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Condensation on Steel Walls

bestbetinc | Posted in General Questions on

I have a room with one wall to the outside that is steel siding on the outside and steel on the inside. Weather drops to 20 below. The problem is the interior steel wall condensates so bad the water runs across the floor. I do keep that room at about 88 degrees and 45 to 50% humidity. I’m looking for solutions to stop the condensation on the steel wall. I was thinking of spray foaming the inside wall. I could spray foam the outside wall but I would prefer not to do that cosmetically. Any ideas? Thanks for any help

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  1. Expert Member
    Michael Maines | | #1

    With that indoor temperature and relative humidity, if the air touches any surface about 65°F or cooler it will condense. You don't have a room, you have a still! You need to find a way to keep the interior steel above 65° (or reduce the temperature and/or RH). That means add insulation, create thermal breaks and make the walls airtight. With steel on the interior and exterior you also have the potential for serious moisture accumulation in the walls, leading to mold and fungal growth. What is your climate zone, what is your existing wall assembly and is it possible to turn down your T and RH?

  2. bestbetinc | | #2

    I am in northern Minnesota. I think they are 10 inch walls with 1 batt of insulation (poorly done I think) I actually see frost at the bottom of the wall sometimes. I can't lower the temp or humidity I raise waxworms in it. So you think spray foam on the inside steel wall would work? How thick? Thanks

  3. user-2310254 | | #3

    Is the wall flat? Can you sacrifice 8 to 10 inches of space on the interior?

    I'm sure Mike will give you a great answer. I'm just wondering if it would be easier/cheaper to install a thick, airtight layer of reclaimed foam. I imagine it would also help with your energy bills.

  4. bestbetinc | | #4

    no it is ribbed. no the racks are connected to the walls

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