How do you insulate a vaulted ceiling?
Bernice from Midland, Ontario wants to know how to get more insulation into her vaulted, or cathedral ceiling. The common problem with structures like this, that we call “compact roofs”, is that there is not usually enough space for a lot of insulation and a lot of ventilation. In fact, when the only space you have is that left by a 2×8 or even a 2×10, you really can’t do a perfect job of both insulation and ventilation. These ceilings often show the location of the rafters by dirt marking on the drywall, because the cold will come in through the wood, chill down the drywall, attract moisture which attracts and holds dirt faster than the rest of the wall — something we call “ghosting”. When you can’t do much about the roof, one of the easiest and quickest ways to beef up the insulation on a ceiling like this is to add 1 to 2 inches of ridged foam insulation right over the drywall and then add more drywall. That prevents all the old stuff from falling out. If you are into major ceiling
