sweating walls in my insulated coop

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by hildymarie, Nov 10, 2009.

  1. hildymarie

    hildymarie In the Brooder

    May 13, 2009
    da UP of Michigan
    We have a shed that we put insulation in the 2x4 walls, with the kraft paper on the inside. We since put up a wall so about 1/3 of it is now our new coop. Knowing that chickens are moisture makers, we put plastic sheeting on the inside to maybe keep it from the insulation. Now the plastic is sweating on the other side of the plastic getting the kraft paper all wet and I know they will mold of we leave it that way. So we took off soem of the plastic and on the worst wall, all of the plastic.
    We talked to a local builder store guy and he was no help. I would have expected to have the inner part sweat, not under the plastic. He said even if we put up plywood or even drywall, it might still do it as it is a unheated building.
    Any ideas? Are we doomed to have uncovered insulation? we dont want the chickens to crap all over it or get into it and eat it. I put some feed bag material on one wall by the roosts hopefully so it will protect the wall and still let it breath. Somehow we thought the plastic would be the thing to do.

  2. greathorse

    greathorse Songster

    Oct 1, 2008
    Northern Colorado
    You need ventilation at the top of the coop, quite a bit of it. You need to be able to get that moist air out of there. Your ccop is too tight.
  3. captainmoose

    captainmoose In the Brooder

    Oct 5, 2009
    SE PA
    You do not put plastic over Kraft faced insulation. the Kraft paper is a vapor barrier, by covering it with plastic you are trapping moisture between the two vapor barriers. I would suggest covering the insulation with plywood and add lots of ventilation.
  4. teach1rusl

    teach1rusl Love My Chickens

    Quote:Ditto! [​IMG]
  5. As everyone is saying, the solution is vents at the top of the coop, and you may wish to use closeable ones to regulate the air during storms so that rain and snow are excluded. Or use snow boards nearby to shield the coop...lots of ways to solve this. The mold is harmful to you and to your birds.
    Also, as explained, you will need to exclude that mold, this may be the biggest job, really.

    Last edited: Nov 11, 2009
  6. chicken ridl

    chicken ridl In the Brooder

    Jul 27, 2009
    I put a vented ridge cap on my coop when roofing.
    You have a gap at the very peak of the roof. must be a pitched roof not a flat roof to do this.
    The plywood was cut about 1-1 1/2 inches short of butting up together. Then shingle up to the gap. Then install the vented cap on top of the shingle with some sealant and screws. Any box store will have the cap and should be able to give some instructions. Then I can use plywood on the under side to close of the gap as needed, but I don't think I will close it at all.

  7. CityChook

    CityChook Songster

    Apr 9, 2008
    Minneapolis, MN
    My Coop
    I have a ridgecap/soffet vents as well and have never shut them. I also have 2 ft. of gable vents that are closeable for bad weather. I have noticed that when I close up the gable vents, it gets sort of smelly pretty quick. Not terrible, but worse than when the gable vents are open. The ridgecap vent is great for pulling air out, but I don't know if it's enough all by itself... JMO

    To the original poster: I'd recommend covering the insulation with plywood -- it can be cheap and thin - and putting in more ventilation, preferably the kind that can be closed if need be. That should take care of your problem.
  8. patandchickens

    patandchickens Flock Mistress

    Apr 20, 2007
    Ontario, Canada
    Hm. The sweating is on the *outside* of the plastic (that is, the non-chickenward side)? If the plastic was installed properly, with all seams and edges taped, chicken moisture should not be getting back there, it'd be moisture *in the wall* condensing out. (If the plastic was not installed properly, such that chicken moisture could get inside the walls, that could be your problem I suppose). My first guess would be that you may have leakage problems in your walls -- from window openings, from the roof, from gaps between siding panels, etc.

    If it is a coop humidity problem, and the inside of the walls is fairly sealed off from the coop air, you normally see your condensation IN the coop, on the least-insulated parts (windows, less-insulated ceiling/walls, etc), or everywhere if the humidity is really high relative to the temperature difference and the degree of insulation.

    So of course you do want to be sure you have lots of ventilation in there, but if I'm understanding you correctly I'd be looking for structural ways that water may be gettting inside your walls, first.

    I don't like vapor barriers in chicken coops under most circumstances, though. I cannot prove it one way or the other but my experience with livestock barns is that it can often be *useful* to have occasional humidity peaks absorbed into the wood of the structure, then released slowly later when the weather is less humid, rather than forcing all that humidity to stay in the air. You can get away with vapor barriers, of course, esp. if installed right; but I am really unconvinced they are usually necessary or desirable (unlike in houses, which function differently).

    JMHO, good luck, have fun,

  9. crazyhen

    crazyhen Crowing

    Aug 26, 2008
    mtns of ,NC.
    The warmth from the chickens will cause the same problem with the plastic getting moist as a windshield that is warmer on one side. Ventilation is definitely the key. Anyway you want your coop to breath some. To tight is not good. Plywood would work or some thicher material that will not get warm on the far side from the chicks body heat and moisture. The insulation is suppose to breath. As long as you do not have your hens in a draft ( air blowing directly on them) they will do well with the cold. Gloria Jean

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