Insulated Metal Porch - Moisture Issue !

Old 01-05-18, 05:32 PM
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Insulated Metal Porch - Moisture Issue !

I enclosed a porch that had an aluminum frame and corrugated sheeting for the roof. The end walls are vinyl siding, 2x4 's insulation and drywall. The long front has the same construction for a knee wall and 6 ft high "Florida" windows that are heavy duty plastic in sliding frames. I knew moisture would collect in the winter on the window edges and the interior screen door surface. Now for the roof, it transferred a lot of heat and was like an oven. The porch frame is divided up into 9 squares. I cut reflectix into squares and aluminum taped them to the framework below the rippled sheets so the roof directly underneath could breath. It worked as any breeze causes it to expand and contract plus it lowered the heat load. I was able to get R-13 up between the frame work.

Now to the moisture issue. I first noticed a problem as the temps cooled and I used a un vented propane heater to work inside. I noticed wet spots forming in the insulation above and when I pulled a section down the reflectix was covered with water spots. I ripped a section down, let everything dry and re installed it covered with 3 mil sheeting. I covered each section and tapped it closed. I have been heating with a newly installed pellet stove and though all was well till I saw a wet spot in the insulation in one of the inner sections. Even though I thought everything was sealed up tight moisture must be getting in there. My plan was to put a drop ceiling to finish it.

Ok, I'm a senior not quite as sharp as I once was and on a fixed income. So what am I missing and what's the least inexpensive way to solve my problem. Would it help open a section up, slice the relectix to allow each section to breath and allow it to dry with the outside air. How would that affect the insulation and air conditioning of the room ?
Old 01-05-18, 06:09 PM
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Use some other type of heat.. not propane. The propane is what is putting the excessive moisture into the air. Electric radiant or your wood stove would be best... it's dry heat. You must have an air leak causing the condensation. More air sealing, possibly thick rigid foam on the ceiling would help... tape all seams.

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