Insulate Cathedral Ceiling

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Insulate Cathedral Ceiling

Post by Cottage76 » Thu Jun 13, 2019 7:27 am

I have a sun room in a 3 season cottage, which is unheated in the winter. However we will use it on the weekends and we use a woodstove for heat during that time. I am thinking of making a cathedral ceiling in this room. However I am concerned about the venting. Currently the vent is at one of the Gable ends, if I convert the space, I will lose this vent. There are vents in the eaves. I know that a ridge vent would solve the vent problem, but this would be a huge job that would not make the project worth it. I have contacted a spray foam company, but again the price is so high it is not worth it. They said if I spray, it will be a "hot roof" and not vents are needed. Could I get away with leaving an inch between the insulation and the roof plywood? And then just having the eave vents? Or is there another way that I am not thinking of?
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Re: Insulate Cathedral Ceiling

Post by Shannon » Thu Jun 13, 2019 7:40 am

If you want to vent it then you need the eave vents and to add a ridge vent. Vents at only one end will not do anything. If you install rigid foam tight to underside of plywood and seal all edges with canned sprayfoam you will be fine with no venting. If you use standard batt type insulation you need a air gap for venting for sure.
Option #2 is purchasing a DIY sprayfoam kit and foaming it yourself.
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