significant issue arises due to a lack of moisture, commonly occurring during winter when we turn on our furnaces. HVAC systems or furnaces take the moisture out of the air, decreasing humidity levels. This loss in humidity can negatively impact our musical instruments, resulting in cracks, open seams, and neck problems. A lack of moisture affects both old and new instruments. Newer instruments are often more susceptible to cracking because the wood is still in its shrinkage stage and has not yet stabilized. However, older instruments, particularly those with many repaired cracks, tend to suffer even more damage from changes in humidity.

I always say that if your nose and skin feel dry, it's time to increase the humidity in your environment. Listen to your body, and you'll be helping your instrument as well. Additionally, if you can maintain a humidity level between 35% and 50%, this will help reduce the growth of viruses and bacteria in the classroom. That's a bonus!

Movement and Moisture: What's the Connection?

Wood is porous and hygroscopic, meaning it can absorb and release moisture. This characteristic causes wood to react to changes in its environment. For example, placing your instrument in a bathroom while taking a shower will cause it to absorb humidity and swell. Conversely, the wood will release moisture and shrink in a dry environment, such as a classroom or on stage. 

How a tree is cut affects how the wood absorbs and releases moisture. When a maker constructs an instrument, they often cut the top and back plates quarter-sawn, as this provides the most dimensional stability. When the wood's moisture

content drops below 30%, the cell walls shrink and become narrower than before, resulting in noticeable shrinkage across the grain. Over time, you may observe the top shrinking to the point where your luthier must bring in the ribs to fit correctly. 

String instruments are particularly susceptible to wood movement due to seasonal and atmospheric changes, which can create challenges for school music programs. To make things even more complicated, when makers build string instruments, they usually use soft spruce for the top and harder maple for the back and sides. These two types of wood expand and contract at different rates. Even the ebony saddle on the spruce top typically shrinks less in proportion, which is why many shops will kerf the saddle before selling the instrument. This practice helps reduce the risk of splits or cracks developing in the end grain or the bottom of the instrument, especially in newer models.

Classroom Humidity Maintenance

Every teacher who has a collection of fully carved or hybrid string instruments should consider purchasing two essential items: a hygrometer and a console humidifier. This is especially important if the school does not provide humidity control in the classroom. Additionally, there are other ways to mitigate the effects of excessive or insufficient humidity in the classroom.

 

• Get a hygrometer- To ensure accurate humidity levels in your classroom, it is vital to use a hygrometer, which measures the amount of water vapor, or humidity, in the air. This tool is essential because the frequent opening and closing of doors, and the presence of many students,
  can significantly affect humidity levels throughout the day.

Place the hygrometer in a stable area away from direct heat sources and drafty spots. Look for an out-of-the-way location to store your instruments, ideally one that maintains a consistent humidity level year-round, around 45%. However, a range of 35% to 50% is also acceptable.

•  Humidify- Dampits and gel packs are a good starting point for proper humidification, but they only work while the
  instrument is in its case or gig bag. For larger storage areas or racks of instruments, a free-standing humidifier is recommended, especially in an orchestra room. Additionally, make sure not to let the tanks dry out during breaks. Thirteen-gallon humidifiers, like this Aircare Evaporative humidifier, can cover 3600 square feet and run up to 48 hours on one fill. That amount of area can cover the entire room! By using this type of humidifier in the classroom, you can maintain a steady humidity level, which can help you save money on repairs.

• Avoid Sudden Temperature Transitions- Keeping the temperature stable when transitioning between different environments is essential. You don’t want to go from an area of 45% humidity and then move to an area of 15%. This shocks the instrument, and the stages are the perfect example. I recently performed on stage for a holiday concert; those lights were intense! Before I knew it, my bow was too tight, and my pitch was low, which led to constant tuning issues. This was a clear sign that I needed to take care of my instrument and put it back in its case right after the concert. After any performance or rehearsal, the instruments should be returned to their case or storage area immediately to acclimate. Do not leave them on the stage. Both your wallet and your instruments will thank you for it.

• Consider Laminated Instruments- Larger instruments, such as cellos and double basses, are more sensitive to dry air and rapid temperature changes than their smaller counterparts, like violins and violas. If you’re looking to buy a student cello or bass, consider choosing a laminated instrument. Laminated wood usually has 3 to 4 layers of thinner wood glued together crosswise. Another excellent option is a hybrid instrument with a laminated back and sides and a solid carved spruce top. This design provides the durability of reinforced wood while still delivering the rich tonal qualities of a traditional solid top.

• Pack Them Up- Pack your instruments into their cases during all school breaks. Many school districts adjust the temperature to save money during this time, and you don’t want to return from leave to a hefty repair bill. For longer breaks, make sure to tune your instruments down a step to relieve any stress that may occur. Be cautious and lower the tuning by one step, as tuning too low may cause the soundpost to fall. Additionally, remember to loosen your bows.

The ideal environment for storing an instrument is consistent temperature and humidity. Maintaining a relative humidity level of 35-50% during storage, transport, and performance can help prevent cracks, warping, and other types of damage to your instrument. Monitoring humidity levels, allowing for gradual climate adjustments, and avoiding extreme conditions is essential. While your classroom may not achieve museum-like storage conditions for your instruments, you can still take significant steps to reduce humidity-related issues, as discussed.