Vapor Barrier and Insulation in Ceiling?

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Jan 21, 2009
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I'm planning on converting an area in my basement into a wine making/storage room. I've read Gold's book "How and Why to Build A Wine Cellar", a bunch of stuff by Dan Piambianchi, and by others. There's a conflict among them, as well as different opinions on how what to use for a vapor barrier and insulation in the ceiling. I've got 2"x10" joists 16" O.C. What have you folks done, ceiling vapor barrier and insulation-wise?
Normal practice is to put the vapour barrier on the warm side of the insulation. If your winemaking area is to be the same temperature as the rest of the basement or upstairs then you don't need a barrier. If your wine storage area will be colder than the surrounding area all the time, then put your barrier on the warm side and all around and not just the ceiling. If the temperature difference is not going to be very much, I would forego the barrier - it is only required where surrounding warm air will actually condense in the cooler area. As far as the materials, there are many available and all should work; amount of insulation can be determined by calculations but R20 should be plenty.
A lot of variables to consider - that's why it is never a straight simple answer.
My main qustion is about the vapor barrier. What's the best way to install that? And, the height to the bottom of the joists is only 7' 3", so if I put in a drop ceiling I'll have to work on my knees.
I definitely agree with djrockinsteve with regards to the vapor barrier. Your local HW store should have some good 7mil or other plastic. Ask the experts! A drop ceiling 6" below that should not cause a problem (of course this is my unprofessional opinion)...Check this link out for some options...
I guess I didn't state my question clearly. I was planning on using 7 mil. poly for the vapor barrier. I just can't figure the proper way to install it in he ceiling. Some "experts" say its OK to wrap the poly around the joists (in effect outlining the ceiling profile-along the subfloor, down the side of the joist, up the other side, along the subfloor, etc). Others say don't do that, use foil backed rigid foam (which is supposed to provide a good vapor barrier and fit it between the joists). I don't believe this method will provide a good enough vapor barrier with moisture able to seep in the joints between the joists and the foam. Besides, with the electric and plumbing running between the joists, it won't be possible to install it. And I do need a vapor barrier because the room above is heated.

Does anyone have a similar situation, and what have you done?
P.S. I can't hang a drop ceiling because the height of the joists in the basement is only 7' 3". With a drop ceiling, the ceiling height would be mighty low.
You might be fine as far as the drop ceiling as code for a ceiling is 6'8" so there is 7" of difference which I believe would be plenty of room and you should be able to keep it even higher then code. Sorry, I dont know much about vapor barriers stuff to helpyou there.
Staple your poly to the joists. Make it possible for air to move thru between the poly and the ceiling/floor above so you don't get a musty smell. Basically you would be making an enclosed room within a room. Add a dehumidifier if need be.

Is there really that much of a problem in this area to have to do this? Sometimes we go to so much trouble and money that when all is said and done it's a mute point.
dj-Are you saying to insulate then between the joists? It seems to me by doing it that way, the vapor barrier would be on the cold side of the room, backwards from what all the "experts" say. If you have a wine room/cellar, how is your ceiling done with the vapor barrier and insulation? Thanks.
Not seeing is making this a little difficult. First if you have a moisture problem you need to address that first. My previous post was skip the insulation if you have excess moisture. Apply the plastic directly to joists and allow an air flow above plastic but below upstairs floor.

