How do you know if your attic is properly protected? It's simple: If you can see the tops of the joists, you've got a problem. If the existing insulation is roughly even with the tops of the joists, add a new layer of unfaced batt insulation perpendicular to the old one, pushing the pieces together so they fit snugly side by side. On the other hand, if the existing layers are more than an inch above (or below) the joists, blown-in cellulose or fiberglass does a better job of filling the crevices. To find out how much you need, depending on where you live, type your ZIP code into the ZIP-Code Insulation Program at the Oak Ridge National Laboratory
. And give yourself a pat on the back for keeping up with fall upkeep.