Breaking gut strings even if the instrument is 'parked'

Question

One of my lever harps got natural gut strings which I am currently not playing (carpal tunnel syndrome, sigh), it's parked in the living room. However, sometimes any gut string will just break at any moment, perhaps once a month usually in the upper 2 octaves (1st and 2nd octave).

The tension is pretty hard but not as hard as a pedal harp. I heard about the breaking point of strings, and that the harp tension is usually around 50%-60% of the breaking point.

Another fact is air humidity by around 40%, pretty constant. Temperature between 19-23 Celsius (66-74 Fahrenheit).

So the question is, why do they break? How can I avoid that? Should I park an instrument by lowering the tension, but what about changes of tension for soundboard and neck?

Answer 1

Surfing various harp-help fora suggests that gut string life is never very long.

Here's one bit of advice from some string-selling shop,

Gut strings are covered with a protective layer of varnish or a lacquer that is slowly worn away by use. Once that protective layer has gone, the string will probably not last much longer as it becomes more hydroscopic (sensitive to moisture and temperature change). A sure sign of this happening is when the fibres of the string starting to fray and peel off. Spotting this will mean that you may be able to pre-empt a string breaking and change it first

So if your strings had been used for a while, they may have been in "stage one" of death, and then time & humidity took their toll on your harp.