That was as good an explanation as I've gotten from anyone yet! Haven't had to deal with this before, so it's a bit of a mystery to me. I was going to go up on the roof to shovel/chip this morning, but the temperature's gone from +3 yesterday to -15 right now, without the windchill!
At least when it's cold, it doesn't leak, but I'll have to instruct the young 'uns in the fine art of water redirection and evacuation if it warms up while I'm in Toronto this week. Bloody great pain in the arse this is...
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