Where is the moisture coming from? Would a dehumidifier help?
I am in the process of building a wine making/wine storage area in the basement as well. I am insulating the walls around the storage area with R12 fiberglass and the ceiling above (floor of main floor) with R12 fiberglass, with no vapour barrier. My storage area will not be cold but it will have a small exposed portion of concrete wall (3'x4') which will keep it cooler than the adjoining areas and, with the insulation, hopefully a constant temperature. I don't believe I will need a vapour barrier because the temp difference will not be that great.
If you feel you need a barrier, then you should probably use rigid foam insulation, with taped seams, over your joists and this will provide both insulation and a vapour barrier with no fear of getting the your barrier on the wrong side of your fiberglass. As mentioned by others, you can then install a drop ceiling - they can be done with as little as 2 inches of headroom, or a drywall one, and if it is just in your storage area, headroom should not be a great concern.
Sorry for the long post!
Get R20 FACED insulation. Skip the plastic for what you want to do. Faced insulation has a built in vapor barrior. Install it with the faced side towards the heated living space, in your case up towards the room above. Don't worry about the 2x10s being covered. They sell boxes of 16.5 inch stiff wires that you push in between the joists to hold the insulation up. Sheetrock or use a Zero Clearance Ceiling Tile Grid System (yes they make such a thing).
P.S. I'm a contractor and wine maker.
contactme: Thanks for the suggestion. I gotta due some checking about using acoustic tiles in such a high moisture area. I know some of the manufacturers make tiles for bathrooms and high humidity areas, but I think they direct proper ventilation need be used. Have you installed tiles in a wine room, and how are they holding up?

Thanks, Mike
OK, Why are you putting in a vapor barrier on ceiling any way? The vapor barrier keeps room moister out of wall cavity. It does not keep vapor out of room. Air space between Vapor barrier and insulation will create a temperature zone allowing condensation and causing a moister problem. Air space above insulation is ok. for most part no vapor barrier is need on ceiling and as far as code is , they aren't required. you need to allow vapor to escape and moister will not build up in ceiling like walls. If it had an addict(pun) above there would be venting to allow it to escape. If you are using a fan to vent room hooked up to a humidity meter to maintain a set humidity then vapor barrier is in order. A drop- ceiling will provide little to no thermal enhancement. If in end you decide you still want a Vapor barrier the go with drywall primer with vapor barrier inn it. it cost the same as poly as far as high cost primer and removes extra labor of stapling plastic up. ( a pain if you have never done it) and is a far better produce . It give continues vapor protection walls to ceiling in entire room, meets codes, and doesn't have any mistake holes in it. You poke holes all over plastic when adding drywall with the nails or screws
mmadmike: I agree with what you're saying. In addition, it seems that by having the vapor barrier on the "warm" side of the room, with the insulation between the barrier and the inside of the wine room,, you'll be trapping all the moist air in with the batting. That is not good for its lifespan. And in growing up working construction for my dad, I hung lots of 6 mil poly and it wasn't fun.

As for why I'm planning on doing it, I've read what the "experts" say about constructing wine cellars, especially Richard M. Gold in his "How and Why to Build a Wine Cellar". I'm going to run up to M&M in Hartford during the week and talk to a couple of the guys who have cellars they've built to see what they've done, and probably just get more confused. Thanks, Mike
I dont biuld walls and ceilings as a hobby, I am an expert. It is what I do daily to pay for my hobbies
You're getting lots of good advice here, but it's still not clear what exactly you've got and what you're doing. As in questions on wine making, more information is better.
Is your storage area separate from your making area? Will the storage area be the only part insulated? Will the storage area be humidity and temperature controlled, like a true wine cellar would be? Do you have an existing moisture problem that needs attention? Will you be creating a lot of moisture that will require ventilation and not just a barrier?
Heating, cooling, ventilation,humidity - all have a bearing on where and when you need a vapour barrier and putting one in the wrong place or when not needed can lead to problems, as Mmadmikes1 has suggested.
Dugger: I was originally thinking of having one area for both making and storing. After thinking more about it, I plan on having seperate storage and making areas. I don't want to be working in a 55 deg. F. space, or have to worry about temp fluctuations because we're in there working. Therefore, the storage area will be temp and humidty controlled. My basement, as is, has no moisture problems. As far as creating moisure goes, it will be from whatever moisture is released from the winemaking process (right now from kits and fresh juice) So, my question regarding a vapor barrier in the ceiling stands-what's the best way to do that? To me, it still seems like if, in the ceiling or the walls, you have a vapor barrier against the warm space, then insulation then your green board or sheet rock, your gonna trap the 70% moisture in your storage room between the vapor barrier and the insulation. Won't that eventually destroy the insulation properties of fiberglass batting?

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