Cellulose wall cavity spray is an effective ways to obtain tightly sealed installations. It is often used in new construction prior to drywall installation when wall and ceiling cavities are open. The cellulose is sprayed directly into the wall cavities, between the studs and against the exterior sheathing, filling the area completely leaving no gaps or voids.
As the dry cellulose insulation is blown from the applicator hose, a small amount of water is added, activating the natural starches or adhesives in the cellulose so it adheres to the surfaces within the wall cavities. Just enough water is added to ensure good adhesion within the cavity.
The cavity is actually overfilled until the cellulose extends beyond the face of the studs. The excess material is removed using a rotating scrubber brush leveling the insulation with the face of the studs. The small amount of moisture added dries quickly, usually within 24 to 48 hours, and is then ready for drywall. The excess material is vacuumed from the floor and recycled back to the blowing machine by a return hose thus virtually eliminating wasted material.
Because this technique requires very specialized equipment and training, sprayed applied (moisture added) cellulose installation must be performed by an experienced professional installer. CIMAC Producer Members can provide recommendations for qualified contractors and installers.