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Very small amounts of insulation in cathedral ceiling, risk of condensation? – GreenBuildingAdvisor
Situation: Zone 4/5. A summer cabin that is used only about a week or so in the winter and mostly in the summer. Currently no insulation. It has a cathedral ceiling on the second floor. The roof is not vented and has dormers. Planning to install air conditioning for cooling.
Standard advice is that the cathedral ceiling can be safely insulated only with closed cell spray foam insulation. However, if a very small amount of permeable insulation (such as 2 inches of rockwool = 8 r value) were put in the cathedral ceiling just to take the edge off winter and summer temperatures, would that still considerably risk condensation? If the risk is substantial, then we would forgo insulation altogether since it’s a rustic cabin which is not worth altering drastically.