# faced or unfaced



## tommyxv (Jun 19, 2013)

Howdy all,

I am getting ready to purchase the fiberglass insulation for my basement remodel.

Some info...It is a condition area. I live in Newark Delaware. I already put 2" XPS rigid foam directly on the concrete walls and also in the rim joists. I have two questions...

1) should I put faced or unfaced fiberglass in the rim and band joist on top of the XPS?

2) should I use faced for unfaced fiberglass in the 2x4 wall cavities?

Thanks


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## Windows on Wash (Aug 30, 2011)

Unfaced on both if it were my home. The painted drywall should serve as your vapor control layer and class III vapor retarder. 

I don't have the codes handy on my phone but I think, will have to check, you don't need one.

Use the air tight drywall approach. 

Here you go: http://www.buildingscience.com/docu...heet-310-vapor-control-layer-recommendations/

Don't need one.


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## tommyxv (Jun 19, 2013)

Thanks for the reply. I see you are not too far from me, all the HD and Lowes don't seem to carry unfaced r-13 for the wall cavities, maybe r-19 for the rim/band joists. I guess just removing the kraft paper is the easier way to go?


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## Windows on Wash (Aug 30, 2011)

Order it or use Roxul.

That or call an insulation supply house.


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## tommyxv (Jun 19, 2013)

I will probably order it then. I'm having HD deliver 80 sheets of rock soon so I will just add it to the order.

Thx


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## Gary in WA (Mar 11, 2009)

Unfaced in the wall, *faced* in the rims. You are in Zone 4, XPS over 1" thick with dew-point at 45%RH, Fig. 2- center; http://www.buildingscience.com/documents/reports/rr-0410-vapor-barriers-and-wall-design

Gary


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## tommyxv (Jun 19, 2013)

Gary in WA said:


> Unfaced in the wall, *faced* in the rims. You are in Zone 4, XPS over 1" thick with dew-point at 45%RH, Fig. 2- center; http://www.buildingscience.com/documents/reports/rr-0410-vapor-barriers-and-wall-design
> 
> Gary


Is it bad that I used 2" XPS?


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## Gary in WA (Mar 11, 2009)

No, that's fine. Figuring your location, three coldest months average temps http://www.usclimatedata.com/climate.php?location=USDE0043 of 35*F minus the 68*F basement temp = 33*F inside foamboard temp with R-19 floor insulation =* 46*F/45%RH *foamboard temp/relative humidity. Very close to the 45*F of the link, asphalt paper-faced would be best. Especially as the rim will be closed off from the direct heat transfer as a wall, it will run cooler equals; higher dew-point there to wet the framing. Use a low-expanding canned foam (window/door) rather than "Big gap filler" closed-cell= with less "give" for movement if an older house without new "engineered" framing; http://www.buildingscience.com/documents/insights/bsi-023-wood-is-good-but-strange/

Gary
PS. you could also use less fibrous insulation to keep the f.b. warmer if already ordered...


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## tommyxv (Jun 19, 2013)

Gary you got me very confused now. LOL 

I have not ordered any fiberglass yet. As of right now, I put 2" XPS in all the rim and band joists with spray foam to seal around the edges. I attached 2" XPS to all the concrete walls, seams caulked and taped with Dow Weather-mate. 
2x4 walls are already framed tight to the XPS.

What is my next step then?

Thanks


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## tommyxv (Jun 19, 2013)

Sorry for the bump... I am ordering the insulation tomorrow along with 70 sheets of mold resistant rock and want to make sure I am clear on what I should be ordering.

1) Faced fiberglass (preferrably asphalt paper-faced) on top of the 2" XPS foam board in the rim and band joist.

AND 

2) Unfaced fiberglass inside 2x4 wall cavities.

Note: All walls and ceilings will be dry-walled

Thanks!


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## Gary in WA (Mar 11, 2009)

Faced in the rims is correct, IF there is no more additional foamboard on the exterior there (it all has to do with the permeability of the siding/sheathing, including f.b.). Unfaced on the walls. With the Code required R-19 and your R-10 XPS, a cavity insulation of R-13 or R-15 (Roxul) is all you need. This (less mass cavity fiber) will raise the dew-point to a safer 51%RH in the rooms before condensation.

Gary


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## tommyxv (Jun 19, 2013)

Thanks for the reply. I really like the Roxul product. I will have to see the total cost difference btw fiberglass and it.

I plan on running a dehumidifier as extra protection. My basement is dry with no leaks. I did the plastic on the slab test I only get a small damp/darker spot on the concrete after a few days, no water on the plastic. 

Thanks again for you input and help.


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## Windows on Wash (Aug 30, 2011)

You won't need to run a dehumidifier if you insulate the basement as you are proposing. That space will be tight as a drum and you won't have any humidity issues.


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## tommyxv (Jun 19, 2013)

Windows on Wash said:


> You won't need to run a dehumidifier if you insulate the basement as you are proposing. That space will be tight as a drum and you won't have any humidity issues.


very good then.

Thanks


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## Nailbags (Feb 1, 2012)

Unfaced! Easier to deal with


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