Matt writes from Saint Louis, Missouri: "During an upstairs closet renovation, I discovered that much of the insulation between the roof joists had fallen into the attic space. The existing insulation was held in place by cardboard stays stapled to the joists and then covered w/ black tar paper (again stapled to the joists).

I installed R-19 Kraft-faced batts in the joist spaces w/ the Kraft facing the open attic space (i.e. to the warm side). However, in reading the packaging info, it recommends against leaving the Kraft-facing exposed b/c of fire hazard.

Is there a product I need to apply over the newly installed insulation to cover the Kraft-facing in order to mitigate the fire hazard or am I forced to remove it all and start over?"

Answer: The Kraft paper facing should be covered with a 15-minute thermal barrier such as half-inch gypsum wall board.

Typically, insulation batts are installed in unheated attics between and on top of the floor joists so the facing is installed down toward the living space. In that case, the thermal barrier is the ceiling of the floor below the attic. It seems that your attic is heated in the winter because the batts are installed in the attic roof rafters instead of the floor joists. In that case, you do need to cover the Kraft paper.