Does stuffing in extra insulation lessen the value?
John writes from Bettendorf, Iowa: “I am getting ready to finish off my garage. I have a couple of questions I hope you can help me with. 1. The exterior walls are 2×4’s and 10′ tall. Can I use material for 2×6 walls to achieve an R19 value instead of the R13 that is obtained using material for 2×4’s? Or does stuffing the extra material actually lessen the value? 2. What insulation should I use to insulate above the already finished ceiling?” Answer: Stuffing a 2×4 wall with R-19 will decrease the R-Value to R-13 so that would not be of value to you. My recommendation is to buy R-15 High Density insulation for that project. Is there an attic above the finished ceiling? If so, check the Owens Corning Web site page for Adding Insulation to an Attic.
