The band-joist area can be a challenge to insulate correctly, with some contractors opting for fiberglass batt rather than the complications of spray foam. For installers working with blown fiberglass or cellulose, National Fiber offers another option. Its Insul-Cube is a fire-rated bag can be filled with blown insulation on-site, then friction-fit between the joists. The amount of insulation used will vary according to the size of the space, and the cubes can be filled-in-place behind pipes or wires. National Fiber | 800.282.7711 |

Editor's Note: A version of this article originally appeared in Remodeling's sister publication JLC: The Journal of Light Construction .