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Insulating porch ceiling

I have an enclosed porch on the front of my house with a shed roof (tar roof) that attaches onto my house at about the second story. I live in the mid-Atlantic area where we have both a heating and cooling (A/C) season. I have run heat/ac ducting out to the space. There was no insulation in the ceiling..just exposed ceiling rafters. I'm trying to make the room a 3-season room (that is to say more efficient). I've insulated the floor w/ fiberglass roll. I've also fixed fiberglass roll between the ceiling rafters but I never finished the ceiling..waiting to see what kind of moisture problems I may have. Well of course, the fiberglass insulation has gotten damp and wet on the exposed side to the roof. My question is...How should I insulate this space? I can put in soffit vents..but cannot put in any type of ridge vent because the shed roof butts up to the house? I was going to remove the fiberglass, put in soffit vents, then put a layer of rigid foam insulation on the rafters...and then my finished ceiling (maintaining an airspace between the ceiling/insulation and the roof). I figured a little movement of air in there is better than none at all. Should I install a vapor barrier before placing the rigid foam? Thanks for any suggestions.

Re: Insulating porch ceiling

No recommendations or comments at all? My first post doesn't seem to be garnering any interest.

Re: Insulating porch ceiling


One option you could look into is using spray foam insulation. This way you won't need to install vents and will also provide a very, very good moisture and insulation barrier.

I've seen kits that you can buy if you wanted to do this yourself. (i.e. enough for a wall or two) but it can be pretty expensive...


Re: Insulating porch ceiling

Spray foam would be ideal, but then the next thing is the tightness of the windows, then the floor, then the old exterior wall. They are also heat-loss targets. You might think about getting the floor sprayed with foam underneath; it will be much less drafty. Fiberglass is IMHO, worthless in the situation you have in your floor, as the air moves right through it.

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