Insulation, faced or not?

[Bigrhamr]

This is a pole building, walls are just metal siding over the girts. I'll be framing in the walls and sheetrocking inside. Planning on R-19 batts, should they have the facing or not?

 

[ripsnortMN]

Faced will give you a vapor barrier. If there will be a great difference in inside temperature vs. outside temperature then I would go with faced. Im in Mn. where it gets stupid cold outside so I just did the faced insulation and I also taped the seams to seal it up good. You could also go with unfaced and then do your own vapor barrier with clear poly.

 

[Identaltech]

seen a lote of people use the unfaced and then follow with the clear poly.
I think its faster to install.
but you do need a vapor barrier.

 

[gesoffen]

You'll need the vapor barrier. That said, I prefer the unfaced and going back and installing a separate vapor barrier. The kraft facing is a PITA to get airtight especially if you have a lot of irregular stud cavities (outlets, spacing, fixtures, etc.).

 

[south pier garage]

last thing you will want is condensation on the warm side of the metal sheathing.

vapor barrier +1.

 

[hidollartoys]

Faced paper is easier to install and hold insulation in place. I then gone back and apply poly barrier over the paper and this really prevents air infilitration and adds another "seemless" vapor barrier.

 

[ripsnortMN]

Faced paper is easier to install and hold insulation in place. I then gone back and apply poly barrier over the paper and this really prevents air infilitration and adds another "seemless" vapor barrier.

If you put poly over the paper moisture will condensate between the two creating mold. This is a big mistake that a lot of people make including myself.

 

[Bigrhamr]

So part 2 for this question is if you want a vapor barrier next to the heated space what do you do if your using blow in insulation for the ceiling? Put a sheet of poly down first?

 

[hidollartoys]

If you put poly over the paper moisture will condensate between the two creating mold. This is a big mistake that a lot of people make including myself.

the mold will form if you do not seal the poly where there are penetrations like electrical boxes and such. There are tape products and other products that are available to accomplish this.

The 2006 IRC requires a vapor "retarder" on the warm in winter side of the thermal insulation. It does not specify what type. The point of a vapor barrier is to prevent warm air from contacting cold air. Even with paper faced insulation it is necessary to seal the paper. This, when done right also requires "taping" and sealing around penetrations.

 

[ripsnortMN]

If you poly over paper faced it will get moisture between the two. Sealed or not it will still happen. Go paper faced or unfaced with poly. Its pointless polying over paper. You would essentially be putting a vapor barrier over a vapor barrier. Both methods will require sealing with house wrap tape.

 

[walrus]

I don't see kraft faced insulation as a vapor barrier, if it is it doesn't work in cold climes.

 

[ddawg16]

Bigr...it helps to have your location in your profile....

It's my understanding that you don't need a vapor barrier if you are in a climate that does not see freezing weather....

The primary purpose of a vapor barrier is to keep mositure from the house getting into the walls where it can freeze....and then cause major problems later when it melts.

So....if you are in a climate like FL....you don't need a vapor barrier....it does not hurt either.....

As for the poly barrier....not a bad idea in the cold areas....it's main benifit besides keeping the moisture at bay, it stops the air flow which can really improve the temp retention.