Roll Insulation

[vinny186]

Which is better for a basement in Chicago: Faced roll insulation or unfaced with a plastic vapor barrier? This is for a concrete foundation and will require 400 sq ft.

 

[oldognewtrick]

Which is better for a basement in Chicago: Faced roll insulation or unfaced with a plastic vapor barrier? This is for a concrete foundation and will require 400 sq ft.

Wall or ceiling?

 

[vinny186]

Wall.

 

[billshack]

be careful not to isolated all the way to the floor. in Canada authorities have expressed concern about the possibility of frost action and structural damage when foundations are insulated from the inside. The concern is that frost will penetrate deeper down the outside of the foundation wall .
what this means if you supper insulate all the way to the floor the ground outside the foundation can freeze and then push in and break the foundation walls. I have seen photos of this. Chicago has the same type of weather as Canada.
In Canada we leave he bottom 18 inch without insulation to avoid this problem.

 

[vinny186]

That's interesting but in Chicago I'm positive inspectors wouldn't pass a basement insulation that didn't go to the floor.
If there is an inch or 2 between the studs and the wall, would fiberglass be ok assuming it wasn't touching the wall? I ask because everyone is recommending either ridged foam or sprayfoam for basement walls.

 

[Sparky617]

In a basement you don't want to use plastic vapor barrier. It will trap any moisture that comes through the foundation and cause mold. The craft paper facing is what is required here. It is permeable enough.

Here is a rather lengthy report from Building Sciences. I haven't had a chance to read the whole thing.

https://www.buildingscience.com/sit...Hygrothermal_Modeling_Basement_Insulation.pdf

 

[billshack]

Vinny, ask them , You will be surprised.