Ice dams in Montana
I am posting for my sister who lives in Whitefish Montana. They just completed a renovation including a new roof and experienced ice dams the first winter 🙁 The plan is to take down the drywall and address the problem with the insulation. The insulation installer used closed cell on part of the underside of the roof but did not go up to the ridge and used fiberglass batts above the ceiling. The theory is that moisture and warm air is entering space through the ceiling and finding its way to the ridge where it meets the cold air from the soffit vents and having a condensation party. The moisture then runs out the baffles. There is also snow melt 3 feet on either side of the ridge. I understand that closed cell has been called a “moisture trap” on this forum but the proposed solution is to extend the closed cell on the ridge. I was wondering if a product like Intello would be helpful. I should mention that there are recessed lights installed in the ceiling which could be a contributor.
Are there alternatives to the closed cell solution? They would like a permanent solution not a bandaid. I know the roofing contractor could have put insulation on the exterior of the roof but that didn’t happen so they can’t do anything about that except shake a fist at the Big Sky.
Also if someone could tell me what the actually R value of the closed cell is during a cold Montana winter (I thought it was like polyiso did not perform as well in cold climates). Cheers, Lisa
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