Should i leave the guitar strings on?

I would just loosen them so they're floppy (detune about one whole step) but not take them all the way off if you're going to be storing the guitar for a year. Be sure to leave it in a hard shell case and store it in a place where the temperature will not get too hot or cold. My parents put my little student guitar up in the attic when I went away to college and over the winter the strings shrank so much from the cold that it snapped the neck right off. Not a big issue since it was a $20 student guitar, but you certainly wouldn't want that to happen to a prize possession. Just put it in a cool, dry place (not attic, basement, or garage) and you should be fine.

Here are a number of articles on long term guitar storage which state that you should loosen the strings, but as others have said, opinions vary:

http://www.guitarsmatrix.com/articles/Guitar+maint...

http://www.sweetwater.com/expert-center/techtips/d...

http://ultimate-guitar-online.com/guitar-storage.h...

That's just a few. When you go to guitar forums though, many guitarists say to store with the strings at playing tension with the argument that the guitar is made for that and it's really not any different than if you had it on a stand and were playing it every day.

Honestly, the string tension is not nearly as critical as the environment (temperature & humidity) when storing a guitar long term. Personally, I would still detune a step to avoid extra tension on the neck if it gets cold and the strings contract. I don't really see what that would hurt. You should probably expect to do a setup once you get back and start playing it again anyway.

I'd recommend you follow the first answer. De-tune the strings a little bit and store the instrument in a place that's not too humid or too dry. Guitars like to be at around 45% humidity and don't like rapid fluctuations of temperature.

Contrary to some of the answers, there is solid reasoning behind loosing the strings. There is an effect called "bellying" where acoustic guitars...even well built ones...develop a slight upward bulge in the top. This is caused by years of string tension "levering" the bridge forward. Even well built guitars like Martin are susceptible to this. As the belly increases, the string height needs to be lowered to compensate. Eventually a neck reset may be needed. Logic would tell you that if you aren't going to use the guitar for a year, you could extend the time before a neck reset by decreasing the string tension.

This advice only applies to acoustic guitars. Solid body electric guitars can't develop a belly and the necks are built to withstand constant string tension.....which is lower anyway because electric strings are lighter gauge.

Opinions vary. Personally I'd leave the strings on, at normal tension. I've owned about 15 or 20 acoustic guitars over a 45 year period, and never had any problem from leaving them at normal tension, even if not playing them for months. Guitars seem to sort of get comfortable with themselves at a certain level of tension. If you change the tension you just might get slight changes affecting intonation or action and causing buzzing etc.

There's good advice about guitar setup from the site given below (can't immediately see your own question covered but there's likely to be something if you check through it). I've saved at least £200 UK by carrying out my own repairs based on the detailed professional (and free) advice there. It's oriented towards acoustic but much the same considerations should apply to semi-acoustics.

I would echo the point about temperature and humidity. The worst things for a guitar are very high or low temperatures, and too low humidity which can cause delamination of the wood.

There's absolutely NO reason to loosen the strings. I don't know why this idea is so widespread, but it's utterly retarded. If the guitar can't handle the tension of the strings, then it's a piece of garbage.

If anything, completely removing the strings would be more likely to cause permanent damage to the guitar than leaving them on and tuned to pitch. Also, changes in temperature and humidity affect the actual wood of the guitar more than the strings. You definitely want to keep it in a safe, climate-controlled environment with a moderate humidity.

The most important thing is where you store the guitar and what the humidity is.

A very dry or damp area must be avoided.

The guitar should not be stored in a closet, attic or basement. A case lying flat is good. I put mine under a bed.