Well, even if the soffits are insulated, they are outside of the heated area of your home, which is why they freeze in the first place. Basically the same thing as bridges being icy because of having cold air above and below. Not to mention that soffits are supposed to have vents, so even with insulation, you could have ice dams above vents anyway. What I'm trying to say is that while I can't answer your question (but I agree with Ah Pook), I'm very interested to hear the answers that you get. Good advise I can offer though is to call your insurance agent and make sure that you have Code Upgrade coverage on your policy. That way, if a hail storm rips through town and trashes your roof, you won't have to foot the bill for things like Drip Edge and Ice & Water shield that a lot of cities/counties require when re-roofing houses. Code Upgrade is usually pretty cheap to have on a policy (like rental on an auto policy) and is well worth the cost.

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