you need vapor barrier?

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by ephraim-em, Mar 31, 2011.

  1. ephraim-em

    ephraim-em New Egg

    Mar 31, 2011
    I am brand new to BYC and to chickens in general. We live in Alaska and I have been researching the subject of chickens this past winter in preparation for the spring remodeling of our unused kids playhouse, which is the first line of industry for us. So, it is 8'x8' by 8' high in center with 4 screened windows currently. It is stick built of mostly 4x4s so with our harsh winters, we surely have to insulate. We can get insulfoam (foam insulation) which is the best for what we have since we did not build "on center" widths between studs and trusses so need to cut the right width. In perusing the site, I did not see that anyone had addressed whether a vapor barrier is necessary. We will be using a heat lamp during the coldest times and will have insulated lexan windows, which are slightly better than single pane glass but not as good as thermal-pane. We plan to finish the walls and ceiling in pre-finished paneling to keep them cleanable. So, for all you contractor types, should we use vapor barrier with the foam? [​IMG]

    Thanks for all the posts...nice to get so many answers to my many questions, even before I have to ask!!
  2. patandchickens

    patandchickens Flock Mistress

    Apr 20, 2007
    Ontario, Canada
    You will find varying opinions here.

    For whatever it's worth, here is mine:

    A chicken coop is not a house. It normally operates at MUCH less temperature differential (vs outdoors) than a house does, which gives less potential for condensation; also it can, and really *should*, have a lot more air exchange than a house does. To the extent that some condensation is inevitable in a well-ventilated basically-unheated coop, it is temporary and due to weather swings.

    Thus, both from the above theoretical considerations *and* from having observed a variety of insulated/noninsulated vaporbarriered/nonvaporbarriered etc livestock housing over the years, I feel that a vapor barrier does not in reality add any benefit in a coop. And if you are not insulating, it is probably best NOT to have a vapor barrier to let the wood act as a buffer for temporary humidity spikes.

    That said, if you really have it in your head that you WANT TO put in a vapor barrier, I am not going to tell you it'll be the end of the world, it won't be. I just don't see livestock housing with vapor barriers as actually performing better than when it's without (except for the aforementioned situation where you sometimes WANT wood etc to be able to temporarily absorb humidity adn then release it again in drier weather)

    Make sure your carpentry on the inside walls is REALLY TIGHT and gap-free, or mice setting up shop in styrofoam-insulated walls can make an awful mess [​IMG]

    Also, note that you may very well not need or want a heat lamp -- don't try to heat the whole coop, if you feel you must heat something just heat the CHICKENS by providing a small pool of lamp warmth over the roost or in one corner, and lower-wattage bulbs are much safer than actual heatlamp bulbs.

    Good luck, have fun,

  3. ephraim-em

    ephraim-em New Egg

    Mar 31, 2011
    Hey Pat, thank you so much!! I also went to your profile and found the articles you had written on Ventilation and The Cold Coop. I just ran them off so my Hub can read them too. It's especially nice to know that living in Ontario, you likely have some cold spells too. Thanks for sharing the wealth of info/experience you blessed! [​IMG]

    Emily Kewin
    Anchorage, Ak
  4. Noymira

    Noymira Chillin' With My Peeps

    Mar 9, 2011
    Chittenden County, VT
    Not much advice to offer, since we haven't finished our shed/coop conversion yet, and I'm not a contractor type. I was also wondering about this!

    Pat's pages are great, aren't they? I'm not quite as far north as either of you, but we still get some pretty strong winter weather here, so I too am insulating our non-electrified coop. I'd love to see pictures of your soon-to-be coop!

  5. Ahab

    Ahab Chillin' With My Peeps

    Jun 28, 2010
    With foam insulation, a vapor barrier is unneeded. With fiberglass, it is; otherwise, over time it'll harbor whole crowds of unpleasant things as moisture accumulates. Note that plywood interior sheathing, which you'd need anyway to keep the chickens from eating the insulation, will serve as a vapor barrier if you caulk the joints.

    Note also that a vapor barrier over fiberglass that isn't airtight is worse than no vapor barrier at all.
  6. dfvellone

    dfvellone Out Of The Brooder

    Dec 17, 2008
    I agree with the previous comment that a vapor barrier without insulation will be a problem.

    My climate is on the cold side here and I insulated my coop with 2" of foam, plywood walls and a cold roof - ceiling is well insulated with a 2" ventilated airspace between the roof decking and the ceiling insulation. No moisture problems at all.

    I used my attached brooder coop this winter for some excess layers and although the ceiling/roof is constructed the same way I'd never got around to adding insulation not planning to use it during cold months, and I got quite a bit of condensation on the ceiling.

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