Is this vapor permeable sheathing?

[Rossn]

1960's home... wall construction is as shown, with face brick on the back side. Silver faced material is thin (maybe 1/8" thick).

I did not notice originally, but in good light, once can see what may be perforations in the surface.

Does anyone recognize if this is a vapor permeable sheathing material?

 

[Dana]

It's probably "semi-permeable", somewhere between 1 perm & 10 perms. It depends a bit on what the facer is laminated onto.

 

[Sponsor]

 

[Rossn]

Thanks, Dana!