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How to Properly Humidify a Guitar Step By Step

How to Properly Humidify a Guitar Step By Step

Guitars are moody instruments that need care. We have all picked up our favorite one off the wall, and for some unknown reason, it felt different than the last time we played it. The cause, though, is simple: wood expands and contracts quickly, with the environment’s humidity level dictating much of the movement.

Having lived in a dry country and toured extensively, I learned what lack of humidity does to a guitar the hard way. To help you avoid taking all your gear to the luthier, I’ll share how to properly humidify a guitar and the major dos and don’ts. 

Understanding Guitar Humidity

Before we get into the steps needed to humidify your guitar, perhaps we should run through why it’s so important to keep an eye on the spaces where you store your guitar.

What Does Lack of Humidity Do to a Guitar?

Buzzing, bad action, rough fret edges, cracks, sinking bridges, and overall moving parts are some of the effects of low humidity on guitars. Every guitar reacts differently depending on its ‘weak spot’ or how long they have been exposed to the dry air. 

Acoustic and electric guitars are both harmed by the lack of humidity or too much of it. In acoustic guitars or hollow body electrics, you can feel more of the effect as the bridge and top sink in; on a solid body electric, the fret buzz and frets popping out are the bigger issues. 

Here’s the general chronological order of issues in guitars left in far-from-ideal conditions:

  • The first thing that moves when the guitar stays in a dry place for too much is the action. On an acoustic, the top starts to sink, and it takes the slightest change to the string angle on the bridge to lower the action enough to cause string buzz. The drier the guitar, the worst the effect on the top.
  • The frets can pop out from the neck as the wood of the neck shrinks, while the metal frets don’t. Besides the buzz, you can feel the rough edges of the frets when you run your hand on the neck. 
  • The tuning keys start to lose as the wood on the headstock shrinks and unscrews the keys.
  • The worst that can happen is cracks in the finish and wood. Even though they don’t hinder playability like the previous two, some cracks can be permanent and hard to fix. Bridge cracks on acoustics are the most dangerous as the bridge can detach from the top.

What Is the Ideal Guitar Humidity Level?

What Is the Ideal Guitar Humidity Level

The ideal humidity for guitars is between 40-60%  RH relative humidity. If the humidity level of your guitar is below 40%, you should take steps to humidify the guitar even if you don’t feel there’s anything off with the playability. Depending on the Tonewoods, and brand, recommended humidity levels vary but are always around 50%.

How to Humidify a Guitar

There are two possible scenarios of humidifying guitars when they are dried up or for maintenance reasons. Depending on what works best for you, you either humidify a guitar inside its case or the room where the guitars hang on walls, stands, or corners.

How to Humidify a Guitar Inside a Hard Case 

Humidifying a guitar in a hard case is easy and can be done using affordable products for guitar or homemade solutions. 

Measure the Guitar’s Humidity Level

Use a hygrometer to measure how dry the guitar is. The results will dictate the next step. 35% – 40% is standard; below 30%, the guitar needs help.

You can measure each guitar’s humidity using Digital Guitar Hygrometers you place on the strings near the soundhole or inside the guitar case. I always keep a hygrometer with my best guitars and check a few times per week, even if I rarely use them.

Whatever the level is, bad or good, you still should take measures to keep the humidity level in check. The lower the humidity level, the more water you must use with the purchased or homemade products to get the guitar back in shape.

Pick a Product or Make One

Guitar Humidifier

Guitar humidifiers are all based on the idea of getting moisture inside the wood without wetting the guitar. Small reusable sponges inside plastic containers or tubes are commonly used. Here are some great examples:

The pro of all these products is that they work well to preserve humidity levels and are safe and affordable. 

The con is that the sponge that keeps the water is tiny and only works to preserve guitars, not to bring back a dried-out instrument unless you re-wet the sponge multiple times and place at least 2 or 3 inside a case.

Many players and even luthiers use homemade solutions with kitchen sponges and towels wrapped in plastic paper with few holes, especially if the guitars are too far gone and you need a lot of moisture in the wood. To avoid wetting the wood directly, you must ensure that whatever you use is only wet from the inside.

For electric guitars, you can only place the humidifiers inside the hard case – in this case, I recommend you place at least two, one near the body and the other on the headstock.

Check and Repeat

Sometimes the guitar is so gone that it will suck up all the water from a sponge and an entire towel. Rewet it, place it back, and wait another day to check on what the display of the hygrometer reads.

