Tom writes from Portsmouth, New Hampshire: "We are adding a sunroom / 3 season room to our house. It will be unheated, but it faces South so it will heat up when sunny. It is full of windows and sliding doors and it is wood frame construction with plywood/tyvex/cedar clapboard siding. "I have two insulating questions: "The roof is 2 x 8 construction so I plan on using your raft-r-mate plus R-19 kraft faced to insulate the roof - unless you have a better option? "I have a 22 inch high knee wall on two sides of the room built with 2x4 construction. The spacing of the studs is not really even since it supports the windows. I'd like to get some of your rigid foam board - a few sheets of 2 Inch and 1.5 inch and cut some squares to fill the cavities with 3.5 inches of foam. How does that sound to you?"

Answer: Your first statement about using R-19 Kraft-faced Fiberglas™ insulation with the Raft-R-Mate attic rafter vents matches our recommendation. However, we recommend using R-13 Fiberglas insulation in the 2 x 4 studded knee wall instead of cutting FOAMULAR® insulation to fit between the studs. Cutting foam insulation tends to be labor intensive and it may be impossible to get a tight fit.