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Insulation in ceiling between living space and unfinished upper floor leaking


SharonD's Avatar
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Join Date: Oct 2004
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02-03-07, 03:53 PM   #1  
Insulation in ceiling between living space and unfinished upper floor leaking

Last year we built an additional floor on our home. We put in freespan I-joists, new roof, subfloor and windows before it started getting cold. We had a new furnace and central air unit installed in July. At that time, because the upstairs wasn't ready, the installers didn't do the ductwork up there when they did the installation. Now, because the agreement isn't clear on what was agreed on, it still isn't done. While it's being worked out, my husband and son didn't want our warm air escaping through the subfloor. They put double layers of R-13 insulation in the bays of the I-joists. We've been doing the work ourselves as we can, working upstairs when it's warm enough. Our family lives on the main floor.

We took down some of the insulation recently and noticed it's damp, wet and/or frosty in some of the bays under the insulation. We'd planned to have the floor opened up & the stairs finished by now so the condensation wouldn't be a factor. Now, with the stair and ductwork delayed and the temperatures below zero here, we'll need to put the insulation back in the bays. How do we keep it from getting condensated again? It's bad enough that it leaks in some places with the insulation out! Should we put it all back and staple a sheet of plastic over it? Should we only put some of the insulation back and staple plastic? Use either plastic or insulation, but not both?

 
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Concretemasonry's Avatar
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02-03-07, 04:10 PM   #2  
Insulation in ceiling between living space and unfinished upper floor leaking

Did the insulation you installed have a barrier that could cause condensation?

You have to find out what is causing the leakage (moisture?).

It is very difficult to dry out wet insulation because it tries to create dead air spaces.

Dick

 
Ed Imeduc's Avatar
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02-03-07, 04:17 PM   #3  
You can have only one layer of paper up in the joist. For now Id put it all back up in the joist. Use like a R19. paper to the room. Then a 6 mil poly over it all as one piece like for a good V/B for now.

 
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02-03-07, 04:47 PM   #4  
Insulation in ceiling between living space and unfinished upper floor leaking

Thank you so much for the fast responses!

The leakage is because the upstairs is below zero and the main floor is 70-73 with 6 people breathing, cooking and using electrical appliances. The insulation is Kraft-faced and R-13. We didn't have any kind of barrier between the wood and the insulation. The fiberglass itself isn't wet, just the paper. We know it wasn't leaking through because the guys got a couple of facefuls of water before they got smart about taking it down.

They're putting the insulation back up now. The wood is dry, or mostly dry, where they're putting it. They're putting up poly, too. Now they have another dilemma.

We have a stack of 12' moisture resistant 1/2" drywall, enough to cover the ceiling and then some. They were planning to get 5/8" tomorrow morning & put it up before the Super Bowl (talk about motivation!). Could they use what we have or should they wait & use the 5/8"? Also, should they remove the plastic before putting up the drywall or leave it up?

We really appreciate both of you helping us!

 
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02-03-07, 04:54 PM   #5  
Dont put any back wet. Dont double it like you did before with paper inside there .Take the paper off the first layer Yes put the 6 mil poly up over it then the drywall

 
SharonD's Avatar
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02-03-07, 05:04 PM   #6  
Insulation in ceiling between living space and unfinished upper floor leaking

Posted By: Ed Imeduc Dont put any back wet. Dont double it like you did before with paper inside there .Take the paper off the first layer Yes put the 6 mil poly up over it then the drywall
They aren't putting any with wet paper up. The insulation is going to function as a sound barrier when the upstairs is done so they're only putting one layer of the R-13 back, paper side out. The poly is to function as a vapor barrier.

Should they put up the 1/2" moisture resistant drywall or wait and put up the 5/8"? They're afraid the drywall will sag if they use 1/2".

 
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02-03-07, 05:08 PM   #7  
Ceiling should be 5/8" use the 1/2" on the walls

 
SharonD's Avatar
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02-03-07, 05:18 PM   #8  
Insulation in ceiling between living space and unfinished upper floor leaking

Thanks so much, Ed! My son, the future comedian, asked if we could double up the 1/2" & have 1" on the ceiling. We told him to keep his day job, lol.

With your help this will be at least one thing that will be done right & we won't need to worry about. I was so glad to see you'd responded! I'll probably be back when we get to finishing the insulation upstairs

Have a great night!

 
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