Keep Maintaining

Even after your guitar is in perfect humidity, you should keep a humidifier or self-made sponge inside the case but only wet it slightly. 

Humidifying a Guitar in The Case Pros and Cons


  • Perfect for keeping perfect conditions on your best guitars
  • Can bring back to normal a very dried-up guitar
  • There are easy homemade solutions
  • There are affordable products that work


  • You need at least a decent case or great gig bag for all guitars
  • Constantly monitoring humidity levels with individual hygrometers
  • Hard to keep up with too many guitars

How to Humidify a Guitar In the Room

Guitar In The Room

Depending on where you live, humidity can go below 5-10% in the winter and, in the summer, over 70%. In the Mediterranean, where I’m based now, humidity levels move from 10% to 70% from season to season.

Unless I take care of the room, I need to take all my 17 guitars to the luthier at least twice a year as I have done in the past, allowing my local repair man to earn their weekly earnings in a day.

If you keep your guitars out of cases, the first step is to ensure the room humidity is right. My home studio is very dry, so I use a standard room humidifier for my studio, as I want my main guitars ready for recording and practice.

Here are some tips on humidifying a room for your guitars:

  • Use a regular hygrometer or the digital display of your home’s central heating/cooling system to measure room humidity. There are phone apps that measure temperature and humidity but are less reliable than the previous two.
  • Pick a humidifier with a relative humidity display and ensure the room is always on the right level. A pro tip is to pick the less noisy one you can find, as sound from the room can bleed even in the best studio mic.
  • Humidify all rooms; you leave any instrument hanging and ready to be played. Keeping guitars in cases surely preserves them better; however, keeping your beautiful 6-string in sight next to the bed is the best motivator to keep practicing.
  • Never leave guitars close to the AC or Heater, and never leave them on for too long. I left the AC accidentally on one weekend while playing another city. When I returned, every guitar in the room, acoustic or electric, had a bad action. My Martin D-28 suffered the worst end of the story, as the neck had shrunk as much as a few frets would visually come out of the fretboard.
  • Use plants If your room has just about the right humidity level and you want to preserve it. My guitar storage room, where all my instruments are in cases, on the other, has an almost perfect humidity level of around 40%. To keep the level constant, I use natural solutions like occasionally spraying water in the air and keeping plants in the room. 

Humidifying the Room Pros and Cons


  • Great to maintain a large number of guitars in the same room
  • Saves the costs of individual guitar cases
  • Easy to monitor humidity Level


  • It’s a slow process for bringing back guitars that are too dried up
  • Room Humidity varies much according to seasons and location 
  • It’s costly to humidify a large room 

When Do I Need to Take a Dried Out Guitar to the Luthier?

Musicnomad Hone Guitar Hygrometer

If none of the fixes above worked after you gave them enough time (3-7 days), the best option is to take the guitar to the luthier for further fixing. Low humidity can mix up with other causes, and even if the levels are back to normal, you’ll most likely need a setup or, in the worst case, when cracks are involved, replace parts.

The trickiest bit is the frets; never try to fix them yourself, as special machinery and experience are required.

It’s All About Good Guitar Habits

Like your practice routine, the small daily habits you built save your guitar, your time, and repair money. Follow up the mandatory wipe to the strings after a show with a humidity level check, and remind yourself to check on your instruments regularly.

Whether you choose the homemade way or buy products, it will still cost less time and effort than repairing the damages lack of humidity causes to a guitar.

How to Properly Humidify a Guitar: FAQs

Question: What causes a guitar to dry out?

• A dry climate
• Leaving the AC or heater on too long
• Extensive traveling with the guitar 
• Not storing the guitars in a case for too long
• Having a very dry room
• Never checking the humidity level of the room or guitar.

Question: Does bringing a guitar in the shower help humidify it?

Answer: Humidifying a guitar is best done slowly in the case or room over a few days. A wet place like the bathroom will humidify the guitar, but it’s not ideal.

Question: What are the symptoms of an overly humid guitar?

Answer: First, the string will tarnish and corrode. In acoustic guitars, the top will start to swell as the wood expands, while the action will stay to feel higher due to the larger string angle on the bridge. If left for too long, the glue can fail, and even the frets can lose.

Read More Humidifying Tips:

Best Guitar Humidifier Solutions & Devices