Humidity and acoustic guitars

Hi there,
last year I bought LAG T70A acoustic guitar for around 200 $ (converted from my currency), it was on discount from cca. 300$. It has solid Engelmann spruce top and sides are laminated sapelli open pore. Apparently they use some technology to make neck and wood resilient to temperature changes and humidity.

But I read and heard so many contradicting info about temperature and humidity that I don’t know what is truth and what is just overreacting. Unfortunately me and my wife had to move to shitty studio apartment in shitty city from my parents place which is nice house in villages. I could write whole book about lamenting city life, noise and everything but that’s digression and luckily it’s only temporary.

The problem is that in this studio now in autumn it can get up to 80% RH. Mostly it hovers around 70% RH. It is kinda cold, but since some maestro architect invested in thermal insulation much more than sound insulation, radiators and heating rarely work. So there is hardly any way to dry up the air, as turning heating to 24C would be way to hot. We also bought some sodium chloride dehumidifier and placed it in small wardrobe where I put guitar and lo and behold, only thing I get is 2-3% lower humidity if that. The product is advertised to dehumidify area up to 36m3, yet can’t dehumidify wardrobe.

It’s driving me insane and crazy and I worry a lot. It’s humid like this for more than month, almost two months. I read many people say 70% is detrimental, whilst other say they have no problem. I asked store owner who sold me that guitar and he said that only thing I need to worry is not to keep it near stove or radiator, which is common sense to me. 200$ is already a fortune to me and I saved whole year to get that guitar. I could try to save up for some hard-shell case instead of gig bag it is in right now, but those cases cost a bloody fortune, sometimes even more than price of my guitar.

So am I just worrying too much or I should do something. If yes, what? Please advise. I did see what neglect can do to guitar at my uncles apartment. Some old parlor guitar completely cracked on backside and sides are barely sticking to the top.

Tnx for any and all advice!

How are you determining what the humidity is? Do you have a hygrometer or are you just going off what the news says it is out side? The inside of a building can be very different to what it is out side.
What is the humidity like in the rest of the year? Is it still fairly high or does it drop down to the low 30’s or 20’s? These thing all play a pert in whether you need to worry or not.

If the humidity stay relatively high above 50% for the rest of the year you don’t need to worry your guitar will find a stable range between 50% and 80%. If the humidity drop below 30% for long periods(months not days) you will need to humidify your guitar when it gets below 40%.
It’s the big changes in a short time that you need to worry about.

Where I live, I have the opposite problem - RH around 20% and I can tell you from personal experience that it does have an impact on guitars, especially acoustics. One of my acoustics has a crack down the center line of the back because it dried out too much. But it took years for that to happen.

If your current living situation is only temporary, I wouldn’t worry too much about 70% humidity. But if you can find a cheap hardcase (maybe used?), get one and keep the guitar in there with the biggest desiccant pack you can find/fit in the case. Even putting a desiccant pack in your gig bag might help.

But you also mention that your heat rarely works… if you have big temperature changes from day to night in the apartment, I would be more worried about that. That means that your guitar is “flexing” every day due to the temp changes. I’d keep the guitar in the place with the most stable temperature in your house to minimize the daily flex.

I have the same problem. @SkyBlue should have less worry as the back and sides being laminated should be less susceptible to cracking.

Pick up these ;

And as previously suggested, get a hard shell case and throw one in. I was able to buy a single one a month ago but it seems the single packs aren’t available.

Yeah, I do have two hygrometers. One in the room I practice and one in the wardrobe I keep the guitar. Humidity did stabilize a bit past few days, and now it’s in range of 50-60%. The humidity did drop to 30% in house before we moved, as heating was constantly on, so had to buy humidifier to keep humidity up. Now, I have issue of keeping it down. What I noticed, AC in this apartment we rent has dry function. So I use that often. As soon as it goes above 70% I turn it on and keep it on until it reaches 50ish. Problem is than it cools down the air a bit and it’s not really warm these days.

