Humidifying Guitars and Not Knowing Why

I was reading on another forum about humidifying your guitar and some of the answers shocked me so I thought I’d ask here. Maybe shed some light on when and why you humidify guitars.

Do you humidify your guitar because someone on the internet say you needed to?

Do you know why you should or shouldn’t humidify you guitar?

Do you own a hygrometer or even know what it is?

The reason I’m asking is one of the people on the other forum insisted on “You should always keep your guitar in it’s case with 2 humidifier. 1 in the sound hold and 1 by the head stock”.
He had his location under his avatar so I checked the year round relative humidity and it was between 40% and 65% on average.

Another person insisted that keeping your guitar in it’s case will protect it from low humidity.

Both of these statements are untrue and can damage your guitar.

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My stable is racked and stacked in the MMS. No cases, no humidifiers. Its a concrete box with patio doors in one side facing East. Its cold in the winter and hot in the Summer but I will drop the window shutters in the morning June to September when I know the mercury will rise. Not for the guitars but for me as I hate playing in an oven. Do they suffer ? Don’t think so. Does it effect tuning ? That’s an every day variant and given the size of the stable, some of the horses need it more frequently others stay stable. And as I tune up the “guitar of the day” it don’t bother me. Seems there is a lot of bunkem out there but hey what’s new ?


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Rick, do you have a suggested website to check relative humidity? I see a year round avg of 70%-80% for Thunder Bay, but that’s gotta be way overstated for the winter. I don’t have a great understanding of guitars and humidity, but I do want to treat my guitar right! I have a hygrometer and in the case in the winter it showed humidity in low 40’s. In the summer it’s showing high 40’s.I currently use D’Addario humidipaks

Hi Rick,

I live in a climate humidity varies a lot. My wife has a lower cost classical that was probably built in the 70s. It was fine when we lived in a cool coastal region, but it developed a top that has separated from the sides now.

Humidity outdoors mid spring can be around 8% and should be varying in summer around 40-80% depending on rain. Indoors, it will go from about 20% to 75% based on what it is doing outdoors.

The guitar shop people all tell me that controlling humidity is very important to avoid both cracking I see in the classical body, but also swelling when it is humid for long periods of time. The rapid changes can be trouble as well here. All the shops but one I have been in have a climate controlled room they keep the acoustics and classicals in.

There is also a poorly finished “custom” guitar at my wife’s workplace. It was finished with a logo the company uses and unknown overcoat. The solid body has split along both joints where the 3-pieces are glued together. This “guitar” sat in the workplace on a shelf for display about 3 years before the cracks showed.

For me, I am choosing to avoid the problem by sticking with solid-body electrics. No problem in 2 years, but I am keeping my eye on them. I did need to tighten my screw-joint neck on one of them after about 6 months. It has been ok since.

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The average outdoor relative humidity is completely irrelevant. If the temperature outside is 25°, a relative humidity of 80% means a dew point of 20°. If you warm that air up to 70° indoors, the humidity will be 15%; far too dry for the health of a wooden instrument.

I live in Minnesota. I have a hygrometer in the room where my guitars are. In the very cold Minnesota winters, when the indoor humidity becomes routinely below 40%, I keep my guitars in their cases with humidification devices (and hygrometers.) I have a whole-house humidifier on my furnace, but it’s not possible to keep the indoor air in the house at 50% humidity when it’s bitter cold outside without getting condensation on windows and possibly doing damage to the structure of the house.

When it’s the time of year that the indoor humidity routinely stays above 40%, the guitars are in stands. In fact, in the muggy Midwestern summers, I have to run a dehumidifier to keep it from getting too damp.

@TheMadman_tobyjenner seems Normandy has a pretty stable RH being close to the sea and you problibly don’t heat you home with forced air in the winter. So your one of the lucky ones. Same goes for Justin in the UK and Tasmania being surrounded by an ocean keeps thing humidified.

But this is what I’m talking about I’m sure there a people living close to you that are freaking out and humidifying their guitars when there is no need to.

@Mari63 you can’t go by the out side humidity in Canada. Most homes in Canada have forced air furnaces which really dry out the air inside our homes in the winter. Thunder Bay being on the shores of Lake Superior most likely does have a year round RH of 70% to 80% but in your home in winter if it drops to 40% that is the sweat spot for you guitar. Especially your new Martin.

I use 2 hygrometers that have both been calibrated using the salt test. I’ll find a video and post it.


Great question. My 2 cents…

I never bothered humidifying my guitar(s), especially with keeping in a case as to pull it out of it’s case would slow me from playing. I play every day and just love being able to grab my guitar off it’s stand and play it.

I bought a custom guitar hand made for me about 5 years ago and about 4 years ago we went through a severe / record setting drought. Humidity here is normally quite high, 70% and up, it dropped to around 25%.

One day while sitting beside the custom guitar it cracked, wow, and so loud. The luthier said it was due to the drought. While I don’t dispute that at all, it’s interesting my other acoustic guitars, also acoustic and also solid wood, didn’t crack at all. Admittedly both of them are much older, one is 15 years old, the other over 90. He did repair the crack under warranty.

Recently I bought another hand made custom guitar and have been quite concerned about the risk of another crack. Other guitar players have suggested to me that buying from a small shop luthier increases the risk as they don’t have the larger humidity controlled rooms that the larger manufacturers have. Both of the luthiers I bought from make their guitars at workshops on their residential properties. And both are in a quite humid area of the country (sub tropical).

