Insulation question

[info2x]

Not in my garage but hey...

Ok so was getting ready to paint a room and noticed a really terrible drywall patch, great. Started messing around with it and before I knew it I found some water damage which I've since cut out which brings us to here...



Now I would just buy some regular kraft faced insulation (that that I need a lot), and stick it in there. The previous batts all foil/kraft faced batts, so should I put of a radiant barrier first (and then unfaced insulation) or just throw a regular batt up there and be done with it?

 

[tankd0g]

Did you fix the source of the water problem?

 

[info2x]

Was waiting for that question. Water hasn't been an issue since I moved in 2 years ago.

 

[Steve in Mi]

I think a regular batt would be fine followed up with aluminum foil (food wrap) covered and taped to match the décor if you like.

 

[James-W]

If it were me, I would do something a little different. I have always been told that you do not want any sort of "hole" in the vapor barrier because moisture can get past it and get into the drywall. From the photo you supplied there seem to be places where you have potential moisture leakage past the vapor barrier. What I would do is to pick up a roll of the heavy duty Poly Sheeting / Visqueen and use that for a vapor barrier. If you can put the insulation in from the top, that would be the easiest way of putting in fiberglass insulation. If you don't have access to the top-side it can still be done, it will just be more difficult. But that's my suggestion.

 

[tankd0g]

Was waiting for that question. Water hasn't been an issue since I moved in 2 years ago.

If you are sure it was not caused by condensation I would just put a regular batt up there, otherwise I would tear it all down and put up vapor barrier first.

 

[info2x]

If it were me, I would do something a little different. I have always been told that you do not want any sort of "hole" in the vapor barrier because moisture can get past it and get into the drywall. From the photo you supplied there seem to be places where you have potential moisture leakage past the vapor barrier. What I would do is to pick up a roll of the heavy duty Poly Sheeting / Visqueen and use that for a vapor barrier. If you can put the insulation in from the top, that would be the easiest way of putting in fiberglass insulation. If you don't have access to the top-side it can still be done, it will just be more difficult. But that's my suggestion.

I did think of that. Ended up with a regular batt.

If you are sure it was not caused by condensation I would just put a regular batt up there, otherwise I would tear it all down and put up vapor barrier first.

That's what it looked like when I removed the patch and most of the paper face came with it.



What was left of the insulation that was there. There was blown in on top which is why I didn't notice this when I was playing around in the attic earlier this year.



Here is where I stand right now. Went a little overkill with the screws but considering that the original install that has been popping had regular nails at 20" OC I wasn't taking chances with this one coming down.

 

[Highbeam]

Regular faced batt to match the rest is fine. The drywall, mud, tape, primer, and latex paint will provide the actual vapor barrier.

 

[bfarroo]

is there any real advantage to the foil faced if your going to cover it with drywall anyway? As Highbeam stated most codes consider the drywall, mud, tape and latex primer the vapor barrier.

 

[Steve in Mi]

First, I see no vapor barrier in the photos. The aluminum looking stuff my or may not be an effective radiant reflector but it is not a vapor barrier as is apparent by the random method of attachment and no attempt to cover the wood.

Second, another poster seems to think that a vapor barrier is to keep the moisture from getting to the drywall. Not so! A vapor/moisture barrier is installed to keep moisture from inside the structure getting into the wall cavity wetting the insulation rendering it useless/non functional. The proper location for the moisture barrier is on the warm side, between drywall and studs/ceiling joists.


Third, never heard of this;

is there any real advantage to the foil faced if your going to cover it with drywall anyway? As Highbeam stated most codes consider the drywall, mud, tape and latex primer the vapor barrier.

Perhaps one of you would provide a link to support this double quoted statement. There can be some confusion about the term "vapor" but it would be news to me that standard drywall, mud, tape and water base paint is much of a barrier to moisture.

 

[bfarroo]

I agree that if you doing the job the cost and labor to put up a traditional plastic vapor barrier may be minimal especially if you doing it yourself and have the extra time to do it. For most contractors if you look at the scope of the entire job there is some cost savings for them but could also be one for you especially in the time it takes to put up. The latex primer seals the drywall not allowing moisture to move from the one space to another. Most of the vapor barrier primers have a perm rating of around 0.5. 2 mil poly is somewhere around 0.2. Anything under 1 is considered a vapor retarder. If your already going to tape, mud, and paint the area it just seems redundant to me. There are many articles out there on the subject and many opinions also. Some even against using poly. All you can do is research it yourself and decide what will work best in your situation.