@VeloVagabond Not much in terms of temperature changes… Let me check min/max values in last 24h. From 19.6°C (67.7 F) and 68% RH max, to 18.3°C (65 F) and 57% RH min. So I guess it’s fine? Temperature fluctuates very little, but humidity can fluctuate by 20, sometimes even 30% and quite fast, as when I turn on dry mode of AC it can lower humidity from cca. 75% to below 50% in less than an hour.

I’ll check for hardcase, but hopefully this won’t pose too much of a problem to guitar… It’s lovely instrument but it really needs lot’s of babysitting. Probably I worry too much tho, since it’s not 10000$ all solid wood guitar.

BTW, I heard that guitars get more resilient to changes in temp/humidity over years. Is that true?

It will acclimate to its surroundings, meaning wood absorbs and releases moisture slowly so it will get into a rhythm with the seasonal changes. Your situation doesn’t sound to bad. You seem to be able to humidify when needed and bring the humidity down when it gets really high. Just don’t let it freak you out your guitar won’t suck up a lot of moisture in a short time it would take months to get to the point for any damage to start to happen.

As @stitch said, I think your situation isn’t too bad. Rapid humidity changes aren’t as bad as rapid temperature changes. Wood isn’t going to absorb or release moisture very quickly. I would pay more attention to what the “average” humidity is (don’t know if that can even be measured) over a week or more.

As an example, when I took that guitar with the crack to a luthier to see if he could repair or stop it from propagating, he wanted to keep the guitar in his humidity controlled shop for a couple weeks to rehydrate the wood before he would start the repair.

Get yourself an inexpensive guitar dust/sun cover. They slide right over your guitar and stand and go all the way to the floor. Put a small DampRid on the floor in there. That setup maintained roughly 50% for me this summer when home humidity was about 70%.

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Hi everyone. It’s the middle of winter where I am (Germany) and we’ve got really cold weather right now. Despite me hanging up my clothes to dry in the living room (where my guitar’s on the wall), despite lots of plants in the same room etc. the humidity doesn’t go above 35% at the moment. When I opened the windows to let in fresh air for a brief amount of time(10 minutes), it dropped to 20%.

I really do try to keep the air as humid as possible now. I even let my hair dry in the living room after a shower :joy:

Still: Do I have to be overly concerned? I’ve got a Fender CD60S.
Unfortunately, I’ve got asthma, so I can’t really use humidifiers as they don’t stay as clean as they’d need to be for my lungs despite best efforts…

Any advice?

Yes. I live in Minnesota, with hard winters. When the indoor humidity is consistently below 40% I keep my guitars in their cases with humidification devices when I’m not playing them. A minor inconvenience rather than taking the risk of damage.

Keeping the whole room at a high-enough humidity level during a Minnesota winter would result in condensation on windows at least, and actual damage to the house at worst.

@Estel how are you checking the humidity in you house? I have 2 Analog hygrometers and 2 digital. The two digital ones(one in the Thermostat and one on the humidifier) are about 20% low. I know this because I have tested the analog ones and they are correct.
If you have a digital hygrometer there is a good chance it’s giving you low readings.

If you are worried about your guitar putting it in its case with a humidifier. You can make a humidifier with a sponge and a plastic container with a lid. Poke small holes in the lid and place the damp (not soaking wet) sponge inside and put it in side your guitar case with the guitar. Re moisten sponge as it dries out.
If you can find then water bead work even longer.


Although not ideal, if you stay mostly over 30% you probably won’t have a problem. Especially with a laminated back and sides like your fender. If you spend much time below 30% start casing it with a sponge or a closet with a wet towel hung up. In colorado it is hard to keep higher and even the guitar stores often aim for 30-35%.

Everyone stresses about this to different degrees. I like my guitars out, so I am ok with the 30-40% I maintain. No issues in 2 years anyway.

The problem I have with this approach is that there’s not a warning that you’re about to have a problem so that you can take steps. By the time you realize there’s a problem, the guitar is damaged. I’m not willing to take that chance to avoid the minor inconvenience of casing my guitars in the winter.

This is true. You have to do what you are comfortable with. I am not worried.

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Another solution to this problem is to have a room humidifier running on a schedule to maintain certain humidity 24h. I used guitar humidifier last winter but now went with more automatic solution.