I discussed how to minimize the risk with the luthier who made the latest guitar, a different luthier to the other guitar. I also explained my preference to not keep the guitar in the case every night. The latest guitar was quite expensive for me, cost about double of what the other custom guitar did. It’s particularly delicate / fancy looking.

He agreed with my approach without any stating any strong reservations. My approach is this…

The guitar is kept on its stand 24x7 in our media room which is indoors and sound proofed and insulated to a high level. There is an “R” rating the insulation level has, can’t remember what that is but I built the room and went for the highest level easily available from a local hardware / building supplies store.

i have a hygrometer in the room and it’s been holding at around 65% through this fairly dry winter (I live in Australia). My target humidity is to be above 50%. If it drops below 40% the guitar will go into it’s case at night, which also has a hygrometer, and I’ll use the D’addario humidipak with 2 packs down into the sound hole. I’ll be looking closely at what the hygrometer says the humidity is inside the guitar case when I open it in the mornings.

Like you, I’ve been fascinated by the statements my by others in various forums about humidity and guitar cases. Especially those who simply state you need to put the guitar in it’s case to protect it. If the outside air is dry, so will the air in the case be dry.

Fingers crossed. It certainly wasn’t enjoyable having the other guitar crack as it did in the unseasonably dry weather here.


Your a perfect candidate to have a hygrometer and understand you RH to keep your guitars hydrated. It is true solid body guitars loose moisture a lot slower but
Even solid body electrics can dry out a crack. 8% RH is dry enough to split wood. When they kiln dry lumber for construction they dry it to a moisture content of 7% for straight and look at how much of it cracks.

A hygrometer is about the same price as a set of coated string and can tell you a lot about the condition of you guitars and their environment.
Just don’t freak out if it drops or rises over short period of time it take a long time for a guitar to dry out. Like you said it’s been two years with out a problem but in an other two years you may be wishing you hydrated your guitar when it cracks. Also it take a long time to re hydrate a dry guitar.


I’m perhaps not too far north of you, in Thunder Bay, ON. If it turns out that I can just leave my guitar on the stand in the summer that would be so nice!

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Keep in mind that 40% is in the case, I’m pretty sure it’s lower than that in the house in the winter. That’s useful information though, I should have thought that I need to know what the in-house RH is as well as the in-guitar-case humidity. If I can keep my new Martin on a stand instead of in the case that would be - sweet! :slight_smile:

This is why you need one in the room you keep your guitar. As long as the RH in the room is 40or above your Martin is safe. Take your hygrometer out of the case for a few days and see what your house is
Here’s a video on calibrating Hygrometers. If for cigars but guitar are the same.


Thanks for all the info, Rick, very much appreciated!

This is why I started this thread. To many people on guitar forums tell others they have to keep their guitars in their case and hydrate them without knowing anything about the environment the guitars live in.
This simply isn’t true for everyone. The only time my guitars get put in a case is if they are going to a jam. I live in a very dry environment in the winter but I keep an eye on the RH and act accordingly. It’s good for me as well as the guitars. Nobody like dry itchy skin in the winter.

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Hi @stitch

Oh, I am aware of my house temps and humidity levels. :sunglasses:

They fluctuate a great deal and it is hard to keep on top of it. I usually am trying to increase it. Today is pretty good.
1 is outside about noon. Should go up another 10 degrees before it starts to cool
2 is the outdoor bath, err, pool. Yeah, pool…
3 is a room in the house
4 is display unit, near guitars

I really don’t want to keep an acoustic tied up in a case. My electrics are out and ready to be played when I walk by. I would rarely pick up anything in a case if I needed to take it out to play and fiddle with maintenance of humidity levels. I have wondered about synthetic body options.

106.4 where in the world do you live? :hot_face: That’s hot I’d be in the pool with a cold drink.
41 RH is good inside guitars will be loving that.

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Arizona. And you wouldn’t be in my pool for sure, not with bath water temps. it is NOT cool and refreshing any more. Best place is inside. With a guitar and something cold to drink.

If it rains properly tomorrow, and it may, then in-house humidity can rise to 65% by the following day. this is an example of the drastic changes that I don’t like to think of for keeping a nice acoustic in the house.

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Time to buy a Carbon Fiber Guitar

I have a friend who went to university in Phoenix. He told me he’d remote start the car with the air conditioning on to cool the car down before going anywhere. The exact opposite to what we do in the winter here. We remote start the car to warn it up before we go anywhere.


I think this would affect acoustics more than electrics due to the woods and relative thickness (really, thinness) of them.

Years ago, I had a hobby woodworking. I didn’t have the patience for it but learnt a lot about wood.

Different kinds of wood warp differently, as does the cut. Quartersawn timber is more stable, but less pretty as it’s cut in thinner strips that need to be put together. Large, thin timbers from single cuts would be more at risk. Sudden changes in humidity are more likely to damage than slow - which is probably where the advice to keep a guitar in its case comes from.

My Maton came with a warning to keep it in a certainty humidity range.

Having said that, I keep my guitars out, on the wall, and have no plans to change that. The climate I live in is subtropical. We go through dry spells but nothing like in a desert or where it snows.

I’ve never owned a humidifier nor do i use cases, just hang them on the wall. never noticed any problems. more money making gadgets like honey glazed chocolate covered capacitors :laughing::laughing::laughing:

Hi Raymond,
that you happen to live in a good environment where it is not necessary is nice for you, but don’t ridicule people who have to take this seriously and want to help others with it…I will post pictures soon of my guitar lying upstairs… you can see what wrong circumstances can do :smiling_face_with_tear:

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