Why is there frost under the soffit of an unvented roof?
Here's a new one that I'm hoping someone can help with. My new house with a flat roof and substantial overhang is causing a problem that's difficult to solve. Frost is building up on the underside of the overhang roof deck and when the sun/temperature gets warmer there is water that drips through the tongue and groove soffitting. Please note that the soffits are non vented as the flat roof/attic area of the house is spray foamed so that the "rim joist" of the roof is spray foamed as well as the under deck of the roof area. I do however have led wafer lights in the soffitting and believe that this could be causing the frost build up. However another contractor has told me that you need moisture for frost to occur and that the lights themselves would not cause this. I'm not so sure about that and have had conflicting answers in that regard. Any opinions on this would be greatly appreciated. Thank you.