Our shul has numerous Torah scrolls that are passul (unusable). I'm assuming that they contain missing or rubbed-out letters, and other errors that would invalidate using the Torah.
Our shul occasionally brings in a sofer (scribe) to evaluate a few scrolls. He has checked a few of them and said that they are "beyond being repaired". I don't know who the sofer is, but when I asked the head of the ritual committee who had met with the sofer he said that in one case, the sofer said that the parchment was too brittle to make a correction. In another, he said that he probably could correct it, but because of the parchment's poor condition, it would fade again in a few months, and he would have to continuously correct it, which would make it a costly proposition.
I've listed two conditions that I'm aware of that would "unqualify" fixing a Torah. One, I see, is a physical condition, but I'd like to know what "too brittle" really means and how a sofer evaluates this.
The second criterion seemed to be cost-related. Does that factor qualify to not even bother fixing the Torah? In this case, the shul has enough spare scrolls, that they can manage with others, though, as a Torah reader, I believe that every Torah is precious and should be salvaged even temporarily. Can one make cost a factor?
Lastly, what other factors would allow a sofer or shul to dispense from repairing a Torah?