I don’t have rooftop heating cables on my house, but where I have seen them, they usually work fine. And I don’t think they generate enough heat to harm shingles when installed properly. But even with cables in place, you’re right to boost ventilation and insulation, too. The real cause of rooftop ice build-up is excessive heat loss into your attic. Is the wall that got wet open now? If so, then the insulation will have dried. But if it’s still covered with drywall and vapour barrier, then you should open up the wall cavity, at least in a small area, and see what’s going on, even at this late date.
Last winter I had a lot of rooftop ice build up that led to leaking, and now I plan to install heating cables to prevent the problem in the future. I’ve heard these cables work well, but also that the heat might damage the shingles. What do you think? Will cables be enough to solve my problem? Should I look at boosting insulation and ventilation, too? Some water got into the wall cavities from the leaks. Do I need to rip out the insulation or will it dry by itself?