I get where you’re coming from about air sealing, but I’ve seen cases where even after sealing every obvious gap, ice dams still showed up—especially on older homes with weird roof angles or cathedral ceilings. Sometimes, adding a bit more insulation (even just over the eaves) made a noticeable difference. Not saying heat cables are ideal, but in spots where airflow is tough to fix, they’ve saved me a headache or two. Guess it’s not always one-size-fits-all...
Funny you mention cathedral ceilings—those things are a nightmare for air sealing, aren’t they? I’ve seen folks throw everything at their roofs: insulation, venting, even those heat cables that look like Christmas lights gone rogue. Ever tried adding a vent chute or baffle to get a bit more airflow under the insulation? Sometimes that helps, but in some old houses, you’re basically wrestling with the original builder’s “creative” choices. Curious—did you notice any difference in your energy bills after adding insulation, or was it just less ice outside?