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My 8 year old house with a poured concrete foundation has a condensation problem. I have an 8' x 8' x 42' L concrete room under the front veranda. The ceiling of that room, (the veranda floor) is a poured 4" slab. The entire room has been finished into a storage area, with one end finished into a wine room. This room measures 8' x 8' x 8' with a through the wall 2" diameter hole to the exterior for a cold air source to keep the room cool for wine storage. There is an electric baseboard heater that is thermostatically controlled to 50 oF during the winter months and typically the hole to the exterior is sealed during the winter. I live in a very cold winter climate area.
The room was finished as follows: 2" rigid ship lap styrofoam was glued to the concrete ceiling, and 1" foam was glued to the exterior walls. The room was then framed with 2x4's and the cavities were filled with 3 1/2" fibreglass batts. A 6 mil poly vapour barrier was then applied with 16" overlap as required. Prefinished masonite was used to cover the walls and ceiling.
Now the problem; the wine room has had a moldy, musty smell for some time. Once, there was condensation on the end (outside) wall above grade on the masonite. This was dried and washed up. Sometime later, mold appeared on the room side of the masonite. This was cleaned with a bleach solution, but the smell has lingered. Today, I have completely emptied the room and removed the masonite. The underside of the masonite was clean, with no evidence of mold. I removed some of the 6 mil poly on the exterior walls and there was no moisture condensation on either side of the poly, and when I removed the fibreglass batts, both sides of them were dry, as well as the exposed rigid foam. However, when I removed the 6 mil poly and the fibregalss batts from the ceiling,(the 4" poured slab veranda floor) there was a lot of condensation between the fibreglass batts and the 2" rigid styrofoam. The entire 8' of the ceiling was exposed however the condensation was only found on the first 4' away from the end (outside) wall that has the 2" direct vent to the outside. I removed a 6"x4" piece of the ceiling rigid styofoam from an area with condensation, and the exposed slab appeared dry. So what has caused the condensation between the rigid Styrofoam and the fibreglass batts, and what do I do now to prevent a re-occurrence?
1. Should I remove and not re-install the fibreglass batts? Is just the 2" foam the way to leave the ceiling?
2. Did I have this problem because I had rigid foam then fibreglass batts then a 6 mil poly vapour barrier? Did I trap moisture between the batts and the foam?
3. Is the hole to the outside the problem? Should I seal that hole?
Obviously my objective is to prevent further condensation before I redo the walls and ceiling. I also want this room to stay cooler instead of warmer to keep the wine at optimum temperature. Thanks for any help anyone can provide.
The room was finished as follows: 2" rigid ship lap styrofoam was glued to the concrete ceiling, and 1" foam was glued to the exterior walls. The room was then framed with 2x4's and the cavities were filled with 3 1/2" fibreglass batts. A 6 mil poly vapour barrier was then applied with 16" overlap as required. Prefinished masonite was used to cover the walls and ceiling.
Now the problem; the wine room has had a moldy, musty smell for some time. Once, there was condensation on the end (outside) wall above grade on the masonite. This was dried and washed up. Sometime later, mold appeared on the room side of the masonite. This was cleaned with a bleach solution, but the smell has lingered. Today, I have completely emptied the room and removed the masonite. The underside of the masonite was clean, with no evidence of mold. I removed some of the 6 mil poly on the exterior walls and there was no moisture condensation on either side of the poly, and when I removed the fibreglass batts, both sides of them were dry, as well as the exposed rigid foam. However, when I removed the 6 mil poly and the fibregalss batts from the ceiling,(the 4" poured slab veranda floor) there was a lot of condensation between the fibreglass batts and the 2" rigid styrofoam. The entire 8' of the ceiling was exposed however the condensation was only found on the first 4' away from the end (outside) wall that has the 2" direct vent to the outside. I removed a 6"x4" piece of the ceiling rigid styofoam from an area with condensation, and the exposed slab appeared dry. So what has caused the condensation between the rigid Styrofoam and the fibreglass batts, and what do I do now to prevent a re-occurrence?
1. Should I remove and not re-install the fibreglass batts? Is just the 2" foam the way to leave the ceiling?
2. Did I have this problem because I had rigid foam then fibreglass batts then a 6 mil poly vapour barrier? Did I trap moisture between the batts and the foam?
3. Is the hole to the outside the problem? Should I seal that hole?
Obviously my objective is to prevent further condensation before I redo the walls and ceiling. I also want this room to stay cooler instead of warmer to keep the wine at optimum temperature. Thanks for any help anyone can provide.
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