Tom writes from Cleveland, Ohio: "I have a 1960's ranch house and I'm looking at ripping out wood paneling and replacing it with drywall. I've taken a section of the wall off and there is faced insulation in the walls. (I can't tell what R level it is and I'm not sure those ratings existed in the 60's) I'd like to know if I should remove all the old insulation and replace it with new, or can I put new insulation over the top and not have the mess of ripping out the old insulation? I have 2x4 studs, with a brick exterior. If I do add new insulation should I get faced or get unfaced and add a plastic vapor barrier?"

Answer: The insulation that we manufacture for 2 x 4 studs is at least an R-11. However, I can't be sure what R-value you have exactly because there are also R-13 and R-15 products for walls in some areas. We do not recommend putting additional insulation on the facing. If you choose to replace the insulation, we recommend Kraft-faced insulation 3-1/2" thick. As mentioned above, Owens Corning manufactures R-11, R-13 and R-15 for 2 x 4 stud cavities. Install the Kraft facing toward the warm-in-winter side of the wall.